Recurrent idiopathic membranous nephropathy in the renal allograft: successful treatment with the anti-CD20 monoclonal antibody rituximab.

Idiopathic membranous glomerulonephritis (IMGN) is one of the most common causes of nephrotic syndrome in adults. Disease progression is associated with the magnitude and duration of proteinuria [Reichert LJ, Koene RA, Wetzels JF. Prognostic factors in idiopathic membranous nephropathy. Am J Kidney Dis 1998; 31: 1-11]. Membranous nephropathy is also one of the glomerular diseases that is well described to recur in the transplanted kidney [Kotanko P, Pusey CD, Levy JB. Recurrent glomerulonephritis following renal transplantation. Transplantation 1997; 63: 1045]. There is no definitive therapy for primary membranous glomerulonephritis or recurrent disease in the graft. Cyclophosphamide plus steroids or cyclosporine [Cattran DC, Greenwood C, Ritchie S et al. Canadian Glomerulonephritis Study Group. A controlled trial of cyclosporine in patients with progressive membranous nephropathy. Kidney Int 1995; 47: 1130-1135] have been the preferred agents for the treatment of MGN involving the native kidneys. More recently, several reports have described the use of the anti-CD20 monoclonal antibody rituximab in patients with IMGN. In the current report, we present a patient with ESRD secondary to IMGN who developed nephrotic range proteinuria 5 months after receiving a kidney transplant from a deceased donor. A biopsy of the allograft demonstrated changes compatible with recurrent membranous glomerulonephritis. The patient was treated with four weekly infusions of rituximab over a 1-month period with a significant decrease in proteinuria and an improvement in renal function.