Association of antimalarial drugs with decreased overall and cause specific mortality in systemic lupus erythematosus.

OBJECTIVE: To evaluate the association and dose-response pattern between antimalarial drugs and overall and cause specific mortality in SLE patients. METHODS: Medical records including information on HCQ/chloroquine (CQ) prescription were extracted from Jiangsu Lupus database. The database was designed to collect data from SLE patients that first-hospitalized during 1999-2009 in Jiangsu province, China, and a follow-up for survival status was performed in 2010 and 2015. Cox and restricted cubic spline models were used to estimate the hazard ratio and 95% CI. RESULTS: We identified 221 deaths among 2446 SLE patients in total. Compared with non-users, decreased overall mortality was associated with either HCQ or CQ users, with adjusted hazard ratio (95% CI) of 0.49 (0.35, 0.67) and 0.49 (0.27, 0.87), respectively. The association between HCQ/CQ and overall mortality was similar across subgroups, such as patients with comorbidities and organ involvements. Interestingly, both the time and the daily dosage of HCQ/CQ use were related to decreased mortality of SLE in a linear dose-response relationship. In cause specific analyses, HCQ/CQ was inversely associated with death from renal insufficiency and other organ (cardiopulmonary, gastrointestinal and haematological) involvements, with adjusted hazard ratio (95% CI) of 0.23 (0.09, 0.55) and 0.25 (0.10, 0.62), respectively, yet it was not significantly associated with mortality from infection and neuropsychiatric involvements. CONCLUSION: Antimalarial drugs were associated with lower risk of SLE mortality, especially renal insufficiency- and other organ involvement-related death. The protective effects for survival might be augmented by adherence and full dosage of these drugs.