[Acute renal failure secondary to retroperitoneal fibrosis as first manifestation of lupus nephritis].

Retroperitoneal fibrotic is a fibrous process of the retroperitoneum and can result in ureteral obstruction. Although the pathogenesis is unknown, it is suggested that an immunological mechanism plays a role. It can occur as an isolated finding or be associated with several conditions such as malignancies, infections, connective tissue disease and the action of drugs. However, a few cases of retroperitoneal fibrosis, associated with systemic lupus erythematosus (SLE) have been reported. We describe a case of a 23-year-old female with lupus nephritis who presented with bilateral obstructive nephropathy due to retroperitoneal fibrosis. Treatment with steroids improved both conditions. Our case and previously reported cases of SLE and retroperitoneal fibrosis support the hypothesis that this association is not fortuitous, but reflects a common immunological mechanism.