Macro vitamin B12: an underestimated threat
| Autor: | Catherine Fillée, Reza Soleimani, Tatiana Roy, Damien Gruson, Julien Favresse |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Adult
Male Clinical Biochemistry Polyethylene glycol 030204 cardiovascular system & hematology Young Adult 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Healthy volunteers PEG ratio medicine Humans Peg precipitation 030212 general & internal medicine Vitamin B12 Chromatography medicine.diagnostic_test business.industry Biochemistry (medical) nutritional and metabolic diseases General Medicine Middle Aged Serum samples Healthy Volunteers Reference intervals Vitamin B 12 chemistry Immunoassay Female business Blood Chemical Analysis |
| Zdroj: | Clinical Chemistry and Laboratory Medicine (CCLM). 58:408-415 |
| ISSN: | 1437-4331 1434-6621 2019-0999 |
| DOI: | 10.1515/cclm-2019-0999 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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