INCREASE IN CD4 LYMPHOCYTE SUBSET IN PRETERM LABOR AND DELIVERY

Objective: Peripheral blood T lymphocyte subsets were evaluated in 56 pregnant women in their third trimester of pregnancy (36 with diagnosis of preterm labor and 20 with control normal pregnancy; 10 not in labor with a gestational age <37 weeks and 10 in labor with a gestational age >37) to investigate the role of cell-mediated immunity in the evolution of preterm labor. Methods: Samples of peripheral blood were drawn from the patients at the time of diagnosis. Each evaluation included the analysis of T lymphocyte subsets by using CD3, CD4, and CD8 monoclonal antibodies. Results: At the time of diagnosis, the percentage of CD4+ lymphocytes was significantly higher (P < 0.001) in patients with preterm labor as compared with normal pregnant women in labor or not in labor. The patients who afterwards had a preterm delivery displayed a significantly higher percentage of T helper cells than those who had a term delivery. Conclusions: These data suggest an increase in the reactivity of the immune system which tends to indicate a role for cell-mediated immunity in the evolution of preterm labor and delivery.