Clinicopathologic features and outcomes in endocapillary proliferative IgA nephropathy

Clinical manifestations and histological lesions of IgA nephropathy are variable and correlate with the renal outcome of the patient. The aim of the present study is to clarify the clinicopathological features and the prognosis of patients with IgA nephropathy presenting with dominant diffuse endocapillary proliferative lesions.

The morphological and clinical features of 126 patients with and without diffuse endocapillary proliferation were compared. 29 out of 126 are IgA nephritis patients with diffuse endocapillary proliferation. The others are patients without diffuse endocapillary proliferation. The prognosis of the patients in the 2 groups was analyzed and the effects of diffuse endocapillary proliferation on renal progression in patients with different renal function were also analyzed.

Patients with diffuse endocapillary proliferation show significantly higher proteinuria (p < 0.0001) and crescent percent (p < 0.05). There is no significant difference of renal survival in patients with or without diffuse endocapillary proliferation. Further analysis indicated that patients with diffuse endocapillary proliferation had better renal survival than those without it (log rank, p = 0.0561) if their renal function was normal, whereas renal survival of patients with diffuse endocapillary proliferation was worse than of those without it if their renal function was abnormal (log rank, p = 0.0763).

IgA nephropathy with diffuse endocapillary proliferation shows a better prognosis in the patients with normal renal function, but it is a relative risk factor for end-stage renal disease in patients with abnormal renal function.