COMPARISON OF THE PRIMARY AND SECONDARY ANTIPHOSPHOLIPID SYNDROME - AEUROPEAN MULTICENTER STUDY OF 114 PATIENTS

PURPOSE: To determine whether the features of the antiphospholipid syn drome (APS) are in any way influenced by the presence or absence of sy stemic lupus erythematosus (SLE). We followed up patients with 'primar y' APS (PAPS) and APS secondary to SLE (APS plus SLE) with the objecti ve of comparing laboratory and clinical events and of determining whet her patients with PAPS would have evolution to SLE. PATIENTS AND METHO DS: A total of 114 patients from 3 European referral centers were incl uded in this study. Fifty-six had APS plus SLE and 58 had PAPS. Labora tory and clinical data were collected during an average 2-year period. RESULTS: Patients with PAPS and patients with APS plus SLE had simila r clinical and laboratory profiles, with the exceptions of autoimmune hemolytic anemia, endocardial valve disease, neutropenia, and low C4 l evels, all of which occurred more frequently in patients with APS plus SLE (p values: <0.05, <0.005, <0.01, and <0.001, respectively). On fo llow-up, 10 thrombotic episodes occurred in 10 patients, 8 of whom wer e receiving anticoagulant therapy. No patient with PAPS had either ant i-DNA or anti-extractable nuclear antigen antibodies, and these patien ts had a significantly lower prevalence of antinuclear antibodies (41% ) than patients with APS plus SLE (89%). CONCLUSIONS: Patients with AP S plus SLE and PAPS have similar clinical profiles, although heart val ve disease, hemolytic anemia, low C4 levels, and neutropenia seem to b e more common in patients with APS plus SLE. Patients with APS may dev elop further thrombotic events despite anticoagulation therapy.