Severe hematuria in a hematopoietic cell transplant recipient caused by Ureaplasma urealyticum not by BK virus or adenovirus infection

A 17-year-old male with acute lymphoblastic leukemia developed severe hematuria and scrotal swelling after haploidentical hematopoietic cell transplantation (HCT). Urine culture was negative. BK virus and adenovirus were negative. However, Ureaplasma urealyticum was detected. He showed dramatic improvement after doxycycline treatment. This is the first report in the literature of hemorrhagic cystitis caused by U.urealyticum in a HCT recipient. In HCT recipients with hemorrhagic cystitis, U.urealyticum should be considered as a potential cause.