Regulation of the functional activity of peripheral B lymphocytes in pregnant women with a history of recurrent miscarriage

Abstract

BACKGROUND:The frequency of recurrent miscarriage is up to 5 % of all desired pregnancies and is mainly due to immunological disorders. Dysfunction in the regulation of the functional activity of B lymphocytes is the pathogenetic link in multiple obstetric complications, including habitual miscarriage.
 AIM:The aim of this study was to characterize the regulation of the functional activity of peripheral B lymphocytes in pregnant women with threatened spontaneous miscarriage and a history of habitual miscarriage.
 MATERIALS AND METHODS:We examined 88 women aged 18-40 years at a gestation period of 5-12 weeks. The main group consisted of 36 patients with threatened spontaneous miscarriage at the time of examination and a history of habitual miscarriage. The control group included 28 women with uncomplicated pregnancy. The comparison group consisted of 24 primary pregnant patients with threatened spontaneous abortion at the time of examination. BAFF and APRIL levels in the blood serum were determined by enzyme immunoassay. The content of CD19+BAFFR+B lymphocytes in the lymphocyte gate was evaluated in the peripheral blood by flow cytometry using monoclonal antibodies. Akt mRNA expression was assessed using real-time reverse-transcription quantitative polymerase chain reaction. CD19+В lymphocytes were isolated by direct magnetic separation.
 RESULTS:In the main group, there was an increase in expression of BAFF receptors on peripheral CD19+B lymphocytes and a decrease in the serum BAFF concentration compared to the parameters in the other study groups. We also found a pronounced trend towards a decrease in the serum APRIL level in the main and comparison groups of patients compared to healthy pregnant women. Besides, Akt mRNA expression in peripheral CD19+B lymphocytes was increased in the main group.
 CONCLUSIONS:Threatened habitual abortion is associated with the deficit of the regulatory influence of BAFF and APRIL, which is expressed in the disruption of B cell homeostasis and the weakening of humoral effector mechanisms.