Diabetes Care, Vol 20, Issue 7 1172-1175, Copyright © 1997 by American Diabetes Association
Insulin antibody response to a short course of human insulin therapy in women with gestational diabetes
M Balsells, R Corcoy, D Mauricio, J Morales, A Garcia-Patterson, G Carreras, M Puig-Domingo and A de Leiva
Division of Endocrinology, Diabetes and Nutrition, Hospital de Sant Pau, Universitat Autonoma de Barcelona, Spain.
OBJECTIVE: To assess the insulin antibody (IA) response to human insulin
(HI) therapy in women with gestational diabetes. RESEARCH DESIGN AND
METHODS: IAs were measured by a competitive radiobinding assay in 50 women
with gestational diabetes before and during treatment with HI and after
delivery. At delivery, 15 maternal-cord blood sample pairs were analyzed
for IA. As a reference, we searched for IA in 25 new-onset type I diabetic
patients, before and at 3, 6, and 12 months after insulin therapy. RESULTS:
Insulin autoantibodies (IAAs) were detected in 1 of 50 women with
gestational diabetes and 4 of 16 type I diabetic patients (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 became IA+ and 4 additional women
were found to be positive 2 months postpartum. After 3 months on insulin,
type I diabetic patients showed a higher 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 approximately
50% of women with gestational diabetes and 92% of type I diabetic patients.
In women with gestational diabetes, insulin dose is slightly associated
with IA titers. These IAs apparently cross the placenta. Fetal outcome does
not differ according to the maternal IA status, and IAs disappear gradually
after delivery but may remain positive for 2 years after delivery.