Interférences par une IgM monoclonale dans un bilan biochimique : détection et recommandations Interferences by a monoclonal IgM in biochemical analyses: detection and recommendations

We present a case of analytical interference on three parameters (lactate dehydrogenase, uric acid and alkalin phosphatase), caused by a mono- clonal IgM, evidenced in a patient with Waldenstrom disease. Mechanism of interference was probably related to the formation of complexes between para- protein and lithium heparin, which result in precipitation during clinical che- mistry assays, inducing a bias in the results. Management recommendations in case of suspicion of interference in clinical chemistry analysis are detailed. Are discussed for the case report, clinical consequences, possible mechanisms and evolution of interference under treatment, according to the concentration of the monoclonal protein.