CLINICAL AND MORPHOLOGICAL PREDICTORS FOR END-STAGE RENAL DISEASE IN IDIOPATHIC MEMBRANOUS NEPHROPATHY

摘要

A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN), and a variety of initial factors such as amount of proteinuria has been proposed as prognostic factors. However, the predictors for renal outcome of IMN patients in Taiwan remain unclear. We retrospectively reviewed 82 patients diagnosed with IMN from 1986 to 2006 in Kaohsiung Medical University Hospital. The average creatinine and daily protein loss were 1.14 mgldL and 7.5 gram. Among the patients, 20.9% had advanced histological lesion (stage III-TV) and 58% received steroid and/or immunosuppresants. The renal survival was 85.8% at 5 years and 82% at 10 years. They were divided into three groups: the remission group (31.7%), the persistent proteinuria group (52.4%), and the ESRD group (14.6%). There were no statistical differences in age, gender, hypertension, follow-up time and daily protein loss between these three groups. The ESRD group showed significantly higher BUN, creatinine, cholesterol and irregular thickening of glomerular capillary basement membrane (GBM) at presentation (p < 0.01). Morphological changes such as tubulointerstitial lesions, vascular sclerosis, and focal glomerular sclerosis, did not show any association with outcome. After univariate cox regression analysis, we found that BUN, creatinine, estimated GFR (eGFR), albumin, cholesterol, irregular GBM thickening and steroid or immunosuppressant treatment predicted the renal outcome. However, in multivariate cox regression analysis only eGFR and cholesterol were the independent risk factors. In subgroup survival analysis, patients with eGFR < 60 ml/min/1.73m2 or cholesterol > 300 mg/dl had poor renal outcome. In conclusion, we identified that the representatives of late disease course, namely lower eGFR and higher cholesterol (> 300 mg/dl) at time of biopsy are poor prognostic factors in IMN.