SAT-410 Clinicopathologic Features and Outcomes of Patients with Crescentic Glomerulonephritis with Renal Involvement: A Single-Center, 13-year Retrospective Study from Turkey

Abstract

Crescentic glomerulonephritis (GN) is a group of the disease spectrum characterized by the presence of glomerular crescent formation as the principal histologic finding. We aimed to investigate the etiologic distribution and clinicopathologic features of the patients with biopsy-proven crescentic GN in the last 13 years in our center according to different percentages of crescents. Patients who had renal biopsy-proven glomerular crescent formation and recorded from 2005 to 2018 were retrospectively reviewed. The baseline clinical and laboratory parameters of all patients were obtained at the time of renal biopsy. Renal histopathological data were reviewed by light and immunofluorescence microscopy. According to the percentages of crescentic glomeruli, the patients were divided into three subgroups: group I (crescents <10%), group II (10%≤ crescents ≤30%) and group III (crescents >30%). The clinical, laboratory and histopathological features of patients, risk factors and outcomes were compared among the three groups. A total of 103 patients with biopsy-proven crescentic GN were included in the analysis and followed up. The results according to different percentages of crescents are presented in Table. As the percentage of crescentic glomeruli increased, it was associated with increased levels of baseline serum creatinine (p=0.018), lower baseline estimated glomerular filtration rate (eGFR) (p=0.002) and decreased macroscopic hematuria (p=0.032). In last outpatient clinic visit, eGFR, serum albumin and amounts of proteinuria were not different among the groups (p=0.096). The most common renal biopsy indications were rapidly progressive glomerulonephritis and nephrotic syndrome in all three groups (p=0.031). The disease spectrum of crescentic GN was as follows: 6 (6%) had anti-GBM GN, 16 (15.5%) had lupus nephritis, 27 (26%) had IgA nephropathy, 3 (3%) had infection-related GN, 5 (5%) had membranoproliferative GN, 42 (40.5%) had pauci-immune GN and 4 (4%) had others. There were no significant differences in the histological findings among the three groups except for mesangial cell proliferation and matrix expansion (p=0.002). Twenty three patients (%22.3) required dialysis on admission, including 6 (15%) patients with group II and 17 (36%) patients with group III (p<0.01). By the end of the follow-up period of 30 months, 35 (34%) patients progressed to end-stage renal disease (ESRD), requiring renal replacement therapy (7 (7%) renal transplantation and 28 (27%) dialysis) and 14 (13.5%) patients died. Cox regression analysis for renal survival showed that serum creatinine levels of 3.5 mg/dl or greater (HR= 1.5, 95% CI: 1.9-10.5, p<0.001) on admission and presence of interstitial fibrosis and tubular atrophy score >25% (HR= 2.7, 95% CI: 2-113, p=0.008) on renal biopsy were risk factors for ESRD. Of the etiologic spectrum of crescentic GN, pauci-immune GN had the poor renal and patient outcomes. This study provides valuable information about the disease spectrum of crescentic GN in our country. In patients with crescentic GN who present with different clinical features, an accurate and early diagnosis is essential for both renal and patient survival. Prognosis mostly depends on the degree of renal failure, histopathologic findings and the type of crescentic GN. Studies with larger sample sizes, including national registry data is still needed.