Clinical and Pathological Analysis of 34 Children with Idiopathic IgM Nephropathy

Objective To investigate the clinical and pathological characteristics and prognosis of IgM nephropathy in children.Methods The recent 5 years data of 34 cases with IgM nephropathy in Nanjing Children′s Hospital were reviewed.The clinical characteristics,pathological features and curative effects were analyzed.Seventeen cases with nephritic syndrome were followed up for risk factors in poor prognosis in IgM nephropathy.Results 1.The main clinical manifestations of IgM nephropathy in children included nephritic syndrome(26 cases,76.5%),isolated hematuria(5 cases,14.7%),and proteinuria combined with hematuria(3 cases,8.8%).2.The main pathological manifestations of IgM nephropathy was focal segmental mesangial proliferation(82.4%),11.8% cases showed glomerular minor lesion,and 5.8% cases showed mild diffuse mesangial proliferation.IgM deposited diffusely in mesangial area in all cases,the other glomerular immunofluorescence findings included IgA in 7 specimens,C3 in 12 specimens,C1q in 5 specimens and IgG in 1 specimen.3.There was a high incidence of steroid dependence and resistance in the nephritic syndrome group,and IgM nephropathy was the most frequent pathological pattern of refractory nephrotic syndrome,accounted for 32.3%.Seventeen cases of nephrotic syndrome were followed up,and most of them need corticosteroid in combination with cyclophosphamide or mycophenolate mofetil,7 children were completely remitted,7 children partly remitted,and 3 cases were ineffective,but none had renal dysfunction.Hypertension at the time of renal biopsy was the only significant risk factor in poor prognosis.Conclusions IgM nephropathy in children showed special clinical pathological features and prognosis.Most of the cases were presented with the nephrotic syndrome,and always not sensitive to the prednisone alone.The main pathological findings were mild mesangial proliferation.The treatment of refractory IgM nephropathy should be combined with other immunosuppression agents.