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Fedosov SN, Nexo E. Macro-B12 and Unexpectedly High Levels of Plasma B12: A Critical Review. Nutrients 2024; 16:648. [PMID: 38474776 DOI: 10.3390/nu16050648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/12/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024] Open
Abstract
A low total plasma vitamin B12 supports a clinical suspicion of B12 deficiency, while the interpretation of an unexpectedly normal/high level is marred by controversies. Here, we critically review current knowledge on B12 in blood plasma, including the presence of the so-called "macro-B12". The latter form is most often defined as the fraction of B12 that can be removed by precipitation with polyethylene glycol (PEG), a nonspecific procedure that also removes protein polymers and antibody-bound analytes. Plasma B12 includes B12 attached to transcobalamin and haptocorrin, and an increased concentration of one or both proteins almost always causes an elevation of B12. The total plasma B12 is measured by automated competitive binding assays, often incorrectly referred to as immunoassays, since the binding protein is intrinsic factor and not an antibody. An unexpectedly high level of B12 may be further explored using immunological measurements of haptocorrin and transcobalamin (optionally combined with e.g., size-exclusion chromatography). Nonspecific methods, such as PEG precipitation, are likely to give misleading results and cannot be recommended. Currently, the need for evaluation of a high B12 of unknown etiology is limited since other tests (such as measurements of methylmalonic acid) may better guide the diagnosis of B12 deficiency.
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Affiliation(s)
- Sergey N Fedosov
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark
- Department of Clinical Medicine/Biochemistry, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Ebba Nexo
- Department of Clinical Medicine/Biochemistry, Aarhus University Hospital, 8200 Aarhus N, Denmark
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2
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Lorde N, Parkes J, Sensi H, Valentine R, Baker M, Ford C, Kalaria T, Gama R. High serum total vitamin B12 may mask biologically active B12 deficiency. Ann Clin Biochem 2024:45632241236091. [PMID: 38407076 DOI: 10.1177/00045632241236091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Affiliation(s)
- Nathan Lorde
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Jayne Parkes
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Harminder Sensi
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Ross Valentine
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Morven Baker
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Clare Ford
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Tejas Kalaria
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Rousseau Gama
- Blood Sciences, Black Country Pathology Services, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
- School of Medicine and Clinical Practice, University of Wolverhampton, Wolverhampton, UK
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3
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Guillerme J, Feugray G, Girot H, Brunel V, Muraine MQ. Preliminary evaluation of the diagnostic performance of Roche Elecsys® active vitamin B12 versus total vitamin B12 for vitamin B12 deficiency screening. Ann Clin Biochem 2024; 61:55-62. [PMID: 37503639 DOI: 10.1177/00045632231194157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
INTRODUCTION The prevalence of vitamin B12 deficiency is high in at-risk populations with sometimes irreversible consequences. Beside total B12 (TVB12), active B12 (AVB12) is a promising first-line marker. Only Abbott AVB12 assays were largely evaluated and generally demonstrated benefit in clinical practice. More recently developed Roche AVB12 still requires some investigations. OBJECTIVES Our study aimed to evaluate the Roche Elecsys® AVB12 immunoassay performance versus Roche Elecsys® TVB12 competition assay. DESIGN and Methods: We included 175 patients at Rouen University Hospital who had a TVB12 value <300 pmol/L. We evaluated performance of AVB12 by comparing the results with TVB12 and MMA values in case of disagreement. RESULTS Positive correlation was found between the AVB12 and TVB12. We found a disagreement between TVB12 and AVB12 in 18.8% of cases. Among 33 cases of disagreement, 76% had normal AVB12 but low TVB12, whereas 24% had low AVB12 and normal TVB12. Thirty-one MMA determinations were performed: 71% showed agreement between MMA and AVB12, versus 29% between MMA and TVB12. TVB12 reported a sensitivity (Se) at 66.7%, specificity (Sp) at 20%, positive predictive value (PPV) at 16.7% and negative predictive value (NPV) at 71.4% for the prediction of MMA elevation. We determined an optimized cut-off value of 45.5 pmol/L for AVB12, which reported a Se 66.7%, Sp 60%, PPV 30.7%, and NPV 88.9%. CONCLUSIONS Our results provide preliminary evidence that Roche AVB12 may offer better discrimination than Roche TVB12 in the diagnosis of vitamin B12 deficiency. Further more detailed evaluation is warranted.
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Affiliation(s)
- Jennifer Guillerme
- Department of General Biochemistry, Rouen University Hospital, Rouen, France
| | - Guillaume Feugray
- Department of General Biochemistry, Normandie Univ, UNIROUEN, INSERM U1096 EnVI, F-76000 Rouen, France
| | - Hélène Girot
- Department of General Biochemistry, Rouen University Hospital, Rouen, France
| | - Valéry Brunel
- Department of General Biochemistry, Rouen University Hospital, Rouen, France
| | - Muriel Quillard Muraine
- Department of General Biochemistry, Rouen University Hospital, F-76000 Rouen, CIC-CRB, INSERM U1404, F-76000 Rouen and Normandie UNIV, UNIROUEN, INSERMU1073 ADEN
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4
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Kocaoglu C, Akturk S. Just a vitamin? Should cobalamin (Vitamin B12) levels be checked in children with neurological disadvantages? North Clin Istanb 2023; 10:790-796. [PMID: 38328734 PMCID: PMC10846572 DOI: 10.14744/nci.2022.33279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/20/2022] [Accepted: 12/13/2022] [Indexed: 02/16/2023] Open
Abstract
OBJECTIVE The assay of serum cobalamin (Cbl) level is commonly used to diagnose Cbl deficiency. Unexpectedly, the elevated Cbl levels may be determined in some of the patients and its interpretation is difficult. We investigated the association between elevated Cbl levels and a variety of clinical entities in patients presenting with various neurological symptoms. METHODS The data were obtained from the patients' electronic medical records in a tertiary hospital affiliated with a university. The pediatric patients with serum Cbl levels above 1000 pg/mL were included in the study. The patients with serum Cbl levels below 900 pg/mL and above 200 pg/mL constituted the control group. RESULTS The mean Cbl level of the patients with neurological problems was 1424.2±354.2 pg/mL, whereas the average Cbl level of neurologically healthy was 1316±317.8 pg/mL, and the difference was statistically significant. While the rate of having neurological deficits or symptoms in the study group was found to be 24%, this rate was only 18% in the control group. Unexpectedly, despite elevated Cbl level, the high mean corpuscular volume rate was higher in the study group compared to the control group. CONCLUSION This study highlights the importance of the disorders of Cbl metabolism in patients presenting with various neurological symptoms. In children with neurological deficits, serum Cbl levels should be checked. In case of high Cbl level is determined, patients should be followed up closely, and further investigations should be performed in terms of Cbl metabolism disorders.
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Affiliation(s)
- Celebi Kocaoglu
- Department of Pediatric Intensive Care, University of Health Sciences, Konya City Hospital, Konya, Turkiye
| | - Seyma Akturk
- Department of Pediatrics, University of Health Sciences, Konya City Hospital, Konya, Turkiye
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5
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Delgado JA, Pastor García MI, Jiménez NM, Petit GC, Pablo Cànaves JA, Robles J, Bauça JM. Challenges in the diagnosis of hypervitaminemia B12. Interference by immunocomplexes. Clin Chim Acta 2023; 541:117267. [PMID: 36805891 DOI: 10.1016/j.cca.2023.117267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 02/21/2023]
Abstract
BACKGROUND-AIM High vitamin B12 concentrations are considered a common finding in clinical practice. Thanks to immunoassay accessibility, vitamin B12 has become a usual test in routine health checkups. However, these analytical methods usually present antibody-mediated interferences. Our aim was to propose an algorithm for the screening of antibody-mediated analytical interferences on vitamin B12 immunoassays on the Alinity platform. METHODS Observational, prospective, case-control study was performed during 12 months. Individuals with persistently elevated cobalamin concentrations [>554 pmol/L] were considered as cases in the absence of supplementation or other justifying cause. Individuals under treatment with vitamin B12, or in the context of alcoholism were included as controls. A thorough interference study by macromolecules in immunoassays was performed in serum samples: PEG precipitation, rheumatoid factor, heterophile antibodies and gel permeation chromatography (GPC). Albumin, total B12, IgG and IgM were measured in every GPC collected fraction and chromatograms were drafted. RESULTS Up to 45% of cases presented interference by B12-immunocomplexes and the precipitation for all of them was >50%. The individual with the lowest interfered vitamin B12 result was 661 pmol/L. CONCLUSION The presence of antibody-mediated interferences, mainly B12-immunocomplexes, is a relatively common phenomenon. A simple algorithm for the screening of interferences is useful and reliable in ruling out healthy individuals and highly cost-effective.
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Affiliation(s)
- Jose Antonio Delgado
- Department of Laboratory Medicine, Hospital Universitari Son Espases, Palma, Spain.
| | | | | | - Gemma Costa Petit
- Department of Laboratory Medicine, Hospital Universitari Son Espases, Palma, Spain
| | | | - Juan Robles
- Department of Laboratory Medicine, Hospital Universitari Son Espases, Palma, Spain
| | - Josep Miquel Bauça
- Department of Laboratory Medicine, Hospital Universitari Son Espases, Palma, Spain; Institut d́Investigació Sanitària de les Illes Balears (IdISBa), Spain
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6
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Duim SN, Vlasveld LT, Mezger STP, Mingels AMA, Ramakers CRB, de Boer D, Heil SG, Nexo E, van Rossum AP. "Macro transcobalamin causing raised vitamin B12: Case-based laboratory investigation". Ann Clin Biochem 2022; 59:302-307. [PMID: 35352974 DOI: 10.1177/00045632221087132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Determination of plasma vitamin B12 (B12) is a frequently requested laboratory analysis, mainly employed to establish B12 deficiency. However, an increased level of B12 is a common unexpected finding that may be related to an increased concentration of one of the B12 binding proteins, haptocorrin or transcobalamin. This paper describes the extensive laboratory evaluation of a patient with an elevated level of plasma B12 with various well-established assays. Initial studies suggested the presence of a macromolecule consisting of haptocorrin bound B12. Specific determinations of the B12-binding proteins revealed normal amounts of haptocorrin but a markedly increase in both total and B12 saturated transcobalamin (holo-TC). The results are in accord with the presence of macro-transcobalamin. These experiments reveal that determination of the nature of the B12-macromolecules is troublesome due to differences in assays applied to measure these proteins. In addition, this publication creates awareness of macro-holo-TC as a cause of an unexplained increased B12 level.
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Affiliation(s)
- Sjoerd N Duim
- Department of Clinical Chemistry and Haematology, Haaglanden Medisch Centrum, Den Haag, the Netherlands
| | - L Tom Vlasveld
- Department of Internal Medicine, Haaglanden Medisch Centrum, Den Haag, the Netherlands
| | - Stephanie T P Mezger
- Department of Clinical Chemistry, Central Diagnostic Laboratory, 199236Maastricht University Medical Center, Maastricht, the Netherlands
| | - Alma M A Mingels
- Department of Clinical Chemistry, Central Diagnostic Laboratory, 199236Maastricht University Medical Center, Maastricht, the Netherlands
| | - Christian R B Ramakers
- Department of Clinical Chemistry, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Douwe de Boer
- Department of Clinical Chemistry, Central Diagnostic Laboratory, 199236Maastricht University Medical Center, Maastricht, the Netherlands
| | - Sandra G Heil
- Department of Clinical Chemistry, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Ebba Nexo
- Department of Clinical Biochemistry, 11297Aarhus University Hospital, Aarhus, Denmark
| | - André P van Rossum
- Department of Clinical Chemistry and Haematology, 3573Groene Hart Ziekenhuis, Gouda, the Netherlands
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7
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Wolffenbuttel BHR, Muller Kobold AC, Sobczyńska-Malefora A, Harrington DJ. Macro-B12 masking B12 deficiency. BMJ Case Rep 2022; 15:15/1/e247660. [PMID: 35027389 PMCID: PMC8762123 DOI: 10.1136/bcr-2021-247660] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In clinical practice, the finding of an elevated serum B12 concentration is often the consequence of supplementation with B12 in either oral form or injections. Also, elevated serum B12 may be associated with underlying disorders, like liver diseases or a (haematologic) malignancy. Only a few studies have shown that it may also be the consequence of complex formation of B12-vitamin binding proteins with immunoglobulins, the so-called macro-B12. We describe a young woman who previously was diagnosed with B12 deficiency, and in whom, after cessation of B12 injection treatment, neurologic symptoms re-appeared, and despite this, repeatedly elevated serum B12 concentrations above the upper limit of the assay were found. We demonstrated that this was caused by the presence of macro-B12, which not only resulted in erroneous and longstanding elevated serum B12, but also masked her underlying B12 deficiency.
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Affiliation(s)
- Bruce H R Wolffenbuttel
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Anneke C Muller Kobold
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Agata Sobczyńska-Malefora
- Faculty of Life Sciences and Medicine, King's College London, London, UK
- Nutristasis Unit, Viapath, St Thomas' Hospital, London, UK
| | - Dominic J Harrington
- Faculty of Life Sciences and Medicine, King's College London, London, UK
- Nutristasis Unit, Viapath, St Thomas' Hospital, London, UK
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8
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Soleimani R, Favresse J, Roy T, Gruson D, Fillée C. Macro vitamin B12: an underestimated threat. Clin Chem Lab Med 2021; 58:408-415. [PMID: 31665115 DOI: 10.1515/cclm-2019-0999] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 10/06/2019] [Indexed: 12/25/2022]
Abstract
Background The correct identification of the macro-B12 interference (macroforms) is paramount to avoid potential erroneous clinical decisions. Our objectives were to determine whether immunoassays are affected by the presence of macro-B12 and to validate a polyethylene glycol (PEG) precipitation procedure to detect it. Methods Sixty-two serum samples obtained from healthy volunteers were analyzed to determine recovery and reference intervals (RIs) following PEG precipitation. Thereafter, 50 serum samples with very high levels of B12 (>1476 pmol/L) were randomly selected to search for macro-B12 interferences. Serum samples obtained from healthy volunteers and related PEG aliquots were analyzed on a Cobas® immunoassay. Patients' samples were analyzed on both Cobas® and Architect® immunoassays. Finally, samples suspected to contain macro-B12 were analyzed by size-exclusion chromatography (SEC) to confirm the presence of macro-B12. Results Recovery and post-PEG RIs determined on a Cobas 8000® in healthy volunteers ranged from 68.3% to 108.4% and from 122.1 to 514.4 pmol/L, respectively. Fifteen samples (30%) were found to show macro-B12 while using the recovery criteria, and nine samples (18%) while using the post-PEG RI. The other immunoassay ran on the Architect i2000® was also affected by the presence of macro-B12. Size-exclusion chromatography studies confirmed the presence of macro-B12 (immunoglobulin-B12 complexes). Conclusions The prevalence of macro-B12 in elevated B12 samples is high. We suggest to systematically screen for the presence of macro-B12 with PEG precipitation procedure in samples with elevated B12 levels to avoid potential misdiagnosis or harmful clinical consequences.
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Affiliation(s)
- Reza Soleimani
- Department of Laboratory Medicine, Cliniques Universitaires St-Luc and Université catholique de Louvain, Brussels, Belgium
| | - Julien Favresse
- Department of Laboratory Medicine, Cliniques Universitaires St-Luc and Université catholique de Louvain, Brussels, Belgium
| | - Tatiana Roy
- Department of Laboratory Medicine, Cliniques Saint-Pierre, Ottignies, Belgium
| | - Damien Gruson
- Department of Laboratory Medicine, Cliniques Universitaires St-Luc and Université catholique de Louvain, Brussels, Belgium.,Research Pole of Endocrinology, Diabetes and Nutrition, Institute of Experimental and Clinical Research, Cliniques Universitaires St-Luc and Université catholique de Louvain, Brussels, Belgium.,Clinical Chemistry Service, Cliniques Universitaires Saint Luc, Rosalind Franklin Building, 49 Avenue Mounier, 1200 Brussels, Belgium
| | - Catherine Fillée
- Department of Laboratory Medicine, Cliniques Universitaires St-Luc and Université catholique de Louvain, Brussels, Belgium
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9
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Lecerf M, Kanyavuz A, Rossini S, Dimitrov JD. Interaction of clinical-stage antibodies with heme predicts their physiochemical and binding qualities. Commun Biol 2021; 4:391. [PMID: 33758329 PMCID: PMC7988133 DOI: 10.1038/s42003-021-01931-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/23/2021] [Indexed: 11/09/2022] Open
Abstract
Immunoglobulin repertoires contain a fraction of antibodies that recognize low molecular weight compounds, including some enzymes' cofactors, such as heme. Here, by using a set of 113 samples with variable region sequences matching clinical-stage antibodies, we demonstrated that a considerable number of these antibodies interact with heme. Antibodies that interact with heme possess specific sequence traits of their antigen-binding regions. Moreover they manifest particular physicochemical and functional qualities i.e. increased hydrophobicity, higher propensity of self-binding, higher intrinsic polyreactivity and reduced expression yields. Thus, interaction with heme is a strong predictor of different molecular and functional qualities of antibodies. Notably, these qualities are of high importance for therapeutic antibodies, as their presence was associated with failure of drug candidates to reach clinic. Our study reveled an important facet of information about relationship sequence-function in antibodies. It also offers a convenient tool for detection of liabilities of therapeutic antibodies.
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Affiliation(s)
- Maxime Lecerf
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006, Paris, France
| | - Alexia Kanyavuz
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006, Paris, France
| | - Sofia Rossini
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006, Paris, France
| | - Jordan D Dimitrov
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006, Paris, France.
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10
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Kather S, Sielski L, Dengler F, Jirasek A, Heilmann RM. Prevalence and clinical relevance of hypercobalaminaemia in dogs and cats. Vet J 2020; 265:105547. [PMID: 33129556 DOI: 10.1016/j.tvjl.2020.105547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 08/26/2020] [Accepted: 09/14/2020] [Indexed: 11/28/2022]
Abstract
Hypocobalaminaemia is common in dogs and cats with exocrine pancreatic insufficiency and/or chronic enteropathy. While hypocobalaminaemia has been extensively studied, naturally-occurring serum hypercobalaminaemia (i.e. without supplementation) might be an underestimated finding in small animal medicine. Studies in human medicine have associated hypercobalaminaemia with neoplastic, hepatic and renal disease. Medical records of all dogs and cats with serum cobalamin concentration measurements (2007-2019) were retrospectively analysed; any that had received supplemental cobalamin were excluded from the analysis. Of 654 dogs, 3% (n = 21) were hypercobalaminaemic (median serum cobalamin concentration, 1307 ng/L [965 pmol/L]; range, 914-3561 ng/L [675-2628 pmol/L]). Chronic gastrointestinal signs were common in hypercobalaminaemic dogs (48%). Two of the 21 hypercobalaminaemic dogs were diagnosed with hypoadrenocorticism. Of 323 cats, 11% (n = 34) were hypercobalaminaemic (median serum cobalamin concentration, 1713 ng/L [1264 pmol/L]; range, 1370-3107 ng/L [1011-2293 pmol/L]). The following comorbidities were diagnosed in hypercobalaminaemic cats: chronic enteropathy, 65% (n = 22); acute or chronic pancreatitis, 24% (n = 8); cholangiohepatopathy, 18% (n = 6); gastric lymphoma, 6% (n = 2); and 3% hyperthyroidism (n = 1). Naturally-occurring increased serum cobalamin concentrations occurred infrequently in cats and even less often in dogs. Since hypercobalaminaemia can occur in dogs and cats with severe inflammatory, immune-mediated, and neoplastic conditions, it should not be ignored.
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Affiliation(s)
- Stefanie Kather
- Department for Small Animals, Veterinary Teaching Hospital, College of Veterinary Medicine, University of Leipzig, An den Tierkliniken 23, DE-04103 Leipzig, SN, Germany; Institute of Veterinary Physiology, University of Leipzig, An den Tierkliniken 7, DE-04103 Leipzig, SN, Germany.
| | - Lea Sielski
- Department for Small Animals, Veterinary Teaching Hospital, College of Veterinary Medicine, University of Leipzig, An den Tierkliniken 23, DE-04103 Leipzig, SN, Germany; Institute of Veterinary Physiology, University of Leipzig, An den Tierkliniken 7, DE-04103 Leipzig, SN, Germany
| | - Franziska Dengler
- Institute of Veterinary Physiology, University of Leipzig, An den Tierkliniken 7, DE-04103 Leipzig, SN, Germany
| | - Anika Jirasek
- IDEXX Laboratories, Mörikestrasse 28, Ludwigsburg, DE-71636, BW, Germany
| | - Romy M Heilmann
- Department for Small Animals, Veterinary Teaching Hospital, College of Veterinary Medicine, University of Leipzig, An den Tierkliniken 23, DE-04103 Leipzig, SN, Germany
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11
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Vollbracht C, McGregor GP, Kraft K. Supraphysiological vitamin B12 serum concentrations without supplementation: the pitfalls of interpretation. QJM 2020; 113:619-620. [PMID: 31251363 PMCID: PMC7550708 DOI: 10.1093/qjmed/hcz164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- C Vollbracht
- University Medicine Rostock, Rostock
- Address correspondence to C. Vollbracht, University Medicine Rostock, Rostock, Germany.
| | | | - K Kraft
- University Medicine Rostock, Rostock
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12
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Stenberg R, Böttiger A, Nilsson TK. High levels of vitamin B12 are fairly common in children with cerebral palsy. Acta Paediatr 2020; 109:1493-1494. [PMID: 32056285 DOI: 10.1111/apa.15195] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Reidun Stenberg
- School of Health and Medical Sciences University Health Care Research Center Örebro University Örebro Sweden
| | - Anna Böttiger
- Department of Laboratory Medicine Faculty of Medicine and Health Örebro University Orebro Sweden
| | - Torbjörn K. Nilsson
- Department of Medical Biosciences/Clinical Chemistry Umeå University Umea Sweden
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13
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Vollbracht C, Gündling PW, Kraft K, Friesecke I. Blood concentrations of vitamins B1, B6, B12, C and D and folate in palliative care patients: Results of a cross-sectional study. J Int Med Res 2019; 47:6192-6205. [PMID: 31547720 PMCID: PMC7045681 DOI: 10.1177/0300060519875370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Objective The main purpose of palliative care is symptom relief. Frequently, the symptoms of patients requiring palliative care are the same as common symptoms of vitamin deficiency (e.g. pain, weakness, fatigue, depression). The study aim was to investigate whether patients in palliative care are vitamin deficient. Method This was a monocentre cross-sectional study. Patients attending the palliative care unit of a general hospital in Germany from October 2015 to April 2016 were examined for vitamin blood concentrations and symptoms. Data were analysed using univariate analysis and bivariate correlations. Results Data were available from 31 patients. Vitamin D3 deficiency (<62.5 nmol/L) affected 93.5% of patients, vitamin B6 deficiency (<4.1 ng/mL) 48.4%, vitamin C deficiency (<4.5 mg/L) 45.2%, vitamin B1 deficiency (<35 µg/L) 25.8% and vitamin B12 deficiency (<193 pg/mL) 12.9%. There was a significant negative correlation between vitamin B1 ranges and pain (r = −0.384) and depression (r = −0.439) symptoms. Conclusion All patients showed a deficiency in at least one of the measured vitamins; 68% had concurrent deficiencies in >1 vitamin. A follow-up study using validated questionnaires and a larger sample is needed to investigate the effects of targeted vitamin supplementation on quality of life and symptom burden.
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Affiliation(s)
- Claudia Vollbracht
- Hochschule Fresenius, University of Applied Sciences, Idstein, Germany.,Chair of Naturopathy, University Medicine Rostock, Rostock, Germany
| | - Peter W Gündling
- Hochschule Fresenius, University of Applied Sciences, Idstein, Germany
| | - Karin Kraft
- Chair of Naturopathy, University Medicine Rostock, Rostock, Germany
| | - Iris Friesecke
- Hochschule Fresenius, University of Applied Sciences, Idstein, Germany.,Warnow-Klinik Bützow, Bützow, Germany
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14
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Osborne D, Sobczyńska-Malefora A. Autoimmune mechanisms in pernicious anaemia & thyroid disease. Autoimmun Rev 2015; 14:763-8. [PMID: 25936607 DOI: 10.1016/j.autrev.2015.04.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 04/23/2015] [Indexed: 12/15/2022]
Abstract
Pernicious anaemia (PA) and some types of thyroid disease result from autoimmune processes. The autoimmune mechanisms in these conditions have not been fully elucidated. This review discusses the autoimmune mechanisms involved in PA and how these affect diagnosis and disease progression. In addition to gastric antibodies, antibodies to the vitamin B12 binding protein transcobalamin which can result in high serum B12 levels are also addressed with regard to how they affect clinical practice. The role of autoimmune susceptibility is investigated by comparing PA to one of its most common comorbidities, autoimmune thyroid disease (AITD). Thyroid disease (although not exclusively AITD) and B12 deficiency are both also implicated in the pathology of hyperhomocysteinemia, an elevated homocysteine in plasma. Since hyperhomocysteinemia is a risk factor for cardiovascular occlusive disease, this review also addresses how thyroid disease in particular leads to changes in homocysteine levels.
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Diagnosis of Vitamin B12 Deficiency in Patients With Myeloproliferative Disorders. J Investig Med 2015; 63:636-40. [DOI: 10.1097/jim.0000000000000187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Trehy MR, German AJ, Silvestrini P, Serrano G, Batchelor DJ. Hypercobalaminaemia is associated with hepatic and neoplastic disease in cats: a cross sectional study. BMC Vet Res 2014; 10:175. [PMID: 25103858 PMCID: PMC4236818 DOI: 10.1186/s12917-014-0175-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 07/22/2014] [Indexed: 11/24/2022] Open
Abstract
Background When increased serum cobalamin concentrations are encountered clinically they are usually attributed to parenteral supplementation, dietary factors, or otherwise ignored. However, recently, hypercobalaminaemia has been associated with numerous diseases in humans, most notably neoplastic and hepatic disorders. The aim of this retrospective, observational, cross-sectional study was to determine the significance of increased cobalamin in cats. Results In total, 237 records were retrieved and 174 cats, of various ages and sexes met the inclusion criteria. A total of 42 cats had increased serum cobalamin concentration, and had not received prior supplementation. Multiple logistic regression analysis revealed that increased serum cobalamin concentration was positively related to pedigree breed (pedigree breeds more likely to have increased cobalamin concentration, odds ratio [OR] 4.24, 95% CI 1.78-10.15, P = 0.001), to having liver disease (OR 9.91, 95% CI 3.54-27.68), and to having a solid neoplasm (OR 8.54, 95% CI 1.10-66.45). Conclusions The results of the current study suggest that increased serum cobalamin concentrations should not be ignored in cats with no history of supplementation, and investigation for underlying hepatic or neoplastic disease is warranted.
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Affiliation(s)
| | - Alexander J German
- School of Veterinary Science, University of Liverpool, Leahurst Campus, Chester High Road, Neston CH64 7TE, UK.
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Prentice KM, Gillespie R, Lewis N, Fujimori K, McCoy R, Bach J, Connell-Crowley L, Eakin CM. Hydroxocobalamin association during cell culture results in pink therapeutic proteins. MAbs 2013; 5:974-81. [PMID: 23924851 DOI: 10.4161/mabs.25921] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Process control of protein therapeutic manufacturing is central to ensuring the product is both safe and efficacious for patients. In this work, we investigate the cause of pink color variability in development lots of monoclonal antibody (mAb) and Fc-fusion proteins. Results show pink-colored product generated during manufacturing is due to association of hydroxocobalamin (OH-Cbl), a form of vitamin B12. OH-Cbl is not part of the product manufacturing process; however we found cyanocobalamin (CN-Cbl) in cell culture media converts to OH-Cbl in the presence of light. OH-Cbl can be released from mAb and Fc-fusion proteins by conversion with potassium cyanide to CN-Cbl, which does not bind. By exploiting the differential binding of CN-Cbl and OH-Cbl, we developed a rapid and specific assay to accurately measure B12 levels in purified protein. Analysis of multiple products and lots using this technique gives insight into color variability during manufacturing.
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Affiliation(s)
| | - Ronald Gillespie
- Department of Purification Process Development; Amgen Inc; Seattle, WA USA
| | - Nathan Lewis
- Department of Analytical Sciences; Amgen Inc; Seattle, WA USA
| | - Kiyoshi Fujimori
- Department of Drug Product Development; Amgen Inc; Thousand Oaks, CA USA
| | - Rebecca McCoy
- Department of Cell Sciences and Technology; Amgen Inc; Seattle, WA USA
| | - Julia Bach
- Department of Purification Process Development; Amgen Inc; Seattle, WA USA
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Mills F, Jeffery J, Mackenzie P, Cranfield A, Ayling RM. An immunoglobulin G complexed form of thyroid-stimulating hormone (macro thyroid-stimulating hormone) is a cause of elevated serum thyroid-stimulating hormone concentration. Ann Clin Biochem 2013; 50:416-20. [DOI: 10.1177/0004563213476271] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Macrocomplexes can be the cause of elevated serum hormone concentrations and may cause diagnostic confusion. This is well recognized for prolactin and commonly screened for using polyethylene glycol (PEG) precipitation. The phenomenon and a suitable screening method is less familiar with respect to thyroid-stimulating hormone (TSH). Method Samples sent to the laboratory for routine analysis of thyroid function and found to have a TSH >10 mU/L were evaluated to determine the prevalence of macro-TSH in the Roche Elecsys assay, using PEG precipitation with confirmation by gel filtration chromatography. Results Of 495 samples tested, 3 (0.6%) were found to have macro-TSH. From the distribution of recoveries, a cut-off <25% was determined for identifying samples requiring further investigation for the presence of macro-TSH. Conclusion The prevalence of elevated TSH due to macro-TSH was found to be 0.6%. Laboratories should be aware of this cause of assay interference.
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Affiliation(s)
- Francesca Mills
- Department of Clinical Biochemistry, Derriford Hospital, Plymouth, UK
| | - Jinny Jeffery
- Department of Clinical Biochemistry, Derriford Hospital, Plymouth, UK
| | - Paul Mackenzie
- Department of Clinical Biochemistry, Southend University Hospital, Southend, UK
| | - Alex Cranfield
- Department of Clinical Biochemistry, Southend University Hospital, Southend, UK
| | - Ruth M Ayling
- Department of Clinical Biochemistry, Derriford Hospital, Plymouth, UK
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Ryg J, Nybo M, Hallas J. Cancer incidence in persons with elevated cobalamin levels. Eur J Clin Invest 2013; 43:557-61. [PMID: 23550564 DOI: 10.1111/eci.12076] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/28/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Elevated cobalamin level (ECL) is an epiphenomenon for several cancer types. The clinical significance of ECL at routine testing is, however, unknown. The aim of this study was to examine cancer incidences among persons with ECL. DESIGN In a cohort study, Funen County residents (inhabitants 476,580), Denmark, without cancer or injected cobalamin prescriptions were followed from first cobalamin measurement during 1999-2009. Follow-up was stratified according to age, gender, and whether the cobalamin level was elevated (> 1,200 pmol/L). Data from national registers on age-specific incidence of cancer in the general population were used to calculate standardised morbidity ratio (SMR). RESULTS A total of 490 persons with ECL and 40,104 with non-ECL were followed. Median age was 61 [IQR 44-77] years. Average follow-up was 2.0 years for ECL subjects and 2.7 years for non-ECL subjects. Cancer was diagnosed within the first 6 months of follow-up in 6.7% (CI 4.7-9.3) of ECL subjects and 2.6% (CI 2.4-2.7) of non-ECL subjects. In ECL and non-ECL subjects, SMR for cancer diagnoses were 15.1 (CI 10.4-21.2) and 5.0 (CI 4.7-5.3) within the first 6 months and 3.7 (CI 1.4-8.1) and 1.8 (CI 1.6-2.0) in the following six-month interval. Review of medical records revealed a suspicion of cancer or performance of relevant diagnostic tests in 87% at the time of cobalamin measurement. CONCLUSIONS Persons with ECL have a high incidence of cancer partly explained by the reasons for measuring cobalamin. It remains to be determined whether accidentally found ECL would justify a search for cancers.
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Affiliation(s)
- Jesper Ryg
- Department of Geriatric Medicine, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
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Sturgeon CM, Viljoen A. Analytical error and interference in immunoassay: minimizing risk. Ann Clin Biochem 2011; 48:418-32. [DOI: 10.1258/acb.2011.011073] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Carmel R. Biomarkers of cobalamin (vitamin B-12) status in the epidemiologic setting: a critical overview of context, applications, and performance characteristics of cobalamin, methylmalonic acid, and holotranscobalamin II. Am J Clin Nutr 2011; 94:348S-358S. [PMID: 21593511 PMCID: PMC3174853 DOI: 10.3945/ajcn.111.013441] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cobalamin deficiency is relatively common, but the great majority of cases in epidemiologic surveys have subclinical cobalamin deficiency (SCCD), not classical clinical deficiency. Because SCCD has no known clinical expression, its diagnosis depends solely on biochemical biomarkers, whose optimal application becomes crucial yet remains unsettled. This review critically examines the current diagnostic concepts, tools, and interpretations. Their exploration begins with understanding that SCCD differs from clinical deficiency not just in degree of deficiency but in fundamental pathophysiology, causes, likelihood and rate of progression, and known health risks (the causation of which by SCCD awaits proof by randomized clinical trials). Conclusions from SCCD data, therefore, often may not apply to clinical deficiency and vice versa. Although many investigators view cobalamin testing as unreliable, cobalamin, like all diagnostic biomarkers, performs satisfactorily in clinical deficiency but less well in SCCD. The lack of a diagnostic gold standard limits the ability to weigh the performance characteristics of metabolic biomarkers such as methylmalonic acid (MMA) and holotranscobalamin II, whose specificities remain incompletely defined outside their relations to each other. Variable cutoff selections affect diagnostic conclusions heavily and need to be much better rationalized. The maximization of reliability and specificity of diagnosis is far more important today than the identification of ever-earlier stages of SCCD. The limitations of all current biomarkers make the combination of ≥2 test result abnormalities, such as cobalamin and MMA, the most reliable approach to diagnosing deficiency in the research setting; reliance on one test alone courts frequent misdiagnosis. Much work remains to be done.
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Affiliation(s)
- Ralph Carmel
- Department of Medicine, New York Methodist Hospital, Brooklyn, NY 11215, USA.
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