Lymphocyte subpopulations and intima media thickness in primary antiphospholipd syndrome

Abstract

The aim of this study was to evaluate a possible association between lymphocyte subsets and intima media thickness (IMT) of carotid arteries in primary antiphospholipid syndrome (PAPS). We used a cross-sectional study on PAPS patients ( n = 18) and healthy controls ( n = 16). IgG anti-cardiolipin antibody (aCL), IgG anti-β2glycoprotein-I (anti-β2GPI), IgG anti-β2glycoprotein-I complexed to oxidized low-density lipoprotein (oxLDL) and to a specific oxidized moiety of LDL (oxLig1), and β2GPI-oxLDL were measured by ELISA. Lymphocyte immunophenotyping was performed using pairs of monoclonal antibodies directly labelled with fluorescein isothiocyanate, or phycoerythrin or phycoerythrin-Texas-red-X. Intima media thickness (IMT) of carotid arteries was determined by high-resolution sonography. Total peripheral blood lymphocytes did not differ between PAPS and controls. Memory CD4+/CD45RO + T cells were lower in PAPS than controls ( P = 0.0007) as well as CD16+56+ natural killer cells ( P = 0.02). In PAPS memory T CD45RO + cells positively correlated with IgG anti-β2GPI-oxLig1 ( P = 0.002) and to IMT of carotid arteries (common carotid P = 0.02, bifurcation P = 0.007). Naïve CD4+/CD45RA+ T cells inversely correlated with β2GPI-oxLDL ( P = 0.009). The relation between IgG anti-β2GPI-oxLig1 and IMT of carotid arteries with memory CD45RO + T lymphocytes suggests a role for the latter in PAPS related atherogenesis.