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Büttler RM, Bagci E, Brand HS, Heijer MD, Blankenstein MA, Heijboer AC. Testosterone, androstenedione, cortisol and cortisone levels in human unstimulated, stimulated and parotid saliva. Steroids 2018; 138:26-34. [PMID: 29864449 DOI: 10.1016/j.steroids.2018.05.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/28/2018] [Accepted: 05/30/2018] [Indexed: 11/24/2022]
Abstract
BACKGROUND Recently, measurements of steroids like testosterone, androstenedione, cortisol and cortisone in saliva are more and more applied in diagnostics and scientific studies. This is mainly due to the simple and non-invasive collection of saliva. We aimed to evaluate the optimal way to collect saliva for steroid hormone measurement. METHODS We investigated in twenty volunteers whether there is a difference between steroid hormone concentrations in unstimulated and stimulated saliva collected while chewing, using cotton and synthetic Salivettes®, citric acid or chewing gum. Furthermore, total unstimulated saliva was compared to parotid gland saliva. Testosterone, androstenedione, cortisol and cortisone were measured using Liquid-Chromatography Tandem Mass Spectrometry (LC-MS/MS). RESULTS Salivary testosterone, androstenedione and cortisol concentrations were unaffected by stimulation upon mouth and tongue movements, cortisone levels were on average 16% lower. Concentrations of all hormones were lower in parotid gland saliva compared to total unstimulated saliva (on average 51%, 26%, 66% and 49% lower, for testosterone, androstenedione, cortisol and cortisone, respectively). Concentrations of testosterone as well as androstenedione were lower when using synthetic Salivettes® (58% and 41%, respectively) and were higher when using cotton Salivettes® (217% and 46%, respectively). Cortisol levels in saliva were unaffected by using Salivettes®. However, cortisol and testosterone levels were higher in with chewing gum stimulated saliva (16% and 55%, respectively). Cortisone concentrations were lower in all types of stimulations (on average 25%-35%). CONCLUSION The way saliva is collected should be considered when analysing and interpreting salivary hormone concentrations. We advocate unstimulated saliva collection in simple polypropylene tubes for all steroid measurements.
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Affiliation(s)
- Rahel M Büttler
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Esra Bagci
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Henk S Brand
- Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - Martin den Heijer
- Section of Endocrinology, Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Annemieke C Heijboer
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
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Koehorst SG, Spapens ME, Van Der Kallen CJ, Van 'T Verlaat JW, Blaauw G, Thijssen JH, Blankenstein MA. Progesterone Receptor Synthesis in Human Meningiomas: Relation to the Estrogen-Induced Proteins pS2 and Cathepsin-D and Influence of Epidermal Growth Factor, Forskolin and Phorbol Ester in vitro. Int J Biol Markers 2018; 13:16-23. [PMID: 9681295 DOI: 10.1177/172460089801300104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Autonomous expression of progesterone receptors (PR) in human meningiomas is well established. To evaluate whether, similar to progesterone receptors, other estrogen-inducible proteins are also autonomously expressed in meningiomas, concentrations of pS2 and cathepsin-D (Cath-D) were measured in 52 meningiomas. No pS2 protein was detectable in 52/52 tested meningiomas. The Cath-D protein was measurable in all 52 meningiomas, but the mean concentration of Cath-D in meningioma cytosols was 2.4-fold lower than that of a group of 54 breast tumors (p < 0.001). These results indicate that autonomous expression is a PR-related rather than an estrogen receptor-related phenomenon and, consequently, that estradiol is probably not responsible for PR synthesis in human meningiomas. To evaluate the role of other, non-estradiol-dependent signalling pathways in PR synthesis, the effects of EGF, Forskolin and phorbol ester on PR synthesis were tested in vitro. No PR was detectable after the addition of EGF to six different primary cultures. Forskolin and TPA addition caused a morphological change in meningioma cells, but did not induce PR or pS2 synthesis in two different primary meningioma cultures. We conclude that PR synthesis in human meningiomas cannot be triggered by switching on the signalling pathways activated by these growth factors.
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Affiliation(s)
- S G Koehorst
- Department of Endocrinology, University Hospital Utrecht, The Netherlands
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Westerman BA, Breuer RHJ, Poutsma A, Chhatta A, Noorduyn LA, Koolen MGJ, Postmus PE, Blankenstein MA, Oudejans CBM. Basic Helix-Loop-Helix Transcription Factor Profiling of Lung Tumors Shows Aberrant Expression of the Proneural Gene Atonal Homolog 1 (ATOH1, HATH1, MATH1) in Neuroendocrine Tumors. Int J Biol Markers 2018; 22:114-23. [PMID: 17549667 DOI: 10.1177/172460080702200205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Microarray-based expression profiling studies of lung adenocarcinomas have defined neuroendocrine subclasses with poor prognosis. As neuroendocrine development is regulated by members of the achaetescute and atonal classes of basic helix-loop-helix (bHLH) transcription factors, we analyzed lung tumors for expression of these factors. Out of 13 bHLH genes tested, 4 genes, i.e., achaetescute complex-like 1 (ASCL1, HASH1, Mash1), atonal homolog 1 (ATOH1, HATH1, MATH1), NEUROD4 (ATH-3, Atoh3, MATH-3) and neurogenic differentiation factor 1 (NEUROD1, NEUROD, BE-TA2), showed differential expression among lung tumors and absent or low expression in normal lung. As expected, tumors that have high levels of ASCL1 also express neuroendocrine markers, and we found that this is accompanied by increased levels of NEUROD1. In addition, we found ATOH1 expression in 9 (16%) out of 56 analyzed adenocarcinomas and these tumors showed neuroendocrine features as shown by dopa decarboxylase mRNA expression and immunostaining for neuroendocrine markers. ATOH1 expression as well as NEUROD4 was observed in small cell lung carcinoma (SCLC), a known neuroendocrine tumor. Since ATOH1 is not known to be involved in normal lung development, our results suggest that aberrant activation of ATOH1 leads to a neuroendocrine phenotype similar to what is observed for ASCL1 activation during normal neuroendocrine development and in lung malignancies. Our preliminary data indicate that patients with ATOH1-expressing adenocarcinomas might have a worse prognosis.
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Affiliation(s)
- B A Westerman
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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van Wijk N, Slot RER, Duits FH, Strik M, Biesheuvel E, Sijben JWC, Blankenstein MA, Bierau J, van der Flier WM, Scheltens P, Teunissen CE. Nutrients required for phospholipid synthesis are lower in blood and cerebrospinal fluid in mild cognitive impairment and Alzheimer's disease dementia. Alzheimers Dement (Amst) 2017; 8:139-146. [PMID: 28653034 PMCID: PMC5476966 DOI: 10.1016/j.dadm.2017.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Synaptic membrane formation depends on nutrients that fuel metabolic pathways for the synthesis of constituent phospholipids. Consequently, insufficient availability of such nutrients may restrict membrane formation and contribute to synaptic dysfunction in Alzheimer's disease (AD). We assessed whether blood and cerebrospinal fluid (CSF) concentrations of nutrients related to phospholipid synthesis differ among patients with AD, mild cognitive impairment (MCI), and control subjects. METHODS Concentrations of uridine, choline, folate, homocysteine, and other related metabolites were analyzed in paired blood and CSF samples from subjects selected from the Amsterdam Dementia Cohort with AD (n = 150; age, 66 ± 7 years; 37% female), MCI (n = 148; age, 66 ± 8 years; 37% female), and control subjects (n = 148; age, 59 ± 8 years; 38% female). RESULTS Age- and gender-adjusted analysis of variance revealed different concentrations of circulating uridine, choline, and folate and CSF uridine, folate, and homocysteine (all P < .05) among the three diagnostic groups. Post hoc pairwise comparison showed that subjects with AD had lower CSF uridine, plasma choline and higher CSF homocysteine concentrations, whereas subjects with MCI had lower plasma and CSF uridine, serum and CSF folate, and higher CSF homocysteine concentrations compared with control subjects (all P < .05), with differences ranging from -11 to +22%. DISCUSSION AD and MCI patients have lower levels of nutrients involved in phospholipid synthesis. The current observations warrant exploration of the application of nutritional strategies in the early stages of AD.
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Affiliation(s)
- Nick van Wijk
- Nutricia Advanced Medical Nutrition, Nutricia Research, Utrecht, The Netherlands
| | - Rosalinde E R Slot
- Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Flora H Duits
- Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Marieke Strik
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Egbert Biesheuvel
- Nutricia Advanced Medical Nutrition, Nutricia Research, Utrecht, The Netherlands
| | - John W C Sijben
- Nutricia Advanced Medical Nutrition, Nutricia Research, Utrecht, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Jörgen Bierau
- Department of Clinical Genetics, Maastricht UMC+, Maastricht, The Netherlands
| | - Wiesje M van der Flier
- Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Philip Scheltens
- Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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Vlot MC, Klink DT, den Heijer M, Blankenstein MA, Rotteveel J, Heijboer AC. Effect of pubertal suppression and cross-sex hormone therapy on bone turnover markers and bone mineral apparent density (BMAD) in transgender adolescents. Bone 2017; 95:11-19. [PMID: 27845262 DOI: 10.1016/j.bone.2016.11.008] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 11/02/2016] [Accepted: 11/06/2016] [Indexed: 12/17/2022]
Abstract
Puberty is highly important for the accumulation of bone mass. Bone turnover and bone mineral density (BMD) can be affected in transgender adolescents when puberty is suppressed by gonadotropin-releasing hormone analogues (GnRHa), followed by treatment with cross-sex hormone therapy (CSHT). We aimed to investigate the effect of GnRHa and CSHT on bone turnover markers (BTMs) and bone mineral apparent density (BMAD) in transgender adolescents. Gender dysphoria was diagnosed based on diagnostic criteria according to the DSM-IV (TR). Thirty four female-to-male persons (transmen) and 22 male-to-female persons (transwomen)were included. Patients were allocated to a young (bone age of <15years in transwomen or <14 in transmen) or old group (bone age of ≥15years in transwomen or ≥14years in transmen). All were treated with GnRHa triptorelin and CSHT was added in incremental doses from the age of 16years. Transmen received testosterone esters (Sustanon, MSD) and transwomen received 17-β estradiol. P1NP, osteocalcin, ICTP and BMD of lumbar spine (LS) and femoral neck (FN) were measured at three time points. In addition, BMAD and Z-scores were calculated. We found a decrease of P1NP and 1CTP during GnRHa treatment, indicating decreased bone turnover (young transmen 95% CI -74 to -50%, p=0.02, young transwomen 95% CI -73 to -43, p=0.008). The decrease in bone turnover upon GnRHa treatment was accompanied by an unchanged BMAD of FN and LS, whereas BMAD Z-scores of predominantly the LS decreased especially in the young transwomen. Twenty-four months after CSHT the BTMs P1NP and ICTP were even more decreased in all groups except for the old transmen. During CSHT BMAD increased and Z-scores returned towards normal, especially of the LS (young transwomen CI 95% 0.1 to 0.6, p=0.01, old transwomen 95% CI 0.3 to 0.8, p=0.04). To conclude, suppressing puberty by GnRHa leads to a decrease of BTMs in both transwomen and transmen transgender adolescents. The increase of BMAD and BMAD Z-scores predominantly in the LS as a result of treatment with CSHT is accompanied by decreasing BTM concentrations after 24months of CSHT. Therefore, the added value of evaluating BTMs seems to be limited and DXA-scans remain important in follow-up of bone health of transgender adolescents.
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Affiliation(s)
- Mariska C Vlot
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands; Department of Internal Medicine, section Endocrinology, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Daniel T Klink
- Center of Expertise on Gender Dysphoria, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands; Department of Pediatric Endocrinology, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Martin den Heijer
- Department of Internal Medicine, section Endocrinology, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands; Center of Expertise on Gender Dysphoria, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Joost Rotteveel
- Center of Expertise on Gender Dysphoria, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands; Department of Pediatric Endocrinology, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
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Malekzadeh A, Twaalfhoven H, Wijnstok NJ, Killestein J, Blankenstein MA, Teunissen CE. Comparison of multiplex platforms for cytokine assessments and their potential use for biomarker profiling in multiple sclerosis. Cytokine 2017; 91:145-152. [PMID: 28082233 DOI: 10.1016/j.cyto.2016.12.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 12/22/2016] [Accepted: 12/23/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND The levels of pro and anti-inflammatory cytokines can be altered in different autoimmune pathologies, such as multiple sclerosis (MS). It is likely that cytokines in bodily fluids can provide a good reflection of ongoing disease patho-physiology. In this study we aimed to validate multiplex cytokine platforms and evaluate whether these cytokines are differentially expressed in MS. METHODS Assay validation for simultaneous quantification of IL-1β, IL-6, IL-8 and TNF-α in serum and CSF were performed using both the Luminex-xMAP (Luminex) and Meso Scale Discovery (MSD) platforms. Next, the relation of the pro-inflammatory cytokine 4-plex with disease progression, symptoms and subtypes was studied in paired serum and CSF of MS patients (n=56), and compared with healthy controls (n=203), with the use of the MSD-platform. RESULTS The MSD-platform showed overall better assay characteristics such as, sensitivity, recovery and linearity compared to the Luminex for the 4-plex cytokines in CSF and serum. IL-6, IL-8 and TNF-α (p<0.001) levels were significantly increased in MS serum compared to healthy controls. Moreover, serum IL-1β levels correlated with expanded disability status scale (EDSS) scores (r=-0.34, p<0.05). Additionally, IL-6 and IL-8 CSF levels were both significantly decreased in MS patients compared to non-inflammatory neurological disease controls. Noteworthy, higher IL-8 CSF levels than IL-8 serum levels were observed for MS patients, indicating intrathecal activation of macrophages in MS. CONCLUSION We have demonstrated that the pro-inflammatory 4-plex kit of the MSD-platform shows better assay characteristics in comparison with Luminex kit for quantification of these cytokines in serum and CSF. Overall, the increased levels of IL-6, IL-8 and TNF-α in serum of MS patients compared to healthy controls, support the use of multiple cytokines for future MS biomarker and disease progression research.
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Affiliation(s)
- Arjan Malekzadeh
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
| | - Harry Twaalfhoven
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
| | - Nienke J Wijnstok
- Department of Internal and Vascular Medicine, VU University Medical Center, Amsterdam, The Netherlands.
| | - Joep Killestein
- Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands.
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
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Dirks NF, Martens F, Vanderschueren D, Billen J, Pauwels S, Ackermans MT, Endert E, Heijer MD, Blankenstein MA, Heijboer AC. Determination of human reference values for serum total 1,25-dihydroxyvitamin D using an extensively validated 2D ID-UPLC-MS/MS method. J Steroid Biochem Mol Biol 2016; 164:127-133. [PMID: 26690787 DOI: 10.1016/j.jsbmb.2015.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 10/15/2015] [Accepted: 12/06/2015] [Indexed: 01/18/2023]
Abstract
BACKGROUND To assess a patient's vitamin D status the precursor metabolite 25-hydroxyvitamin D can be determined. However, measurement of 1,25-dihydroxyvitamin D is required when disorders of 1a-hydroxylation, extrarenal 1a-hydroxylation, or vitamin D receptor defects are suspected. METHODS The aim of this study was to determine reference values for 1,25-dihydroxyvitamin D3 and D2 using a 2D ID-UPLC-MS/MS method. RESULTS The LC-MS/MS method, able to measure picomolar concentrations of both 1,25-dihydroxyvitamin D3 and D2 in human serum, was extensively validated. Intra-assay variations were <5% and 8.5% and <7.5% and 11%, for 1,25-dihydroxyvitamin D3 and D2, respectively, over the whole dynamic range (3.1-376 and 3.1-652pmol/L). Limit of quantitation was 3.4pmol/L for both compounds. Our method correlated well with a published LC-MS/MS method (r=0.87) and with the average 1,25-dihydroxyvitamin D3 results of the vitamin D External Quality Assessment Scheme (DEQAS) determined with LC-MS/MS (r=0.93). Reference ranges, determined in 96 plasma samples of healthy volunteers were 59-159pmol/L and <17pmol/L for respectively 1,25-dihydroxyvitamin D3 and D2. The female part of the reference group showed a statistically significant decrease of 1,25-dihydroxyvitamin D3 concentrations with age. The presence of significantly higher average 1,25-dihydroxyvitamin D3 levels in premenopausal women taking oral contraceptive pills compared to postmenopausal women suggests that this effect is estrogen-related, as estrogens lead to a higher vitamin D binding protein. CONCLUSIONS The major finding of the present study is a reference interval of 59-159pmol/L for 1,25-dihydroxyvitamin D3 determined with a highly sensitive and precise LC-MS/MS method.
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Affiliation(s)
- Niek F Dirks
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands
| | - Frans Martens
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands
| | - Dirk Vanderschueren
- Department of Clinical and Experimental Medicine KU Leuven, Laboratory of Clinical and Experimental Endocrinology, Leuven, Belgium; Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Jaak Billen
- Department of Clinical and Experimental Medicine KU Leuven, Laboratory of Clinical and Experimental Endocrinology, Leuven, Belgium; Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Steven Pauwels
- Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium; Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Mariëtte T Ackermans
- Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center, Amsterdam, The Netherlands
| | - Erik Endert
- Department of Clinical Chemistry, Laboratory of Endocrinology, Academic Medical Center, Amsterdam, The Netherlands
| | - Martin den Heijer
- Department of Internal Medicine, Endocrinology, VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, Endocrine Laboratory, VU University Medical Center, Amsterdam, The Netherlands.
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Kuijper EAM, Houwink EJF, van Weissenbruch MM, Heij HA, Blankenstein MA, Huijser J, Martens F, Lambalk CB. Urinary gonadotropin measurements in neonates: a valuable non-invasive method. Ann Clin Biochem 2016; 43:320-2. [PMID: 16824286 DOI: 10.1258/000456306777695582] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background: To measure low neonatal gonadotropin levels, a sensitive non-invasive method is optimal. The aim of the current study was to validate the Architect i2000SR, an automated immunoassay analyser for the measurement of gonadotropins in unextracted neonatal urine samples against serum gonadotropin levels as a gold standard. Methods: Blood and urine were sampled from 30 approximately six-week-old male and female neonates undergoing elective paediatric surgery. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured and the urine results were corrected for creatinine. Results: The agreement between neonatal serum and urinary FSH was 0.904 (3-5 h between samples) and 0.704 (18-20 h). For LH, the correlation coefficients were 0.785 and 0.507, respectively. Conclusion: We conclude that gonadotropins can be reliably measured using the Architect on randomly voided, non-extracted urine samples collected from neonates by an adhesive device. Urinary gonadotropin levels are a proper reflection of the serum levels.
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Affiliation(s)
- E A M Kuijper
- Department of Obstetrics and Gynecology, Division of Reproductive Medicine, VU University medical center, VUmc, and Emma Children's Hospital AMC, 1007 MB Amsterdam, The Netherlands.
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Heijboer AC, Savelkoul E, Kruit A, Endert E, Blankenstein MA. Inaccurate First-Generation Testosterone Assays Are Influenced by Sex Hormone–Binding Globulin Concentrations. ACTA ACUST UNITED AC 2016; 1:194-201. [DOI: 10.1373/jalm.2016.020065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 05/27/2016] [Indexed: 11/06/2022]
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Holla FK, Postma TJ, Blankenstein MA, van Mierlo TJM, Vos MJ, Sizoo EM, de Groot M, Uitdehaag BMJ, Buter J, Klein M, Reijneveld JC, Heimans JJ. Prognostic value of the S100B protein in newly diagnosed and recurrent glioma patients: a serial analysis. J Neurooncol 2016; 129:525-532. [PMID: 27401156 PMCID: PMC5020117 DOI: 10.1007/s11060-016-2204-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/03/2016] [Indexed: 12/03/2022]
Abstract
The S100B protein is associated with brain damage and a breached blood–brain barrier. A previous pilot study showed that high serum levels of S100B are associated with shorter survival in glioma patients. The aim of our study was to assess the prognostic value in terms of survival and longitudinal dynamics of serum S100B for patients with newly diagnosed and recurrent glioma. We obtained blood samples from patients with newly diagnosed and recurrent glioma before the start (baseline) and at fixed time-points during temozolomide chemotherapy. S100B-data were dichotomized according to the upper limit of the reference value of 0.1 μg/L. Overall survival (OS) was estimated with Kaplan–Meier curves and groups were compared with the log rank analysis. To correct for potential confounders a Cox regression analysis was used. We included 86 patients with newly-diagnosed and 27 patients with recurrent glioma. Most patients in both groups had baseline serum levels within normal limits. In the newly diagnosed patients we found no significant difference in OS between the group of patients with S100B levels >0.1 μg/L at baseline compared to those with <0.1 μg/L. In the patients with recurrent glioma we found a significantly shorter OS for patients with raised levels. In both groups, S100B values did not change significantly throughout the course of the disease. Serum S100B levels do not seem to have prognostic value in newly diagnosed glioma patients. In recurrent glioma patients S100B might be of value in terms of prognostication of survival.
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Affiliation(s)
- F K Holla
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - T J Postma
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
| | - M A Blankenstein
- Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - T J M van Mierlo
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - M J Vos
- Department of Neurology, Medical Center Haaglanden, The Hague, The Netherlands
| | - E M Sizoo
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - M de Groot
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - B M J Uitdehaag
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
- Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
| | - J Buter
- Medical Oncology, VU University Medical Center, Amsterdam, The Netherlands
| | - M Klein
- Medical Psychology, VU University Medical Center, Amsterdam, The Netherlands
| | - J C Reijneveld
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - J J Heimans
- Department of Neurology, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
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Teunissen CE, Durieux-Lu S, Blankenstein MA, Oude Voshaar RC, Comijs HC. The inflammatory marker GDF-15 is not independently associated with late-life depression. J Psychosom Res 2016; 83:46-9. [PMID: 27020076 DOI: 10.1016/j.jpsychores.2016.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 02/29/2016] [Accepted: 03/07/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Growth differentiation factor-15 (GDF-15) is an inflammatory molecule that reacts to cell stress. Since major depression is associated with inflammation, we examined whether GDF-15 levels are elevated in patients with late-life depression. METHODS Plasma GDF-15 levels were analyzed in 350 patients diagnosed with major depressive disorder in the last six months and 128 non-depressed controls from the Netherlands Study of Depression in Older persons (age ≥ 60 years). Major depressive disorder and age of onset were assessed with the Composite International Diagnostic Interview. Severity of depressive symptoms was measured with the Inventory of Depressive Symptoms (IDS-30). Multiple linear regression models were applied to study depression (diagnosis, onset age, severity, antidepressant drug use) as determinant of GDF-15 level, adjusted for demographic and clinical variables. RESULTS Plasma GDF-15 levels were 22% higher in patients with major depression compared to controls. Within the depressed group, levels were higher in patients with older age of onset. GDF-15 levels showed a small, positive correlation to the levels of the inflammatory mediators IL-6 and C-reactive protein (r=0.23, and 0.24, p<0.05). This increase was independent from comorbidities, such as cardiovascular disease, rheumatism and diabetes, and anti-inflammatory drugs. However, this increase was dependent on lifestyle factors as smoking, physical activity and alcohol use. Within the depressed subgroup, neither depression severity or antidepressant drug use was associated with GDF-15 levels in the fully adjusted models. CONCLUSION The inflammatory factor GDF-15 does not seem to be an independent inflammatory marker for late-life major depressive disorder.
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Affiliation(s)
- C E Teunissen
- Dept. of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands.
| | - S Durieux-Lu
- Dept. of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
| | - M A Blankenstein
- Dept. of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, The Netherlands
| | - R C Oude Voshaar
- University of Groningen, University Medical Center Groningen, Interdisciplinary Center for Psychopathology of Emotion Regulation (ICPE), Groningen, The Netherlands
| | - H C Comijs
- GGZ inGeest/Department Psychiatry, EMGO Institute for Care and Health Research, VU University Medical Center, Amsterdam, The Netherlands
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12
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Jongbloed W, Bruggink KA, Kester MI, Visser PJ, Scheltens P, Blankenstein MA, Verbeek MM, Teunissen CE, Veerhuis R. Amyloid-β oligomers relate to cognitive decline in Alzheimer's disease. J Alzheimers Dis 2016; 45:35-43. [PMID: 25547634 DOI: 10.3233/jad-142136] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Amyloid-β (Aβ)-oligomers are neurotoxic isoforms of Aβ and are a potential diagnostic biomarker for Alzheimer's disease (AD). OBJECTIVES 1) Analyze the potential of Aβ-oligomer concentrations in cerebrospinal fluid (CSF) to diagnose and predict progression to AD in a large clinical study sample. 2) Monitor Aβ-oligomer concentrations over-time, both in early and advanced stages of AD. 3) Examine the relation between Aβ-oligomer levels in CSF and cognitive functioning. METHODS 24 non-demented, 61 mild cognitive impairment (MCI), and 64 AD patients who underwent lumbar puncture and cognitive testing at baseline and follow-up were selected from the memory clinic based Amsterdam Dementia Cohort. CSF samples were analyzed for standard AD-biomarkers and Aβ-oligomer levels using a validated in-house Aβ-oligomer specific enzyme-linked immunosorbent assay. Aβ-oligomer levels were analyzed as indicators of disease progression (follow-up AD diagnosis) and cognitive decline, respectively. RESULTS Patient groups did not differ in Aβ-oligomer concentrations at baseline or follow-up. Baseline CSF Aβ-oligomer levels were similar in MCI patients that develop AD as in stable MCI patients. MCI and AD patients showed an annual decrease in Aβ-oligomer levels of 9.4% and 6.8%, respectively. A decrease in Aβ-oligomer levels over time was strongly associated with more severe cognitive decline in AD patients. CONCLUSION Despite the limited diagnostic potential of Aβ-oligomer levels in CSF to differentiate between patient groups, and between MCI-AD and MCI-stable patients, changes in CSF Aβ-oligomer levels were related to cognitive decline. Therefore, CSF Aβ-oligomers may aid in the selection of patients with a more aggressive disease course.
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Affiliation(s)
- Wesley Jongbloed
- Department of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Kim A Bruggink
- Department of Neurology, Department of Laboratory Medicine, Donders Institute for Brain, Cognition and behaviour, Alzheimer Centre Nijmegen, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Maartje I Kester
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Pieter-Jelle Visser
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands Department of Psychiatry and Neuropsychology, Alzheimer Center Limburg, University of Maastricht, Maastricht, The Netherlands
| | - Philip Scheltens
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Marcel M Verbeek
- Department of Neurology, Department of Laboratory Medicine, Donders Institute for Brain, Cognition and behaviour, Alzheimer Centre Nijmegen, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Robert Veerhuis
- Department of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
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13
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Büttler RM, Peper JS, Crone EA, Lentjes EGW, Blankenstein MA, Heijboer AC. Reference values for salivary testosterone in adolescent boys and girls determined using Isotope-Dilution Liquid-Chromatography Tandem Mass Spectrometry (ID-LC-MS/MS). Clin Chim Acta 2016; 456:15-18. [PMID: 26920638 DOI: 10.1016/j.cca.2016.02.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 02/17/2016] [Accepted: 02/22/2016] [Indexed: 11/25/2022]
Abstract
The measurement of testosterone in saliva is an attractive alternative to serum analysis due to the simple and non-invasive sample collection. In children and adolescents salivary testosterone is mainly measured to investigate whether puberty has started or not. This study aimed to establish reference values for salivary testosterone during puberty in boys and girls. We measured salivary testosterone using ID-LC-MS/MS in a cohort of 131 girls and 123 boys of whom each had salivary testosterone measured at two time points during puberty. Salivary testosterone concentrations start to increase with the start of puberty around eight years and continuously increase up to adult concentrations in the following ten years. Reference values were calculated using the Lambda-Mu-Sigma (LMS)-curve fitting method and provided per year from 8 to 26 years of age in boys and girls. These reference ranges may help clinicians and researchers to interpret salivary testosterone results in both individual patients and study subjects.
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Affiliation(s)
- Rahel M Büttler
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands
| | - Jiska S Peper
- Institute of Psychology, Leiden University, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Eveline A Crone
- Institute of Psychology, Leiden University, Leiden, the Netherlands; Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Eef G W Lentjes
- Department of Clinical Chemistry & Haematology, University Medical Center, Utrecht, the Netherlands
| | - Marinus A Blankenstein
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands
| | - Annemieke C Heijboer
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands.
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14
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Büttler RM, Martens F, Fanelli F, Pham HT, Kushnir MM, Janssen MJW, Owen L, Taylor AE, Soeborg T, Blankenstein MA, Heijboer AC. Comparison of 7 Published LC-MS/MS Methods for the Simultaneous Measurement of Testosterone, Androstenedione, and Dehydroepiandrosterone in Serum. Clin Chem 2015; 61:1475-83. [PMID: 26503965 DOI: 10.1373/clinchem.2015.242859] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/08/2015] [Indexed: 11/06/2022]
Abstract
BACKGROUND Recently, LC-MS/MS was stated to be the method of choice to measure sex steroids. Because information on the mutual agreement of LC-MS/MS methods is scarce, we compared 7 published LC-MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and dehydroepiandrosterone (DHEA). METHODS We used 7 published LC-MS/MS methods to analyze in duplicate 55 random samples from both men and women. We performed Passing-Bablok regression analysis and calculated Pearson correlation coefficients to assess the agreement of the methods investigated with the median concentration measured by all methods, and we calculated the intraassay CV of each method derived from duplicate results and the CVs between the methods. RESULTS Median concentrations of testosterone were 0.22-1.36 nmol/L for women and 8.27-27.98 nmol/L for men. Androstenedione and DHEA concentrations were 0.05-5.53 and 0.58-18.04 nmol/L, respectively. Intraassay CVs were 2.9%-10%, 1.2%-8.8%, 2.7%-13%, and 4.3%-16% for testosterone in women, testosterone in men, androstenedione, and DHEA. Slopes of the regression lines calculated by Passing-Bablok regression analysis were 0.92-1.08, 0.92-1.08, 0.90-1.13, and 0.91-1.41 for all testosterone values, testosterone in women, androstenedione, and DHEA. Intermethod CVs were 14%, 8%, 30%, and 22% for testosterone in women, testosterone in men, androstenedione, and DHEA. CONCLUSIONS In general, the LC-MS/MS methods investigated show reasonable agreement. However, some of the assays show differences in standardization, and others show high variation.
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Affiliation(s)
- Rahel M Büttler
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, Netherlands
| | - Frans Martens
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, Netherlands
| | - Flaminia Fanelli
- Endocrinology Unit and Center for Applied Biomedical Research, Department of Medical and Surgical Sciences, S. Orsola Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Hai T Pham
- Biocrates Life Sciences AG, Innsbruck, Austria
| | - Mark M Kushnir
- Department of Pathology, University of Utah, Salt Lake City, UT; ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT
| | - Marcel J W Janssen
- Laboratory of Clinical Chemistry and Hematology, VieCuri Medical Center Venlo, Netherlands
| | - Laura Owen
- Department of Clinical Biochemistry, University Hospital of South Manchester, Manchester, UK
| | - Angela E Taylor
- Centre for Endocrinology, Diabetes and Metabolism, School of Clinical and Experimental Medicine, University of Birmingham, UK
| | - Tue Soeborg
- Department of Growth and Reproduction, Rigshospitalet, Copenhagen University Hospital, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Marinus A Blankenstein
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, Netherlands
| | - Annemieke C Heijboer
- Endocrine Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, Netherlands;
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15
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Del Campo M, Jongbloed W, Twaalfhoven HAM, Veerhuis R, Blankenstein MA, Teunissen CE. Facilitating the Validation of Novel Protein Biomarkers for Dementia: An Optimal Workflow for the Development of Sandwich Immunoassays. Front Neurol 2015; 6:202. [PMID: 26483753 PMCID: PMC4586418 DOI: 10.3389/fneur.2015.00202] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/31/2015] [Indexed: 01/11/2023] Open
Abstract
Different neurodegenerative disorders, such as Alzheimer’s disease (AD) and frontotemporal dementia (FTD), lead to dementia syndromes. Dementia will pose a huge impact on society and thus it is essential to develop novel tools that are able to detect the earliest, most sensitive, discriminative, and dynamic biomarkers for each of the disorders. To date, the most common assays used in large-scale protein biomarker analysis are enzyme-linked immunosorbent assays (ELISA), such as the sandwich immunoassays, which are sensitive, practical, and easily implemented. However, due to the novelty of many candidate biomarkers identified during proteomics screening, such assays or the antibodies that specifically recognize the desired marker are often not available. The development and optimization of a new ELISA should be carried out with considerable caution since a poor planning can be costly, ineffective, time consuming, and it may lead to a misinterpretation of the findings. Previous guidelines described either the overall biomarker development in more general terms (i.e., the process from biomarker discovery to validation) or the specific steps of performing an ELISA procedure. However, a workflow describing and guiding the main issues in the development of a novel ELISA is missing. Here, we describe a specific and detailed workflow to develop and validate new ELISA for a successful and reliable validation of novel dementia biomarkers. The proposed workflow highlights the main issues in the development of an ELISA and covers several critical aspects, including production, screening, and selection of specific antibodies until optimal fine-tuning of the assay. Although these recommendations are designed to analyze novel biomarkers for dementia in cerebrospinal fluid, they are generally applicable for the development of immunoassays for biomarkers in other human body fluids or tissues. This workflow is designed to maximize the quality of the developed ELISA using a time- and cost-efficient strategy. This will facilitate the validation of the dementia biomarker candidates ultimately allowing accurate diagnostic conclusions.
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Affiliation(s)
- Marta Del Campo
- Neurochemistry Laboratory, VU University Medical Center , Amsterdam , Netherlands ; Department of Clinical Chemistry, VU University Medical Center , Amsterdam , Netherlands
| | - Wesley Jongbloed
- Department of Clinical Chemistry, VU University Medical Center , Amsterdam , Netherlands
| | - Harry A M Twaalfhoven
- Neurochemistry Laboratory, VU University Medical Center , Amsterdam , Netherlands ; Department of Clinical Chemistry, VU University Medical Center , Amsterdam , Netherlands
| | - Robert Veerhuis
- Neurochemistry Laboratory, VU University Medical Center , Amsterdam , Netherlands ; Department of Psychiatry, VU University Medical Center , Amsterdam , Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center , Amsterdam , Netherlands
| | - Charlotte E Teunissen
- Neurochemistry Laboratory, VU University Medical Center , Amsterdam , Netherlands ; Department of Clinical Chemistry, VU University Medical Center , Amsterdam , Netherlands
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16
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Bui HN, Sluss PM, Hayes FJ, Blincko S, Knol DL, Blankenstein MA, Heijboer AC. Testosterone, free testosterone, and free androgen index in women: Reference intervals, biological variation, and diagnostic value in polycystic ovary syndrome. Clin Chim Acta 2015; 450:227-32. [PMID: 26327459 DOI: 10.1016/j.cca.2015.08.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 08/21/2015] [Accepted: 08/21/2015] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The objective of our study was to determine reference intervals and biologic variation for testosterone (T), free testosterone (fT), and free androgen index (FAI) in women with accurate methods and to test the discriminative value of these parameters in a polycystic ovary syndrome (PCOS)-population. METHODS Serum was obtained daily during a normal menstrual cycle from 25 healthy women (677 data-points). A single serum sample was obtained from 44 PCOS-patients. T was measured by LC–MS/MS and by Architect® 2nd generation T Immunoassay. Sex hormone-binding globulin was measured to calculate fT and FAI. Results: Reference intervals which were established in healthy women with an ovulatory menstrual cycle were T = 0.3-1.6 nmol/L and 0.5-2.0 nmol/L, fT = 5.2-26 pmol/L and 7.2-33 pmol/L, and FAI = 0.4-2.9 and 0.6-4.4, by LC-MS/MS and immunoassay, respectively. T, fT and FAI were higher in PCOS patients than in controls (p b 0.0001). The areas under the curve of receiver operator characteristic (ROC) plots were not different for T, fT, or FAI when T was measured by LC–MS/MS versus immunoassay based on prediction of PCOS. FAI and fT were the strongest predictors of PCOS. CONCLUSIONS When based upon the appropriate reference intervals and ROC analysis, LC-MS/MS and second generation immunoassay have equivalent clinical utility for the diagnosis of PCOS.
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Affiliation(s)
- H N Bui
- Dept. of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - P M Sluss
- Clinical Pathology Core Laboratory, Massachusetts General Hospital, Boston, MA, USA
| | - F J Hayes
- Reproductive Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | - S Blincko
- Abbott Diagnostics, Wiesbaden, Germany
| | - D L Knol
- Dept. of Epidemiology and Biostatistics, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - M A Blankenstein
- Dept. of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - A C Heijboer
- Dept. of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
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17
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Adema AY, Vervloet MG, Blankenstein MA, Heijboer AC. α-Klotho is unstable in human urine. Kidney Int 2015; 88:1442-1444. [PMID: 26244922 DOI: 10.1038/ki.2015.238] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 05/28/2015] [Accepted: 06/04/2015] [Indexed: 11/09/2022]
Abstract
α-Klotho is an interesting new biomarker in kidney and cardiovascular disease. As α-Klotho is primarily expressed in renal epithelial tissue, various papers have reported α-Klotho concentrations in urine. As these studies did not address the reliability of urinary α-Klotho measurements and as urine is known to be a complex milieu, we investigated the stability of α-Klotho in both fresh catheter and fresh voided urine. α-Klotho was measured in these fresh urine samples and in the same samples under several other conditions. Storage of fresh catheter urine for 3 h at 37 °C, comparable to storage in the bladder, led to a 82% decrease in α-Klotho concentrations. Compared with fresh voided urine, α-Klotho concentrations decreased on an average of 45 and 82% after storage at -80 °C and -20 °C, respectively. An additional freeze-thaw cycle further decreased α-Klotho concentrations. The addition of a protease inhibitor or 0.1% albumin partly prevented degradation in fresh voided urine. Thus, α-Klotho is highly unstable in urine. Future studies showing results of urinary α-Klotho should mention conservation conditions and prove the reliability of the α-Klotho measurements.
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Affiliation(s)
- Aaltje Y Adema
- Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands
| | - Marc G Vervloet
- Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands.,Institute for Cardiovascular Research VU (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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18
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Heijboer AC, Oosterwerff M, Schroten NF, Eekhoff EMW, Chel VGM, de Boer RA, Blankenstein MA, Lips P. Vitamin D supplementation and testosterone concentrations in male human subjects. Clin Endocrinol (Oxf) 2015; 83:105-10. [PMID: 25557316 DOI: 10.1111/cen.12711] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/26/2014] [Accepted: 12/19/2014] [Indexed: 01/07/2023]
Abstract
OBJECTIVE A possible association between serum 25-hydroxyvitamin D and testosterone levels has been reported; however, contradictory results have emerged. DESIGN To investigate a causal link between vitamin D and testosterone status, we studied the effect of vitamin D supplementation on serum testosterone concentrations in three independent intervention studies including male patients with heart failure (study 1), male nursing home residents (study 2) and male non-Western immigrants in the Netherlands (study 3). METHODS In study 1, 92 subjects were randomized to either vitamin D (2000 IU cholecalciferol daily) or control. Blood was drawn at baseline, after 3 and 6 weeks. In study 2, 49 vitamin D deficient subjects received either vitamin D (600 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. In study 3, 43 vitamin D deficient subjects received either vitamin D (1200 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. Serum 25-hydroxyvitamin D levels were measured using LC-MS/MS or radioimmunoassay. Testosterone levels were measured using a 2nd generation immunoassay. RESULTS Serum 25-hydroxyvitamin D levels significantly increased in all treatment groups (median increase of 27, 30 and 36 nmol/l in studies 1, 2 3, respectively) but not in the control groups. The documented increase in 25-hydroxyvitamin D levels, however, did not affect mean testosterone concentrations at the end of the study (median increase of 0, 0.5 and 0 nmol/l in studies 1, 2 and 3, respectively). CONCLUSIONS In this post hoc analysis of three small clinical trials of limited duration in men with normal baseline testosterone concentrations, vitamin D supplementation was not associated with an increase in circulating testosterone concentrations.
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Affiliation(s)
- Annemieke C Heijboer
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands
| | - Mirjam Oosterwerff
- Department of Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - Nicolas F Schroten
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Elisabeth M W Eekhoff
- Department of Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - Victor G M Chel
- Overduin Katwijk, Katwijk, the Netherlands
- Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands
| | - Rudolf A de Boer
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands
| | - Paul Lips
- Department of Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands
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Jongbloed W, van Dijk KD, Mulder SD, van de Berg WD, Blankenstein MA, van der Flier W, Veerhuis R. Clusterin Levels in Plasma Predict Cognitive Decline and Progression to Alzheimer’s Disease. J Alzheimers Dis 2015; 46:1103-10. [DOI: 10.3233/jad-150036] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Wesley Jongbloed
- Department of Clinical Chemistry, Neurochemistry Laboratory, VU University Medical Center, Amsterdam, The Netherlands
| | - Karin D. van Dijk
- Department of Anatomy and Neurosciences, Section Functional Neuroanatomy, VU University Medical Center, Amsterdam, The Netherlands
- Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Sandra D. Mulder
- Department of Clinical Chemistry, Neurochemistry Laboratory, VU University Medical Center, Amsterdam, The Netherlands
- VUmc Alzheimer Center, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Wilma D.J. van de Berg
- Department of Anatomy and Neurosciences, Section Functional Neuroanatomy, VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A. Blankenstein
- Department of Clinical Chemistry, Neurochemistry Laboratory, VU University Medical Center, Amsterdam, The Netherlands
| | - Wiesje van der Flier
- VUmc Alzheimer Center, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Robert Veerhuis
- Department of Clinical Chemistry, Neurochemistry Laboratory, VU University Medical Center, Amsterdam, The Netherlands
- Department of Psychiatry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
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20
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van der Voorn B, Martens F, Peppelman NS, Rotteveel J, Blankenstein MA, Finken MJ, Heijboer AC. Determination of cortisol and cortisone in human mother's milk. Clin Chim Acta 2015; 444:154-5. [DOI: 10.1016/j.cca.2015.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/09/2015] [Accepted: 02/09/2015] [Indexed: 11/16/2022]
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Büttler RM, Martens F, Kushnir MM, Ackermans MT, Blankenstein MA, Heijboer AC. Simultaneous measurement of testosterone, androstenedione and dehydroepiandrosterone (DHEA) in serum and plasma using Isotope-Dilution 2-Dimension Ultra High Performance Liquid-Chromatography Tandem Mass Spectrometry (ID-LC–MS/MS). Clin Chim Acta 2015; 438:157-9. [DOI: 10.1016/j.cca.2014.08.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/10/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
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22
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Affiliation(s)
- Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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23
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Trentini A, Comabella M, Tintoré M, Koel-Simmelink MJA, Killestein J, Roos B, Rovira A, Korth C, Ottis P, Blankenstein MA, Montalban X, Bellini T, Teunissen CE. N-Acetylaspartate and neurofilaments as biomarkers of axonal damage in patients with progressive forms of multiple sclerosis. J Neurol 2014; 261:2338-43. [DOI: 10.1007/s00415-014-7507-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
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Engels MAJ, Twisk JWR, Blankenstein MA, van Vugt JMG. First-trimester screening for down syndrome with serum sampling at different gestational ages: the effect on screening performance. Fetal Diagn Ther 2014; 36:293-8. [PMID: 25170623 DOI: 10.1159/000362186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 03/11/2014] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The objective of this study was to evaluate the performance of first-trimester Down syndrome (DS) screening with serum sampling at different weeks of gestation. MATERIAL AND METHODS We studied 35,431 singleton pregnancies (2005-2011), including 145 DS cases. Screening performance was determined in different maternal age groups with serum sampling between weeks 9 + 0 and 13 + 6. RESULTS No significant differences were found between the detection rates at different gestational weeks. The false-positive rate (FPR) in week 9 (6%) was comparable to the FPR in week 10 (6.5%; p = 0.214), whereas it was significantly lower compared to weeks 11 (7.2%; p = 0.007), 12 (7.4%; p = 0.003) and 13 (8.5%; p < 0.001). The odds of receiving a false-positive result was significantly increased with serum sampling in week 11 (OR 1.32, 95% CI 1.08-1.63; p = 0.008) for women ≥36 years and from week 12 onwards (OR 1.28, 95% CI 1.01-1.61; p = 0.04) for women <36 years. There were no differences in mean log10 multiple of the median values of pregnancy-associated plasma protein-A, free β-human chorionic gonadotrophin or nuchal translucency between both age groups, nor in mean maternal age between the different gestational weeks in either age group. DISCUSSION Early serum sampling (<11 weeks) resulted in higher screening performance. The impact of the increase in the FPR was highest in women ≥36 years.
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Affiliation(s)
- Melanie A J Engels
- Department of Obstetrics and Gynaecology, VU University Medical Center, Amsterdam, The Netherlands
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Mulder SD, Vandermeulen L, Scheltens P, Blankenstein MA, Veerhuis R. P3‐031: AMYLOID‐BETA DEGRADATION BY HUMAN ASTROCYTES IS IMPAIRED BY APOJ AND APOE. Alzheimers Dement 2014. [DOI: 10.1016/j.jalz.2014.05.1118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kester MI, Teunissen C, Sutphen C, Macy E, Ladenson J, Xiong C, Blankenstein MA, Scheltens P, Flier WM, Morris JC, Holtzman D, Fagan AM. P1‐149: CSF VILIP‐1 AND YKL‐40, NOVEL CANDIDATE BIOMARKERS TO DIAGNOSE, PREDICT, AND MONITOR ALZHEIMER'S DISEASE. Alzheimers Dement 2014. [DOI: 10.1016/j.jalz.2014.05.386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | | | - Courtney Sutphen
- Washington University in St. LouisSt. LouisMissouriUnited States
| | - Elizabeth Macy
- Washington University School of MedicineSt. LouisMissouriUnited States
| | - Jack Ladenson
- Washington University in St. LouisSt. LouisMissouriUnited States
| | - Chengjie Xiong
- Washington University School of MedicineSt. LouisMissouriUnited States
| | | | | | | | - John Carl Morris
- Washington University in St. LouisSt. LouisMissouriUnited States
| | - David Holtzman
- Washington University in St. LouisSt. LouisMissouriUnited States
| | - Anne M. Fagan
- Washington University in St. LouisSt. LouisMissouriUnited States
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Deurloo KL, Linskens IH, Heymans MW, Heijboer AC, Blankenstein MA, van Vugt JMG. ADAM12s and PP13 as first trimester screening markers for adverse pregnancy outcome. Clin Chem Lab Med 2014; 51:1279-84. [PMID: 23241612 DOI: 10.1515/cclm-2012-0566] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/26/2012] [Indexed: 11/15/2022]
Abstract
BACKGROUND The aim of the study was to assess the screening performance of first trimester maternal serum measurements of A-disintegrin-and-metalloprotease 12-s (ADAM12s) and placental protein 13 (PP13) for preeclampsia (PE), gestational hypertension (GH) and small-for-gestational-age (SGA) fetuses. METHODS In this retrospective case-control study 220 pregnant women were matched for gestational and maternal age at sampling. Results were expressed as multiples of the median (MoM) and compared using Kruskal-Wallis and Mann-Whitney U-test. Screening performance was assessed by receiver operator characteristics (ROC) curves and area under the curve (AUC). RESULTS Seventeen cases of PE, 30 cases of GH and eight cases of SGA fetuses were matched with 165 controls. ROC-analysis yielded AUCs for ADAM12s and PP13 of 0.63 and 0.59 for PE, 0.68 and 0.57 for GH and 0.59 and 0.62 for SGA, respectively. Combined ADAM12 and PP13 did not improve the AUC value. When the specificity was set at 80%, corresponding detection rate of ADAM12s was 52% for GH. CONCLUSIONS Combined ADAM12s and PP13 measurements do not predict adverse pregnancy outcome, but decreased first trimester ADAM12s levels are associated with GH.
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Affiliation(s)
- Koen L Deurloo
- Department of Obstetrics and Gynecology, VU University Medical Center, Amsterdam, The Netherlands.
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Heijboer AC, Zimmerman Y, de Boer T, Coelingh Bennink H, Blankenstein MA. Peculiar observations in measuring testosterone in women treated with oral contraceptives supplemented with dehydroepiandrosterone (DHEA). Clin Chim Acta 2014; 430:92-5. [PMID: 24406275 DOI: 10.1016/j.cca.2013.12.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 12/24/2013] [Accepted: 12/27/2013] [Indexed: 11/17/2022]
Abstract
Total testosterone is considered to be decreased during the use of combined oral contraceptives. There is, however, considerable concern about the quality of testosterone assays, especially at low levels. We aimed to confirm testosterone levels measured by direct radioimmunoassay in a recent clinical trial with a state-of-the-art LC-MSMS method. Surplus specimens with known testosterone levels collected during the study (Clinical Trial Registration number ISRCTN06414473) were reanalyzed with an LC-MSMS method. This method was compared to another LC-MSMS method that had shown to concur excellently to a reference method. Follow-up experiments were designed to explain the results. In contrast to our expectation, LC-MSMS measurements did not corroborate the data obtained by radioimmunoassay. Subsequent experiments showed that this could be attributed to a strong dependency of the radioimmunoassay on SHBG. Testosterone results (n = 198) obtained by direct radioimmunoassay showed a negative correlation to SHBG levels (r = -0.676; p<0.001). By contrast, testosterone results obtained by LC-MSMS were not related to SHBG (r = 0.100; NS). In conclusion, our results indicate that total testosterone measurements during oral contraceptive use are unreliable when performed with assays sensitive to the SHBG concentration. The discrepancy with the literature can most likely be explained by the sensitivity of the immunoassay used to SHBG. Given the sharp increase in SHBG during the use of many oral contraceptives, total testosterone may not decrease, whereas its bioavailability, estimated by free testosterone levels, will be diminished. Studies aiming at restoration of testosterone homeostasis during oral contraception need to take this into account.
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Affiliation(s)
- Annemieke C Heijboer
- Department of Clinical Chemistry, VU University Medical Center Amsterdam, The Netherlands.
| | | | | | | | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center Amsterdam, The Netherlands
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Mulder SD, Nielsen HM, Blankenstein MA, Eikelenboom P, Veerhuis R. Apolipoproteins E and J interfere with amyloid-beta uptake by primary human astrocytes and microglia in vitro. Glia 2014; 62:493-503. [PMID: 24446231 DOI: 10.1002/glia.22619] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 11/30/2013] [Accepted: 12/06/2013] [Indexed: 12/12/2022]
Abstract
Defective clearance of the amyloid-β peptide (Aβ) from the brain is considered a strong promoter in Alzheimer's disease (AD) pathogenesis. Astrocytes and microglia are important mediators of Aβ clearance and Aβ aggregation state and the presence of amyloid associated proteins (AAPs), such as Apolipoproteins E and J (ApoE and ApoJ), may influence Aβ clearance by these cells. Here we set out to investigate whether astrocytes and microglia differ in uptake efficiency of Aβ oligomers (Aβoligo ) and Aβ fibrils (Aβfib ), and whether the Aβ aggregation state and/or presence of AAPs affect Aβ uptake in these cells in vitro. Adult human primary microglia and astrocytes, isolated from short delay post-mortem brain tissue, were exposed to either Aβoligo or Aβfib alone or combined with a panel of certain AAPs whereafter Aβ-positive cells were quantified using flow cytometry. Upon exposure to Aβ combined with ApoE, ApoJ, α1-antichymotrypsin (ACT) and a combination of serum amyloid P and complement C1q (SAP-C1q), a clear reduction in astrocytic but not microglial Aβoligo uptake, was observed. In contrast, Aβfib uptake was strongly reduced in the presence of AAPs in microglia, but not in astrocytes. These data provide the first evidence of distinct roles of microglia and astrocytes in Aβ clearance. More importantly we show that Aβ clearance by glial cells is negatively affected by AAPs like ApoE and ApoJ. Thus, targeting the association of Aβ with AAPs, such as ApoE and ApoJ, could serve as a therapeutic strategy to increase Aβ clearance by glial cells.
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Affiliation(s)
- Sandra D Mulder
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands; Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands
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Del Campo M, Hoozemans JJM, Dekkers LL, Rozemuller AJ, Korth C, Müller-Schiffmann A, Scheltens P, Blankenstein MA, Jimenez CR, Veerhuis R, Teunissen CE. BRI2-BRICHOS is increased in human amyloid plaques in early stages of Alzheimer's disease. Neurobiol Aging 2014; 35:1596-604. [PMID: 24524963 DOI: 10.1016/j.neurobiolaging.2014.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/31/2013] [Accepted: 01/08/2014] [Indexed: 10/25/2022]
Abstract
BRI2 protein binds amyloid precursor protein to halt amyloid-β production and inhibits amyloid-β aggregation via its BRICHOS-domain suggesting a link between BRI2 and Alzheimer's disease (AD). Here, we investigate the possible involvement of BRI2 in human AD pathogenesis. BRI2 containing BRICHOS-domain was increased up to 3-fold in AD hippocampus (p = 0.003, n = 14/group). Immunohistochemistry showed BRI2 deposits associated with amyloid-β plaques in early pathologic stages (Braak-III; Thal-2/3). We observed a decrease in the protein levels of ADAM10 (p = 0.02) and furin (p = 0.066), as well as an increase in SPPL2b (p < 0.0001) in AD hippocampus. Because these enzymes are involved in BRI2 processing, their changes may lead to aberrant processing of BRI2 promoting its deposition and likely affecting BRI2 function. Loss of BRI2 function in AD was supported by the decreased presence of BRI2-amyloid precursor protein complexes in the hippocampus of AD patients compared with control subjects. In conclusion, our data obtained from human samples indicate that in early stages of AD there is an increased deposition of BRI2, which likely leads to impaired BRI2 function thereby influencing AD pathophysiology.
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Affiliation(s)
- Marta Del Campo
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands; Alzheimer Center, VU University Medical Center, Amsterdam, the Netherlands.
| | - Jeroen J M Hoozemans
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
| | - Lois-Lee Dekkers
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| | | | - Carsten Korth
- Department of Neuropathology, Heinrich Heine University Medical School, Düsseldorf, Germany
| | | | - Philip Scheltens
- Alzheimer Center, VU University Medical Center, Amsterdam, the Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| | - Connie R Jimenez
- Department of Medical Oncology and OncoProteomics Laboratory, VU University Medical Center, Amsterdam, the Netherlands
| | - Robert Veerhuis
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands; Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands; Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands; Neurochemistry Laboratory, VU University Medical Center, Amsterdam, the Netherlands
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Engels MAJ, Bhola SL, Twisk JWR, Blankenstein MA, van Vugt JMG. Evaluation of the introduction of the national Down syndrome screening program in the Netherlands: age-related uptake of prenatal screening and invasive diagnostic testing. Eur J Obstet Gynecol Reprod Biol 2013; 174:59-63. [PMID: 24405726 DOI: 10.1016/j.ejogrb.2013.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 05/23/2013] [Accepted: 12/03/2013] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To study the effect of different government prenatal screening (PNS) policies on the uptake of PNS and prenatal diagnostic testing (PND) over the periods 2001-2003 (PNS on request), 2004-2006 (permission to offer the first-trimester combined test (FCT) to women of advanced maternal age (AMA), with women aged <36 years informed on explicit request) and 2007-2010 (introduction of population screening) and to evaluate whether trends in uptake are related to maternal age. The indication AMA for PND is still warranted, and the costs for FCT are only reimbursed for AMA women. STUDY DESIGN Analysis of data on the first- and second-trimester screening program (n=41,600) for Down syndrome (DS) and on PND (n=10,795) performed from 2001 to 2010 in the region North-Holland of the Netherlands. To evaluate the actual participation in PNS and PND in different maternal age groups, estimation of the age distribution of women who underwent a fetal anomaly scan in 2009 (n=14,481) was used as a reference population (participation of 85.2%). RESULTS The overall uptake of FCT was 35.2% in 2010. Over the years the number of FCT in all age groups increased significantly (P<0.001). Overall the number of PND decreased significantly; the number of PND for AMA decreased and the number of PND for increased risk at FCT (in women <36 and ≥36 years) increased (P<0.05). Since 2004 significantly more DS cases were detected with FCT in AMA women and fewer with PND for AMA, and since 2007 more DS cases were detected with FCT in women <36 years (P<0.001). CONCLUSION The effect of the national screening program is limited. Significantly more women opt for PNS but the overall uptake remains low, especially in younger women. A significant number of AMA women still opt for PND for AMA. The choice for FCT and PND for AMA seems dependent on background risk. To accomplish a more effective screening policy, reimbursement of the cost of the test should apply to all women and the indication for PND for AMA should be abolished.
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Affiliation(s)
- Melanie A J Engels
- Department of Obstetrics and Gynecology, VU University Medical Center, Amsterdam, The Netherlands.
| | - Shama L Bhola
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands
| | - Jos W R Twisk
- Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - John M G van Vugt
- Department of Obstetrics and Gynecology, VU University Medical Center, Amsterdam, The Netherlands
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Koel-Simmelink MJA, Vennegoor A, Killestein J, Blankenstein MA, Norgren N, Korth C, Teunissen CE. The impact of pre-analytical variables on the stability of neurofilament proteins in CSF, determined by a novel validated SinglePlex Luminex assay and ELISA. J Immunol Methods 2013; 402:43-9. [PMID: 24275679 DOI: 10.1016/j.jim.2013.11.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 09/04/2013] [Accepted: 11/14/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Neurofilament (Nf) proteins have been shown to be promising biomarkers for monitoring and predicting disease progression for various neurological diseases. The aim of this study was to evaluate the effects of pre-analytical variables on the concentration of neurofilament heavy (NfH) and neurofilament light (NfL) proteins. METHODS For NfH an in-house newly-developed and validated SinglePlex Luminex assay was used; ELISA was used to analyze NfL. RESULTS For the NfL ELISA assay, the intra- and inter-assay variation was respectively, 1.5% and 16.7%. Analytical performance of the NfH SinglePlex Luminex assay in terms of sensitivity (6.6pg/mL), recovery in cerebrospinal fluid (CSF) (between 90 and 104%), linearity (from 6.6-1250pg/mL), and inter- and intra-assay variation (<8%) were good. Concentrations of both NfL and NfH appeared not negatively affected by blood contamination, repeated freeze-thaw cycles (up to 4), delayed processing (up to 24hours) and during long-term storage at -20°C, 4°C, and room temperature. A decrease in concentration was observed during storage of both neurofilament proteins up to 21days at 37°C, which was significant by day 5. CONCLUSIONS The newly developed NfH SinglePlex Luminex assay has a good sensitivity and is robust. Moreover, both NfH and NfL are stable under the most prevalent pre-analytical variations.
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Affiliation(s)
- Marleen J A Koel-Simmelink
- Department of Clinical Chemistry, VU University Medical Center Amsterdam, PO Box 7057, 1007MB Amsterdam, The Netherlands.
| | - Anke Vennegoor
- Department of Neurology, VU University Medical Center Amsterdam, PO Box 7057, 1007MB Amsterdam. The Netherlands.
| | - Joep Killestein
- Department of Neurology, VU University Medical Center Amsterdam, PO Box 7057, 1007MB Amsterdam. The Netherlands.
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center Amsterdam, PO Box 7057, 1007MB Amsterdam, The Netherlands.
| | | | - Carsten Korth
- Neurodegeneration Unit, Department Neuropathology, University of Düsseldorf Medical School, Moorenstrase 5, 40225 Düsseldorf, Germany.
| | - Charlotte E Teunissen
- Department of Clinical Chemistry, VU University Medical Center Amsterdam, PO Box 7057, 1007MB Amsterdam, The Netherlands.
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Reijnders CMA, van Essen HW, van Rens BTTM, van Beek JHGM, Ylstra B, Blankenstein MA, Lips P, Bravenboer N. Increased expression of matrix extracellular phosphoglycoprotein (MEPE) in cortical bone of the rat tibia after mechanical loading: identification by oligonucleotide microarray. PLoS One 2013; 8:e79672. [PMID: 24255709 PMCID: PMC3821845 DOI: 10.1371/journal.pone.0079672] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 09/24/2013] [Indexed: 11/18/2022] Open
Abstract
Skeletal integrity in humans and animals is maintained by daily mechanical loading. It has been widely accepted that osteocytes function as mechanosensors. Many biochemical signaling molecules are involved in the response of osteocytes to mechanical stimulation. The aim of this study was to identify genes involved in the translation of mechanical stimuli into bone formation. The four-point bending model was used to induce a single period of mechanical loading on the right tibia, while the contra lateral left tibia served as control. Six hours after loading, the effects of mechanical loading on gene-expression were determined with microarray analysis. Protein expression of differentially regulated genes was evaluated with immunohistochemistry. Nine genes were found to exhibit a significant differential gene expression in LOAD compared to control. MEPE, Garnl1, V2R2B, and QFG-TN1 olfactory receptor were up-regulated, and creatine kinase (muscle form), fibrinogen-B beta-polypeptide, monoamine oxidase A, troponin-C and kinesin light chain-C were down-regulated. Validation with real-time RT-PCR analysis confirmed the up-regulation of MEPE and the down-regulation of creatine kinase (muscle form) and troponin-C in the loaded tibia. Immunohistochemistry showed that the increase of MEPE protein expression was already detectable six hours after mechanical loading. In conclusion, these genes probably play a role during translation of mechanical stimuli six hours after mechanical loading. The modulation of MEPE expression may indicate a connection between bone mineralization and bone formation after mechanical stimulation.
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Affiliation(s)
- Christianne M. A. Reijnders
- Department of Internal Medicine, Endocrine Section, VU University Medical Center, Amsterdam, The Netherlands
| | - Huib W. van Essen
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Birgitte T. T. M. van Rens
- Department of Internal Medicine, Endocrine Section, VU University Medical Center, Amsterdam, The Netherlands
- Faculty of Human Movement Sciences, VU University, Amsterdam, The Netherlands
| | - Johannes H. G. M. van Beek
- Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
| | - Bauke Ylstra
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
- Research Institute MOVE, Amsterdam, The Netherlands
| | | | - Paul Lips
- Department of Internal Medicine, Endocrine Section, VU University Medical Center, Amsterdam, The Netherlands
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
- * E-mail:
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Abstract
BACKGROUND Clusterin (ApoJ) is an amyloid-associated protein and plays an important role in Alzheimer's disease (AD) pathology. Recent genome-wide association studies have indicated that certain genetic variants increase the risk of developing AD. To determine if the expression of clusterin is different in AD patients, both systemically and locally in the brain, differs between (subgroups of) AD patients and non-AD cases, an assay available that detects clusterin in both plasma and cerebrospinal fluid (CSF) with equal sensitivity would be helpful. METHODS We compared four different commercially available antibodies in their ability to detect recombinant clusterin and immune-purified human clusterin. Specificity was tested on western blot and in ELISA systems, and selection was based on the ability to detect clusterin in CSF and plasma. A sandwich ELISA was developed and validated with monoclonal antibody G7 as capture, and rabbit polyclonal (Alexis) antibodies for detection. RESULTS Our ELISA measured clusterin concentrations in plasma and CSF with dynamic ranges of 2-70 mg/L and 0.5-40 mg/L, respectively. The assays showed 99.8% recovery in CSF and 97% recovery in plasma. Intra-assay coefficient of variation was 1.4% and inter-assay 8.8%. The assay shows no cross-reactivity with related apolipoproteins. Clusterin quantification is dependent on the type of storage for plasma samples. A single freeze/thaw cycle caused fluctuations of clusterin concentrations in plasma, while clusterin in CSF is stable for up to five cycles. CONCLUSIONS We have successfully developed a clusterin ELISA that reliably measures CSF and plasma clusterin concentrations. In a pilot study, all samples gave results that were well within the dynamic range of the assay, with low variations. Freshly stored plasma samples are crucial for accurate clusterin quantification.
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Affiliation(s)
- Wesley Jongbloed
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands VUmc Alzheimer Center, Neuroscience Campus Amsterdam, Amsterdam, The Netherlands
| | - Maaike A C Herrebout
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Robert Veerhuis
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands
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Zimmerman Y, Eijkemans MJC, Coelingh Bennink HJT, Blankenstein MA, Fauser BCJM. The effect of combined oral contraception on testosterone levels in healthy women: a systematic review and meta-analysis. Hum Reprod Update 2013; 20:76-105. [PMID: 24082040 PMCID: PMC3845679 DOI: 10.1093/humupd/dmt038] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
UNLABELLED BACKGROUND; Combined oral contraceptives (COCs) reduce levels of androgen, especially testosterone (T), by inhibiting ovarian and adrenal androgen synthesis and by increasing levels of sex hormone-binding globulin (SHBG). Although this suppressive effect has been investigated by numerous studies over many years, to our knowledge no systematic review concerning this issue had been performed. This systematic review and meta-analysis was performed to evaluate the effect of COCs on concentrations of total T, free T and SHBG in healthy women and to evaluate differences between the various types of COCs (e.g. estrogen dose, type of progestin) and the assays used to assess total T and free T. METHODS A review of the literature was performed using database searches (MEDLINE, EMBASE and the Cochrane Central Register of Clinical Trials) and all publications (from inception date until July 2012) investigating the effect of COCs on androgen levels in healthy women were considered eligible for selection. Three reviewers were involved in study selection, data extraction and critical appraisal. For the meta-analysis, data on total T, free T and SHBG were extracted and combined using random effects analysis. Additional subgroup analyses were performed to evaluate differences between the various types of COCs (e.g. estrogen dose, type of progestin) and the assays used to assess total T or free T. RESULTS A total of 151 records were identified by systematic review and 42 studies with a total of 1495 healthy young women (age range: 18-40 years) were included in the meta-analysis. All included studies were experimental studies and 21 were non-comparative. Pooling of the results derived from all the included papers showed that total T levels significantly decreased during COC use [mean difference (MD) (95% confidence interval, CI) -0.49 nmol/l (-0.55, -0.42); P < 0.001]. Significantly lower levels of free T were also found [relative change (95% CI) 0.39 (0.35, 0.43); P < 0.001], with a mean decrease of 61%. On the contrary, SHBG concentrations significantly increased during all types of COC use [MD (95% CI) 99.08 nmol/l (86.43, 111.73); P < 0.001]. Subgroup analyses revealed that COCs containing 20-25 µg EE had similar effects on total and free T compared with COCs with 30-35 µg EE. In addition, suppressive effects on T levels were not different when comparing different types of progestins. However, subgroup analyses for the estrogen dose and the progestin type in relation to changes in SHBG levels did show significant differences: COCs containing second generation progestins and/or the lower estrogen doses (20-25 µg EE) were found to have less impact on SHBG concentrations. CONCLUSIONS The current literature review and meta-analysis demonstrates that COCs decrease circulating levels of total T and free T and increase SBHG concentrations. Due to the SHBG increase, free T levels decrease twice as much as total T. The estrogen dose and progestin type of the COC do not influence the decline of total and free T, but both affect SHBG. The clinical implications of suppressed androgen levels during COC use remain to be elucidated.
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Affiliation(s)
- Y Zimmerman
- Pantarhei Bioscience, PO Box 464, 3700 AL Zeist, The Netherlands
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van Harten AC, Smits LL, Teunissen CE, Visser PJ, Koene T, Blankenstein MA, Scheltens P, van der Flier WM. Preclinical AD predicts decline in memory and executive functions in subjective complaints. Neurology 2013; 81:1409-16. [PMID: 24049134 DOI: 10.1212/wnl.0b013e3182a8418b] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We assessed whether preclinical Alzheimer disease (AD) based on CSF biomarkers at baseline predicts decline in cognitive functioning as measured by repeated neuropsychological tests for 4 cognitive domains in patients with subjective complaints. METHODS We included 132 patients with subjective complaints from our memory clinic-based Amsterdam Dementia Cohort, who underwent lumbar puncture and had repeated (range 2-7) neuropsychological evaluations. Follow-up was 2 ± 1 years. CSF biomarkers amyloid-β (Aβ42), total tau (Tau), and hyperphosphorylated tau-181 were used to define National Institute on Aging-Alzheimer's Association (NIA-AA) preclinical AD stages. Predictive value of preclinical AD stages as defined by CSF biomarkers, individual biomarkers, and Aβ42/tau ratio was assessed using linear mixed models. Outcome measures were compound z scores for memory, attention, executive functioning, language, and global cognition. Analyses were adjusted for age, sex, and education. RESULTS Patients were 61 ± 8 years old; 56 (42%) were women. Average baseline Mini-Mental State Examination score was 28.3 ± 1.5. Patients who fulfilled criteria for preclinical AD (stage 1: n = 11 + stage 2: n = 10) showed decline over time in memory (β ± SE -0.41 ± 0.14, p < 0.01), executive functions (-0.21 ± 0.08, p < 0.01), and global cognition (-0.29 ± 0.10, p < 0.01). There were no differences in cognitive decline between NIA-AA preclinical AD stages 1 and 2. In patients with normal CSF biomarkers, we observed memory improvement (0.19 ± 0.07, p < 0.01) and stable performance in all other domains. CONCLUSIONS CSF evidence of preclinical AD in patients with subjective complaints predicted cognitive decline over time, encompassing more than memory alone. Executive functioning and global cognitive functioning also deteriorated. On the other hand, 2-year prognosis for patients without evidence of AD pathophysiology was good.
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Affiliation(s)
- Argonde C van Harten
- From the Alzheimer Center (A.C.v.H., L.L.S., P.J.V., T.K., P.S., W.M.v.d.F.), Department of Neurology (A.C.v.H., L.L.S., P.S., W.M.v.d.F.), Neuroscience Campus Amsterdam (A.C.v.H., L.L.S., C.E.T., P.J.V., P.S., W.M.v.d.F.), Department of Clinical Chemistry (C.E.T., M.A.B.), Department of Medical Psychology (T.K.), and Department of Epidemiology/Biostatistics (W.M.v.d.F.), VU University Medical Center, Amsterdam; and the Department of Psychiatry and Neuropsychology/Alzheimer Center Limburg (P.J.V.), School for Mental Health and Neurosciences, Maastricht University Medical Center, Maastricht, the Netherlands
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Verwey NA, Hoozemans JJM, Korth C, van Royen MR, Prikulis I, Wouters D, Twaalfhoven HAM, van Haastert ES, Schenk D, Scheltens P, Rozemuller AJM, Blankenstein MA, Veerhuis R. Immunohistochemical characterization of novel monoclonal antibodies against the N-terminus of amyloid β-peptide. Amyloid 2013; 20:179-87. [PMID: 23829200 DOI: 10.3109/13506129.2013.797389] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Abstract Amyloid β-peptide (Aβ) is a key molecule in Alzheimer's disease (AD). Reliable immunohistochemical (IHC) methods to detect Aβ and Aβ-associated factors (AAF) in brain specimens are needed to determine their role in AD pathophysiology. Formic acid (FA) pre-treatment, which is generally used to enable efficient detection of Aβ with IHC, induces structural modifications within the Aβ, as well as in AAF. Consequently, interpretation of double IHC stainings becomes difficult. Therefore, serial stainings of two newly produced monoclonal antibodies (mAbs) VU-17 and IC16 and two other mAbs (6E10 and 3D6) were performed with four different pre-treatments (no pre-treatment, Tris/EDTA, citrate and FA) and additionally six IHC characteristics were scored: diffuse/compact/classic plaques, arteries with cerebral Aβ angiopathy, dyshoric angiopathy, capillaries with dyshoric angiopathy. Subsequently, these stainings were compared with IHC procedures, which are frequently used in a diagnostic setting, employing mAbs 4G8 and 6F/3D with FA pre-treatment. IHC Aβ patterns obtained with VU-17 and, IC16 and 3D6 without the use of FA pre-treatment were comparable to those obtained with 4G8 and 6F/3D upon FA pre-treatment. Omission of FA pre-treatment gives the advantage to allow double IHC stainings, detecting both Aβ and AAF that otherwise would have been structural modificated upon FA pre-treatment.
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Affiliation(s)
- Nicolaas A Verwey
- Department of Neurology and Alzheimer Center, VU University Medical Center, the Netherlands.
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Duits FH, Kester MI, Scheffer PG, Blankenstein MA, Scheltens P, Teunissen CE, van der Flier WM. Increase in Cerebrospinal Fluid F2-Isoprostanes is Related to Cognitive Decline in APOE ε4 Carriers. ACTA ACUST UNITED AC 2013; 36:563-70. [DOI: 10.3233/jad-122227] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Flora H. Duits
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Maartje I. Kester
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Peter G. Scheffer
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Philip Scheltens
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Charlotte E. Teunissen
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Wiesje M. van der Flier
- Alzheimer Center & Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
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Duits F, Teunissen C, Bouwman F, Visser PJ, Mattsson N, Zetterberg H, Blennow K, Hansson O, Minthon L, Andreasen N, Marcusson J, Wallin A, Olde Rikkert M, Tsolaki M, Parnetti L, Herukka S, Hampel H, De Leon M, Schröder J, Aarsland D, Blankenstein MA, Scheltens P, Van der Flier W. O1–09–06: The ‘CSF Alzheimer's profile’: Easily said, but what do we mean? Alzheimers Dement 2013. [DOI: 10.1016/j.jalz.2013.04.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Flora Duits
- VU University Medical Center Amsterdam Netherlands
| | | | | | | | - Niklas Mattsson
- University of California, San Francisco San Francisco California United States
- University of Gothenburg, Sweden Mölndal Sweden
| | | | - Kaj Blennow
- Sahlgrenska Academy University of Gothenburg Mölndal Sweden
| | - Oskar Hansson
- Depatment of Neurology Skåne University Hospital Malmö Sweden
| | | | | | | | | | | | - Magda Tsolaki
- Aristotle University of Thessaloniki Thessaloniki Greece
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40
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Dijk K, Jongbloed W, Bergh W, Scheltens P, Mulder S, Eikelenboom P, Blankenstein MA, Van der Flier W, Veerhuis R. P1–133: Clusterin: An early biomarker for Alzheimer's disease? Alzheimers Dement 2013. [DOI: 10.1016/j.jalz.2013.05.355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Karin Dijk
- VU University Medical Center Amsterdam Netherlands
| | | | - Wilma Bergh
- VU University Medical Center Amsterdam Netherlands
| | | | | | | | | | | | - Rob Veerhuis
- VU University Medical Center Amsterdam Netherlands
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Teunissen C, Durieux‐LIu S, Krudop W, Pijnenburg Y, Swieten J, Blankenstein MA. P1–247: Serum progranulin is affected by variability in pre‐analytical and biobanking procedures. Alzheimers Dement 2013. [DOI: 10.1016/j.jalz.2013.05.471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | - John Swieten
- Erasmus University Medical Center Rotterdam Netherlands
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42
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Harten A, Smits L, Teunissen C, Visser PJ, Blankenstein MA, Scheltens P, Van der Flier W. O3–03–02: CSF biomarkers predict longitudinal decline in memory and executive functioning in patients with subjective complaints. Alzheimers Dement 2013. [DOI: 10.1016/j.jalz.2013.04.249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Argonde Harten
- Alzheimer Center, VU University Medical Center, Amsterdam Amsterdam Netherlands
| | - Lieke Smits
- Alzheimer Center, VU University Medical Center, Amsterdam Amsterdam Netherlands
| | - Charlotte Teunissen
- Department of Clinical Chemistry VU University Medical Center Amsterdam Netherlands
| | - Pieter Jelle Visser
- Alzheimer Center, VU University Medical Center, Amsterdam Amsterdam Netherlands
| | | | - Philip Scheltens
- Alzheimer Center, VU University Medical Center, Amsterdam Amsterdam Netherlands
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Abstract
BACKGROUND α-Klotho is a protein mainly produced in the kidney. Its circulating form has been suggested to link renal damage and distant tissue pathology. As three assays to measure α-Klotho became commercially available, we performed an evaluation of these commercially available Klotho assays. METHODS We studied within-run variation, between-run variation, matrix effects, linearity, and recovery of added recombinant human Klotho in the α-Klotho assays of IBL (IBL International GmbH, Hamburg, Germany), Cusabio (Cusabio Biotech, Wuhan, China) and USCN (USCN life Science, Inc., Wuhan, China) using both serum and ethylenediaminetetraacetic acid plasma. RESULTS Within run variation was 4, 13 and 32% for the IBL, Cusabio and USCN assay, respectively. Agreement between serum and EDTA plasma was good in the IBL assay, but poor in the USCN and Cusabio assays however improved after modifications in the Cusabio assay. Standardization and agreement between assays was poor. CONCLUSIONS The commercially available methods for the measurement of α-Klotho differ in quality. Some of the manufacturers should improve their assays in order to produce accurate results so that reliable conclusions can be drawn from studies in which these assays are used.
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Affiliation(s)
- Annemieke C Heijboer
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands
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Bui HN, Blankenstein MA, Heijboer AC. Isotopically labelled testosterone derivatives as internal standards in liquid chromatography-tandem mass spectrometry. Ann Clin Biochem 2013; 50:275-6. [DOI: 10.1177/0004563212473277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Hong N Bui
- Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007MB, Amsterdam, The Netherlands
| | - Marinus A Blankenstein
- Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007MB, Amsterdam, The Netherlands
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007MB, Amsterdam, The Netherlands
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de Waal H, Stam CJ, de Haan W, van Straaten ECW, Blankenstein MA, Scheltens P, van der Flier WM. Alzheimer's disease patients not carrying the apolipoprotein E ε4 allele show more severe slowing of oscillatory brain activity. Neurobiol Aging 2013; 34:2158-63. [PMID: 23587637 DOI: 10.1016/j.neurobiolaging.2013.03.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 02/22/2013] [Accepted: 03/11/2013] [Indexed: 11/17/2022]
Abstract
The objective of this study was to quantitatively assess the relationship between apolipoprotein (APOE) genotype and electroencephalographic oscillatory brain dynamics in Alzheimer's disease (AD) patients and control subjects and its regional distribution. We obtained resting-state electroencephalographs of 320 AD patients and 246 control subjects, categorized into APOE ε4 carriers and noncarriers. Peak frequency and relative power in 4 different frequency bands were calculated. We tested the associations between APOE genotype and relative power in 4 brain regions. Peak frequency was comparable in APOE ε4 carrying and noncarrying control subjects, but lower in APOE ε4 noncarrying AD patients. In control subjects, APOE ε4 carriers had a different regional distribution of alpha power than noncarriers. We found no APOE effect in beta, delta, and theta bands. In AD, APOE ε4 noncarriers had lower alpha and higher delta power than carriers. This difference was most pronounced in the parieto-occipital region. In the theta band, APOE ε4 noncarriers had a different regional distribution of power compared with carriers. In conclusion, the most pronounced effect of genotype was seen in AD patients, and APOE ε4 noncarriers showed slower activity, especially in parieto-occipital regions.
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Affiliation(s)
- Hanneke de Waal
- Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, the Netherlands.
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46
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Mattsson N, Zegers I, Andreasson U, Bjerke M, Blankenstein MA, Bowser R, Carrillo MC, Gobom J, Heath T, Jenkins R, Jeromin A, Kaplow J, Kidd D, Laterza OF, Lockhart A, Lunn MP, Martone RL, Mills K, Pannee J, Ratcliffe M, Shaw LM, Simon AJ, Soares H, Teunissen CE, Verbeek MM, Umek RM, Vanderstichele H, Zetterberg H, Blennow K, Portelius E. Reference measurement procedures for Alzheimer's disease cerebrospinal fluid biomarkers: definitions and approaches with focus on amyloid β42. Biomark Med 2013; 6:409-17. [PMID: 22917143 DOI: 10.2217/bmm.12.39] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD) are increasingly used in clinical settings, research and drug trials. However, their broad-scale use on different technology platforms is hampered by the lack of standardization at the level of sample handling, determination of concentrations of analytes and the absence of well-defined performance criteria for in vitro diagnostic or companion diagnostic assays, which influences the apparent concentration of the analytes measured and the subsequent interpretation of the data. There is a need for harmonization of CSF AD biomarker assays that can reliably, across centers, quantitate CSF biomarkers with high analytical precision, selectivity and stability over long time periods. In this position paper, we discuss reference procedures for the measurement of CSF AD biomarkers, especially amyloid β42 and tau. We describe possible technical approaches, focusing on a selected reaction monitoring mass spectrometry assay as a candidate reference method for quantification of CSF amyloid β42.
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Affiliation(s)
- Niklas Mattsson
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, the Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden.
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Bui HN, Schagen SEE, Klink DT, Delemarre-van de Waal HA, Blankenstein MA, Heijboer AC. Salivary testosterone in female-to-male transgender adolescents during treatment with intra-muscular injectable testosterone esters. Steroids 2013; 78:91-5. [PMID: 23123742 DOI: 10.1016/j.steroids.2012.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 09/25/2012] [Accepted: 10/01/2012] [Indexed: 11/17/2022]
Abstract
INTRODUCTION In our hospital, female-to-male (FtM) transgender adolescents from the age of 16 are treated with two- or four-weekly intra-muscular injections of testosterone-esters. Some patients treated with four-weekly injections have complaints of fatigue and experience mood swings towards the end of the inter-injection period, which calls for an evaluation of the time-course of testosterone levels between injections. Evaluation of salivary testosterone is a practical approach for sequential measurements. Since only ∼2% of total serum testosterone is present in saliva, a sensitive assay is necessary. The objective was to develop an isotope dilution-liquid chromatography-tandem mass spectrometry method (ID-LC-MS/MS) for salivary testosterone measurements and to evaluate the testosterone profiles after testosterone-ester mixture injections in FtM-adolescents. EXPERIMENTAL FtM treated with 125 mg/2 weeks or with 250 mg/4 weeks depots of testosterone-ester mixture collected saliva at different time intervals. Salivary testosterone was measured by a thoroughly validated ID-LC-MS/MS assay. RESULTS An ID-LC-MS/MS method for measuring salivary testosterone was developed with adequate accuracy and specificity. The reference range was established at 135-400 pmol/L. Testosterone levels peaked supra-physiologically immediately post-injection, and decreased to levels within the male reference range after nine days in all patients. 250 mg/4 weeks depots resulted in values below the reference range at the end of the 4 weeks. DISCUSSION The development of an adequate ID-LC-MS/MS method for measuring salivary testosterone allowed us to investigate the testosterone profile in FtM-adolescents after testosterone-esters mixture injections. These injections lead to extreme concentrations which may affect the wellbeing of the patients.
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Affiliation(s)
- Hong N Bui
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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Bui HN, Sluss PM, Blincko S, Knol DL, Blankenstein MA, Heijboer AC. Dynamics of serum testosterone during the menstrual cycle evaluated by daily measurements with an ID-LC-MS/MS method and a 2nd generation automated immunoassay. Steroids 2013; 78:96-101. [PMID: 23127814 DOI: 10.1016/j.steroids.2012.10.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/26/2012] [Accepted: 10/09/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Testosterone concentrations in normally cycling women are assumed to be elevated around the time of ovulation. The clinical relevance of changing testosterone concentrations during the menstrual cycle, however, is unclear. Poor performance of current direct immunoassays for testosterone at low concentrations confounds this issue. Therefore, our objective was to assess daily testosterone fluctuation during the menstrual cycle by a thoroughly validated isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) method and to evaluate whether an ARCHITECT® 2nd Generation Testosterone fully automated immunoassay is equally suited for this purpose. METHODS Testosterone was measured in serum obtained daily during the menstrual cycle of 25 healthy women, characterized by biochemical and physical examination. RESULTS Performance of the ID-LC-MS/MS method was concordant with a published reference method (y=1.007x-0.056 nmol/L; r=0.9998). Comparison of the immunoassay to ID-LC-MS/MS yielded y=1.095x+0.104 nmol/L (r=0.9031). Overall, testosterone concentrations were higher mid-cycle, but a peak was not discernible in each individual. Apart from a persistent positive bias, the immunoassay measured the same testosterone profiles as the ID-LC-MS/MS method. The reference interval in women was 0.30-1.69 nmol/L (8.7-48.7 ng/dL) for ID-LC-MS/MS and 0.50-2.00 nmol/L (14.4-57.7 ng/dL) for the immunoassay. CONCLUSION The elevation of mid-cycle testosterone concentrations is statistically significant, although not clinically relevant since day-to-day variation is higher and independent of the menstrual cycle. In this light, a single testosterone measurement might not be reflective of the overall testosterone status in an individual. Measurements obtained using the 2nd generation immunoassay gave comparable results across the menstrual cycle.
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Affiliation(s)
- Hong N Bui
- Dept. of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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van Harten AC, Visser PJ, Pijnenburg YA, Teunissen CE, Blankenstein MA, Scheltens P, van der Flier WM. Cerebrospinal fluid Aβ42 is the best predictor of clinical progression in patients with subjective complaints. Alzheimers Dement 2012; 9:481-7. [PMID: 23232269 DOI: 10.1016/j.jalz.2012.08.004] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 07/27/2012] [Accepted: 08/16/2012] [Indexed: 10/27/2022]
Affiliation(s)
- Argonde C. van Harten
- Alzheimer Center; VU University Medical Center; Amsterdam The Netherlands
- Department of Neurology; VU University Medical Center; Amsterdam The Netherlands
| | - Pieter Jelle Visser
- Alzheimer Center; VU University Medical Center; Amsterdam The Netherlands
- Department of Neurology; VU University Medical Center; Amsterdam The Netherlands
- Department of Psychiatry and Neuropsychology/Alzheimer Center Limburg; School for Mental Health and Neurosciences, Maastricht University Medical Center; Maastricht The Netherlands
| | - Yolande A.L. Pijnenburg
- Alzheimer Center; VU University Medical Center; Amsterdam The Netherlands
- Department of Neurology; VU University Medical Center; Amsterdam The Netherlands
| | - Charlotte E. Teunissen
- Department of Clinical Chemistry; VU University Medical Center; Amsterdam The Netherlands
| | | | - Philip Scheltens
- Alzheimer Center; VU University Medical Center; Amsterdam The Netherlands
- Department of Neurology; VU University Medical Center; Amsterdam The Netherlands
| | - Wiesje M. van der Flier
- Alzheimer Center; VU University Medical Center; Amsterdam The Netherlands
- Department of Neurology; VU University Medical Center; Amsterdam The Netherlands
- Department of Epidemiology/Biostatistics; VU University Medical Center; Amsterdam The Netherlands
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Jongbloed W, Kester MI, Flier WM, Veerhuis R, Scheltens P, Blankenstein MA, Teunissen CE. Discriminatory and predictive capabilities of enzyme‐linked immunosorbent assay and multiplex platforms in a longitudinal Alzheimer's disease study. Alzheimers Dement 2012; 9:276-83. [DOI: 10.1016/j.jalz.2012.01.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 12/02/2011] [Accepted: 01/13/2012] [Indexed: 10/27/2022]
Affiliation(s)
- Wesley Jongbloed
- Department of Clinical Chemistry Neurological LaboratoryVU University Medical CenterAmsterdamThe Netherlands
| | - Maartje I. Kester
- Department of Neurology and Alzheimer CenterVU University Medical CenterAmsterdamThe Netherlands
| | - Wiesje M. Flier
- Department of Neurology and Alzheimer CenterVU University Medical CenterAmsterdamThe Netherlands
- Department of Epidemiology and BiostatisticsVU University Medical CenterAmsterdamThe Netherlands
| | - Robert Veerhuis
- Department of Clinical Chemistry Neurological LaboratoryVU University Medical CenterAmsterdamThe Netherlands
| | - Philip Scheltens
- Department of Neurology and Alzheimer CenterVU University Medical CenterAmsterdamThe Netherlands
| | - Marinus A. Blankenstein
- Department of Clinical Chemistry Neurological LaboratoryVU University Medical CenterAmsterdamThe Netherlands
| | - Charlotte E. Teunissen
- Department of Clinical Chemistry Neurological LaboratoryVU University Medical CenterAmsterdamThe Netherlands
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