Assessment of Lupus Nephritis in a Multicenter Retrospective Egyptian Cohort: Initial Characteristics, Influence of Age and Gender, Outcome, and Potential Association with Disease Damage

Abstract

The study aimed to evaluate the association of demographic, clinical, and histopathologic characteristics with renal and disease outcomes. Persistent lack of partial or complete remission despite sequential induction therapy, chronic kidney disease (CKD) or endstage renal disease (ESRD), and/or mortality were determined as poor renal outcomes. Disease damage was investigated through the Systemic Lupus International Collaborating Clinics/ American College of Rheumatology Damage Index (SDI). Of 201 biopsy-proven lupus nephritis patients, a poor outcome was present in 56 (27.9%) patients, with nine (4.5%), 22 (10.9%), and 29 (14.4%) patients demonstrating lack of response, CKD, and ESRD, respectively, and the prevalence of mortality was 5.5% (11/201). The outcome was poor among males [29/201 (14.4%)] [P = 0.008; odds ratio (OR): 2.8; 95% confidence interval (CI): 1.2–6.4], yet comparable between adult- and juvenile-onset patients [80/201 (39.8%) (≤16 years)] (P = 0.6; OR: 0.8; 95% CI: 0.4–1.6). Hypertension (P <0.001; OR: 6.3; 95% CI: 2.6–14.9), elevated creatinine (P <0.001; OR: 5.2; 95% CI: 2.6–10.3), and hematuria (P <0.001; OR: 3.7; 95% CI: 1.9–7.5) at presentation, and fibrinoid necrosis [P <0.001; odds ratio (OR): 4.1; 95% confidence interval (CI): 2.1–8.1], wire loops (P = 0.006; OR: 2.4; 95% CI: 1.2–4.6), crescents (P <0.001; OR: 5.4 95% CI: 2.8–10.5), interstitial fibrosis (P = 0.001; OR: 2.7; 95% CI: 1.4–5.1), and acute vascular lesions (P = 0.004; OR: 3.6; 95% CI: 1.4–9.4) on biopsy were associated with a poor outcome. Chronic glomerular (P = 0.003) and acute vascular lesions (P <0.001), and a higher chronicity index (r = 0.1; P = 0.006) on biopsy, and frequent renal (r = 0.3; P <0.001) and extra-renal flares (r = 0.2; P <0.001) were associated with higher SDI scores. Among the studied renal and extra-renal parameters, independent predictors of higher disease damage solely included frequent renal flares (ᵝ= 1; P <0.001). To conclude, a poor renal outcome (27.9%) was associated with distinct features. Disease damage was associated with frequent renal flares.