The Presence of Antiphospholipid Antibodies in Six Primary Sjögrenʼs Syndrome Patients with Cutaneous Vasculopathy

Abstract

Some studies have reported the presence of antiphospholipid antibodies (Abs) in primary Sjögrenʼs syndrome patients. We have previously shown that the presence of antiphospholipid Abs, including lupus anticoagulant (LAC), anti-cardiolipin (aCL) Abs, and anti-phosphatidylserinea-prothrombin complex (aPSPT) Abs, may play some role in cutaneous vasculitis. At our university hospital, we evaluated the clinical, serological, and immunohistological findings in six primary Sjögrenʼs syndrome patients who had cutaneous vasculopathy. According to the guidelines provided by the Subcommittee on Lupus Anticoagulant/Phospholipid Dependent Abs, we measured LAC in plasma. Serum aCL Abs, anti-β2-glycoprotein I (anti-β2GPI) Abs, and aPSPT Abs were analyzed by enzyme-linked immunosorbent assay. We detected LAC in 5 (83%) of the 6 patients. All 6 patients were positive for aPSPT Abs. High serum levels of IgM aPSPT were found (19.4±5.9 U/ml; normally, less than 10 U/ml) in five (83%) of the patients. Direct immunofluorescence (DIF) examinations of four patients revealed IgM deposits in the affected vessel walls in all four of them. The present results suggest that aPSPT Abs may play some role in the development of cutaneous vasculopathy in primary Sjögrenʼs syndrome.