Purpose The purpose of this paper is to determine the factors predictive of flares in systemic lupus erythematosus (SLE) patients. Methods A case-control study nested within the Grupo Latino Americano De Estudio de Lupus (GLADEL) cohort was conducted. Flare was defined as an increase ≥4 points in the SLEDAI. Cases were defined as patients with at least one flare. Controls were selected by matching cases by length of follow-up. Demographic and clinical manifestations were systematically recorded by a common protocol. Glucocorticoid use was recorded as average daily dose of prednisone and antimalarial use as percentage of time on antimalarial and categorized as never (0%), rarely (>0-25%), occasionally (>25%-50%), commonly (˃50%-75%) and frequently (˃75%). Immunosuppressive drugs were recorded as used or not used. The association between demographic, clinical manifestations, therapy and flares was examined using univariable and multivariable conditional logistic regression models. Results A total of 465 cases and controls were included. Mean age at diagnosis among cases and controls was 27.5 vs 29.9 years, p = 0.003; gender and ethnic distributions were comparable among both groups and so was the baseline SLEDAI. Independent factors protective of flares identified by multivariable analysis were older age at diagnosis (OR = 0.929 per every five years, 95% CI 0.869-0.975; p = 0.004) and antimalarial use (frequently vs never, OR = 0.722, 95% CI 0.522-0.998; p = 0.049) whereas azathioprine use (OR = 1.820, 95% CI 1.309-2.531; p < 0.001) and SLEDAI post-baseline were predictive of them (OR = 1.034, 95% CI 1.005-1.064; p = 0.022). Conclusions In this large, longitudinal Latin American cohort, older age at diagnosis and more frequent antimalarial use were protective whereas azathioprine use and higher disease activity were predictive of flares.
Keywords: Systemic lupus erythematosus; antimalarials; flares; risk factors.