#1104 Clinicopathological characteristics and predictors of survival and renal function in pulmonary-renal syndrome: a single-center experience

Abstract Background and Aims Pulmonary-Renal Syndrome (PRS) is a severe and life-threatening condition characterized by simultaneous pulmonary and renal involvement, commonly associated with ANCA-associated vasculitis (AAV) and anti-GBM disease. Despite advances in immunosuppressive therapies, PRS continues to pose significant challenges due to high mortality rates and progression to end-stage kidney disease (ESKD). This study aims to evaluate the survival rates and prognostic factors associated with renal outcomes in patients with PRS. Methods A retrospective study was conducted on 33 patients diagnosed with PRS at the Nephrology Department of Ibn Sina University Hospital between January 2019 and January 2024. Patients were included based on defined pulmonary and renal impairment criteria, serological positivity for ANCA, anti-GBM, or other autoantibodies, and histopathological evidence of crescentic glomerulonephritis. Clinical, laboratory, and histopathological parameters were analyzed, and treatment responses were assessed over a one-year follow-up period. Statistical analysis was performed to identify predictors of ESKD and mortality. Results The mean age of the cohort was 49.6 years, with a male predominance (51.5%). Common clinical manifestations included hemoptysis (45.5%), hypertension (57.6%), and anuria (57.6%). MPO-ANCA positivity was observed in 39.4% of patients, while PR3-ANCA and anti-GBM positivity were present in 6.1% and 9.1%, respectively. Renal biopsy revealed crescentic glomerulonephritis in 69.8% of cases, with Type III (pauci-immune) being the most frequent. Patients who progressed to ESKD had significantly higher baseline creatinine levels (143 vs. 75 mg/L, P = 0.011) and a higher incidence of anuria (90% vs. 50%, P = 0.004). The overall mortality rate was 39.4%, with non-survivors showing trends toward lower hemoglobin, higher CRP, and hypoalbuminemia, although these differences were not statistically significant. Conclusion PRS remains a highly fatal condition with a substantial risk of ESKD despite aggressive immunosuppressive therapy. Elevated baseline creatinine and anuria were strong predictors of poor renal outcomes. Early recognition and individualized treatment strategies may improve survival and renal prognosis. Future research should focus on optimizing therapeutic approaches to reduce morbidity and mortality in PRS patients.