Apoptosis in patients with primary antiphospholipid antibody syndrome

Aim: Dysregulated apoptosis has been implicated in autoimmune diseases. In the present study, we investigated the apoptosis-related cytokines and apoptosis in patients with primary antiphospholipid syndrome (pAPS). Method: We prospectively recruited 12 pAPS patients, 17 antiphospholipid antibody (APA)-positive systemic lupus erythematosus (SLE) patients without APS manifestations (APA + SLE), 13 SLE patients with secondary APS (APS + SLE) and 10 healthy controls (HCs). Plasma levels of soluble apoptosis-inducing ligands and cytokines, and the expression levels of apoptosis-inducing ligands in peripheral blood mononuclear cells, were determined. In addition, blood lymphocytes/monocytes apoptosis were determined in six pAPS patients and six HCs, using flow cytometric analysis of caspase 3, 8 and 9 activities. Results: There was a trend toward higher plasma levels of soluble tumor necrosis factor (TNF)-related apoptosis-inducing ligand (sTRAIL), interleukin-10 (IL-10) and TNF-α in pAPS patients when compared with HCs. We also observed higher plasma levels of IL-10 and TNF α in APA + SLE and APS + SLE patients when compared with HCs. However, there was no significant difference in blood lymphocytes/monocytes apoptosis between pAPS patients and HCs. Conclusion: There was a trend toward elevated plasma levels of sTRAIL, IL-10 and TNF-α, but no evidence for dysregulated apoptosis in pAPS patients.