Objectives: Hypertension is the most frequent complication of pregnancy after 24th week of gestation, occurring in 8% of pregnancies and being the main cause of perinatal mortality and morbidity. It is classified as preeclampsia (PE) or transient hypertension (TH). According to some statements PE and TH are distinct syndromes of different pathogenesis. There are even opinions emphasizing that in most cases TH is in fact undiagnosed chronic hypertension. The role of immunological system in pathogenesis of PE is well known but the hypothesis that immunological events are engaged in pathogenesis of chronic hypertension has not been proved so far. Assuming that TH is closer in its pathogenesis to chronic hypertension than to PE it would be possible to differentiate between TH and PE using some immunological tests. If PE and TH are the same, the differences would be insignificant.
Design: The aim of this study was to check the hypothesis that peripheral blood lymphocyte subsets analysis is an useful tool in differentiation between PE and TH and confirmation of their distinct origin.
Materials and methods: The study groups consisted of 19 pregnant women with PE (mean age 25.5 +/- 2.5 years, mean gestational age 32.5 +/- 2.5 weeks, 84.2% primiparae) and 14 pregnant women with TH (mean age 27.0 +/- 3.0 years, mean gestational age 33.5 +/- 3.0 weeks, 100% primiparae) diagnosed between 30-37 week of gestation. All women were matched according to gestational age and race. They had no renal diseases or chronic hypertension prior to pregnancy neither had any features of them during the study. Exclusion criteria were: uterine contractions, infection and therapy with steroids before blood sampling. PE and TH were defined according to USA National Health Institute criteria. Peripheral blood was obtained by venipuncture. Standard immunofluorescent marking techniques for whole blood with one-step monoclonal antibodies were performed. Lymphocyte subsets (CD19+, CD3+, CD4+, CD8+, CD3-/CD16+/CD56+, CD3+/CD16+/CD56+, CD8+/CD28+, CD4+/CD45RA+, CD4+/CD45RO+, CD3+/CD69+) analysis was done with flow-cytometer FACSCalibur with 488 nm argon laser. The lymphocyte cells region was chosen with LeucoGATE and analysis performed with SimulSET v.3.1 programme. Statistical analysis was based on Student T test.
Results: The differences in peripheral blood lymphocyte subsets composition between PE and TH were insignificant.
Conclusion: Is that on the basis of peripheral blood lymphocyte subsets analysis PE and TH despite different clinical symptoms seem to have common pathogenesis. However there is possibility that changes observed in peripheral blood are not significantly different in PE and TH because of their low importance for immunopathogenesis.