Clinical follow-up of 54 patients with IgM-nephropathy.

The clinical course of mesangial glomerulopathy with IgM deposits (IgM-nephropathy) was studied in 54 patients. The initial manifestations of the disease were nephrotic syndrome in 18, proteinuria in 21, proteinuria together with hematuria in 4 and isolated hematuria in 11 patients. The nephrotic syndrome was steroid-responsive in 60% of cases and of these 80% were steroid-dependent. During a 5-year postbiopsy follow-up 3 patients went into terminal uremia and in 6 more patients a milder renal insufficiency was observed. Three patients were rebiopsied and in 2 of these the second biopsy specimen disclosed typical focal and segmental glomerulosclerosis. Hematuria was a favorable sign, as no patient with hematuria showed progressive impairment of renal function. The prevalence of hypertension in the whole material was 37%. At close of follow-up 35% of all patients were in clinical remission. It is suggested that IgM-nephropathy associated with abundant proteinuria or the nephrotic syndrome represents a distinct disorder from that associated with hematuria. While the nephrotic type often manifested itself with a morphologic change and a tendency to develop renal insufficiency, the hematuric type showed female predominance, a high tendency to spontaneous clinical remission and a favorable clinical course.