AN IMMUNOLOGICAL AND GENETIC-STUDY OF PATIENTS WITH GESTATIONAL DIABETES-MELLITUS

The aim of the study was to evaluate the frequency of islet cell (ICA) and insulin (IAA) antibodies and of HLA antigen typing in a group of subjects diagnosed with gestational diabetes mellitus (GDM) in a scree ning-diagnostic program during pregnancy. ICA, complement-fixing (CF) ICA and other autoantibodies, absolute number and percentage of lympho cyte subpopulations, and HLA antigens were evaluated in 68 women with GDM and compared with those of matched controls. ICA were found in 2 ( 2.9%) and IAA in 1 (1.5%). Both ICA-positive women had CF-ICA; one of them was receiving insulin therapy, while the other was on a special d iet. No correlations were found between ICA and IAA, nor between IAA a nd insulin treatment. As far as lymphocyte subsets were concerned, we found a significant increase in the absolute number of total and activ ated (CD3+HLA-DR+) T lymphocytes and a significant increase in the abs olute number and percentage of suppressor/cytotoxic T lymphocytes (CD8 ) and NK lymphocytes (CD57) in GDM patients compared with normal pregn ant controls. Concerning frequency for HLA A, B, C, DR antigens in the GDM population, only Cw(7) was found to be significantly increased an d A(10) significantly decreased in comparison with controls. Our study suggests that GDM is a heterogeneous disorder in which few patients p resent with the immunologic and genetic markers of type 1 diabetes.