High impact of antiphospholipid syndrome on irreversible organ damage and survival of patients with systemic lupus erythematosus

Background: Thrombosis is a frequent cause of morbidity and death in patients with systemic lupus erythematosus (SLE). Whether antiphospholipid syndrome (APS) is the cause of increased irreversible organ damage and mortality in lupus patients is not well established. Methods: Prospective inception cohort of 202 patients with SLE (American College of Rheumatology criteria). Antiphospholipid syndrome was defined according to the Sapporo criteria. Irreversible damage was measured using the Systemic Lupus International Collaborating Clinics-American College of Rheumatology damage index (SDI) at 6 months and 1, 3, 5, 10, 15, 20, and 25 years after the diagnosis of SLE. All deaths were documented. Results: A total of 88% of patients were women. Twenty-eight patients met criteria for definite APS. Mean (SD) follow-up was 9.7 (6.0) years. Nine patients could not be contacted for follow-up. All patients with APS experienced thrombosis, most of them in the arterial bed. Damage was more severe in patients with APS than in those without APS (median SDI score, 2 vs 0 at 5 years; P < .001; 4 vs 1 at 15 years; P < .001). Cumulative survival at 15 years was lower in patients with APS than in those without APS (65% vs 90%, P = .03). Older age at diagnosis, lupus nephritis, and APS were independent predictors of mortality. Conclusions: Antiphospholipid syndrome with thrombotic manifestations is a major predictor of irreversible organ damage and death in patients with SLE.