IgG4-related retroperitoneal fibrosis with acute kidney injury: a case report and literature review.

IgG4-related retroperitoneal fibrosis is a rare cause of renal dysfunction that usually manifests as obstructive nephropathy (sometimes with extrarenal manifestations). Due to the non-specific symptoms at the onset of the disease and often latent course, special laboratory and instrumental examination methods are usually needed to establish a diagnosis. The article describes a clinical case of a relapse of IgG4-related retroperitoneal fibrosis in a 53-year-old patient, who developed bilateral ureterohydronephrosis with postrenal acute kidney injury after the withdrawal of glucocorticoid therapy.