Decreased synthesis of interleukin-2 (IL-2) in insulin-dependent diabetes mellitus.

Synthesis of interleukin-2 (IL-2) by lymphocytes from 26 insulin-dependent diabetic subjects (IDDM) was compared with that by lymphocytes from 24 nondiabetic control subjects. The control group produced 1.001 +/- 0.071 U/ml (mean +/- SEM). The IDDM group, containing patients diagnosed between 5 days and 10 yr before testing, produced only 0.59 +/- 0.050 U/ml (P less than 0.002). IL-2 synthesis by 6 non-insulin-dependent diabetic subjects (NIDDM) was not decreased (mean +/- SEM, 1.20 +/- 0.04 U/ml). Moreover, decreased levels of IL-2 production was found with lymphocytes of patients in good control, as well as those in poor control. These data suggest that decreased IL-2 synthesis is specific for IDDM, not explainable solely as a consequence of poor metabolic control, and thus, might be involved in the pathogenesis of the disease.