INSULIN ANTIBODY-RESPONSE TO A SHORT-COURSE AT HUMAN INSULIN THERAPY IN WOMEN WITH GESTATIONAL DIABETES

OBJECTIVE - To assess the insulin antibody (IA) response to human insu lin (HI) therapy in women with gestational diabetes. RESEARCH DESIGN A ND METHODS - Us were measured by a competitive radiobinding assay in 5 0 women with gestational diabetes before and during treatment with HI and after delivery. At delivery, 15 maternal-cord blood sample pairs w ere analyzed for IA. As a reference, we searched for IA in 25 new-onse t type I diabetic patients. before and at 3, 6, and 12 months after in sulin therapy RESULTS - Insulin autoantibodies (IAAs) were detected in 1 of 50 women with gestational diabetes and 4 of 16 type I diabetic p atients (P < 0.05). At the end of pregnancy after 9.3 +/- 6.8 weeks on insulin therapy, 22 of 50 (44%) women with gestational diabetes becam e IA(+) and 4 additional women were found to be positive 2 months post partum, After 3 months on insulin, ripe I diabetic patients showed a h igher rate of IA positivity (92%, P < 0.001). IA titers at the end of pregnancy were associated with the cumulative insulin dose (r = 0.29, P < 0.05). Postpartum, IA disappeared slowly in most IA(+) women, but two women still showed IA 2 years after delivery. Titers in cord blood were strongly related to those in maternal blood (r = 0.74, P < 0.01) . The rate of adverse fetal outcome did not differ in IA(-) and IA(+) mothers (27 vs. 40%, NS). CONCLUSIONS - HI is immunogenic, and a short course of HI therapy induces IA in similar to 50% of women with gesta tional diabetes and 92% of type I diabetic patients. In women with ges tational diabetes. insulin dose is slightly associated with IA titers. These Us apparently cross the placenta. Fetal outcome does not differ according to the maternal IA status, and Us disappear gradually after delivery but may remain positive for 2 years after delivery.