Lymphocyte subpopulation frequency and presence of anti-cardiolipin and anti-nuclear antibodies in peripheral blood of Kuwaiti women experiencing recurrent pregnancy loss

Abstract

Recurrent pregnancy loss (RPL) is often associated with elevated levels of serum antiphospholipid antibodies, which contribute to the pathology of the disorder by promoting formation of thromboses, leading to placental infarction and fetal loss. Patients with recurrent pregnancy loss also exhibit pathological alterations in composition and activity of peripheral blood lymphocytes, which may be indicative of an autoimmune processes. This investigation examines the correlation between levels of anticardiolipin antibody (AC) and specific subsets of the lymphocyte repertoire in RPL patients, with the objective of further characterising the immunological basis for RPL. Non-pregnant Kuwaiti women with a history of RPL were subdivided into two cohorts based on presence or absence of elevated plasma antibodies to cardiolipin. Whole blood from these individuals was analysed by flow cytometry for selected lymphocyte subsets and compared with a non-RPL control population. When compared with controls and low AC titre subjects, women with a high AC titre exhibited significantly elevated percentages of pathogenic CD5 + B cells; two categories of activated T cells including CD4 + CD25 + and CD8 + CD25; NK cells and CD3 + NK cells; naive (CD4 + CD45RA + ) cells; and transitional (CD45RO + CD45RA + ) cells. In conclusion, women with elevated levels of AC antibodies possess substantially higher levels of activated T cells and pathogenic B cells, suggesting a fundamental predisposition to immune-mediated rejection of the fetus by these patients. Further characterisation of this phenomenon may allow development of novel intervention methods for management of RPL.