Evaluation of Immunological Parameters in Pregnant Women: Low Levels of B and NK Cells

Abstract

Objective To describe the immunological and hematological reference intervals of low-risk pregnant women. Methods A cross-sectional retrospective database analysis of a basic and translational study analyzing the hematological evaluation blood counts and immunophenotyping of TCD3 +, TCD4 +, TCD8 +, B, and natural killer (NK) cells of the peripheral blood in 79 low-risk pregnant women and of 30 control women from the state of Pernambuco, Brazil, was performed. Results No significant differences were detected between the hematological profiles of the 2 nd and 3 rd trimesters. Nevertheless, the median level of B cells decreased significantly in the 2 nd (174 × 10 3 μL; p < 0.002) and 3 rd trimesters (160 × 10 3 μL; p < 0.001), compared with the control group (296 × 10 3 μL). Similarly, the median level of NK cells was lower in the 2 nd (134 × 10 3 μL; p < 0.0004) and 3 rd trimesters (100 × 10 3 μL, p < 0.0004), compared with the control group (183 × 10 3 μL). In contrast, relative TCD4+ and TCD8+ levels increased in the 2 nd and 3 rd trimesters compared with the controls (TCD4 +: 2 nd trimester = 59%; p < 0.001; 3 rd trimester = 57%; p < 0.01; control = 50%; and TCD8 +: 2 nd trimester = 31%; p < 0.001; 3 rd trimester = 36%; p < 0.01; control = 24%). Conclusion Low-risk pregnant women have ∼ 40% less B and NK cells in the peripheral blood, compared with non-pregnant women. These parameters may improve health assistance for mothers and contribute to define reference values for normal pregnancies.