1
|
Bliddal S, Derakhshan A, Xiao Y, Chen LM, Männistö T, Ashoor G, Tao F, Brown SJ, Vafeiadi M, Itoh S, Grineva EN, Taylor P, Ghafoor F, Vaidya B, Hattersley A, Mosso L, Oken E, Kishi R, Alexander EK, Maraka S, Huang K, Chaker L, Bassols J, Pirzada A, López-Bermejo A, Boucai L, Peeters RP, Pearce EN, Nelson SM, Chatzi L, Vrijkotte TG, Popova PV, Walsh JP, Nicolaides KH, Suvanto E, Lu X, Pop VJM, Forman JL, Korevaar TIM, Feldt-Rasmussen U. Association of Thyroid Peroxidase Antibodies and Thyroglobulin Antibodies with Thyroid Function in Pregnancy: An Individual Participant Data Meta-Analysis. Thyroid 2022; 32:828-840. [PMID: 35596568 DOI: 10.1089/thy.2022.0083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Objectives: Thyroid autoimmunity is common in pregnant women and associated with thyroid dysfunction and adverse obstetric outcomes. Most studies focus on thyroid peroxidase antibodies (TPOAbs) assessed by a negative-positive dichotomy and rarely take into account thyroglobulin antibodies (TgAbs). This study aimed at determining the association of TPOAbs and TgAbs, respectively, and interdependently, with maternal thyroid function. Methods: This was a meta-analysis of individual participant cross-sectional data from 20 cohorts in the Consortium on Thyroid and Pregnancy. Women with multiple pregnancy, pregnancy by assisted reproductive technology, history of thyroid disease, or use of thyroid interfering medication were excluded. Associations of (log2) TPOAbs and TgAbs (with/without mutual adjustment) with cohort-specific z-scores of (log2) thyrotropin (TSH), free triiodothyronine (fT3), total triiodothyronine (TT3), free thyroxine (fT4), total thyroxine (TT4), or triiodothyronine:thyroxine (T3:T4) ratio were evaluated in a linear mixed model. Results: In total, 51,138 women participated (51,094 had TPOAb-data and 27,874 had TgAb-data). Isolated TPOAb positivity was present in 4.1% [95% confidence interval, CI: 3.0 to 5.2], isolated TgAb positivity in 4.8% [CI: 2.9 to 6.6], and positivity for both antibodies in 4.7% [CI: 3.1 to 6.3]. Compared with antibody-negative women, TSH was higher in women with isolated TPOAb positivity (z-score increment 0.40, CI: 0.16 to 0.64) and TgAb positivity (0.21, CI: 0.10 to 0.32), but highest in those positive for both antibodies (0.54, CI: 0.36 to 0.71). There was a dose-response effect of higher TPOAb and TgAb concentrations with higher TSH (TSH z-score increment for TPOAbs 0.12, CI: 0.09 to 0.15, TgAbs 0.08, CI: 0.02 to 0.15). When adjusting analyses for the other antibody, only the association of TPOAbs remained statistically significant. A higher TPOAb concentration was associated with lower fT4 (p < 0.001) and higher T3:T4 ratio (0.09, CI: 0.03 to 0.14), however, the association with fT4 was not significant when adjusting for TgAbs (p = 0.16). Conclusions: This individual participant data meta-analysis demonstrated an increase in TSH with isolated TPOAb positivity and TgAb positivity, respectively, which was amplified for individuals positive for both antibodies. There was a dose-dependent association of TPOAbs, but not TgAbs, with TSH when adjusting for the other antibody. This supports current practice of using TPOAbs in initial laboratory testing of pregnant women suspected of autoimmune thyroid disease. However, studies on the differences between TPOAb- and TgAb-positive women are needed to fully understand the spectrum of phenotypes.
Collapse
Affiliation(s)
- Sofie Bliddal
- Department of Medical Endocrinology and Metabolism, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Arash Derakhshan
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
- Academic Center for Thyroid Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Yi Xiao
- Section of Biostatistics, Department of Public Health, Copenhagen University, Copenhagen, Denmark
| | - Liang-Miao Chen
- Department of Endocrinology and Rui'an Center of the Chinese-American Research Institute for Diabetic Complications, Third Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Tuija Männistö
- Northern Finland Laboratory Center Nordlab and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Ghalia Ashoor
- Harris Birthright Research Center for Fetal Medicine, King's College Hospital, London, United Kingdom
| | - Fangbiao Tao
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, China
- Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, China
| | - Suzanne J Brown
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Marina Vafeiadi
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Sachiko Itoh
- Center for Environmental and Health Sciences, Hokkaido University, Sapporo, Japan
| | | | - Peter Taylor
- Thyroid Research Group, Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Farkhanda Ghafoor
- Research & Innovation, Shalamar Institute of Health Sciences, Lahore, Pakistan
| | - Bijay Vaidya
- Department of Endocrinology, Royal Devon and Exeter Hospital NHS Foundation Trust, University of Exeter Medical School, Exeter, United Kingdom
| | - Andrew Hattersley
- University of Exeter Medical School, Royal Devon & Exeter Hospital, Exeter, United Kingdom
| | - Lorena Mosso
- Endocrinology Department and Center of Translational Endocrinology (CETREN), Department of Endocrinology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Emily Oken
- Division of Chronic Disease Research Across the Lifecourse, Department of Population Medicine, Hypertension and Diabetes, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Reiko Kishi
- Center for Environmental and Health Sciences, Hokkaido University, Sapporo, Japan
| | - Erik K Alexander
- Division of Endocrinology, Hypertension and Diabetes, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Spyridoula Maraka
- Division of Endocrinology and Metabolism, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Knowledge and Evaluation Research Unit, Division of Endocrinology, Diabetes, Metabolism and Nutrition, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
- Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA
| | - Kun Huang
- Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, China
| | - Layal Chaker
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
- Academic Center for Thyroid Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Judit Bassols
- Maternal-Fetal Metabolic Research Group, Girona Biomedical Research Institute (IDIBGI), Dr. Josep Trueta Hospital, Girona, Spain
| | - Amna Pirzada
- Shifa Institute of Medical Technology, Shifa International Hospital, Islamabad, Pakistan
| | - Abel López-Bermejo
- Pediatric Endocrinology Research Group, Girona Biomedical Research Institute (IDIBGI), Dr. Josep Trueta Hospital, Girona, Spain
| | - Laura Boucai
- Division of Endocrinology, Department of Medicine, Memorial Sloan-Kettering Cancer Center, Weill Cornell University, New York, New York, USA
| | - Robin P Peeters
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
- Academic Center for Thyroid Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, Massachusetts, USA
| | | | - Leda Chatzi
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Tanja G Vrijkotte
- Department of Public Health, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research Institute, Amsterdam, the Netherlands
| | - Polina V Popova
- Institute of Endocrinology, Almazov National Medical Research Centre, St. Petersburg, Russia
- Department of Internal Diseases and Endocrinology, St. Petersburg Pavlov State Medical University, St. Petersburg, Russia
- World-Class Research Center for Personalized Medicine, Almazov National Medical Research Centre, St. Petersburg, Russia
| | - John P Walsh
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Australia
- Medical School, University of Western Australia, Crawley, Australia
| | - Kypros H Nicolaides
- Department of Women and Children's Health, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Eila Suvanto
- Department of Obstetrics and Gynecology and Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Xuemian Lu
- Department of Endocrinology and Rui'an Center of the Chinese-American Research Institute for Diabetic Complications, Third Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Victor J M Pop
- Department of Medical and Clinical Psychology, Tilburg University, Tilburg, the Netherlands
| | - Julie Lyng Forman
- Section of Biostatistics, Department of Public Health, Copenhagen University, Copenhagen, Denmark
| | - Tim I M Korevaar
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
- Academic Center for Thyroid Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Ulla Feldt-Rasmussen
- Department of Medical Endocrinology and Metabolism, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
2
|
Zdraveska N, Kocova M. Thyroid function and dysfunction in preterm infants-Challenges in evaluation, diagnosis and therapy. Clin Endocrinol (Oxf) 2021; 95:556-570. [PMID: 33864279 DOI: 10.1111/cen.14481] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 11/30/2022]
Abstract
Thyroid hormone levels have a crucial role for optimal brain development from gestation through the first 2 postnatal years. However, thyroid hormones vary with gestational age, and their levels vary between term and preterm infants. Preterm newborns are prone to thyroid dysfunction which is now more frequently observed with the advances of neonatal care and improved survival of extremely premature infants. Thus, hypothyroxinaemia of prematurity associated with delayed TSH elevation is very common in low birth weight premature infants most likely due to the immaturity of the hypothalamic-pituitary thyroid axis. Furthermore, postnatal illness, medications and iodine status may contribute to the thyroid dysfunction or affect the interpretation of the thyroid function tests. Despite available guidelines, timing of screening and optimal treatment of thyroid dysfunction in premature infants remains controversial. Furthermore, it is unknown whether untreated thyroid dysfunction in premature babies affects neurodevelopmental outcome. In the vast majority of preterm infants, hypothyroxinaemia is transient; however, permanent hypothyroidism due to thyroid dysgenesis or enzyme defects might also occur. Therefore, careful monitoring of thyroid function and long-term follow-up is needed to assess an appropriate therapeutic approach. This article reviews thyroid physiology in preterm infants, the influences of gestation and other neonatal conditions on thyroid function tests, optimal timing of screening and possible predictors to differentiate transient hypothyroxinaemia from permanent hypothyroidism.
Collapse
Affiliation(s)
- Nikolina Zdraveska
- Medical Faculty, University Ss. Cyril and Methodius Skopje, University Children's Hospital, Skopje, Macedonia
| | - Mirjana Kocova
- Medical Faculty, University Ss. Cyril and Methodius Skopje, University Children's Hospital, Skopje, Macedonia
| |
Collapse
|
3
|
Gant Kanegusuku A, Araque KA, Nguyen H, Wei B, Hosseini S, Soldin SJ. The effect of specific binding proteins on immunoassay measurements of total and free thyroid hormones and cortisol. Ther Adv Endocrinol Metab 2021; 12:2042018821989240. [PMID: 33552466 PMCID: PMC7844449 DOI: 10.1177/2042018821989240] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 01/03/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Immunoassay (IA) measurements of thyroid hormones have previously given inaccurate results of triiodothyronine (T3), free triiodothyronine (FT3), and free thyroxine (FT4) when concentrations of TBG are low. We evaluate the hypothesis that abnormal concentrations of specific binding proteins (BPs) affect IA measurements and provide results which might misguide the diagnosis and treatment of patients. This study assesses IAs for the measurement of T3, FT3, and cortisol when levels of TBG and CBG are high or low. Comparisons are made between IA and LC-MS/MS. METHODS Serum or plasma samples with high (>95th percentile, n = 25) or low (<5th percentile, n = 27) concentrations of BP were collected. The concentrations of T3, FT3, and cortisol were measured by validated IA and liquid chromatography tandem mass spectrometry (LC-MS/MS) methods. Spearman correlation and Wilcoxon matched-pairs signed rank analyses were used to compare the two methods. RESULTS When TBG levels are <5th percentile, the differences between the IA and LC-MS/MS results for T3 and FT3 are statistically significant (T3, p = 0.0011; FT3, p = 0.0003). When CBG levels are >95th percentile, the difference between the IA and LC-MS/MS measurements of cortisol is statistically significant (p = <0.0001). CONCLUSION Abnormal BP concentrations appear to affect the accuracy of IA measurements of T3, FT3, and cortisol. The population of patients with either high or low levels of BPs is significant. Our samples reflect that 65% of women aged between 15 and 49 years are taking oral contraceptives in the US, and thus have elevated levels of BPs. In this group, IA results for cortisol are falsely low. Our samples reflect that patients with protein losing diseases have low BP concentrations. Among a group with renal complications, IA measurements of T3 are overestimated, while those of FT3 are underestimated. Are the Food and Drug Administration and diagnostic companies adequately assessing the accuracy of IA tests?
Collapse
Affiliation(s)
- Anastasia Gant Kanegusuku
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Katherine A. Araque
- Endocrinology Pituitary Institute, Pacific Neuroscience Institute, John Wayne Cancer Institute, Santa Monica, CA, USA
| | - Hung Nguyen
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Bin Wei
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Saman Hosseini
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Steven J. Soldin
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, 10 Center Drive, Building 10, Bethesda, MD 20892–0001, USA
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University, Washington, DC, USA
| |
Collapse
|
4
|
Gozet T, Serdar M, Akın-Levi C, Ucal Y, Ozpinar A. Assessment of thyroid function during postpartum period with total thyroxine and total triiodothyronine levels measured by LC-MS/MS. J LIQ CHROMATOGR R T 2018. [DOI: 10.1080/10826076.2018.1511994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Tuba Gozet
- Faculty of Pharmacy, Department of Analytical Chemistry, Altinbas University, Istanbul, Turkey
| | - Muhittin Serdar
- School of Medicine, Department of Medical Biochemistry, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Cansu Akın-Levi
- School of Medicine, Department of Medical Biochemistry, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Yasemin Ucal
- School of Medicine, Department of Medical Biochemistry, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| | - Aysel Ozpinar
- School of Medicine, Department of Medical Biochemistry, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
| |
Collapse
|
5
|
Welsh KJ, Stolze BR, Yu X, Podsiadlo TR, Kim LS, Soldin SJ. Assessment of thyroid function in intensive care unit patients by liquid chromatography tandem mass spectrometry methods. Clin Biochem 2017. [DOI: 10.1016/j.clinbiochem.2016.11.022 pmid: 27890823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
6
|
Welsh KJ, Stolze BR, Yu X, Podsiadlo TR, Kim LS, Soldin SJ. Assessment of thyroid function in intensive care unit patients by liquid chromatography tandem mass spectrometry methods. Clin Biochem 2016; 50:318-322. [PMID: 27890823 DOI: 10.1016/j.clinbiochem.2016.11.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 11/17/2016] [Accepted: 11/19/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Patients with non-thyroidal illness syndrome have many abnormalities in thyroid hormone tests. Such patients have medical comorbidities associated with low serum proteins and are on multiple medications that interfere with thyroid hormone measurement by immunoassay platforms. It is unknown if these thyroid hormone measurements reflect physiologic conditions or if they are artifacts of testing methodology. METHODS Fifty patients were selected from the intensive care unit (ICU) from our institution. Total and free thyroid hormones in plasma were measured by gold standard liquid chromatography-tandem mass spectrometry (LC-MSMS). The results were compared to the Roche Cobas 6000. Patient medical comorbidities and binding protein levels were assessed. RESULTS Concentrations of total 3,5,5'-triidothyronine (TT3) and total thyroxine (TT4) were significantly more likely to be low by LC-MSMS compared to immunoassay. Free 3,5,5'-triidothyronine (FT3) levels were similar by immunoassay and LC-MSMS. However, FT4 concentrations were mildly elevated for many patients when measured by ultrafiltration LC-MSMS (19/50, 38%) compared to 1/50 (2%) when measured by immunoassay (p=0.0001). Decreased albumin and thyroxine binding globulin were common and patients were on an average of 11.7±5.0 medications, all factors known to interfere with results found on immunoassays. CONCLUSIONS Marked discrepancies in thyroid hormone measurement were noted between reference LC-MSMS and a common immunoassay platform. It is hypothesized that T4 binding to low affinity albumin is displaced by several drugs, raising concentrations of FT4 by LC-MSMS compared to immunoassay, and that the immunoassay values are falsely decreased due to low binding proteins in our patient population.
Collapse
Affiliation(s)
- Kerry J Welsh
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892, United States; (SJS) Departments of Endocrinology and Metabolism, Georgetown University, Washington, DC, United States
| | - Brian R Stolze
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892, United States; (SJS) Departments of Endocrinology and Metabolism, Georgetown University, Washington, DC, United States
| | - Xiaolin Yu
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892, United States; (SJS) Departments of Endocrinology and Metabolism, Georgetown University, Washington, DC, United States
| | - Trisha R Podsiadlo
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892, United States; (SJS) Departments of Endocrinology and Metabolism, Georgetown University, Washington, DC, United States
| | - Lisa S Kim
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892, United States; (SJS) Departments of Endocrinology and Metabolism, Georgetown University, Washington, DC, United States
| | - Steven J Soldin
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892, United States; (SJS) Departments of Endocrinology and Metabolism, Georgetown University, Washington, DC, United States.
| |
Collapse
|
7
|
|
8
|
Vuong AM, Webster GM, Romano ME, Braun JM, Zoeller RT, Hoofnagle AN, Sjödin A, Yolton K, Lanphear BP, Chen A. Maternal Polybrominated Diphenyl Ether (PBDE) Exposure and Thyroid Hormones in Maternal and Cord Sera: The HOME Study, Cincinnati, USA. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:1079-85. [PMID: 25893858 PMCID: PMC4590759 DOI: 10.1289/ehp.1408996] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 04/14/2015] [Indexed: 05/17/2023]
Abstract
BACKGROUND Polybrominated diphenyl ethers (PBDEs) reduce blood concentrations of thyroid hormones in laboratory animals, but it is unclear whether PBDEs disrupt thyroid hormones in pregnant women or newborn infants. OBJECTIVES We investigated the relationship between maternal PBDE levels and thyroid hormone concentrations in maternal and cord sera. METHODS We used data from the Health Outcomes and Measures of the Environment (HOME)Study, a prospective birth cohort of 389 pregnant women in Cincinnati, Ohio, who were enrolled from 2003 through 2006 and delivered singleton infants. Maternal serum PBDE concentrations were measured at enrollment (16 ± 3 weeks of gestation). Thyroid hormone concentrations were measured in maternal serum at enrollment (n = 187) and in cord serum samples (n = 256). RESULTS Median maternal serum concentrations of BDEs 28 and 47 were 1.0 and 19.1 ng/g lipid, respectively. A 10-fold increase in BDEs 28 and 47 concentrations was associated with a 0.85-μg/dL [95% confidence interval (CI): 0.05, 1.64] and 0.82-μg/dL (95% CI: 0.12, 1.51) increase in maternal total thyroxine concentrations (TT4), respectively. Both congeners were also positively associated with maternal free thyroxine (FT4). We also observed positive associations between BDE-47 and maternal total and free triiodothyronine (TT3 and FT3). A 10-fold increase in BDE-28 was associated with elevated FT3 concentrations (β = 0.14 pg/mL; 95% CI: 0.02, 0.26). In contrast, maternal PBDE levels were not associated with thyroid hormone concentrations in cord serum. CONCLUSIONS These findings suggest that maternal PBDE exposure, particularly BDEs 28 and 47, are associated with maternal concentrations of T4 and T3 during pregnancy.
Collapse
Affiliation(s)
- Ann M Vuong
- Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
IMPORTANCE Subclinical hypothyroidism (SCH) is a common clinical entity with a putative role in a wide range of disorders. The impact of SCH on mortality and markers of morbidity has been demonstrated, but studies have shown inconsistent results. Evidence regarding the effect of levothyroxine treatment on reversing morbidity markers is emerging, but the value of treatment is still unclear. OBJECTIVE The objectives of this review were to assess recent, high-quality studies evaluating the role of SCH in cardiovascular health, cognition, mood, pregnancy, anemia, and renal disease; to examine the effects of levothyroxine on reducing mortality or reversing markers of morbidity in these conditions; and to consider how new research insights may help guide clinical practice. EVIDENCE REVIEW A PubMed search was conducted (using 'subclinical hypothyroidism' [Title/Abstract] AND morbidity [MeSH Subheading] as search criteria) and was restricted to human studies published in the English language between 1990 and 2013. Subsequent searches of retrieved articles yielded further studies, which were included based on quality. Emphasis was given to large observational studies, well-conducted meta-analyses, and randomized controlled trials. FINDINGS The difficulty of diagnosing SCH, particularly in the elderly, may underlie many of the conflicting results seen in the literature. Increased understanding of the at-risk patient population will result in better selection of study subjects and, likely, unequivocal results. Regardless of the current confusion, emerging evidence suggests that certain markers of morbidity are reversed by levothyroxine therapy across the disorders examined here. CONCLUSION AND RELEVANCE Future large, well-controlled studies will not only clarify the role of SCH but also help identify patients for whom levothyroxine treatment will provide the most benefit.
Collapse
Affiliation(s)
- James V Hennessey
- Department of Medicine, Division of Endocrinology, Beth Israel Deaconess Medical Center , Boston, MA , USA
| | | |
Collapse
|
10
|
Greaves RF, Zacharin MR, Donath SM, Inder TE, Doyle LW, Hunt RW. Establishment of hormone reference intervals for infants born <30weeks' gestation. Clin Biochem 2014; 47:101-8. [DOI: 10.1016/j.clinbiochem.2014.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/27/2014] [Accepted: 06/02/2014] [Indexed: 10/25/2022]
|
11
|
Carvalho GAD, Perez CLS, Ward LS. The clinical use of thyroid function tests. ACTA ACUST UNITED AC 2014; 57:193-204. [PMID: 23681265 DOI: 10.1590/s0004-27302013000300005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 03/07/2013] [Indexed: 01/07/2023]
Abstract
Laboratory tests are essential for accurate diagnosis and cost-effective management of thyroid disorders. When the clinical suspicion is strong, hormonal levels just confirms the diagnosis. However, in most patients, symptoms are subtle and unspecific, so that only biochemical tests can detect the disorder. The objective of this article is to do a critical analysis of the appropriate use of the most important thyroid function tests, including serum concentrations of thyrotropin (TSH), thyroid hormones and antithyroid antibodies. Through a survey in the MedLine database, we discuss the major pitfalls and interferences related to daily use of these tests and recommendations are presented to optimize the use of these diagnostic tools in clinical practice.
Collapse
Affiliation(s)
- Gisah Amaral de Carvalho
- Serviço de Endocrinologia e Metabologia, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brasil.
| | | | | |
Collapse
|
12
|
Jonklaas J, Sathasivam A, Wang H, Gu J, Burman KD, Soldin SJ. Total and free thyroxine and triiodothyronine: measurement discrepancies, particularly in inpatients. Clin Biochem 2014; 47:1272-8. [PMID: 24936679 DOI: 10.1016/j.clinbiochem.2014.06.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 06/04/2014] [Accepted: 06/06/2014] [Indexed: 11/24/2022]
Abstract
OBJECTIVE We compared the performance of tandem mass spectrometry versus immunoassay for measuring thyroid hormones in a diverse group of inpatients and outpatients. METHODS Thyroxine (T4), triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3) were measured by liquid chromatography tandem mass spectrometry and immunoassay in 100 patients and the two assays were compared. RESULTS T4 and T3 values measured by the two different assays correlated well with each other (r=0.91-0.95). However, the correlation was less good at the extremes (r=0.51-0.75). FT4 and FT3 concentrations measured by the two assays correlated less well with each other (r=0.75 and 0.50 respectively). The studied analytes had poor inverse correlation with the log-transformed TSH values (r=-0.22-0.51) in the population as a whole. The strongest correlations were seen in the groups of outpatients (r=-0.25-0.61). The weakest degree of correlation was noted in the inpatient group, with many correlations actually being positive. CONCLUSION The worst between-assay correlation was demonstrated at low and high hormone concentrations, in the very concentration ranges where accurate assay performance is typically most clinically important. Based on the lesser susceptibility of mass spectrometry to interferences from conditions such as binding protein abnormalities, we speculate that mass spectrometry better reflects the clinical situation. In this mixed population of inpatients and outpatients, we also note failure of assays to conform to the anticipated inverse linear relationship between thyroid hormones and log-transformed TSH.
Collapse
Affiliation(s)
| | - Anpalakan Sathasivam
- Division of Endocrinology, Georgetown University, Washington, DC, USA; Section of Endocrinology Medstar Washington Hospital Center, Washington, DC, USA
| | - Hong Wang
- Medstar Health Research Institute, Hyattsville, MD, USA
| | - Jianghong Gu
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Kenneth D Burman
- Section of Endocrinology Medstar Washington Hospital Center, Washington, DC, USA
| | - Steven J Soldin
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
13
|
Bliddal S, Feldt-Rasmussen U, Boas M, Faber J, Juul A, Larsen T, Precht DH. Gestational age-specific reference ranges from different laboratories misclassify pregnant women's thyroid status: comparison of two longitudinal prospective cohort studies. Eur J Endocrinol 2014; 170:329-39. [PMID: 24277773 DOI: 10.1530/eje-13-0672] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES Correct interpretation of thyroid status during pregnancy is vital to secure fetal development. Pregnancy-related changes in maternal thyroid status necessitate the use of gestational age-specific reference ranges. In this study, we investigated between-laboratory reproducibility of thyroid reference ranges in pregnant women. DESIGN Comparison of two longitudinal prospective cohort studies including 255 (cohort 1) and 101 (cohort 2) healthy antibody-negative Danish pregnant women attending prenatal care at Copenhagen University Hospital. METHODS Different immunoassays were used to measure thyroid hormone levels in the two cohorts. Thyroid hormone reference ranges were established for every 5 weeks of gestation. Differences between cohorts were explored through mixed-model repeated measures regression analyses. By applying reference ranges from one cohort to the other, the proportion of women who would be misclassified by doing so was investigated. RESULTS TSH increased and free thyroxine (FT4) decreased as pregnancy progressed. Results indicated highly significant differences between cohorts in free triiodothyronine (F=21.3, P<0.001) and FT4 (F=941, P<0.001). TSH levels were comparable (P=0.09). Up to 90.3% of the women had FT4 levels outside their laboratory's nonpregnant reference range, and up to 100% outside the other cohort's gestational-age-specific reference ranges. Z-score-based reference ranges markedly improved comparison between cohorts. CONCLUSION Even in the same region, the use of gestational-age-specific reference ranges from different laboratories led to misclassification. Up to 100% of maternal FT4 levels fell outside the other cohort's reference range despite similar TSH levels. In clinical practice, thyroid testing of pregnant women without adding method specificity to gestational age-dependent reference ranges will compromise patient safety.
Collapse
Affiliation(s)
- Sofie Bliddal
- Department of Endocrinology, Section 2132, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
The free hormone hypothesis states that a hormone's physiological effects depend on the free hormone concentration, not the total hormone concentration. Although the in vivo relationship between free hormone and protein-bound hormone is complex, most experts have applied this view to the design of assays used to assess the free hormone concentration in the blood sampled for testing in vitro. The history of the measurement of free thyroxine, probably the most frequently requested free hormone determination, offers a good example of the approaches that have been taken. Methods that require physical separation of the free hormone from the protein-bound hormone must address both the potential disturbance in the equilibrium between the two, as well as the challenge of quantifying small levels of hormone accurately and precisely. The implementation of mass spectrometry in the clinical laboratory has helped to develop proposed reference measurement procedures. These must be utilized to standardize the variety of immunoassay approaches that currently represent options commercially available to the routine clinical laboratory. Practicing endocrinologists should discuss the details of the free hormone assays offered by the clinical laboratory they utilize for patient result reporting, and clinical laboratories should implement the recommendations of published guidelines to ensure that free hormone results using commercially available immunoassays are as accurate and precise as possible.
Collapse
Affiliation(s)
- James D Faix
- Stanford University School of Medicine, USA; Department of Pathology, Stanford University Medical Center, USA; Stanford Clinical Lab at Hillview, MC:5627, 3375 Hillview Avenue, Palo Alto, CA 94304-1204, USA.
| |
Collapse
|
15
|
Chevrier J. Invited commentary: Maternal plasma polybrominated diphenyl ethers and thyroid hormones--challenges and opportunities. Am J Epidemiol 2013; 178:714-9. [PMID: 23924577 DOI: 10.1093/aje/kwt138] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Thyroid hormones play a fundamental role in fetal and child development. While iodine deficiency-related maternal and child hypothyroidism may cause severe mental retardation, recent evidence suggests that milder forms of maternal hypothyroidism and hypothyroxinemia during pregnancy are also associated with altered neurodevelopment. On the other hand, hyperthyroidism during pregnancy has been associated with adverse fetal outcomes. Findings published by Abdelouahab et al. in the American Journal of Epidemiology (Am J Epidemiol. 2013;178(5):701-713) suggest that plasma concentrations of maternal polybrominated diphenyl ethers (PBDEs), which were used as flame retardants until recently and are detected in the tissues of virtually every North American, are associated with umbilical cord and maternal thyroid hormone levels during pregnancy. Although PBDEs have been consistently shown to reduce levels of free and total thyroxine in experimental animal studies, the direction of associations in human studies has been inconsistent. In this commentary, I discuss challenges beyond the factors often cited in the epidemiologic literature to explain inconsistent findings which more specifically apply to the study of PBDEs and thyroid hormones. These include the determination of iodine intake status, the method used to adjust for blood lipid concentrations, the measurement of free thyroid hormone levels, the possible effect of PBDE metabolites, and the potential for reverse causality.
Collapse
Affiliation(s)
- Jonathan Chevrier
- Center for Environmental Research and Children's Health, School of Public Health, University of California-Berkeley, 1995 University Avenue, Berkeley, CA 94720-7392, USA.
| |
Collapse
|
16
|
Monneret D, Guergour D, Vergnaud S, Laporte F, Faure P, Gauchez A. Evaluation of LOCI® technology-based thyroid blood tests on the Dimension Vista® analyzer. Clin Biochem 2013. [DOI: 10.1016/j.clinbiochem.2012.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
17
|
Wu AH, French D. Implementation of liquid chromatography/mass spectrometry into the clinical laboratory. Clin Chim Acta 2013; 420:4-10. [DOI: 10.1016/j.cca.2012.10.026] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 10/11/2012] [Indexed: 10/27/2022]
|
18
|
van Deventer HE, Soldin SJ. The expanding role of tandem mass spectrometry in optimizing diagnosis and treatment of thyroid disease. Adv Clin Chem 2013; 61:127-52. [PMID: 24015601 DOI: 10.1016/b978-0-12-407680-8.00005-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This review discusses the state-of-the-art measurement of free and total thyroid hormones in clinical laboratories. We highlight some of the limitations of currently used immunoassays and critically discuss physical separation methods for the measurement of free thyroid hormone. Physical separation methods, such as equilibrium dialysis or ultrafiltration, followed by tandem mass spectrometry for the measurement of free thyroid hormones offer many advantages, which we feel, can deepen our understanding of thyroid hormone metabolism and improve patient diagnosis and care. Problems with direct analogue immunoassay methods for FT4/FT3 as well as immunoassay methods for total T3 at low T3 concentrations and during pregnancy are highlighted. Improved diagnosis and patient management can be achieved utilizing tandem mass spectrometry for these measurements.
Collapse
|
19
|
Chevrier J, Harley KG, Kogut K, Holland N, Johnson C, Eskenazi B. Maternal Thyroid Function during the Second Half of Pregnancy and Child Neurodevelopment at 6, 12, 24, and 60 Months of Age. J Thyroid Res 2011; 2011:426427. [PMID: 22132346 PMCID: PMC3202128 DOI: 10.4061/2011/426427] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/26/2011] [Accepted: 07/07/2011] [Indexed: 12/02/2022] Open
Abstract
Although evidence suggests that maternal hypothyroidism and mild hypothyroxinemia during the first half of pregnancy alters fetal neurodevelopment among euthyroid offspring, little data are available from later in gestation. In this study, we measured free T4 using direct equilibrium dialysis, as well as total T4 and TSH in 287 pregnant women at 27 weeks' gestation. We also assessed cognition, memory, language, motor functioning, and behavior in their children at 6, 12, 24, and 60 months of age. Increasing maternal TSH was related to better performance on tests of cognition and language at 12 months but not at later ages. At 60 months, there was inconsistent evidence that higher TSH was related to improved attention. We found no convincing evidence that maternal TH during the second half of pregnancy was related to impaired child neurodevelopment.
Collapse
Affiliation(s)
- Jonathan Chevrier
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA 94704-7392, USA
| | | | | | | | | | | |
Collapse
|
20
|
Zota AR, Park JS, Wang Y, Petreas M, Zoeller RT, Woodruff TJ. Polybrominated diphenyl ethers, hydroxylated polybrominated diphenyl ethers, and measures of thyroid function in second trimester pregnant women in California. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:7896-905. [PMID: 21830753 PMCID: PMC3191110 DOI: 10.1021/es200422b] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Prenatal exposure to polybrominated diphenyl ethers (PBDEs) may disrupt thyroid function and contribute to adverse neurodevelopmental outcomes. We conducted a pilot study to explore the relationship between serum concentrations of lower-brominated PBDEs (BDE-17 to -154), higher-brominated PBDEs (BDE-183 to -209), and hydroxylated PBDE metabolites (OH-PBDEs) with measures of thyroid function in pregnant women. Concentrations of PBDEs, OH-PBDEs, thyroid-stimulating hormone (TSH), total thyroxine (T(4)), and free T(4) were measured in serum samples collected between 2008 and 2009 from 25 second trimester pregnant women in California. Median concentrations of lower-brominated PBDEs and OH-PBDEs were the highest reported to date in pregnant women. Median concentrations of BDE-47 and the sum of lower-brominated PBDEs (ΣPBDE(5)) were 43.1 ng/g lipid and 85.8 ng/g lipid, respectively, and the sum of OH-PBDEs (ΣOH-PBDE(4)) was 0.084 ng/mL. We observed a positive association between the weighted sum of chemicals known to bind to transthyretin (ΣTTR binders) and TSH levels. We also found positive associations between TSH and ΣPBDE(5), ΣOH-PBDE(4), BDE-47, BDE-85, 5-OH-BDE47, and 4'-OH-BDE49, and an inverse association with BDE-207. Relationships with free and total T(4) were weak and inconsistent. Our results indicate that PBDE exposures are elevated in pregnant women in California and suggest a relationship with thyroid function. Further investigation is warranted to characterize the risks of PBDE exposures during pregnancy.
Collapse
Affiliation(s)
- Ami R Zota
- Program on Reproductive Health and the Environment, University of California, San Francisco, Oakland, California 94612, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Golombek SG, Alpan G, Frey M, Corbi D, Lagamma EF. Stability of thyroid hormones during continuous infusion. J Perinat Med 2011; 39:471-5. [PMID: 21501101 DOI: 10.1515/jpm.2011.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We investigated the stability of thyroid hormones during a mode of continuous drug infusion via polypropylene tubing using the same conditions that would be applied to treating patients in a hospital setting. The diluted thyroid hormones were prepared using aseptic technique, stored at 2-8°C (36-46°F) and tested within 24 h of preparation for stability and percent recovery from within plastic tubing. Experiments were done in duplicate with triplicate sets of readings for each assay point. Only T(4) prepared with 5% dextrose water (D5W) containing 1 mg/mL albumin remained constant, stable, predictable and accurate over time under various conditions. Other methods of preparation lost drug by adhering to the plastic containers and tubing by as much as 40% of starting concentration. T(3) recovery in the presence of 1 mg/mL of albumin was 107±2% (mean±standard error of the mean) of anticipated drug concentrations. We conclude from this series of experiments that to maintain an accurate and stable dosing of patients receiving intravenous thyroid hormones, 1 mg/mL of albumin must be added to the infusate to prevent lost on the plastic intravenous tubing.
Collapse
Affiliation(s)
- Sergio G Golombek
- Division of Newborn Medicine, Department of Pediatrics, The Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, New York 10595, USA.
| | | | | | | | | |
Collapse
|
22
|
Lopez-Espinosa MJ, Fitz-Simon N, Bloom MS, Calafat AM, Fletcher T. Comparison between free serum thyroxine levels, measured by analog and dialysis methods, in the presence of perfluorooctane sulfonate and perfluorooctanoate. Reprod Toxicol 2011; 33:552-555. [PMID: 21530636 DOI: 10.1016/j.reprotox.2011.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 04/01/2011] [Accepted: 04/01/2011] [Indexed: 01/09/2023]
Abstract
Results from animal studies have shown that negative associations between serum levels of free thyroxine (FT4) and perfluorooctane sulfonate (PFOS) at concentrations much higher than those reported for any exposed population may be due to bias in analog methods used for measuring FT4. We aimed to assess if there is evidence of differences between human FT4 measurements in serum by an analog and a dialysis method due to the presence of PFOS or perfluorooctanoate (PFOA) in a population of 50 adults with typical US serum PFOS concentrations but higher PFOA concentrations. Mean analog-dialysis difference was -0.02 (95% CI=-0.06, 0.02). Regressing the difference between FT4 measurements on either PFOA or PFOS serum concentrations yielded slopes close to zero. The present findings do not indicate any observable bias from the use of the analog with respect to the dialysis method, across the range of PFOS and PFOA concentrations in this population.
Collapse
Affiliation(s)
- Maria-Jose Lopez-Espinosa
- Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, United Kingdom.
| | - Nicola Fitz-Simon
- Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, United Kingdom.
| | - Michael S Bloom
- Departments of Environmental Health Sciences and Epidemiology and Biostatistics, School of Public Health, University at Albany, State University of New York, Rensselaer, New York, NY 12114, United States.
| | - Antonia M Calafat
- National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341, United States.
| | - Tony Fletcher
- Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, 15-17 Tavistock Place, London WC1H 9SH, United Kingdom.
| |
Collapse
|
23
|
Bliddal S, Rasmussen AK, Sundberg K, Brocks V, Feldt-Rasmussen U. Antithyroid drug-induced fetal goitrous hypothyroidism. Nat Rev Endocrinol 2011; 7:396-406. [PMID: 21403664 DOI: 10.1038/nrendo.2011.34] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Maternal overtreatment with antithyroid drugs can induce fetal goitrous hypothyroidism. This condition can have a critical effect on pregnancy outcome, as well as on fetal growth and neurological development. The purpose of this Review is to clarify if and how fetal goitrous hypothyroidism can be prevented, and how to react when prevention has failed. Understanding the importance of pregnancy-related changes in maternal thyroid status when treating a pregnant woman is crucial to preventing fetal goitrous hypothyroidism. Maternal levels of free T(4) are the most consistent indication of maternal and fetal thyroid status. In patients with fetal goitrous hypothyroidism, intra-amniotic levothyroxine injections improve fetal outcome. The best way to avoid maternal overtreatment with antithyroid drugs is to monitor closely the maternal thyroid status, especially estimates of free T(4) levels.
Collapse
Affiliation(s)
- Sofie Bliddal
- Department of Medical Endocrinology, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
24
|
Bliddal S, Rasmussen ÅK, Sundberg K, Brocks V, Skovbo P, Feldt-Rasmussen U. Graves' disease in two pregnancies complicated by fetal goitrous hypothyroidism: successful in utero treatment with levothyroxine. Thyroid 2011; 21:75-81. [PMID: 21162688 DOI: 10.1089/thy.2010.0286] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Treatment of Graves' disease during pregnancy with antithyroid drugs (ATDs) poses a risk of inducing hypothyroidism and, thus, development of a goiter to the fetus. PATIENT FINDINGS We report two patients referred to our department after discovery of a fetal goiter by ultrasound examination in the second trimester of pregnancy. The women receiving 400 mg/day propylthiouracil and 10 mg/day thiamizole, respectively, had thyrotropin and total thyroxine values within the normal reference range but a lowered free thyroxine level. Fetal blood sampling by cordocentesis revealed severe fetal hypothyroidism as the cause of goiter development. Reduction of maternal ATD dose and injection of levothyroxine intra-amniotically quickly reduced the goiter size, and both babies were born euthyroid and without goiters. SUMMARY Two pregnant women with Graves' disease were overtreated with ATDs inducing iatrogenic goiter in the fetuses. Successful treatment with intra-amniotic levothyroxine injections rendered the babies euthyroid and nongoitrous at birth. CONCLUSIONS Correct interpretation of thyroid function tests during pregnancy in general--and during ATD therapy of Graves' disease in particular--is difficult. Awareness of pregnancy-related changes in maternal thyroid status, and a close teamwork among endocrinologists, obstetricians, and experts in fetal medicine, is pivotal in ensuring normal growth and development of the unborn child of these patients.
Collapse
Affiliation(s)
- Sofie Bliddal
- Department of Medical Endocrinology, Copenhagen University Hospital, Copenhagen University, Copenhagen, Denmark
| | | | | | | | | | | |
Collapse
|
25
|
Williams F, Hume R. The measurement, definition, aetiology and clinical consequences of neonatal transient hypothyroxinaemia. Ann Clin Biochem 2010; 48:7-22. [PMID: 20930033 DOI: 10.1258/acb.2010.010174] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This review focuses on neonatal transient hypothyroxinaemia, a condition characterized by temporary postnatal reductions in concentrations of Total T4 or Free T4, with normal or low concentrations of thyroid stimulating hormone (TSH). There is neither an agreed quantitative definition, nor an agreed mode of measurement for the condition. Transient hypothyroxinaemia is not routinely monitored yet it is thought to affect about 50% of preterm infants; it was thought to be without long-term sequelae but observational studies indicate that neurodevelopment may be compromised. The aetiology of transient hypothyroxinaemia is complex. There are significant contributions from the withdrawal of maternal-placental thyroxine transfer, hypothalamic-pituitary-thyroid immaturity, developmental constraints on the synthesis and peripheral metabolism of iodothyronines and iodine deficiency. It is not possible to distinguish clinically, or from laboratory measurements, whether transient hypothyroxinaemia is an independent condition or simply a consequence of non-thyroidal illness and/or drug usage. An answer to this question is important because studies of thyroid hormone replacement have been instigated, with mixed results. Until the aetiology of transient hypothyroxinaemia is better understood it would seem prudent not to routinely supplement preterm infants with thyroid hormones. Iodine deficiency, non-thyroidal illness and drug usage are the most modifiable risk factors for transient hypothyroxinaemia and are the clear choices for attempts at reducing its incidence. We suggest that transient hypothyroxinaemia in preterm infants is defined as a normal or low TSH concentration in conjunction with a concentration of Total T4, that is ≤10th percentile of cord Total T4 of the equivalent gestational age had the infant remained in utero.
Collapse
Affiliation(s)
- Fiona Williams
- Clinical and Population Sciences and Education, Human Brain Development Group, Mackenzie Building, Ninewells Hospital and Medical School Campus, Kirsty Semple Way, Dundee DD2 4BF, UK.
| | | |
Collapse
|
26
|
Chevrier J, Harley KG, Bradman A, Gharbi M, Sjödin A, Eskenazi B. Polybrominated diphenyl ether (PBDE) flame retardants and thyroid hormone during pregnancy. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1444-9. [PMID: 20562054 PMCID: PMC2957927 DOI: 10.1289/ehp.1001905] [Citation(s) in RCA: 215] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 06/11/2010] [Indexed: 05/02/2023]
Abstract
BACKGROUND Human exposure to polybrominated diphenyl ether (PBDE) flame retardants has increased exponentially over the last three decades. Animal and human studies suggest that PBDEs may disrupt thyroid function. Although thyroid hormone (TH) of maternal origin plays an essential role in normal fetal brain development, there is a paucity of human data regarding associations between exposure to PBDEs and maternal TH levels during pregnancy. OBJECTIVES Our goal was to determine whether PBDE serum concentrations are associated with TH levels in pregnant women. METHODS We measured the concentration of 10 PBDE congeners, free thyroxine (T4), total T4, and thyroid-stimulating hormone (TSH) in 270 pregnant women around the 27th week of gestation. RESULTS Serum concentrations of individual PBDE congeners with detection frequencies > 50% (BDEs 28, 47, 99, 100, and 153) and their sum (ΣPBDEs) were inversely associated with TSH levels. Decreases in TSH ranged between 10.9% [95% confidence interval (CI), -20.6 to 0.0] and 18.7% (95% CI, -29.2 to -4.5) for every 10-fold increase in the concentration of individual congeners. Odds of subclinical hyperthyroidism (low TSH but normal T4) were also significantly elevated in participants in the highest quartile of ΣPBDEs and BDEs 100 and 153 relative to those in the first quartile. Associations between PBDEs and free and total T4 were not statistically significant. Results were not substantially altered after the removal of outliers and were independent of the method used to adjust for blood lipid levels and to express ΣPBDEs. CONCLUSIONS Results suggest that exposure to PBDEs is associated with lower TSH during pregnancy. Findings may have implications for maternal health and fetal development.
Collapse
Affiliation(s)
- Jonathan Chevrier
- Center for Children's Environmental Health Research, School of Public Health, University of California-Berkeley, Berkeley, California 94704-7392 , USA.
| | | | | | | | | | | |
Collapse
|
27
|
|
28
|
Lee RH, Spencer CA, Montoro MN, Aghajanian P, Goodwin TM, Miller EA, Petrovic I, Braverman LE, Mestman JH. Effect of thyroid peroxidase antibodies on thyroid-stimulating hormone reference limits in a primarily Latina population. Obstet Med 2009; 2:154-6. [DOI: 10.1258/om.2009.090039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2009] [Indexed: 11/18/2022] Open
Abstract
The aim of the paper is to determine the prevalence of thyroid peroxidase antibodies (TPOAb) and assess its effect on the thyroid-stimulating hormone (TSH) reference range during pregnancy in a primarily Latina population. Serum samples were collected from healthy pregnant women and non-pregnant controls. TSH reference ranges were calculated when TPOAb-positive patients were either included or excluded. A total of 134 pregnant women and 107 non-pregnant controls were recruited. Positive TPOAb titres were found in 23 (17.2%) of the 134 pregnant women, and in 14 (13.1%) of the 107 non-pregnant controls. When the TPOAb-positive women were included in the TSH analysis, the upper reference limit using two different methods was consistently higher: 0–2.2 fold in the non-pregnant women, 2.01–2.78 fold in the first trimester, 3.18–4.7 fold in the second and 1.05–1.42 fold in the third. The lower TSH reference limit was not affected by the inclusion of TPOAb-positive subjects. In conclusion, inclusion of TPOAb-positive patients results in higher upper reference limits during pregnancy.
Collapse
Affiliation(s)
- Richard H Lee
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
| | - Carole A Spencer
- Department of Medicine, Boston University Medical Center, Boston, MA
| | - Martin N Montoro
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
- Department of Medicine, Boston University Medical Center, Boston, MA
| | - Paola Aghajanian
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
| | - T Murphy Goodwin
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
| | - Erin A Miller
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
| | - Ivana Petrovic
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
| | - Lewis E Braverman
- Department of Medicine, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA, USA
| | - Jorge H Mestman
- Department of Obstetrics and Gynecology, Los Angeles County–University of Southern California Medical Center, Los Angeles, CA
- Department of Medicine, Boston University Medical Center, Boston, MA
| |
Collapse
|
29
|
Jonklaas J, Kahric-Janicic N, Soldin OP, Soldin SJ. Correlations of free thyroid hormones measured by tandem mass spectrometry and immunoassay with thyroid-stimulating hormone across 4 patient populations. Clin Chem 2009; 55:1380-8. [PMID: 19460839 DOI: 10.1373/clinchem.2008.118752] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Accurate measurement of free thyroid hormones is important for managing thyroid disorders. Ultrafiltration liquid chromatography tandem mass spectrometry (LC-MS/MS) can reliably measure the concentrations of small molecules, including thyroid hormones. Our study was designed to compare free thyroid hormone measurements performed with immunoassay and LC-MS/MS. METHODS We studied the performance of LC-MS/MS in 4 different populations comprising pediatric patients, euthyroid adults, and healthy nonpregnant and pregnant women. The samples obtained from each population numbered 38, 200, 28, and 128, respectively. Free thyroxine, free triiodothyronine, and thyroid-stimulating hormone (TSH) concentrations were documented. RESULTS LC-MS/MS measurement of free thyroid hormones provided better correlation with log-transformed serum TSH in each population and also the populations combined. The correlations between free thyroxine measured by LC-MS/MS and log TSH in the pediatric outpatients and healthy adults were -0.90 and -0.77, respectively. The correlations for immunoassay were -0.82 and -0.48. The correlations between free triiodothyronine measured by LC-MS/MS and TSH for both pediatric and healthy adult populations were -0.72 and -0.68, respectively. CONCLUSIONS Free thyroid hormone concentrations measured by LC-MS/MS correlate to a greater degree with log TSH values compared to concentrations measured by immunoassay. This correlation was maintained across the patient populations we studied and may reflect the accuracy and specificity of LC-MS/MS. The superior ability of LC-MS/MS to enable documentation of the well-known thyroid hormone-TSH relationship supports the use of this measurement technique in a variety of clinical situations.
Collapse
Affiliation(s)
- Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University Medical Center, Washington, DC 20007, USA.
| | | | | | | |
Collapse
|
30
|
Wilcox RB, Nelson JC. Counterpoint: legitimate and illegitimate tests of free-analyte assay function: we need to identify the factors that influence free-analyte assay results. Clin Chem 2009; 55:442-4. [PMID: 19168550 DOI: 10.1373/clinchem.2008.120154] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- R Bruce Wilcox
- Department of Biochemistry and Departments of Internal Medicine and Pathology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | | |
Collapse
|
31
|
Abstract
The incidence of low neonatal free thyroxine (T(4)) assay results is methodology-dependent. Nonanalog free T(4) assay results represent free T(4) concentrations when free T(4) is the only form of T(4). Similar analog-based free T(4) assay results are produced by an extraordinary range of free T(4) concentrations, when free T(4) is the only form of T(4). Adding albumin or transthyretin to free T(4) concentrations greatly decreased free T(4) concentrations, as expected, but increased analog-based free T(4) assay results. By contrast, adding thyroxine-binding globulin decreased free T(4) concentrations and free T(4) assay results; but these free T(4) concentrations were not represented by assay results. There was no specificity for the free form of T(4) versus bound forms of T(4) in some free T(4) assay results. The protein that binds T(4) can have a major influence on some of the total T(4) assay results that may be used in free T(4) index methods.
Collapse
Affiliation(s)
- Jerald C Nelson
- Loma Linda University School of Medicine, Loma Linda, CA, USA
| | | | | |
Collapse
|
32
|
Abstract
BACKGROUND Our objective was to determine the performance of liquid chromatography-tandem mass spectrometry (LC-MS/MS) in documenting both group and individual relationships between thyroid hormone and thyroid-stimulating hormone (TSH) concentrations. METHODS This was a prospective analysis of 50 euthyroid patients undergoing thyroidectomy. Thyroxine (T(4)), triiodothyronine (T(3)), free T(4) (FT(4)), and TSH levels were documented on two occasions before thyroidectomy. After thyroidectomy, patients were treated with levothyroxine (LT(4)) to achieve either a normal or low serum TSH concentration. All laboratory evaluations were repeated twice while patients were taking LT(4). Thyroid hormone concentrations were documented by both immunoassay and LC-MS/MS, and their relationship with TSH was studied both in the entire group and in individual patients pre- and postthyroidectomy. RESULTS FT(4) and total T(3) correlated better with the log-transformed TSH when measured by LC-MS/MS. Postthyroidectomy the closest correlation was between log TSH and FT(4) (r = 0.86, p < 0.001). The next best correlation was between log TSH and total T(3) (r = 0.71, p < 0.001). When all data points were combined, the slope of the relationship between log TSH and total T(3) was relatively blunted compared with the log TSH-FT(4) slope (slope - 0.39 vs. - 1.38; p < 0.001), perhaps suggesting autoregulation of T(3) in response to the altered conditions postthyroidectomy. CONCLUSION LC-MS/MS is an excellent tool for documenting the known physiological phenomenon of a log-linear relationship between TSH and thyroid hormone concentrations. In a group of patients studied pre- and postthyroidectomy, both FT(4) and total T(3) measured by tandem mass spectrometry correlate well with TSH. However, T(3) correlates slightly less well and has a relatively blunted relationship with the log-transformed TSH. These paired data suggest that in LT(4)-replaced patients T(3) concentrations are held stable in the face of fluctuating T(4) concentrations.
Collapse
Affiliation(s)
- Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University Medical Center, Washington, District of Columbia 20007, USA.
| | | |
Collapse
|
33
|
Chevrier J, Eskenazi B, Holland N, Bradman A, Barr DB. Effects of exposure to polychlorinated biphenyls and organochlorine pesticides on thyroid function during pregnancy. Am J Epidemiol 2008; 168:298-310. [PMID: 18550560 DOI: 10.1093/aje/kwn136] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In this study, the authors' objective was to determine whether serum concentrations of polychlorinated biphenyls (PCBs), hexachlorobenzene, p,p'-dichlorodiphenyl trichloroethane (DDT), o,p'-DDT, and p,p'-dichlorodiphenyl dichloroethylene (DDE) are associated with thyroid function during pregnancy. These compounds, as well as thyroid-stimulating hormone, total thyroxine, and free thyroxine, were measured in serum samples collected between October 1999 and October 2000 from 334 pregnant women living in the Salinas Valley, California. Data were analyzed by multivariate linear regression. After adjustment for covariates, seven of the 19 PCB congeners detected in more than 75% of participants and the sum of those congeners were negatively associated with free thyroxine concentrations. PCBs 44, 52, and 183 remained significant after the exclusion of two outliers. Hexachlorobenzene concentrations were negatively associated with both free thyroxine and total thyroxine. PCB and hexachlorobenzene concentrations were strongly correlated, which hampered the authors' ability to identify their independent associations with thyroid function. None of the exposures under study were associated with thyroid-stimulating hormone. Results suggest that exposure to PCBs and/or hexachlorobenzene at background levels may affect thyroid function during pregnancy. These findings are of particular significance, since thyroid hormones of maternal origin may play an essential role in fetal neurodevelopment.
Collapse
Affiliation(s)
- Jonathan Chevrier
- Center for Children's Environmental Health Research, School of Public Health, University of California, Berkeley, Berkeley, CA 94704-7380, USA
| | | | | | | | | |
Collapse
|
34
|
Thienpont LM. A Major Step Forward in the Routine Measurement of Serum Free Thyroid Hormones. Clin Chem 2008; 54:625-6. [DOI: 10.1373/clinchem.2007.100164] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Linda M Thienpont
- Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Belgium
| |
Collapse
|
35
|
Abstract
The evaluation of hormonal status in critically ill patients is challenging and has many pitfalls. This article reviews proper assessment of glycemic status AND adrenal and thyroid function during critical care.
Collapse
Affiliation(s)
- Olga V Sakharova
- Yale University School of Medicine, Department of Internal Medicine, Section of Endocrinology, 333 Cedar Street, New Haven, CT 06520-8020, USA
| | | |
Collapse
|
36
|
Deming DD, Rabin CW, Hopper AO, Peverini RL, Vyhmeister NR, Nelson JC. Direct equilibrium dialysis compared with two non-dialysis free T4 methods in premature infants. J Pediatr 2007; 151:404-8. [PMID: 17889078 DOI: 10.1016/j.jpeds.2007.03.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 02/15/2007] [Accepted: 03/20/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To compare the incidence of low free T4 values reported by a direct equilibrium dialysis method to their incidence reported by 2 non-dialysis methods. STUDY DESIGN Ninety-five infants, < or = 33 weeks gestational age at birth, admitted to Loma Linda University Children's Hospital before day 3 of life were studied. Infants were grouped by gestational age ranges: < or = 27, 28-30, and 31-33 weeks. Free T4 determinations were measured at 3, 7, and 14 days of life with 3 different free T4 methods. Gestational age-specific newborn reference ranges were available for the direct equilibrium dialysis method only. The only reference ranges available for the non-dialysis free T4 methods were not gestational age specific. Using available reference ranges we classified free T4 values as either low or not low. The incidence of low free T4 values was compared at 3, 7, and 14 days of life. RESULTS Low direct equilibrium dialysis free T4 values were substantially less frequent than non-dialysis free T4 values. CONCLUSION Substantial free T4 inconsistencies occur between dialysis and non-dialysis free T4 methods in preterm infants. It is unclear how much of this inconsistency is method dependent and how much is reference range dependent.
Collapse
Affiliation(s)
- Douglas D Deming
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
| | | | | | | | | | | |
Collapse
|
37
|
Abstract
Laboratory tests are the most commonly used aids in the diagnosis and monitoring of individuals who have thyroid disease. This article briefly summarizes the common methods of laboratory testing relating to thyroid disease and discusses specific information for individual tests on methods of analysis, their limitations, and situations where caution should be used in interpreting the results of thyroid tests.
Collapse
Affiliation(s)
- D Robert Dufour
- Pathology and Laboratory Medicine Service, Veterans Affairs Medical Center, and George Washington University Medical Center, 2300 Eye Street, NW, Washington, DC 20037, USA.
| |
Collapse
|
38
|
Gu J, Soldin OP, Soldin SJ. Simultaneous quantification of free triiodothyronine and free thyroxine by isotope dilution tandem mass spectrometry. Clin Biochem 2007; 40:1386-91. [PMID: 17936741 DOI: 10.1016/j.clinbiochem.2007.08.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Revised: 07/31/2007] [Accepted: 08/07/2007] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study was designed to improve our previously developed tandem mass spectrometry (MS/MS) method for free thyroxine (FT4) by enhancing sensitivity and permitting simultaneous measurements of both free triidothyronine (FT3) and FT4 using a smaller plasma/serum sample. DESIGN AND METHODS An API-5,000 tandem mass spectrometer equipped with TurboIonSpray source and Shimadzu HPLC system was employed to perform the analysis using isotope dilution with deuterium labeled internal standard, T4-d(5). Four hundred microliters of human plasma/serum was filtered through a Centrifree YM-30 ultrafiltration device by centrifugation, and 450 microL of internal standard in methanol was then added to 150 microL of ultrafiltrate for deproteinization. After centrifugation, 500 microL of supernatant was diluted with 400 microL of distilled de-ionized water and a 650 microL aliquot was injected onto a C-18 column. After washing, the switching valve was activated and the analytes were eluted from the column with a water/methanol gradient into the MS/MS system. Quantification by multiple reaction-monitoring (MRM) analysis was performed in the negative mode. RESULTS The within-day and between-day coefficients of variation (CVs) were <or=9% for FT3 and <or=7% for FT4 at all concentrations tested. Accuracy ranged between 95% and 105%. The 2.5th-97.5th percentile for FT3 and FT4 was 0.09-0.4 ng/dL (1.4-6.2 pmol/L) and 0.8-2.1 ng/dL (10-26 pmol/L), respectively. The results correlated only moderately well with the immunoassays. CONCLUSIONS We describe an improved simple, accurate and fast isotope dilution tandem mass spectrometry method for the simultaneous determination of FT3 and FT4 in human serum/plasma samples.
Collapse
Affiliation(s)
- Jianghong Gu
- Department of Laboratory Medicine, Children's National Medical Center, 111 Michigan Avenue, NW, Washington, DC, USA
| | | | | |
Collapse
|
39
|
Fritz KS, Wilcox RB, Nelson JC. A Direct Free Thyroxine (T4) Immunoassay with the Characteristics of a Total T4 Immunoassay. Clin Chem 2007; 53:911-5. [PMID: 17363415 DOI: 10.1373/clinchem.2006.083915] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Direct free thyroxine (T4) measurements have been linked to both T4-binding serum protein concentrations and protein-bound T4 concentrations. Whether this is evidence of a relationship to total T4 concentrations has not been reported.
Methods: We compared an analog-based direct free T4 immunoassay and a total T4 immunoassay. Each assay was applied to the fractions of serum T4 obtained by ultrafiltration and equilibrium dialysis. Both were applied to serum-based solutions in which free T4, T4-binding proteins, protein-bound T4, and total T4 were systematically varied, held constant, or excluded.
Results: Neither the free T4 assay nor the total T4 assay detected dialyzable or ultrafilterable serum T4. Both assays detected and reported the T4 retained with serum proteins. Both free and total T4 results were related to the same total T4 concentrations in the presence and absence of T4-binding proteins. Both results were similarly related to total T4 concentrations when free T4 was held constant while total T4 was varied. Both were similarly related to a total T4 concentration that was held constant while free T4 progressively replaced protein-bound T4. These free T4 results, like total T4 results, were unresponsive to a 500-fold variation in dialyzable T4 concentrations.
Conclusion: New experiments extend the characterization of a longstanding and incompletely characterized analog-based free T4 immunoassay. These free T4 measurements relate to total T4 concentrations in the same way that total T4 measurements do.
Collapse
Affiliation(s)
- Kristofer S Fritz
- Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | | | | |
Collapse
|
40
|
Kahric-Janicic N, Soldin SJ, Soldin OP, West T, Gu J, Jonklaas J. Tandem mass spectrometry improves the accuracy of free thyroxine measurements during pregnancy. Thyroid 2007; 17:303-11. [PMID: 17465859 PMCID: PMC3641793 DOI: 10.1089/thy.2006.0303] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Pregnancy is a time of rapidly changing demands on the thyroid axis, and knowledge of thyroid hormone levels, especially during the first trimester, is important for ensuring maternal and fetal health. The thyroid hormone assays currently in use become more inaccurate at extremes of binding protein concentrations and when heterophilic antibodies are present. Pregnancy is characterized by both these conditions, making accurate determination of free thyroid hormone levels by conventional direct analog immunoassay methods difficult. The objective of this study was to characterize the performance of a novel tandem mass spectrometric assay for free thyroxine during the physiologic conditions of pregnancy. DESIGN Healthy women without a history of thyroid abnormalities were recruited from the obstetrics and gynecology and endocrinology clinics of a university medical center and their thyroid status was monitored. Free thyroxine levels were assessed by both immunoassay and tandem mass spectrometry during the course of their pregnancy. Serum thyrotropin levels were also measured. The distributions of free thyroid concentrations obtained by the two assays were compared. MAIN OUTCOME The tandem mass spectrometry and immunoassay values did not correlate well with each other. However, tandem mass spectrometry values correlated well with the current gold standard equilibrium dialysis values. Moreover, the good agreement between equilibrium dialysis and tandem mass spectrometry was maintained across all weeks of gestation. CONCLUSIONS We conclude that tandem mass spectrometry has a superior performance to immunoassay for the measurement of free thyroxine during pregnancy. Furthermore, it is ideally suited to generating trimester-specific reference intervals for free thyroxine levels. Future studies will determine if it is a better assay to use in most clinical circumstances.
Collapse
Affiliation(s)
| | - Steven J. Soldin
- Division of Endocrinology, Georgetown University Medical Center, Washington, DC
- Bioanalytic Core Laboratory, General Clinical Research Center, Georgetown University Medical Center, Washington, DC, and Department of Laboratory Medicine, Children’s National Medical Center, Washington, DC
| | - Offie P. Soldin
- Division of Endocrinology, Georgetown University Medical Center, Washington, DC
- Departments of Oncology and Medicine, Georgetown University Medical Center, Washington, DC
| | - Threvia West
- Department of Obstetrics and Gynecology, Georgetown University Medical Center, Washington, DC
| | - Jianghong Gu
- Bioanalytic Core Laboratory, General Clinical Research Center, Georgetown University Medical Center, Washington, DC, and Department of Laboratory Medicine, Children’s National Medical Center, Washington, DC
| | - Jacqueline Jonklaas
- Division of Endocrinology, Georgetown University Medical Center, Washington, DC
| |
Collapse
|
41
|
Clarke W, Schiel JE, Moser A, Hage DS. Analysis of free hormone fractions by an ultrafast immunoextraction/displacement immunoassay: studies using free thyroxine as a model system. Anal Chem 2007; 77:1859-66. [PMID: 15762597 DOI: 10.1021/ac040127x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A system was developed for measuring the noncomplexed or free fraction of a hormone in serum based on the combined use of ultrafast immunoextraction with a chromatographic displacement immunoassay. This approach was tested using L-thyroxine as a model analyte. Items considered in the development of this technique included the choice of immunoassay format and the selection of conditions for removal of thyroxine's free fraction from samples without significant interference from its protein-bound fraction. The final method had an effective extraction time of 90 ms and allowed the amount of free thyroxine to be determined within 30 s after sample injection. The limit of detection was 6 pM (S/N = 3) for a 100-microL sample, and the linear response extended up to at least 100 pM. This technique gave good correlation versus reference methods when used for the determination of free thyroxine in serum samples. Advantages of this method included its speed and its ability to analyze a sample with no pretreatment other than standard filtration. The same approach could be adapted for other hormones or drugs by using appropriate antibodies and labeled analogues for such agents.
Collapse
Affiliation(s)
- William Clarke
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, USA
| | | | | | | |
Collapse
|
42
|
Abstract
Euthyroid women experience dramatic changes in their thyroid physiology in order to accommodate the presence of placental and fetal tissues. These adaptations to the pregnant state make it crucial to develop reliable trimester-specific intervals for thyroid parameters. Use of non-pregnant reference intervals could lead to erroneous assessment of thyroid status in this rapidly changing hormonal environment. Only with a full appreciation of physiologic changes in thyroid parameters during a euthyroid pregnancy, can thyroid dysfunction be appropriately diagnosed and managed. Iodine sufficiency during pregnancy can be achieved with supplementation using a multivitamin. Both hypothyroidism and hyperthyroidism should be diagnosed using the appropriate reference intervals for pregnancy. Hypothyroid women are best treated with a specific brand of levothyroxine. Hypothyroidism should ideally be treated prior to conception. If newly recognized during pregnancy, it should be fully treated as early as possible. Frequent monitoring of thyroid status is essential as many women demonstrate an increased requirement for thyroid hormone during the first trimester. Although mild hyperthyroidism may be well tolerated during pregnancy, overt hyperthyroidism requires treatment. Thionamides are the mainstay of therapy. Following their initiation, close monitoring is required to avoid maternal and fetal hypothyroidism. There are occasional circumstances when other medical therapy or surgical therapy may be employed for hyperthyroidism. Thyroidectomy is generally safe in the second trimester in an appropriately prepared woman. There is limited data about the role and safety of oral contrast agents, iodine, amiodarone, and perchlorate. Radioiodine therapy is contradicted during pregnancy.
Collapse
Affiliation(s)
- Thien-Giang Bach-Huynh
- Division of Endocrinology and Metabolism, Georgetown University, Suite 232, Bldg. D, 4000 Reservoir Road, NW, Washington, DC 20007, USA
| | | |
Collapse
|
43
|
Van Uytfanghe K, Stöckl D, Ross HA, Thienpont LM. Use of Frozen Sera for FT4 Standardization: Investigation by Equilibrium Dialysis Combined with Isotope Dilution-Mass Spectrometry and Immunoassay. Clin Chem 2006; 52:1817-21. [PMID: 16840583 DOI: 10.1373/clinchem.2006.070425] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Serum-free thyroxine (FT4) testing is recommended for diagnosis or monitoring of thyroid dysfunction, particularly in cases of hormone binding abnormalities. However, the poor intermethod agreement among commercial FT4 assays suggests a need for standardization with a hierarchically higher measurement procedure. To that purpose, we applied equilibrium dialysis (ED) in combination with isotope dilution-liquid chromatography/tandem mass spectrometry (ID-LC-tandem MS).
Methods: After ED, we collected dialysate into tubes containing [13C6]-T4 for ID and [13C9]-T4 as carrier, purified the samples by solid-phase extraction, and analyzed them with LC/tandem MS. We evaluated the procedure’s analytical performance and tested its suitability for measurement of hypo-, eu-, and hyperthyroid serum FT4 concentrations. We conducted a pilot method comparison study with 3 commercial assays to investigate whether frozen sera could be used for the purpose of FT4 standardization.
Results: The within-run, between-run, and total CVs (inclusive ED) were 3.7%, 4.2%, and 5.6%, respectively (17.7 pmol/L; n = 20). The mean accuracy, estimated from recovery experiments with dialysate and dialysis buffer supplemented at 8.7, 18.7, and 33.5 pmol/L, and from analysis of certified sera gravimetrically diluted to 9.8, 19.2, and 34.8 pmol/L, was 98.0% to 102.8%. The procedure’s limit of detection and limit of quantification were 0.5 and 1.3 pmol/L, respectively. The method comparison demonstrated the suitability of the selected sera for standardization of FT4 assays and confirmed the lack of assay comparability.
Conclusions: We demonstrated that the described ED-ID-LC/tandem MS procedure and the selected type of sera qualify for standardization of FT4 measurements.
Collapse
Affiliation(s)
- Katleen Van Uytfanghe
- Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | | | | | | |
Collapse
|
44
|
Haviland MG, Sonne JL, Anderson DL, Nelson JC, Sheridan-Matney C, Nichols JG, Carlton EI, Murdoch WGC. Thyroid hormone levels and psychological symptoms in sexually abused adolescent girls. CHILD ABUSE & NEGLECT 2006; 30:589-98. [PMID: 16781773 DOI: 10.1016/j.chiabu.2005.11.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 10/31/2005] [Accepted: 11/06/2005] [Indexed: 05/10/2023]
Abstract
OBJECTIVE To explore the relationships between psychological symptoms and thyroid hormone levels in adolescent girls who had experienced the traumatic stress of sexual abuse. METHOD The study design was cross-sectional/correlational. Subjects (N=22; age range=12-18 years) had their blood drawn, and they completed 2 psychological tests (depression and general distress/posttraumatic stress disorder [PTSD]). A pediatrician completed a sexual abuse questionnaire after reviewing law enforcement and Child Protective Services reports and conducting forensic interviews and medical examinations. RESULTS Girls' average free T4, total T4, free T3, total T3, and TSH levels were within age-specific laboratory reference range limits, as were most individual concentrations. The strongest correlations (p<.05) were between free T3 and PTSD total score (-.50), PTSD-avoidance/numbing (-.49), and general distress (-.48); and between total T3 and depression (-.46), general distress (-.45), and PTSD-arousal (-.44). CONCLUSIONS Our findings support one of the two contemporary models of the relationships between thyroid hormones (i.e., free and total T3) and psychological symptoms (i.e., depression, general distress, and PTSD)--one of "shutting down" (vs. "activation") in the face of trauma.
Collapse
Affiliation(s)
- Mark G Haviland
- Department of Psychiatry, Loma Linda University School of Medicine, 11374 Mountain View Avenue, Loma Linda, CA 92354-3842, USA
| | | | | | | | | | | | | | | |
Collapse
|
45
|
De Groot LJ. Non-thyroidal illness syndrome is a manifestation of hypothalamic-pituitary dysfunction, and in view of current evidence, should be treated with appropriate replacement therapies. Crit Care Clin 2006; 22:57-86, vi. [PMID: 16399020 DOI: 10.1016/j.ccc.2005.10.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This article documents the role of hypothalamic hypothyroidism and decreased T4-->T3 conversion as the cause of low T4 and T3 in non-thyroidal illness syndrome (NTIS). This article also presents the arguments for administration of replacement triiodothyronine (T3) and thyroxine (T4) hormone in patients who have NTIS. It is impossible to be certain at this time that it is beneficial to replace hormone, or whether this could be harmful. Only a prospective study will be adequate to prove this point, and probably this would need to involve hundreds of patients. If effective, thyroid hormone replacement will be one of many beneficial treatments given the patient, rather than a single magic bullet, which would reverse all the metabolic changes going wrong in these severely ill patients.
Collapse
Affiliation(s)
- Leslie J De Groot
- Endocrine Division, Brown University, Box G, Room E-308, 70 Ship Street, Providence, RI 02920, USA.
| |
Collapse
|
46
|
Laurberg P, Andersen S, Bülow Pedersen I, Carlé A. Hypothyroidism in the elderly: pathophysiology, diagnosis and treatment. Drugs Aging 2005; 22:23-38. [PMID: 15663347 DOI: 10.2165/00002512-200522010-00002] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Some degree of hypothyroidism is common in the elderly. It affects 5-20% of women and 3-8% of men. The occurrence varies with genetics with a high prevalence in Caucasians, and the disease is more common in populations with a high iodine intake. The common causes of hypothyroidism are autoimmune destruction of the thyroid gland and previous thyroid surgery or radioiodine therapy. Various types of medication, including amiodarone, cytokines and lithium, often induce hypothyroidism. Symptoms may be atypical and measurement of serum thyroid-stimulating hormone (TSH) levels should be part of biochemical testing for undiagnosed medical conditions in elderly subjects. The finding of an elevated serum TSH level should be confirmed by repeated testing and supplemented with measurements of serum levels of thyroxine (T(4)) and thyroid peroxidase antibodies to verify, quantify and subclassify the abnormality. The recommended and appropriate replacement therapy for hypothyroidism is levothyroxine sodium. The initial replacement dose should be low if heart disease is suspected. Because of the long half-life of levothyroxine sodium small dosage adjustments may be performed by adding or withdrawing a tablet once or twice weekly. Levothyroxine sodium is only partly absorbed after oral ingestion, and food, minerals, drugs and tablet composition influence absorption. Studies performed a few years ago suggested that a combination of levothyroxine sodium and liothyronine may improve clinical results, but recent more comprehensive studies have not supported this hypothesis. Accordingly, liothyronine replacement is not documented to be of benefit. If liothyronine is added to replacement, the liothyronine dose should be kept low, within the physiological range and, preferably be administered twice daily. Thyroid hormone therapy has no beneficial effect above placebo in elderly individuals with normal serum TSH levels and T(4) levels. The major risk of levothyroxine sodium therapy is over-replacement, with anxiety, muscle wasting, osteoporosis and atrial fibrillation as adverse effects. Subclinical hypothyroidism with elevated serum TSH levels but T(4) levels within the laboratory reference range is a mild variant of overt hypothyroidism. Patients with subclinical hypothyroidism should be informed about the disease and offered the possibility of replacement. Only some patients treated for subclinical hypothyroidism will feel better after therapy. In elderly patients on replacement therapy, care should include estimation of serum TSH level once or twice a year, with small dosage adjustments of levothyroxine sodium to keep serum TSH level within the normal range.
Collapse
Affiliation(s)
- Peter Laurberg
- Department of Endocrinology and Medicine, Aalborg Hospital, Aarhus University Hospital, DK-9000 Aalborg, Denmark.
| | | | | | | |
Collapse
|
47
|
Abstract
Clinical laboratories often use analogue-based immunoassays to estimate serum free thyroxine (FT(4)) concentrations. These assays yield FT(4) estimates that correlate closely with thyroxine (T(4)) binding protein concentrations. This correlation implies that either T(4) binding proteins or protein bound T(4) contribute to analogue-based FT(4) values. To study the contributions made by T(4) binding proteins to these FT(4) estimates further, four analogue-based FT(4) assays were applied to: (1) FT(4) solutions without T(4) binding proteins, (2) to T(4) binding protein solutions without T(4), and (3) to total T(4) solutions containing T(4) binding protein, FT(4), and protein-bound T(4). The FT(4) estimates obtained with these solutions ranged from 0.2-8.6 ng/dL, when FT(4) concentrations ranged from less than 0.2-12,000 ng/dL. In the FT(4) solutions, gravimetrically determined FT(4) concentrations were 500-12,000 ng/dL (0.5-12.0 microg/dL) without protein-bound T(4), and the FT(4) estimates obtained were 0.3-6.9 ng/dL. In the total T(4) solutions, dialyzable FT(4) concentrations were less than 0.2-59 ng/dL, retained T(4) concentrations were 499.8-11,441 ng/dL, and the analogue-based FT(4) estimates obtained were 0.2-8.6 ng/dL. Similar FT(4) estimates (0.2-8.6 ng/dL and 0.3-6.9 ng/dL) were obtained with similar concentrations of either protein-bound T(4) or FT(4). Similar test results were associated with similar total T(4) concentrations, not similar FT(4) concentrations. Protein-bound T(4) and T(4) binding protein contributed variably to test results. T(4) quantifications included large analytical losses that are unaccounted for. These assays passed tests of correlation with FT(4) concentrations, but they failed tests of specificity for FT(4) and accuracy in T(4) quantification.
Collapse
Affiliation(s)
- Jerald C Nelson
- Department of Medicine, Loma Linda University School of Medicine, Loma Linda, California, USA.
| | | | | | | |
Collapse
|
48
|
Rabin CW, Hopper AO, Job L, Peverini RL, Clark SJ, Deming DD, Nelson JC, Vyhmeister NR. Incidence of low free T4 values in premature infants as determined by direct equilibrium dialysis. J Perinatol 2004; 24:640-4. [PMID: 15306825 DOI: 10.1038/sj.jp.7211109] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The incidence of transient reductions in serum free T(4) (FT(4)) in premature infants may be overestimated because certain FT(4) analytical methods underestimate FT(4) concentrations. Transient reductions of FT(4) measurements have been reported in the majority of premature newborn infants. Direct equilibrium dialysis (DED) does not underestimate FT(4) concentrations and is the best available technique to measure serum FT(4) in the premature infant. OBJECTIVE To evaluate the incidence of low FT(4) concentrations in premature infants using DED to measure FT(4). DESIGN/METHOD We measured FT(4) by DED in infants with birth weight <1500 g. Infants were excluded if the following conditions were present: congenital anomalies or maternal thyroid disorders. Free T(4) was measured at 14 days of life. Low FT(4) was defined using a statistical definition of FT(4) measurements <10.3 pmol/l (0.8 ng/dl). RESULTS Free T(4) was measured by DED in 114 infants. Low FT(4) levels were seen in nine infants (7.9%). CONCLUSION The incidence of low FT(4) was much lower than previously reported when FT(4) was measured using DED indicating that methodological issues are involved in the variability among estimates of the frequency of transient reduction in FT(4).
Collapse
Affiliation(s)
- Christopher W Rabin
- Department of Pediatrics, Coleman Pavilion Room 11121C, Loma Linda University School of Medicine, 11175 Campus Street, Coleman Pavilion, Suite 11121, Loma Linda, CA 92354, USA
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Sapin R, d'Herbomez M. Free thyroxine measured by equilibrium dialysis and nine immunoassays in sera with various serum thyroxine-binding capacities. Clin Chem 2003; 49:1531-5. [PMID: 12928239 DOI: 10.1373/49.9.1531] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Rémy Sapin
- Laboratoire Universitaire de Biophysique, Unité d'Analyses Endocriniennes, Université Louis Pasteur/Centre National de la Recherche Scientifique Unité Mixte de Recherche 7004, Faculté de Médecine, 67085 Strasbourg Cedex, France.
| | | |
Collapse
|
50
|
d'Herbomez M, Forzy G, Gasser F, Massart C, Beaudonnet A, Sapin R. Clinical evaluation of nine free thyroxine assays: persistent problems in particular populations. Clin Chem Lab Med 2003; 41:942-7. [PMID: 12940522 DOI: 10.1515/cclm.2003.143] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Over the past decade, numerous papers have addressed the various methodological problems encountered with free thyroxine (FT4) assays. We evaluated the clinical performance of nine FT4 assays in five centres, using a panel of 310 sera: 156 from euthyroid controls; 27 from hyperthyroid patients; 34 from untreated hypothyroidism; 22 from patients with renal failure; 30 from women in the last trimester of pregnancy; 23 from patients on thyroid substitutive therapy; and 18 from patients treated with amiodarone. Only three methods showed a Gaussian distribution of FT4 concentrations. Reference ranges were calculated using the 2.5th and 97.5th percentiles. A significant difference was observed between FT4 values in men and women. The areas under the receiver operating characteristic (ROC) curves ranged from 0.996 to 1 for hyperthyroidism and from 0.973 to 1 for hypothyroidism. In sera from patients with renal failure and from pregnant women, method-dependent biases were observed and confirmed with dilution experiments. In conclusion, current FT4 assays show good performance regarding the diagnosis of overt dysthyroidism. Nevertheless, FT4 measurements are still vulnerable to method-dependent artefacts in particular populations such as patients with renal failure and pregnant women.
Collapse
|