[Effects on M-protein on laboratory data]

We describe two patients with abnormal immunoglobulins: Case 1 was a non-diabetic patient with IgA-kappa type M-protein whose serum fructosamine(FRA) value was markedly elevated; and Case 2 was a patient with pseudo-leukocytosis induced by the interaction of etylenediaminetetraacetic acid(EDTA) and IgG-kappa type M-protein. The M-protein in Case 1 was found to be conjugated to serum albumin by immunoelectrophoresis. By gel filtration, the FRA peak of the patient's serum was shown in the high molecule weight fraction. The glycation of IgA-kappa type M-protein was clearly demonstrated by FRA staining after fractionation by serum protein electrophoresis. Although serum FRA values of other non-diabetic patients with IgA type M-protein were elevated, patients with IgG type M-protein and IgM type M-protein had low or normal serum FRA values. In Case 2, the white blood cell count of the patient's blood anti-coagulated with EDTA was 52,300/microliter as determined using an automated counter, but was within normal limits when counted manually by light microscopy using a hemacytometer. The white precipitates were formed by the interaction of the patient's serum with EDTA. Immunofixation electrophoresis revealed that the precipitates were IgG2-kappa type M-protein.