CONTEMPORARY KIDNEY OUTCOMES AMONG PATIENTS WITH LUPUS NEPHRITIS IN THE UNITED STATES

O036 / #542 Topic: AS15 - Lupus Nephritis-Clinical ABSTRACT CONCURRENT SESSION 06: LUPUS NEPHRITIS – CLINICAL OUTCOMES, PREDICTION AND THERAPY 23-05-2025 1:40 PM - 2:40 PM Background/Purpose Lupus nephritis (LN) affects up to 50% of patients with systemic lupus erythematosus (SLE) and is associated with excess morbidity and mortality. Prior studies have demonstrated a disproportionate impact on Black patients. We sought to determine the burden of adverse kidney outcomes in a large, contemporary United States LN inception cohort. Methods We identified an SLE inception cohort from TriNetX, an electronic health record (EHR) database with patients from academic and nonacademic medical centers across the United States. We included patients with SLE (≥2 ICD codes ≥30 days and ≤2 years apart) between January 2005 and August 2021 with at least 5 years of enrollment prior to the first ICD code. We identified patients with LN, defined as ≥1 LN code (ICD-10 M32.14 or M21.15), ≥2 nephritis codes (ICD-9 580-583, ICD-10 N00-N05), or ≥2 codes for proteinuria or kidney failure (ICD-9 791.0, 584-586, ICD-10 R80.9, N17-18) and a kidney biopsy. Patients were followed until the end of the study period, death, or disenrollment from the database. We assessed kidney health outcomes, including development of chronic kidney disease (CKD) stage ≥3 and end-stage kidney disease (ESKD), as well as the frequency and timing of kidney transplantation among those with LN-ESKD, according to various demographic subgroups such as sex and race/ethnicity. Results There were 24,957 SLE patients in the inception cohort, including 3748 (15%) with LN (Table 1). Early onset of LN occurring within 6 months of SLE diagnosis was observed in 61% of patients with LN, and the overall mean time to LN onset was 1.4 years (SD 2.3). Of those with LN, 1190 (32%) developed ESKD. Patients with LN were younger at onset (42.4 vs 48.9 years) and more commonly Black (42 vs 28%) or Hispanic (15 vs 9%) than overall SLE patients. Black individuals comprised nearly half of all patients with LN and ESKD. The 5-year risks of CKD stage ≥3 and ESKD among patients with LN were 68% and 35%, respectively. The risks of CKD stage ≥3 and ESKD were higher among Black than White individuals with LN (CKD stage ≥3 adjusted OR [aOR] 1.34 [95% CI 1.13-1.59] and ESKD aOR 1.25 [95% CI 1.05-1.49]) as well as males compared to females with LN (CKD stage ≥3 aOR 1.28 [95% CI 1.05-1.56] and ESKD aOR 1.37 [95% CI 1.12-1.67]). Among those with LN-ESKD, the onset of ESKD occurred after a mean of 2.1 (SD 2.3) years following LN diagnosis, and 426 (36%) patients received a kidney transplant during the study period after a mean of 3.4 years (SD 3.2) from LN-ESKD onset (Table 2). Patients with early onset of LN had a shorter time to ESKD onset and kidney transplantation (P = 0.02 for both). Table 1. Baseline Characteristics of Patients with Systemic Lupus Erythematosus, Lupus Nephritis, and Lupus Nephritis with End-Stage Kidney Disease Table 2. Outcomes by Race/Ethnicity and Sex Among Patients with Lupus Nephritis with End-Stage Kidney Disease Conclusions In this large EHR-based inception cohort of patients with SLE and LN in the United States, we observed a considerable risk of ESKD, especially among Black and male patients, occurring in around one-third of all patients with LN. Only slightly over one-third of patients with LN-ESKD ever received a kidney transplant. Limitations include the possibility of misclassification with the use of administrative codes. These findings highlight the need for strategies to improve LN and ESKD outcomes.