Retrospective Analysis of Hemorrhagic Cystitis After Unrelated Donor Hematopoietic Stem Cell Transplantation In a Chinese Population.
Authors: Jing Jing , Wu Kangni , Luo Yi , Shi Jimin , Tan Yamin , He Jingsong , Zheng Weiyan , Xiao Haowen , Cai Zhen , Lin Maofang , Ye Xiujin , Huang He 
Published: October 2019

Abstract
Abstract 4546
Hemorrhagic cystitis (HC), occurring mostly within first month after allogeneic hematopoietic stem cell transplantation (allo-HSCT), is a common complication which often requires prolonged hospitalization, considerable expense, and occasionally causes significant morbidity. The data from different transplantation centers about this complication are different in the incidence, risk factors, therapeatic strategies and outcome. In this study, we retrospectively analyzed the incidence, risk factors, prophylaxis and treatment regimens of HC after unrelated donor HSCT(URD-HSCT)in our center From October 2000 to February 2008, 168 consecutive patients underwent URD-HSCT were enrolled,including 113 male patients and 55 female patients. The median age was 26 years (range,8-52 years). The main myeloablative conditioning regimens used were busulfan/cyclophosphamide (BuCy) without total body irradiation (TBI); Reduced-intensity conditioning regimens (RIC) were predominantly fludarabine-based combinations without irradiation. Anti-thymocyte globulin(ATG) were added to the conditioning regimen in the patients receiving HLA-mismatched URD-HSCT. The prophylaxis regimen for HC included intravenous mesna,hyperhydration and intermittent diuretic. The diagnosis of HC was based on the presence of sustained microscopic or macroscopic hematuria in the absence of other clinical conditions such as urinary bacteria and fungi infection. It could be clinically graded to I to IV according to hematuria and divided into early onset (EOHC) and delayed (LOHC) according to the time of onset. In total, 27 of 168 patients (16.1%) developed HC at a median interval of 40 days post engraftment (range, 8–89 days). Among them,11 patients developed grade I (6.5%), 10 patients developed grade II (6.0%), 6 patients developed grade III (3.6%), while no patients with grade IV. Five patients(2.98%) presented EOHC and 22 patients (13.17%) presented LOHC. We discovered that in 27 patients with HC only 3 were female (11.1%), however in 141 patients without HC, 52(36.9%) were female (P<0.05). Patients with HC had a higher incidence of acute graft-versus-host disease (aGVHD) (92.6% vs 47.5%, P<0.001) and grades II-IV aGVHD (P<0.001), which is consist with previous reports. Furthermore, 16 patients (59.3%) with HC were ≥30-year-old, 50 patients (35.5%) without HC, were ≥30-year-old (P<0.05). Multivariate analysis showed that primary disease type, donor 's gender or age, stem cell source, myeloablative or nonmyeloablative conditioning regimen, HLA or ABO blood mismatching, the existence of CMV seropositivity were not significantly associated with the risk of HC. All patients achieved excellent response after being treated with alkalinization of the urine, hyperhydration with intravenous fluid. Several patients also received urethral catheterization to bladder washout. No patient died of HC. In conclusion, our results demonstrated that recipient 's gender, aGVHD and recipient's age(≥30-year-old), were three risk factors associated with HC. Other risk factors which had been reported to be related to HC in literatures did not show significant impact in our study. Although effective prophylaxis has significantly decreased the incidence of HC, up to date, the precise pathogenesis of HC has not been well elucidated. More clinical and mechanisms researches should to be explored.

Disclosures:
No relevant conflicts of interest to declare.