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.