Protective effect of antimalarials on the most frequently affected damage domains in SLE: Data from a multiethnic Latin American cohort

Objective: To assess the effect of antimalarials (AMs) on overall damage and on its most frequently affected domains, as measured by the Systemic Lupus International Collaborating Clinics Damage Index (SDI) in patients from the GLADEL cohort. Methods: New damage was defined as a ≥1 point increase in SDI since cohort entry. AMs users were those who received AMs for at least 6 months after entering the cohort. AMs users and non-users were matched for age, sex, ethnicity, and baseline SDI using stratified random sampling. Two comparisons were carried out: patients with and without new damage, and AM users versus non-users. Propensity score matching was used to determine the effect of AM use on the most frequently affected damage domains. Results: A total of 850 patients were included; 419 (49.3%) were AM users and 431 (50.7%) non-users. During a median follow-up of 48.5 (IQR 19.3, 69.0) months, 472 (55.5%) developed damage. The most affected domains were skin (18.4%), renal (14.6%), neuropsychiatric (10.8%), musculoskeletal (6.9%), and cardiovascular (4.5%). AMs use was associated with a lower proportion of patients accruing damage at follow-up (170 [40.6%] vs 208 [48.3%]; p = .028). AMs were protective against overall damage (HR 0.7, 95% CI [0.5–0.9]; p = .002), renal (HR 0.4, 95% CI [0.3–0.6]; p [jls-lt/] .001), and neuropsychiatric damage (HR 0.5, 95% CI [0.3–0.9]; p = .022). Conclusion: AM use is independently associated with a lower probability of overall, renal, and neuropsychiatric damage accrual. These findings support early and sustained AM treatment in lupus patients, unless contraindicated.