• Diabetes;
  • insulin;
  • lymphocyte subsets;
  • pregnancy;
  • Treg

Problem:  We hypothesize that the normal immunologic responses by the maternal immune system during pregnancy are not as well-regulated in gestational diabetes (GD) patients as in healthy pregnant women.

Method of study:  Using two-color flow cytometry we evaluated frequencies of peripheral blood lymphocytes in 20 GD patients being treated with insulin; 43 GD patients treated with dietary therapy but no insulin; 44 women experiencing normal pregnancies; and 48 non-pregnant women.

Results:  When compared with healthy pregnant women, both GD cohorts showed higher percentages CD4+CD25+ (P < 0.05), CD4+CD45RO+ (P < 0.05) and CD4+CD29+ (P < 0.01) but lower percentages of CD4+CD45RA+ (P < 0.05). Higher percentages of the activated phenotypes CD8+CD25+ and CD8+HLA-DR+ cells in the diet-treated cohort and CD4+HLA-DR+ cells in insulin-treated GB cohort, were observed compared with healthy pregnant subjects (P < 0.05).

Conclusions:  Expanded populations of activated peripheral blood T cells are associated with GD, suggesting that normal maternal immunosuppression is less effective in GD-afflicted women.