Risk Factors for Pediatric Hemorrhagic Cystitis Following HCT

Researchers in Poland have identified several risk factors for the development of BK virus (BKV) haemorrhagic cystitis in children undergoing haematopoietic cell transplantation (HCT). Based on the identified factors, they concluded that “Excessive immune response is related to GVHD [graft-vs-host disease] and immunosuppressants may play a critical role in the development of BKV hemorrhagic cystitis. “

According to the study, the results of which are published in the Annals of Hematology, “[Hemorrhagic cystitis] remains frequent and troublesome, especially in the clinically severe phase, often causing long-term hospitalization, but rarely contributing to the death of children after HCT. “

This study was designed to determine the incidence and clinical course of BKV in children undergoing transplantation. The study included 133 patients tested for BKV colonization and infection. BKV haemorrhagic cystitis occurred in 36 (27%) of patients. Of the study population, patients had acute lymphoblastic leukemia (ALL; 57 patients), acute myeloblastic leukemia (AML; 11 patients), myelodysplastic syndromes (MDS; 10 patients), severe anaplastic anemia (SAA; 19 patients), primary immunodeficiencies (PID; 12 patients) and other diseases.

Using univariate analysis, several factors were associated with the occurrence of hemorrhagic cystitis, including age greater than 5 years, peripheral blood transplantation, matched unrelated donor transplantation, busulfan cyclophosphamide melphalan conditioning regimen and AML. In addition, the researchers noted that acute GVHD and gut GVHD were significantly associated with BKV hemorrhagic cystitis.

In the multivariate analysis, an increased incidence of haemorrhagic cystitis was associated with AML, age above 5 years, corresponding unrelated donor transplants and children with GVHD.

A total of 13 patients died, including 10 with BKV haemorrhagic cystitis; however, the researchers noted that none of the deaths were attributed to BKV infection.


Salamonowicz-Bodzioch M, Frączkiewicz J, Czyżewski K, et al. Prospective analysis of BKV hemorrhagic cystites in children and adolescents undergoing hematopoietic cell transplantation. Ann Hematol. Published online March 4, 2021.doi: 10.1007 / s00277-021-04454-7

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