[Immune reconstitution inflammatory syndrome (IRIS) of the small bowel in an immunocompromised patient suffering from systemic lupus erythematosus and non-tuberculous mycobacteriosis].

An overwhelming immune reaction resulting in granulomatous inflammation after infection with opportunistic pathogens is termed immune reconstitution inflammatory syndrome (IRIS). It has mainly been described in patients with human immunodeficiency virus (HIV) infection on highly active antiretroviral therapy (HAART) who show a significant increase of low CD4 T cells (initially <50/microl). IRIS may lead to organ damage and differential diagnosis is often difficult. We report the case of a 38-year-old female patient who developed a Mycobacteria genavense infection of the liver and the bowel after several immunosuppressive therapies for systemic lupus erythematosus. CD4 T cell counts as low as 17/microl were found and immunosuppressive therapy was stopped. Despite several courses of antibiotic treatment and rising CD4 T cell counts, severe malabsorption persisted. Upper endoscopy revealed a continuous inflammation with pseudopolyps of the small bowel and histologically, a granulomatous infiltrate was detected. After exclusion of a persisting infection by Mycobacteria genavense, IRIS of the small bowel was suspected and treatment with prednisolone was started. The clinical and histological picture improved significantly, the number of CD25(+)CD4(+) cells decreased in the lamina propria of the duodenum under treatment with prednisolone and Foxp3+ regulatory T cells (Treg) accumulated around granulomas. This case shows that IRIS is not restricted to HIV patients but may also occur in otherwise immunosuppressed patients. Due to different treatment strategies, distinguishing IRIS from infectious diseases is essential. The role of Treg in IRIS has to be elucidated.