Introduction: The quality of assay methods for HbA1c assessment has importantly improved last decades, however analytical interferences due to variants of hemoglobin remain of matter vigilance. Immunological interferences, although no longer described, may also occur.
Observation: A 84-years-old woman without significant medical history was explored for polyneuropathy. Additional investigation as HbA1c was requested. As no value of HbA1c was obtained when assayed with immunoassay (Roche Tina-quant Hemoglobin A1c Gen.3), the analysis was made with high-performance liquid chromatography (HPLC) (ADAMS A1c). This later method gave 5.8% of HbA1c. Hemoglobin electrophoresis was normal. Antibody interference was considered. After washing blood cells, HbA1c level was 5.6% using the immunoassay. Both rheumatoid factor and heterophilic antibodies could be involved.
Conclusion: Ultimately, one should bear in mind the possibility of antibody interference with HbA1c assessed using an immunological assay. It must be considered in case of unavailable result or when clinical findings and laboratory results show discrepancies. Washing blood cells would be a handy method to discard antibody interference.
18 - 21 May 2019
European Society of Endocrinology