Protective effect of hydroxychloroquine in systemic lupus erythematosus. Prospective long-term study of an Israeli cohort.

Systemic lupus erythematosus-associated irreversible organ/system damage was previously associated with various clinical and demographic features. We analysed the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI) in a cohort of 151 Israeli patients followed for a mean (+/- s.d.) period of 45.7 +/- 37.4 months. Mean score of SLICC/ACR DI at the first and last encounters were 0.17 +/- 64 and 1.64 +/- 2.1, respectively (P < 0.0001). Multiple logistic regression analyses disclosed a statistically significant positive correlation with corticosteroid and cyclophosphamide therapy. Hydroxychloroquine therapy was significantly associated with lower SLICC/ACR DI. Although the size of our study group did not allow us to find specific organs/systems which were associated with the protective effect of hydroxychloroquine, we suggest this is due to the antiatherogenic effects attributed to antimalarial therapy in SLE.