Rituximab as Treatment for Lupus Nephritis: Data From the Peruvian ALMENARA Lupus Cohort.

Objective: The aim of this study was to evaluate the response to rituximab (RTX) as treatment for lupus nephritis (LN) in a Latin American Lupus cohort.

Methods: The medical records from LN patients from a single-center cohort spanning between January 2012 and December 2020 were reviewed. Demographic factors (age at diagnosis and baseline, gender), disease duration, previous and concomitant treatments, serum creatinine, and 24-hour proteinuria (24-HP) levels at baseline, and 6th and 12th months were obtained. Complete response (CR) or responder status was defined according to the LUNAR, AURORA-1, and BLISS-LN trials.

Results: Thirty-six patients received RTX as induction treatment; 32 (88.9%) were women. Their age at baseline and disease duration were 32.6 (11.7) and 7.6 (6.5) years, respectively. The time between renal biopsy and RTX use was 2.64 (4.41) years. At baseline, serum creatinine and 24-HP levels were 1.5 (1.5) mg/dL and 3.4 (2.8) g, respectively. At months 6 and 12, serum creatinine levels were 1.6 (1.6) and 1.6 (1.5) mg/dL, and 24-HP were 2.2 (2.2) and 1.6 (1.5) g, respectively. According to LUNAR and AURORA-1 criteria, CR at 6th and 12th months were 6/34 (17.6%) and 8/30 (26.7%) and 6/34 (17.6%) and 7/31 (22.6%) patients, respectively. According to BLISS-LN criteria, responders at 6th and 12th months were 9/34 (26.5%) and 10/31 (32.3%) patients, respectively.

Conclusions: CR and responder status were reached in less than one third of LN patients treated with RTX, regardless of the criteria used to define them. However, serum creatinine levels did not increase, and there was a decrease in proteinuria levels during the follow-up.