Hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation: experience in a pediatric oncological institution.

Objective: To analyze the risk factors associated with hemorrhagic cystitis (HC) severity and the treatment strategies available in HC patients following allogeneic hematopoietic stem cell transplantation (AHSCT).

Materials and methods: A retrospective study of medical records was carried out. Patients with HC following AHSCT treated from 2017 to 2021 were divided into two groups according to severity -mild and severe. Demographic data, disease-specific characteristics, urological sequelae, and overall mortality were compared between both groups. The hospital's protocol was used for patient management.

Results: 33 episodes of HC were collected in 27 patients, 72.7% of whom were male. HC incidence following AHSCT was 23.4% (33/141). 51.5% of HCs were severe (grades III-IV). Severe graft host disease (GHD) (grades III-IV) and thrombopenia at HC onset were associated with severe HC (p= 0.043 and p= 0.039, respectively). This group had longer hematuria times (p< 0.001) and required more platelet transfusions (p= 0.003). In addition, 70.6% required bladder catheterization, but only 1 case needed percutaneous cystostomy. None of the patients with mild HC required catheterization. No differences were found in terms of urological sequelae or overall mortality.

Conclusions: Severe HC could be predicted thanks to the presence of severe GHD or thrombopenia at HC onset. Severe HC can be managed with bladder catheterization in most of these patients. A standardized protocol may help reduce the need for invasive procedures in patients with mild HC.