T lymphocyte subsets in primary antiphospholipid syndrome.

Abstract

To study T, natural killer (NK) and B blood cell subsets in primary antiphospholipid syndrome (APS). We studied 10 patients with primary APS and 12 healthy subjects. Blood lymphocytes counts, proportions of B cells (CD19+), total CD5 and CD5 B cells, NK cells (CD16+CD56+), T cells (CD3+), CD4+ helper (naive CD4+CD45RA+, memory CD4+CD45RO+ and CD4+CD29+, activated CD4+CD25+), CD8 (immunoregulatory CD8+CD57+, activated CD8+HLA-DR+) T cell subsets were measured by flow cytometry analysis. In the primary APS group, we observed a lower total lymphocyte count (p = 0.009), an expansion of naive CD4 cells (p = 0.025), a lower proportion of memory CD4 cells (p = 0.04) and an increased ratio of naive/memory CD4 cells (p = 0.015). Blood T cells phenotypes in primary APS differ markedly from healthy controls, indicating that immunologic abnormalities in primary APS might extend beyond autoantibody production.