Clinico-pathological features of idiopathic membranous nephropathy(IMN)in 413 adult cases

Objective To determine the clinico-pathological features of histologically confirmed idiopathic membranous nephropathy(IMN)in 413 adult patients. Methods A number of 413 patients of biopsy-proven IMN in Zhongshan Hospital,Fudan University from Mar.,1983 to June 2011 were involved.Data were retrospectively collected. Results Of the 413 IMN patients(236 males and 177 females,mean age 50.2±15.5 years)involved,the median pre-biopsy course was 2 months(0.1-336).Two hundred and fifty(60.5%)patients had proteinuria 3.5g/24h,285(69.0%)had hypoalbuminia,218(52.8%)had nephrotic syndrome,150(36.3%)had hematuria,199(48.2%)had hypertension.A total of 238(57.6%)patients had an estimated glomerular filtration rate(eGFR)≥90mL·min-1·1.73 m-2,while 61(14.8%)patients had an eGFR 60 mL·min-1·1.73 m-2.Compared with the female patients,male patients had more severe proteinuria,higher serum creatinine level and lower eGFR(P0.05).Both age and urine protein quantification had positive correlation with the level of serum creatinine and negative correlation with eGFR(P0.05).Pathological stageⅠandⅡ of IMN with diffuse tubulointerstitial lesions were the dominant pathologic pattern,which accounted for 81.4% cases. Conclusions Renal biopsy should be recommended to patients with grave proteinuria and/or impaired renal function,especially when the patients are of male gender,old age or have hypertension,since tubulointerstitial lesions and advanced pathological stages were more common in those patients.