[Erythrocytosis associated to idiopathic membranous nephropathy. Case report].

A patient with idiopathic membranous nephropathy and nephrotic syndrome developed inappropriately high red blood cell counts, unrelated to the level of serum creatinine. This unusual event could be explained by an overstimulation of the erythropoietin hormone due to hypoperfusion associated to the nephrotic syndrome.