Peripheral Immunological Cells in Pregnant Women and their Change during Diabetes

Abstract

During the last decades the incidence of diabetes has dramatically increased as well as the number of pregnant diabetic women. There is still missing data regarding patterns and shifts of immune cell populations due to pregnancy with or without diabetes. The study aimed to investigate the impact of pregnancy, type 1 diabetes (T1D) and gestational diabetes mellitus (GDM) on different immune cells in female. The number and proportion of CD3-, CD4-, CD8- and γδ T-cells as well as B-, NK-, NKT- and dendritic cells (DC) incl. rate of apoptosis was analyzed in peripheral blood samples from 24 non-pregnant women, 24 pregnant controls, 25 non-pregnant T1D, 18 women with GDM and 15 pregnant T1D (PT1D) women. Compared to healthy controls, healthy pregnant women had reduced numbers of lymphoid DC and γδ T-cells, while women with gestational diabetes presented with increased numbers of γδ T-cells. Pregnant women with T1D showed increased NKT cells and a decrease of NK cells compared to healthy pregnant or non-pregnant T1D women. Apoptosis of γδ T-cells in healthy pregnant women was found to be decreased in comparison to their non-pregnant controls while apoptosis of myeloid and lymphoid DC was increased in pregnant T1D in comparison to non-pregnant T1D. Those results may indicate that increased complication rates during diabetic pregnancies might be due to an impaired adaptation of the immune system.

Unveiling the pathophysiology of gestational diabetes: Studies on local and peripheral immune cells

“…Schober et al found higher levels of HLA‐DR‐ in memory Treg cells in the diet‐treated group and increased percentage of activated Tregs cells (HLA‐DR + ) in the insulin‐treated patients. Moreover, they observed that the suppressive activity of total circulating Treg was decreased in GDM.…”

“…Besides its role in pregnancy, γδT lymphocyte seems to be involved in the pathogenesis of inflammatory conditions . Friebe‐Hoffmann et al and Lapolla et al detected an increased percentage of circulating CD3 + TCRγδ cells in GDM compared to controls. To date, there are no other reports on this topic.…”

“…Sheu et al reported that there was no difference in Treg population between GDM and controls, but they did not describe which markers were used to define the cell subset. Accordingly, two other studies including more specific markers showed no differences in the percentage of total TCD4 + and TCD4 + CD25 + FOXP3 + CD127 − between controls and GDM …”

“…T lymphocyte and its subpopulations are the most investigated cells in GDM due to its recognized role in maternal immune response. Five studies reported the percentage of total circulating TCD3 + TCD4 + , and two of them analysed the frequency of total TCD8 + as well . Friebe‐Hoffman et al found a lower frequency of TCD4 + in GDM patients compared to controls, while the others did not …”

“…These parameters have been used to assess several Treg subpopulations in PB, making it difficult to compare the results of different studies. Currently, there are four papers addressing this topic, but each one has used a specific marker to characterize the Treg subset . Mahmoud et al showed increased levels of CD4 + CD25 + in GDM patients compared to controls.…”