Circulating immune complexes in diabetics: the influence of sex, age, duration of disease and type of treatment.

The influence of sex, age, duration of diabetes and type of antidiabetic treatment on soluble immune complexes levels was investigated in the sera of 276 randomly selected diabetics. Immune complexes were detected by the solid phase C1q binding test. The prevalence of immune complexes was significantly higher in insulin treated than in non-insulin treated diabetics. Within the insulin treated group, the prevalence in diabetics of 11-20 yr duration was significantly higher than in the remainder. No difference in immune complexes levels was found between males and females. The age of the patients did not have any correlation with the levels of immune complexes. These findings suggest that some of the immune complexes detected in randomly selected diabetics are related to insulin treatment, reflecting either differences in the type of diabetes or the effects of heterologous insulin.