The Etiological Study On The Late-onset Hemorrhagic Cystitis Post Hematopoietic Stem Cell Transplantation

Objective: To study the role of polyomavirus infection in the development of the late onset hemorrhagic cystitis (LOHC) post hematopoietic stem cell transplantation (HSCT), and analyze the risk factors of LOHC post HSCT.Methods: (1)Patient characteristics: From August 2006 to April 2008, 113 patients undergoing HSCT were enrolled in this study. There were 68 males and 45 females, aged from 10 to 62 years ( median age was 33 years). The diagnoses were AML in 32 cases, ALL in 22 cases, CML in 27 cases, other diseases in 32 cases. Twenty-nine patients received autologous transplantation, and 51 patients received transplants from match sibling donors, 24 from unrelated donors, 9 from partially matched family donors. The condition regimen included modified BU/CY, TBI plus CY, BEAM and some others, according to the type of the donor and disease. All HSCT patients were divided into HC group and no-HC group, and three subgroups as grade 1, grade 2 and grade 3-4 by the severity of HC.(2)Virus detection: Medistream urine and blood samples were collected early in the morning once before transplantation then weekly after HSCT till the end of hospitalization. Control group included 40 healthy adults. Virus DNA were extracted from the urine and plasma samples of all HSCT recipients. BK virus DNA was amplified by qualitative PCR. Digestion of the PCR products with BamH I before electrophoresis was used to discriminate between BKV and JCV sequences. A standard DNA with known number of virus copies was prepared by a positive BKV control amplification. Real-Time quatitative PCR was used to quantify BKV DNA in the urine samples. CMV antigen was detected in all patients peripheral blood by Immunofluorescence histochemical examination. Adenovirus DNA was also detected by qualitative PCR in the same samples. Different roles of various virus in the development of LOHC post HSCT were then analyzed.(3) The different clinical characteristics between groups were compared in factors ofsex, age, condition regimen, donor type, CMV infection, BKV viruria, grade II to IV GVHD and severe infection, which reveals the risk factors of LOHC post HSCT.Results: (1) LOHC occurred in 22 of the 113 patients undergoing transplantation, with an incidence rate of 19.5 % , all HC patients were allogenetic transplants recipients.There were HC of grade 1 in 7 cases, grade 2 in 11 cases, grade 3 in 3 cases, and grade 4 in one case. The median onset time of HC was 44 (13～114) days post transplantation.(2)BK viruria was detected in 50 of all 113 HSCT patients (44.2%), including BKV viruria in 49 cases, and JCV in one case. The lowest virus copies detected from HSCT patients by quantitative PCR was 24.4 copies/μl, and the highest copies was 1.03×109 copies/μl. BK virus was not detected in 40 control individuals and all blood samples. Twenty-one of 22 HC patients had positive results in detection of BK viruria, with the infection rate of 95.5%, which was much higher than that of no-HC patients (31.9%), P=0.000.The mean time of BK viruria detection in HC patients was 25 days post transplantation , earlier than the onset time of HC (47 days), P=0.002. The persistence time of BK viruria was also longer than that of HC ( 6 weeks vs11 days). But neither difference was found between those HC groups of three grades in the onset time and persistence time of HC, nor in the first time of positive detection. Meanwhile, the persistence time of BK viruria in HC patients of grade 3-4 was longer than that of other two groups ( 13 vs 6 and 5 weeks) P=0.042. On the other hand ,the mean level of BK virus DNA in the first positive samples of the HC patients was 104copies/μl, then climbed to 105 copies/μl in 60% of HC patients on the onset time of HC, and finally dropped back to 104copies/μl weeks after the HC was resolved.CMV antigen virema was found in 21 of the 113 HSCT patients, including 9 patients with HC ( infection rate in HC was 40.9%), which was higher than the no-HC patients. The mean onset time of CMV antigen virema was 35 days post HSCT, similar to the onset time of HC (45 days post HSCT). No adenovirus DNA was discovered from all samples on the onset time of HC and one month post transplantation, and nor in control group. (3) Severe infection developed in 10 of the 22 HC patients (45.5%), and CMV antigen was detected in 9 of the 22 HC patients. Nine of 22 HC patients developed grade II-IV aGVHD, the median onset time of aGVHD was similar to that of HC. Univariate analysis indicated that unrelated donors or partially matched family donors, condition regimen with CTX or Bu or ATG/ALG, CMV virema, BKV viruria, aGVHD of gradeⅡ-Ⅳ, severe infection were associated with the occurrence of LOHC. Cox's proportional hazard regression analysis showed that only BKV viruria, aGVHD of gradeⅡ-Ⅳwere the independent risk factors of the LOHC.Conclusions: (1)BK viruria is a main pathogenic cause of the LOHC post HSCT. The occurrence of BKV viruria in HSCT patients, together with the increasing of BK virus copies in urine, and a high level of 105 copies/μl may indicate a possible development of HC.(2) Unrelated donors or partially matched family donors, condition regimen including CTX or Bu or ATG/ALG, CMV antigenemia, BKV viruria, acute GVHD of gradeⅡ-Ⅳ, severe infection were associated with the occurrence of LOHC. Only BKV viruria, acute GVHD of gradeⅡ-Ⅳwere the independent risk factors of LOHC. Acute GVHD may contribute to occurrence of the LOHC.