Treatment of retroperitoneal fibrosis by mycophenolate mofetil and corticosteroids

Abstract

Retroperitoneal fibrosis is an idiopathic disorder that leads to compression of the uterer, vena cava, and aorta by retroperitoneal mass. Findings strongly suggest an autoimmune aetiology. Beside surgery, immunosuppression with corticosteroids, azathioprine, and tamoxifen has been reported. Immunosuppressive therapy was, however, successful only in early stages of disease. Once anuric renal failure due to retroperitoneal fibrosis had occurred, conventional immunosuppressive therapy failed in every patient in a series of 60. The new immunosuppressive drug mycophenolate mofetil, a selective inhibitor of T and B lymphocytes, blocks various autoimmune processes. Mycophenolate mofetil also decreases the rate of rejection after renal transplantation and has been successfully used to treat systemic vasculitis, IgA nephropathy, and bullous pemphigoid. We tried mycophenolate mofetil in a man aged 38 years with advanced retroperitoneal fibrosis. On admission he was completely anuric, potassium concentration was 7·6 mmol/L, serum creatinine 2060 mol/L, and C-reactive protein 131 mg/L. Antinuclear antibodies, antineutrophilic cytoplasmic antibodies, and rheumatoid factor were negative. Computed tomography of the abdomen showed a large retroperitoneal mass (figure) with a craniocaudal extension of 8 cm, which caused bilateral ureteral obstruction, hydronephrosis, and compression of the vena cava and aorta. Retrograde pyelogram revealed medial deviation of both ureters, with a 12 cm stenosis on the left side and a 3 cm stenosis on the right side. A computed-tomography-guided biopsy of the retroperitoneal mass showed chronic inflammation with fibrosis and an infiltration of lymphocytes, plasma cells, and eosinophils. Aetiology of retroperitoneal fibrosis was idiopathic since evidence for drug-induced origin or associates diseases could not be detected. The patient underwent one haemodialysis session. After endoscopic insertion of two double J catheters in both uterers, immunosuppressive therapy was started with mycophenolate mofetil 2 g/daily and prednisone (250 mg on 3 days, followed by 50 mg/day). Prednisone was decreased every week by 10 mg. After 10 weeks, the retroperitoneal mass had regressed and the double J catheters were removed. 8 months after immunosuppressive therapy was started, there was an almost complete remission of the retroperitoneal mass. Serum creatinine concentration was 88·4 mol/L. Prednisone (5 mg) was stopped after 12 months. Mycophenolate mofetil was continued for a further 6 months and relapse did not occur. Despite the advanced stage of disease, combined mycophenolate mofetil and prednisone led to remission of retroperitoneal fibrosis, which made surgery unnecessary.