Prognosis of Untreated Patients with Idiopathic Membranous Nephropathy

TLDR

The optimal treatment for idiopathic membranous nephropathy remains controversial, as the disease often follows a benign course while immunosuppressive regimens offer uncertain benefits and significant risks. To investigate the natural history of idiopathic membranous nephropathy in patients receiving only symptomatic therapy, the authors prospectively studied 100 biopsy‑confirmed cases. Patients were managed with diuretics or antihypertensives only, and were followed prospectively with biannual measurements of proteinuria and serum creatinine over an average of 52 months. Over a mean 52‑month follow‑up, 88 % of patients retained adequate kidney function at five years and 73 % at eight years, with poorer outcomes in men and those over 50, yet most untreated patients achieved spontaneous remission and the data argue against routine use of glucocorticoids or immunosuppressives.

Abstract

Defining the most appropriate treatment for patients with idiopathic membranous nephropathy is a matter of controversy. The course of the disorder is often benign, and the immunosuppressive regimens used in some patients have uncertain benefits and substantial risks. We studied the natural history of idiopathic membranous nephropathy in patients who received only symptomatic therapy.We prospectively studied 100 consecutive patients (68 men and 32 women; mean [+/- SD] age, 51 +/- 17 years) with biopsy-proved idiopathic membranous nephropathy. The patients received diuretic or antihypertensive drugs as needed, but no glucocorticoid or immunosuppressive drugs. We examined the patients and measured their urinary protein excretion and serum creatinine concentrations every 6 months for a mean of 52 months.Twenty-four (65 percent) of the 37 patients followed for at least five years had complete or partial remission of proteinuria; in 6 others (16 percent), end-stage renal disease developed, and they required dialysis. As calculated by the Kaplan-Meier method, the estimated probability (+/- the standard error of the estimate) of retaining adequate kidney function was 88 +/- 5 percent after five years and 73 +/- 7 percent after eight years. The prognosis was poorer in men and in patients over 50 years of age, but not in patients with the nephrotic syndrome, hypertension, or hypercholesterolemia.Most untreated patients with idiopathic membranous nephropathy maintain renal function for prolonged periods and are likely to have spontaneous remission. These results do not support the use of glucocorticoids and immunosuppressive drugs in patients with idiopathic membranous nephropathy.