Absolute counts of leukocyte subsets in peripheral blood in pregnancies complicated by preterm prelabour rupture of membranes

BackgroundThis study aimed to assess variations in the absolute counts of various leukocyte subsets in the peripheral blood of women with pregnancies affected by preterm prelabour rupture of membranes (PPROM), in relation to the presence of intra-amniotic inflammation (IAI).MethodsThe study included fifty-two women with singleton pregnancies experiencing PPROM. Absolute counts of different leukocyte subpopulations, such as granulocytes, monocytes, lymphocytes, T cells and their subsets, B cells and their subsets, and NK cells and their subsets, were measured in maternal peripheral blood samples using multicolour flow cytometry. IAI was identified by elevated concentrations of interleukin 6 (IL-6) in the amniotic fluid, which was collected through transabdominal amniocentesis.ResultsWomen with IAI exhibited higher absolute counts of leukocytes (p = 0.003), granulocytes (p = 0.008), and monocytes (p = 0.009). However, the presence of IAI did not significantly affect the absolute counts of lymphocytes or their subpopulations.ConclusionsThe study found that IAI is associated with changes in the absolute counts of leukocytes from the innate immunity compartment in the peripheral blood of women with pregnancies complicated by PPROM. Conversely, it does not significantly alter the counts of cells from the adaptive immune system. The changes observed may reflect the natural, temporal, and localised characteristics of IAI. Preterm birth is the most serious complication in contemporary perinatal medicine. Preterm birth, which is defined as a labour before the completion of 37 weeks of pregnancy, is often accompanied by premature rupture of the amniotic membranes and drainage of amniotic fluid. Such a situation is often complicated by inflammation, which adversely affects the health of the foetus. A number of procedures and markers have been developed for the diagnosis of inflammation, but they are determined from hard-to-reach amniotic fluid. It is therefore appropriate to try to find reliable markers of inflammation in the much more accessible maternal peripheral blood. Such a marker can be increased numbers of leukocytes, which have been repeatedly investigated in this context. However, little attention is directed to other leukocyte populations and especially to various lymphocyte subpopulations. This study aimed to test changes in absolute counts of different types of leukocytes and lymphocyte subpopulations in women with premature rupture of membranes with respect to ongoing inflammation. The results of the study showed that inflammation is accompanied by increased numbers of leukocytes, granulocytes and monocytes, however, the results did not show significant changes in the number of lymphocytes and their subpopulations.