Evaluation of T-cell receptor CD3+ gamma delta in gestational diabetes mellitus.

Few studies have shown a significant increase of CD3+ T-cell receptor (TCR) gamma delta in the early phases of type 1 diabetes. We wished to determine if CD3+ TCR gamma delta is involved in the pathogenesis of gestational diabetes mellitus (GDM). We studied 29 GDM patients and 21 normal pregnant women. Lymphocyte subpopulations (CD3+ TCR alpha beta, CD3+ TCR gamma delta), islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GAD) and protein tyrosine phosphatase antibodies (IA2-Ab) were evaluated in all patients. The percentage of CD3+ TCR gamma delta was significantly higher in GDM women than in the control group (5.1 +/- 2.9% vs 3.7 +/- 1.7%; p < 0.05). No abnormalities of the other lymphocyte subpopulations were found. All subjects were negative for ICA; 2 GDM patients were positive for GAD, but no relationship was found between GAD positivity and CD3+ gamma delta levels in these 2 patients. Further follow-up studies of these patients are required to verify if the CD3+ TCR gamma delta receptor is a useful marker for diabetes development.