Prognosis of Idiopathic Membranous Nephropathy after Complete Remission of Proteinuria

Kang, Mi Jung; Jin, Kyu Bok; Sung, Jung Hoon; Hwang, Eun Ah; Han, Seung Yeup; Park, Sung Bae; Kim, Hyun Chul

Abstract

BACKGROUND
The natural history of idiopathic membranous nephropathy is often benign, but approximately 30% of the patients develop renal insufficiency and progress to end-stage renal failure over 5 to 15 years. Several retrospective analyses have been performed to identify favorable factors influencing the long-term prognosis of idiopathic membranous nephropathy. However, little attention has been paid to the significance of remission of proteinuria in this disease. METHODS: Forty-six patients with biopsy-proven idiopathic membranous nephropathy who achieved complete remission (CR) of proteinuria between 1982 and 2003 were enrolled. We retrospectively analyzed the clinical and laboratory data between persistent remission group and relapsing group after CR of proteinuria. RESULTS: Complete remission of proteinuria was seen in 46 patients (31%) and was obtained 7-170 months (mean 38 months) after discovery of the disease. During mean 89 months follow-up, 74% of the patients remained in remission and 26% relapsed. However, proteinuria disappeared again spontaneously in some patients so that at last follow-up 83% of the patients are in CR. The probability of remaining free of proteinuria at 5 and 10years after CR was 0.73 and 0.60, respectively. 5 and 10years renal survival in patient with CR were 100%, respectively, whereas those of patient without remission were 89 % and 75%, respectively, which was significantly different (p<0.05). We could not find any specific clinical factors favored maintenance of remission, except serum level of creatinine and serum cholesterol during remission, which are significantly less in patients with persistent remission. CONCLUSION: In conclusion, CR of proteinuria is a strong predictor of long-term favorable outcome in patients with idiopathic membranous nephropathy.