SOLUBLE IMMUNE-COMPLEXES IN SERA OF NEWLY DIAGNOSED INSULIN-DEPENDENT DIABETICS AND IN TREATED DIABETICS

Abstract

Soluble immune complexes were detected by the [human Burkitt''s lymphoma] Raji cell assay in 7 out of 13 newly diagnosed insulin-dependent diabetics, 6 of whom had islet cell antibodies (ICAb) in the serum. None of the others had ICAb. The titers for a wide range of viral antibodies were similar in these 13 diabetics as in age- and sex-matched controls, except for antibodies to Coxsackie B4. Six had titers of Coxsackie B4 antibodies greater than or equal to 1:32, but only 3 of these had evidence of immune complexes in the serum, and these were not correlated with the titers of Coxsackie B4 antibodies. None of these diabetics had antibodies to insulin and none of their age- and sex-matched controls had evidence of immune complexes in the serum. Fifty-three percent of 32 diabetics treated with insulin and 10% of 52 diabetics requiring oral hypoglycemic agents (OHA) or diet had evidence of immune complexes in the serum, compared to 6% of control subjects. High titers of insulin antibodies correlated with evidence for immune complexes. There was a stronger tendency for immune complexes to occur in the presence of moderate titers of insulin antibodies when the age at onset of insulin-dependent diabetes was less than 30 yr. Out of 16 patients treated with heterologous insulin for 13 yr or more, and who also had late diabetic complications, 12 had immune complexes in the serum.