Intestinal microsporidiosis occurring in two renal transplant recipients treated with mycophenolate mofetil

Background. Intestinal microsporidiosis is a major cause of chronic diarrhe a and malabsorption in patients with human immunodeficiency virus. Its occu rrence in transplant recipients has exceptionally been reported to date. Methods. We report what we believe are the first two cases of intestinal mi crosporidiosis in renal transplant recipients. The patients were treated wi th mycophenolate mofetil. Results. The clinical presentation was chronic diarrhea with massive weight loss. Stool analysis revealed microsporidian spores, identified as Enteroc ytozoon bieneusi spores by polymerase chain reaction. The onset of this opp ortunistic infection in these two patients is believed to be secondary to a n increase in immunosuppression after azathioprine replacement by mycopheno late mofetil. The withdrawal of mycophenolate mofetil led to clinical recov ery. Conclusion. The incidence of microsporidiosis will probably increase in tra nsplant recipients treated with powerful immunosuppressants. Therefore, we recommend a systematic search for microsporidian spores in stool specimens in cases of unexplained diarrhea in these patients.