Thrombotic microangiopathy in systemic lupus erythematosus: A cohort study in North Taiwan

Abstract

Objectives: Thrombotic microangiopathy (TMA) co-existing with SLE is rarely reported. This study aimed to investigate the triggering factors, clinical features and outcomes of SLE patients with TMA in Northern Taiwan. Methods: Twenty-five TMA cases out of 2461 SLE patients admitted to Taipei Veterans General Hospital, between 2000 and 2010, were enrolled. Results: When TMA occurred, 16 (64.0%) patients had infection; 22 (88.0%) were in an active disease state with a SLEDAI score >10. Among the infection group, 13 (81.3%) had an increase in the SLEDAI score of ≥4. We found that older age (≥50 years), low platelets (≤20 000/nm3), presence of infection, acute renal failure (ARF) or four or more TMA features were independent risk factors for persistent haematological abnormalities (P < 0.05); older age (≥50 years) and a high reticulocyte index (>2%) were the risk factors for persistent renal function impairment (P < 0.05). The overall mortality rate was 52.0% (13 out of 25); older age (≥40 years), low complement value, presence of infection (P < 0.001), two or more infection sources, ARF and four or more TMA features were the statistically significant factors contributing to a higher mortality rate. Patients receiving plasma exchange seven times or more had a significantly higher rate of improvement in renal function and haematological abnormalities. Conclusions: Our study showed that infection was one of the major triggers for the flare-up of SLE disease activity and occurrence of TMA in SLE. Infection is also a strong risk factor for outcome in SLE patients with TMA. Plasma exchange can be considered as an adjuvant treatment modality. © The Author 2010. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved.