Abstract: Objective  To analyze the pathogenesis regularity and treatment of IgM nephropathy in adults with kidney disease.Methods  The clinicopathological and treatment  data were collected from 52 patients of IgM nephropathy confirmed by renal biopsy.Results  A  prevalence  of  IgM nephropathy of  4.9%(52/1 045)  accounted for all primary glomerular diseases on renal biopsies. The majority of the patients presented with nephrotic syndrome. The mean age was (20.1±10.3) years old. The malefemale ratio was 1.6∶1. 16 cases with hypertension at onset accounted for 30.7%.There were 5 patients with acute renal failure. The mean 24hour urine protein level was (4.44±1.48) g. The mean albumin  level was (16.68±4.65)  g/L. The mean cholesterol level was (12.75±3.64) mmol/L. The mean triglycerides level was (12.75±3.64) mmol/L. The most common morphologic change consisted of mild and moderate mesangial cell proliferaion of the glomeruli，found in 40 biopsies （76.9%），severe hyperplasia  in  3 biopsies（5.7%）. The morphological pattern of FSGS was found in 9 cases（17.3%）. IgM was the sole localizing immunoglobulin，and it was the predominant globulin in  34 cases（65.3%），IgM+C3 accounted for  23.0%(12/52). 14 cases( 26.9%)  were sensitive to glucocorticoid. There were 26 cases(50%) of glucocorticoid dependence. There were 12 cases(23%) of glucocorticoid resistance. Combined with cyclophosphamide treatment， clinical remission in 30 cases， the total clinical remission rate was 57.6%; invalid cases were 19 cases( 36.5%); 3 worsening cases(5.7%). Conclusion  A high incidence with IgM  nephropathy in young men. The majority of the patients presented with idiopathic nephrotic syndrome. The most common morphologic change consisted of mild and moderate mesangial cell proliferaion of the glomeruli.Predominant IgM deposition in mesangium was the sole localizing immunoglobulin. Glucocorticoid dependent was the most    common response. Clinical complete remission rate was increased in glucocorticoid with cyclophosphamide.

Key words: glomerulonephritis, IGM；therapies, investigational；pathology；therapeutic effect