The prevalence of islet-cell antibodies and complement-fixing islet-cell antibodies in Japanese diabetics.

The presence of complement-fixing islet-cell antibodies (CF-ICA) and islet-cell antibodies (ICA) was examined in 355 patients with different types of diabetes mellitus in the Japanese population by an indirect immunofluorescence test (IFT). The overall prevalence of ICA, which were stained as a homogenous cytoplasmic fluorescence in islet cells, was 7 per cent (5/67) in insulin-dependent (Type I) diabetics, 4 per cent (6/137) in noninsulin-dependent (Type II) diabetics treated with insulin and 2 per cent (1/58) in Type II diabetics treated with oral hypoglycemic agents. None of 84 Type II diabetics receiving diet alone and 9 diabetics associated with chronic pancreatitis had ICA. CF-ICA, which were stained as a "ring-shaped" fluorescence in a part of the cytoplasma, were demonstrated in 5 out of 12 cases (42%) whose sera possessed ICA. The lower prevalence and remarkably shorter persistence of ICA and CF-ICA in Japanese diabetics than those observed in Caucasian diabetics may be explained by the heterogenous immunological response in different races or possible heterogeneity of Type I diabetics.