Clinico-pathological characterization and outcome of primary focal segmental glomerular sclerosis with deposition of IgM

Objective To explore the clinico-pathological features and outcomes of primary focal segmental glomerular sclerosis with IgM deposition. Methods One hundred and two patients with primary focal segmental glomerular sclerosis (pFSGS) in Hangzhou hospital of traditional Chinese medicine between 1996 and 2012 were retrospectively studied. The patients were divided into IgM deposition group (n=66) with IgM deposition in glomeruli and none-IgM deposition group (n=36)without IgM deposition. Baseline and clinical characteristics of all FSGS patients were assessed and outcomes were reviewed. The survival rates of the patients were analyzed using theKaplan-Meiermethod. Results (1) There were not difference in age, sex ratio, incidence of microscopic hematuria, hypertension, renal insufficiency, eGFR, Ccr and Scr between two groups. However, proteinuria, incidence of nephrotic syndrome, urine microalbumin, urine NAG, serum cholesterol, serum high-density lipoprotein, and serum IgM in IgM deposition group were significantly higher than those in none-IgM deposition group (P＜0.05), serum albumin and serum IgA in IgM deposition group were significantly lower than those in none-IgM deposition group (P＜0.05). (2) The IgM deposition group had a significantly higher incidence of glomerular deposition of IgA, IgG, C3, C1q and fibrinogen than none-IgM deposition group (P＜0.05). The score of mesangial matrix proliferation in the IgM deposition group was lower than that in none-IgM deposition group (P＜0.05). (3) fifty-four patients (35 patients in IgM deposition group and 19 patients in none-IgM deposition group） were followed-up for a median of 64.6 (22.8, 103.8) months. Progression to renal failure was observed in 5 patients of IgM deposition group and none in none-IgM deposition group. Compared with the none-IgM deposition, the survival rates in the IgM deposition group were statistically lower (P＜0.05).Conclusions PFSGS patients with IgM deposition were severer in proteinuria, higher incidence ofIgA, IgG, C3, C1q and fibrinogen deposition in glomeruli and worse outcome than those without IgM deposition.