Predictive Factors of the Use of Rituximab and Belimumab in Spanish Lupus Patients.

: To analyze the characteristics and the predictive factors of the use of rituximab and belimumab in daily practice in patients from the inception cohort Registro Español de Lupus (RELES). : The study included 518 patients. We considered patients treated with biologics who received at least one dose of rituximab or belimumab, and possible indications of those manifestations registered at the same time or in the previous 2 months of the start of the therapy. : In our cohort, 37 (7%) patients received at least one biological treatment. Rituximab was prescribed in 26 patients and belimumab in 11. Rituximab was mainly prescribed for hemolytic anemia or thrombocytopenia (11 patients, 42%), lupus nephritis and neuropsychiatric lupus (5 patients each, 19%). Belimumab was mostly used for arthritis (8 patients, 73%). In the univariate analysis, the predictive factors at diagnosis for the use of biologic therapy were younger age ( = 0.022), a higher SLEDAI ( = 0.001) and the presence of psychosis ( = 0.011), organic mental syndrome (SOCA) ( = 0.006), hemolytic anemia ( = 0.001), or thrombocytopenia ( = 0.01). In the multivariant model, only younger age, psychosis, and hemolytic anemia were independent predictors of the use of biologics. : Rituximab is usually given to patients with hematological, neuropsychiatric and renal involvement and belimumab for arthritis. Psychosis, hemolytic anemia and age at the diagnosis of lupus were independent predictive factors of the use of biological agents. Their global effects are beneficial, with a significant reduction in SLE activity and a low rate of side effects.