Abstract:

ABSTRACT Objective: To investigate the clinic-pathological features and outcomes of patients with eosinophilic granulomatosis with polyangiitis and renal involvement. Methodology: Fourteen patients diagnosed as eosinophilic granulomatosis with polyangiitis （EGPA） were investigated in this retrospective study. All of them had renal involvement and were performed renal biopsy. Their clinic-pathological features and outcomes were analyzed. Results: They were 8 female and 6 male with age from 20 to 70 years old, and the vasculitis duration from 1～600 months. They accounted for 6.76% of all ANCA associated vasculitis in the same period in our hospital .All patients had positive serum ANCA, among them, 12（85.7%）were p-/MPO-ANCA. The most common onset symptom was asthma (57.1%, n=8)，the others were hemoptysis (21.4%, n=3)、gross hematuria（14.3%, n=2）and arthritis (7.14%, n=1). All patients had increased peripheral eosinophil ratio from 10% to 45% with the average of 18.1±9.8%) accompanied with elevated serum IgE levels of 541± 462g/l. Except one, the other 13 patients had both hematuria and proteinuria. The mean urine protein was 2.90±3.53 g/24h, 5 (35%) had nephrotic syndrome, and 2 had gross haematuria. All patients presented renal dysfunction with a high level of Scr 498.6±288.6umol/l, and 7 patients required initial renal replacement therapy. Renal biopsy showed paci-immune segmental necrotizing glomerulonephritis with crescent formation in 13 patients (6 mixed class, 4 crescentic class, 2 focal class, and one sclerotic class), and acute interstitial nephritis in one. 12 patients (85.7%) had eosinophil infiltration in renal interstitium, and 3 showed eosinophil granuloma. All patients received corticosteroid with immunosuppressant therapy. 5 patients of those who required initial renal replacement therapy got rid of dialysis, one entered maintenance hemodialysis, and one died. 12 patients were followed up for 6 to 83 months (median 43.5), 2 patients were in completely remission ( normal renal function and urine analysis), 9 progressed to chronic renal failure, one developed to ESRD and one had extra-renal relapse. Conclusion: The renal involvement of eosinophilic granulomatosis with polyangiitis was severe and the renal histological lesions were diverse. Aggressive immunosuppressive therapy could effectively improve renal function, but the overall renal prognosis was poor. Early diagnosis and treatment were needed to improve the long-term renal survival.

Key words:  eosinophilic granulomatosis with polyangiitis, renal damage,   antineutrophil cytoplasmic antibody , antineutrophil cytoplasmic antibody associated vasculitis