The Clinical Significance Of T Lymphocyte Subsets And Their PD-1 Expression In Peripheral Blood Of Pregnant Women With Gestational Diabetes Mellitus

Gestational diabetes mellitus(GDM),defined by the American Diabetes Association(ADA)as "diabetes diagnosed during pregnancy that is not clearly overt diabetes",is the most common complication of pregnancy.Recent studies proved that GDM is an autoimmune disorder resulting from impaired immune regulation.Programmed cell death protein 1(PD-1)is most critical immune checkpoint regulating and maintaining the subtle equilibrium of immune response and tolerance.We speculated that PD-1 might be involved in the impairment of immune homeostasis and thus contribute to an increased and persistent T cell auto-reaction.[Objective] To investigate PD-1 expression on T cell subsets in patients of GDM,healthy pregnant women and healthy female donors,to clarify whether this immunoregulatory molecule is involved in the physiopathology of GDM and to explore the dynamic variation of PD-1 and the pathological process of GDM.[Method] Peripheral blood was taken from age matched patients with GDM(n=50),normal pregnant woman(n=50)and women of childbearing age to analyze the ratio of CD3~+T,CD4~+T and CD8~+T and the PD-1 expression on CD4~+T cells and CD8~+T cells with flow cytometry,and then correlation between these index and clinical related index was investigated.28 cases of patients after treatment were following up to explore the dynamic variation of PD-1 and the pathological process of GDM.[Result] 1.The percentages of CD3~+T and CD8~+T in GDM are significantly lower than those of the normal pregnant women(P<0.05).The CD4~+T percentage in GDM is significantly higher than that of the normal pregnant women(P<0.05).The CD4~+T/CD8~+T is significantly higher than that the normal pregnant women(P<0.05).The percentages of CD3~+T and CD4~+T in GDM are lower than the normal childbearing women with statistically significance(P<0.05).There is no significantly difference of CD8~+T percentage between the two groups(P>0.05).The CD4~+T/CD8~+T is significantly lower than that of the normal childbearing women(P<0.05).2.The percentages of CD4~+PD-1+T cells and CD8~+PD-1+T cells in GDM are significantly lower than those in the normal pregnant women(P<0.01).The percentage of CD4~+PD-1+ T cells in GDM is close to the normal childbearing women,the difference has no statistical significance(P>0.05),but the expression of CD8~+PD-1+ T cells in gestational diabetes mellitus is significantly higher than the normal childbearing women(P<0.01).3.After treatment,the percentages of CD4~+PD-1+ and CD8~+PD-1+T cells in GDM are significantly increased(P<0.05).The percentage of CD4~+PD-1+ T and CD8~+PD-1+T in ideal blood sugar control groups are approximate to the normal pregnant groups with the same gestational age(P>0.05).The percentages of CD4~+PD-1+ T and CD8~+PD-1+T in poor blood sugar control groups are lower than those in the normal pregnant groups with the same gestational age(P<0.05).[Conclusion] This study provides evidence of the immunological imbalance during GDM.Especially,the lower expression of PD-1 molecule on the T cell subsets might play an important role in the pathogenesis of GDM.PD-1 expression on T cell subsets is a promising diagnostic and therapeutic indicator of GDM.