Association between a high BK virus load in urine samples of patients with graft-versus-host disease and development of hemorrhagic cystitis after hematopoietic stem cell transplantation

[Haemorrhagic cystitis following hematopoietic stem cell transplantation: Prophylaxis, diagnosis, and treatment. Guidelines from the SFGM-TC]

Hemorrhagic cystitis (HC) is a common complication after allogeneic hematopoietic cell transplantation (allo-HCT). Its manifestations range from microscopic hematuria without urinary symptoms to extensive and prolonged macroscopic hemorrhage requiring invasive interventions that can often prolong the duration of hospitalization and result in significant morbidity. The early onset of HC is related to allo-HCT conditioning regimen, whereas the late onset form is secondary to viral infection, most commonly due to BK virus. In the framework of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) practice harmonization workshops held in Lille in September 2021, the prophylaxis, the diagnostic approach and the treatments of HC following allografting were reviewed after analysis of published studies.

Incidence of hemorrhagic cystitis following unmanipulated peripheral blood stem cell transplantation in acute Leukemia: A retrospective single-center risk factor analysis

BACKGROUND

Hemorrhagic cystitis (HC) is an important adverse event experienced after hematopoietic stem cell transplantation (HSCT). Severe HC could lead to significant morbidity, prolonged hospitalization with increased health-care costs, and may cause considerable mortality.

OBJECTIVES

In order to investigate the influence of different contributing factors other than BK viruria on HC occurrence in a homogenous population, we retrospectively analyzed the potential risk factors.

STUDY DESIGN

We conducted a retrospective study among 200 patients (median age 12.4 years, IQR: 7.9-16.1) with acute leukemia who received peripheral blood allogenic HSCT after radiation-free myeloablative conditioning regimen, in pediatric cell therapy department of Research Institute for Oncology, Hematology and Cell Therapy (RIOHCT), Tehran, Iran, between December 2014 and December 2021. Associations between risk factors and outcomes were examined by univariable and multivariable logistic regression models.

RESULTS

A total of 46 patients (23%) had developed HC during the study period. The median onset of HC was 29 (IQR: 24-37) days post-transplant, and it persisted for a median of 33 (7-270) days. The incidence of HC in our patients was estimated to be 3 in 1000 cases (95% CI: 2-4). The results of multivariable logistic model shows that the chance of HC in T-cell acute lymphoblastic leukemia (ALL) compared to B-cell All is nearly five times more (OR = 4.88; 95%CI: (1.51-15.78), P = 0.008). The incidence of HC in patients who underwent HSCT from haploidentical donors was significantly higher than full matched donors (P < 0.001). Undergoing transplant from a matched unrelated and haploidentical donor both augment the chance of HC in about six times more than matched related donors (OR = 6.36; 95%CI: (1.58-25.49), P = 0.009 and OR = 5.7; 95%CI: (1.83-17.75), P = 0.003, respectively). In patients who developed HC compared to non-HC group, overall survival was much worse (P < 0.001).

DISCUSSION

Most studies have failed to demonstrate any relationship between late-onset HC and the dose of cyclophosphamide. In our study, although the dose of cyclophosphamide was similar in HSCT from MRD and MUD, the hazard of HC incidence was significantly higher in the latter group. This could be accredited to ATG, as in patients in the MRD group who had not received any ATG, the incidence of HC was much lower than the patients who had underwent HSCT from MUD or haploidentical donor group.

CONCLUSIONS

Patients with T-cell ALL and those who under haploidentical HSCT had the highest incidence of HC.

JC polyomavirus: a short review of its biology, its association with progressive multifocal leukoencephalopathy, and the diagnostic value of different methods to manifest its activity or presence

INTRODUCTION

JC polyomavirus is the causative agent of progressive multifocal leukoencephalopathy (PML), a demyelinating disease resulting from the lytic infection of oligodendrocytes that may develop in immunosuppressed individuals: HIV1 infected or individuals under immunosuppressive therapies. Understanding the biology of JCPyV is necessary for a proper patient management, the development of diagnostic tests, and risk stratification.

AREAS COVERED

The review covers different areas of expertise including the genomic characterization of JCPyV strains detected in different body compartments (urine, plasma, and cerebrospinal fluid) of PML patients, viral mutations, molecular diagnostics, viral miRNAs, and disease.

EXPERT OPINION

The implementation of molecular biology techniques improved our understanding of JCPyV biology. Deep sequencing analysis of viral genomes revealed the presence of viral quasispecies in the cerebrospinal fluid of PML patients characterized by noncoding control region rearrangements and VP1 mutations. These neurotropic JCPyV variants present enhanced replication and an altered cell tropism that contribute to PML development. Monitoring these variants may be relevant for the identification of patients at risk of PML. Multiplex realtime PCR targeting both the LTAg and the archetype NCCR could be used to identify them. Failure to amplify NCCR should indicate the presence of a JCPyV prototype speeding up the diagnostic process.

Clinical study of late-onset hemorrhagic cystitis after allo-HSCT without in vitro T-cell depletion

This study is to investigate the hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) without in vitro T-cell depletion. Patients receiving allo-HSCT in 2019 were enrolled. The occurrence and clinical characteristics of HC after HLA-identical HSCT and haploidentical HSCT were retrospectively analyzed. BK, JC, cytomegalovirus, and other viruses were monitored when HC occurred. Conventional HC treatment was performed. Additionally, 5 cases of severe refractory HC were treated with adipose-derived mesenchymal stem cell (ADSC) besides conventional HC treatment. Totally, 54 patients with allo-HSCT were enrolled, including 12 cases with HLA-identical HSCT and 42 cases with haploidentical HSCT. Among them, 17 developed late-onset HC (LOHC). There was no early-onset HC. The median onset time was 33.5 (9-189) days, with a median duration of 19 (5-143) days. There were 8 cases of grade III HC and 2 cases of grade IV HC. The cumulative incidence of LOHC in 54 patients was 29.6%, and the cumulative incidence of LOHC in 42 patients with haploidentical HSCT was 40.5%. The 1-year expected progression-free survival (PFS) of 26 patients without HC was 86.6%, and the 1-year expected PFS of 16 HC patients was 74.5%. However, there was no statistically significant difference (P = .326). The urine BK virus of 14 patients was positive, with the lowest of 1.98 × 105 copies/mL, and the highest of 8.96 × 105 copies/mL. For the 5 patients with severe refractory HC, the lowest infusion dose of ADSC was 0.9 × 106/kg and the highest was 1.4 × 106/kg. All 5 patients were cured. The incidence of LOHC is higher after haploidentical HSCT. LOHC is positively correlated with urine BK virus. LOHC has no obvious effect on the overall PFS of patients. ADSC infusion has a good therapeutic effect on severe and prolonged LOHC.

Incidence of late-onset hemorrhagic cystitis and its effect on PFS in acute leukemia patients after haplo-PBSCT: The 5-year single-center data

We conducted a single-center 5-year retrospective study on the occurrence of hemorrhagic cystitis (HC) and its effect on survival after haploid high-dose peripheral blood stem cell transplantation (haplo-PBSCT) in patients with acute leukemia. We retrospectively analyzed 153 patients with acute leukemia who were treated with non-in vitro T-cell depleted haplo-PBSCT and myeloablative conditioning regimen. All patients were followed up for more than 180 days after transplantation. HC occurrence and its effect on long-term progression free survival (PFS) were retrospectively analyzed. Totally, 64 out of 153 patients had late onset HC (LOHC). No early onset HC occurred. The median onset time was 38.5 (17-163) days after transplantation. The cumulative incidence of LOHC was 41.8%. The cumulative incidence of LOHC in patients under 27 years old (50.0%) and in ALL patients (54.1%) was significantly higher than that in patients over 27 years old (34.5%) and in AML patients (36.9%), respectively. The cumulative incidence of mild LOHC was 44.2% and that of severe LOHC was 28.6%. However, urine copies of BK virus were not related to LOHC duration. There was no significant difference in 3-year expected PFS between AML and ALL patients with and without LOHC, or between LOHC duration more than and less than 38.5 days (P>0.05). Conclusively, LOHC incidence is higher in patients under 27 years old and in ALL patients. LOHC occurrence is related to urine BK virus copy, but not blood BK virus load. LOHC duration and severity has no significant effect on PFS.

[Clinical study of mesenchymal stem cells from third-party donors in the treatment of refractory late onset hemorrhagic cystitis after allogeneic hematopoietic stem cell transplanation]

Objective: To examine the efficacy and safety of third-party bone marrow-derived mesenchymal stem cells (MSCs) in the treatment of refractory delayed hemorrhagic cystitis (LOHC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Twenty patients with refractory LOHC received conventional therapy combined with MSCs obtained from third-party donors' bone marrow (BM) . MSCs were given intravenously at a dose of 1 × 10(6) cells/kg once weekly until either the symptoms improved or no changes in LOHC were seen after continuous infusion four times. BK viruria (BKV) -DNA, JC viruria (JCV) -DNA, and CMV-DNA were detected by real-time quantitative PCR before and 8 weeks after the MSCs infusion. Results: ① Of the 20 patients with refractory LOHC, 15 were males, and 5 were females, and the median age was 35 (15-56) years. There were 5 cases of acute lymphoblastic leukemia (ALL) , 9 cases of acute myeloid leukemia (AML) , 5 cases of myelodysplastic syndrome (MDS) , and 1 case of maternal plasma cell like dendritic cell tumor (BPDCN) . There were 4 cases of HLA identical transplantation and 16 cases of HLA incomplete transplantation. ②The median number of MSC infusions for each patient was 3 (range: 2-8) . Seventeen patients achieved complete response, and one had a partial response after treatment. The overall response rate was 90%. Over a median follow-up period of 397.5 days (range 39-937 days) post-transplantations, 13 patients survived, and 7 died. The causes of death included aGVHD (1 case) , infections (5 cases) , and TMA (1 case) . ③The copy numbers of BKV-DNA and CMV-DNA in urine in the 8th week after MSCs infusion were significantly lower than those observed before treatment (11342.1×10(8) copies/L vs 5.2×10(8) copies/L, P=0.016; 3170.0×10(4) copies/L vs 0.2×10(4) copies/L, P=0.006, respectively) , while JCV-DNA did not significantly differ when compared to before treatment (P=0.106) . ④ No adverse reactions related to MSC infusion occurred in any of the 20 patients. Conclusion: Third-party bone marrow-derived MSC has significant efficacy and good safety in the treatment of refractory LOHC after allogeneic HSCT.

Risk factors associated with hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation

Hemorrhagic cystitis (HC) is a common complication of allogeneic hematopoietic stem cell transplantation (HSCT). The incidence is about 7% to 68%, and some patients have to suffer a long period of frequent, urgent, and painful urination, which brings great pain. This study aimed to analyze risk factors of HC and its effect on patient survival. We collected the medical records of 859 patients who underwent HSCT at our hospital between August 2016 and August 2020. Patients with and without HC were matched using propensity score matching at a 1:1 ratio based on sex, age, and diagnosis, and logistic regression analyses were used to identify factors associated with HC. We used Kaplan–Meier curves to analyze the survival rates of patients in the HC and non-HC groups. We also analyzed the relationship between BK viral load and the occurrence of HC using receiver operating characteristic curve (ROC) analysis. After propensity score matching, there were 131 patients each in the HC and non-HC groups. In the HC group, 89 patients (67.9%) had mild HC (stage II°) and 43 (32.1%) had severe HC (stage III–IV). The median interval between stem cell transplantation and HC development was 31 (3–244) days. Univariate analysis indicated that donor age, hematopoietic stem cell source, HLA, acute graft-versus-host disease, busulfan, anti-thymocyte globulin (ATG), total body irradiation, cytomegalovirus (CMV) (urine), and BK polyomavirus (BKV) (urine) were significantly associated with HC. ATG, CMV (urine), and BKV (urine) were independent risk factors for HC based on the multivariate analysis. The Kaplan–Meier survival analysis showed no significant difference between the HC and non-HC groups (P = .14). The 1- and 2-year survival rates in the HC group were 78.4% and 69.6%, respectively, and the corresponding rates in the non-HC group were 84.4% and 80.7%, respectively. ROC analysis indicated that a urine BKV load of 1 × 10⁷ copies/mL was able to stratify the risk of HC. In conclusion, when the BKV load is >1 × 10⁷, we need to be aware of the potential for the development of HC.

BKV Related Hemorrhagic Cystitis-An Insight into Risk Factors and Later Complications-An Analysis on Behalf of Polish Adult Leukemia Group

Simple Summary

Despite noticeable progress in allogeneic hematopoietic stem cell transplantation, potential viral reactivations are still one of the most challenging complications. The aim of our study was to identify predictive and risk factors associated with the occurrence of the BK virus related hemorrhagic cystitis following hematopoietic stem cell transplantation. Furthermore, we investigated the impact of various factors on the clinical course of patients after hematopoietic stem cell transplantation. We confirmed that >0.75 × 10³ BK virus copies/mL in serum at day +21 after allogeneic hematopoietic stem cell transplantation has a strong predictive ability for hemorrhagic cystitis. Thus, we believe that our findings could be helpful in establishing the predictive validity of the BK viral load measurement in polyomavirus BK-associated hemorrhagic cystitis and survival.

Abstract

BK virus reactivation increases the likelihood of hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplant (HCT). In this study, we aimed to identify predictive and risk factors associated with the increased occurrence of this condition following HCT. On a group of 124 patients aged ≤71 years old (median 40 years) who underwent HCT, we analyzed sex, age, time from diagnosis to transplantation, type of conditioning, donor’s relationship, age, and sex, the impact of immunosuppression with different drugs, and acute and chronic GVHD, BK viremia and viruria as potential factors increasing the risk of BK-related HC after HCT. HC occurred among 24 patients (24/124; 29.2%). A significant correlation was observed between HC incidences after HCT, BK viremia and viruria, and acute GVHD occurrence. Furthermore, the level of BKV DNA in serum at day +21 (>0.75 × 10³) significantly impacted the patients’ survival time. According to our results, the likelihood ratio of BKV-DNA on day +21 in serum is 6.25, indicating that this diagnostic test has the potential to be utilized in a clinical setting. These findings may be used as a voice in the discussion on implementing an optimal preemptive treatment in BKV reactivation after allogeneic HCT.

Pretransplant BK Virus-Specific T-Cell-Mediated Immunity and Serotype Specific Antibodies May Have Utility in Identifying Patients at Risk of BK Virus-Associated Haemorrhagic Cystitis after Allogeneic HSCT

BK polyomavirus (BKPyV) persists lifelong in renal and urothelial cells with asymptomatic urinary shedding in healthy individuals. In some immunocompromised persons after transplantation of hematopoietic stem cells (HSCT), the BKPyV high-rate replication is associated with haemorrhagic cystitis (HC). We tested whether the status of BKPyV immunity prior to HSCT could provide evidence for the BKPyV tendency to reactivate. We have shown that measurement of pretransplant anti-BKPyV 1 and 4 IgG levels can be used to evaluate the HC risk. Patients with anti-BKPyV IgG in the range of the 1st-2nd quartile of positive values and with positive clinical risk markers have a significantly increased HC risk, in comparison to the reference group of patients with "non-reactive" anti-BKPyV IgG levels and with low clinical risk (LCR) (p = 0.0009). The predictive value of pretransplant BKPyV-specific IgG was confirmed by determination of genotypes of the shed virus. A positive predictive value was also found for pretransplant T-cell immunity to the BKPyV antigen VP1 because the magnitude of IFN-γ T-cell response inversely correlated with posttransplant DNAuria and with HC. Our novel data suggest that specific T-cells control BKPyV latency before HSCT, and in this way may influence BKPyV reactivation after HSCT. Our study has shown that prediction using a combination of clinical and immunological pretransplant risk factors can help early identification of HSCT recipients at high risk of BKPyV disease.

Presentation of BK polyomavirus-associated hemorrhagic cystitis after allogeneic hematopoietic cell transplantation

BK polyomavirus (BKPyV) has been associated with hemorrhagic cystitis (HC) after allogeneic hematopoietic cell transplantation (HCT), but the natural history of HC and factors associated with the clinical course are incompletely understood. We retrospectively analyzed allogeneic HCT patients transplanted from 2007-2017 who presented after platelet engraftment or after day 28 post-HCT with BKPyV-associated HC (BKPyV-HC), which was defined as a positive urine BKPyV PCR, ≥1 plasma BKPyV viral load result, and macroscopic hematuria (Bedi grade ≥2). Factors associated with resolution of macroscopic hematuria and resolution of all cystitis symptoms within 90 days after HC diagnosis were investigated in multivariable models. In 128 patients with BKPyV-HC, the median times from diagnosis to resolution of all symptoms, macroscopic hematuria, and urinary clots (present in 55% [71/128]) were 24 days (15-44), 17 days (10-30), and 14 days (5-26), respectively. Ninety percent of patients had BKPyV viremia at the onset of HC with a median viral load of 1850 copies/mL (interquartile range, 240-8550). In multivariable models, high plasma viral load (≥10 000 copies/mL) and cytopenias at the beginning of BKPyV-HC were significantly associated with longer macroscopic hematuria and cystitis symptoms. Use of cidofovir was not associated with shorter duration of illness. In conclusion, BKPyV-HC after allogeneic HCT is characterized by prolonged and severe symptoms and requires improved management strategies. High-grade viremia and cytopenias were associated with a longer duration of BKPyV-associated HC. Accurate descriptions of disease and factors associated with prolonged recovery will inform end points of future clinical trials.

Risk factors of BK viral hemorrhagic cystitis in allogenic hematopoietic stem cell transplantation

Reactivation of BK virus (BKV) can occur during intensive immunosuppression such as in allogenic hematopoietic stem cell transplant (AHSCT) recipients for whom a systematic PCR urine test for BKV will be positive in 50% to 100% of patients. Only 5% to 40% will develop BKV hemorrhagic cystitis (HC). Thus, BKV PCR testing is useful to confirm a diagnosis of BKV-HC but not to predict its occurrence. The aim of this retrospective study was to ascertain the risk factors of developing BKV HC, mostly in patients receiving posttransplant cyclophosphamide. The study looked at data from Grenoble Alpes University Hospital included in the national retrospective register ProMISe, administered by the "Société Francophone de Greffe de Moelle et de Thérapie Cellulaire". Urine BKV PCR was performed when patients presented grade ≥ 2 hematuria with clinical symptoms of cystitis. BKV-HC was defined as an association of clinical symptoms of cystitis, grade ≥ 2 hematuria and BKV viruria > 7 log₁₀ copies/ml. From January 2014 to January 2018, 168 AHSCTs were considered for analysis, of which 43 (25.6%) developed BKV-HC and 44.9% of the subgroup that received posttransplant cyclophosphamide. After logistic regression, the risk factors associated with BKV-HC were reduced to posttransplantation exposure to cyclophosphamide (OR 4.25, [1.66; 10.87], P = .02), age < 40 y (OR 3.85 [1.51; 9.80], P = .005) and corticosteroid therapy (OR 3.86, [1.59; 9.36], P = .003). Exposure to cyclophosphamide, younger age (<40) and corticosteroid therapy are potential risk factors for BKV-HC.

Prospective analysis of BKV hemorrhagic cystitis in children and adolescents undergoing hematopoietic cell transplantation

BK virus is one of the most common causes of hemorrhagic cystitis (HC) in children undergoing hematopoietic cell transplantation (HCT). Viruses can be found in urine and serum samples of immunocompromised patients. Malignant diseases, age, cell source, day of granulocyte reconstitution, conditioning regimen, or use of total body irradiation may play an important role in BKV epidemiology, development of hemorrhagic cystitis course, and outcome. The aim of this study was to evaluate the incidence, clinical course, and risk factors for BKV-HC in children undergoing HCT. A total number of 133 patients who were prospectively tested for BKV colonization/infection were enrolled into this multicenter analysis. Episodes of BKV-HC occurred in 36/133 (27%) enrolled subjects. In a univariate analysis for BKV-HC incidence, the following factors were significant: age >5 years, peripheral blood transplantation, matched unrelated donor (MUD) transplantation, busulfan-cyclophosphamide-melphalan conditioning regimen, and acute myeloblastic leukemia (AML) diagnosis. Presence of acute graft-versus-host disease (aGVHD) in liver and gut GVHD was a significant risk factor of BKV-HC. No BKV-attributed deaths were reported. In multivariate analysis, the incidence of HC was significantly higher in patients with AML, age >5 years, MUD transplants, and children with GVHD. HC is a frequent complication after HCT among children causes prolonged hospitalization but rarely contributes to death. We identified risk factors of BKV-HC development in children, with focus on aGVHD: we concluded that excessive immune reaction connected with GVHD and immunosuppression drugs might play a pivotal role in the development of BKV-HC.

Management of BK virus-associated haemorrhagic cystitis in allogeneic stem cell transplant recipients

BK virus (BKV)-related haemorrhagic cystitis (HC) is an important cause of morbidity following allogeneic haematopoietic stem cell transplantation (HSCT). The various risk factors include high-level BKV viruria and/or viremia, myeloablative conditioning, acute graft versus host disease (GVHD), cytomegalovirus viremia, and unrelated or HLA-mismatched donor. The presence of high plasma BK viral load and cytopenias have been implicated as important predictors for protracted disease course. These patients frequently require hospitalisation which may extend for several weeks. Supportive measures in the form of analgesics, intravenous hydration, bladder irrigation, and transfusion support remain the mainstay of management. Various drugs have been used with limited success in this setting. These include antiviral drugs, fluoroquinolones, leflunomide, growth factors, clotting factors, estrogens, and prostaglandins. The role of adoptive cellular immunotherapy has also been explored but lacks clinical validation. The strategies aimed at expediting urothelial repair like hyperbaric oxygen therapy (HBOT), intravesical fibrin glue and platelet-rich plasma (PRP) are emerging. Some patients with severe disease do require surgical intervention to relieve urinary obstruction. The frequent co-occurrence of acute GVHD and CMV disease further complicates the management in such patients. There is an unmet need for effective and evidence-based options for the prevention and management of this disease. Due to lack of robust data supported by randomised trials, the acceptability of the available guidelines to simplify the treatment is expected to be low. Despite the availability of various treatment options, the management of BKV-related HC in day-to-day practice continues to be a challenge. The aim of this article is to put forward an up-to-date review of the preventive and therapeutic strategies for BKV-related HC.

Treatment protocols for BK virus associated hemorrhagic cystitis after hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) represents a vital curative choice for many disease. However its outcome can be hampered by a variety of transplant associated complications. Hemorrhagic cystitis (HC) considered as one of the major difficulties after HSCT. HC symptoms comprise hematuria, dysuria, burning during urination, urinary frequency, urgency and incontinency, abdominal or suprapubic pain, urinary obstruction, and renal or bladder damage. There are a lot of causes for HC development. BK virus reactivation is one of the major causes of HC after HSCT. There is still no standard and approved treatment protocol for BK virus associated HC (BKV-HC). Treatment of HC is according to the local standard operating procedures, depending on the cause and severity. In this study we will review the current treatments available for this disease. We have divided the therapeutic procedures into 5 categories including conservative therapy, complimentary options, surgical procedures, pharmacological treatments and adoptive cell therapy. We believe that comparing the advantages and disadvantages of different therapies make it easier to choose the best treatment protocol. In addition, we had a greater focus on adoptive cell therapy, because it is a relatively new introduced method and might be a logical alternative to conventional treatments for refractory patients. In total, no definitive recommendation is possible for current available treatments because these procedures have only been utilized sporadically in a limit number of patients. Furthermore, a number of treatment options are only experimental and definitely need more effort.

Development and validation of a risk assessment tool for BKPyV Replication in allogeneic stem cell transplant recipients

BACKGROUND

BK polymavirus (BKPyV), a member of the family Polyomaviridae, is associated with increased morbidity and mortality in allogeneic stem cell transplant recipients.

METHODS

In our previous retrospective study of 2477 stem cell transplant patients, BKPyV replication independently predicted chronic kidney disease and poor survival. In this study, using the same cohort, we derived and validated a risk grading system to identify patients at risk of BKPyV replication after transplantation in a user-friendly modality. We used 3 baseline variables (conditioning regimen, HLA match status, and underlying cancer diagnosis) that significantly predicted BKPyV replication in our initial study in a subdistribution hazard model with death as a competing risk. We also developed a nomogram of the hazard model as a visual aid. The AUC of the ROC of the risk-score-only model was 0.65. We further stratified the patients on the basis of risk score into low-, moderate-, and high-risk groups.

RESULTS

The total risk score was significantly associated with BKPyV replication (P < .0001). At 30 days after transplantation, the low-risk (score ≤ 0) patients had a 9% chance of developing symptomatic BKPyV replication, while the high-risk (score ≥ 8) of the population had 56% of developing BKPyV replication. We validated the risk score using a separate cohort of 1478 patients. The AUC of the ROC of the risk-score-only model was 0.59. Both the total risk score and 3-level risk variable were significantly associated with BKPyV replication in this cohort (P < .0001).

CONCLUSIONS

This grading system for the risk of symptomatic BKPyV replication may help in early monitoring and intervention to prevent BKPyV-associated morbidity, mortality, and kidney function decline.

Prospective Analysis of Hemorrhagic Cystitis and BK Viremia in Allogeneic Hematopoietic Stem Cell Transplantation

Objective

BK virus (BKV) infection has been shown to be related to hemorrhagic cystitis (HC) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). There are conflicting data regarding the association between BKV titers in plasma and clinical disease as well as the risk factors for BKV-related HC. Our aim is to study the risk factors and relationship with plasma BK viral load for development of HC in a prospective analysis.

Materials and Methods

We prospectively evaluated 59 patients who received allo-HSCT between 2014 and 2016 by quantitative BK virus polymerase chain reaction (PCR) (Altona Diagnostics, Germany) from blood samples at days 0, 30, 60, and 90 after allo-HSCT. The patients were monitored for signs and symptoms of HC.

Results

HC was diagnosed in 22 patients (37%) at a mean of 100 days (range: 0-367 days). In multivariate analysis, the usage of cyclophosphamide (sub-distribution hazard ratio [sdHR]: 7.82, confidence interval [CI]: 1.375-39.645, p=0.02), reactivated CMV (sdHR: 6.105, CI: 1.614-23.094, p=0.008), and positive BKV viremia (sdHR: 2.15, CI: 1.456-22.065, p=0.01) significantly increased the risk of developing HC. Patients with higher viral loads at day 30 and day 60 were diagnosed with more severe HC (p<0.001). Median BK viral loads of >101.5 copies/mL at day 0 (sensitivity 0.727, specificity 0.875), >98.5 copies/mL at day 30 (sensitivity 0.909, specificity 0.875), and >90.0 copies/mL at day 60 (sensitivity 0.909, specificity 0.875) were indicative of HC.

Conclusion

Our study showed that administration of cyclophosphamide, CMV reactivation, and BK virus positivity were associated with HC. Plasma BK virus PCR titers at days 0, 30, and 60 after transplant were sensitive tools for predicting clinically proven HC.

Targeting IL-11 in the treatment of BK virus-associated haemorrhagic cystitis-A promising new approach

The BK polyomavirus (BKPyV) has pathogenic relevance especially in immunocompromised patients. No causal therapy has been established yet. Therefore, new therapeutic targets need to be identified in experimental studies. A 3D organotypic cell culture model with primary urothelial cells and fibroblasts was used as infection model. The detection of virus replication was performed with quantitative polymerase chain reaction (qPCR), and immunohistochemistry (IHC) was also used for analysis. Interleukin levels were measured by enzyme‐linked immunosorbent assay (ELISA). Interestingly, the signal transducer and activator of transcription 3 (STAT3) pathway seems to be activated during infection with BKPyV, for example phosphorylated STAT3 is significantly (P < 0.0001) elevated on day 6 following infection. Therefore, we performed ELISAs for involved interleukins in STAT3 pathway. Interleukin 11 (IL‐11) was significantly (P = 0.026) elevated at day 9. Subsequently, 3D cultures were treated with IL‐11 neutralizing antibody. At day 9 following infection, the median virus replication rate is 4.4 × 10⁶ copies/ml. The difference to replication rate without treatment was significantly lower at day 6 (P < 0.0001) and at day 9 (P < 0.0001), respectively. STAT3 pathways seem to be involved during BKPyV infection and need further investigation in experimental studies. A very promising target for treatment might be IL‐11.

BK virus infection in allogeneic hematopoietic cell transplantation: An update on pathogenesis, immune responses, diagnosis and treatments

In hematopoietic cell transplantation (HCT) patients, BK polyomavirus (BKPyV) infection results in significant morbidity mainly due to hemorrhagic cystitis (HC). Despite increased knowledge acquired over recent decades, no treatment has shown effectiveness in the management of organ damage in HCT allografts. This review summarizes the current knowledge on BKPyV, from the virus constitution to the pathophysiology and immune-related mechanisms. We next focus on BKPyV-induced HC in HCT to discuss the benefit of monitoring BKPyV viruria and viremia in the management of patients. At last, we review currently used therapeutics, along with future promising therapies to propose clinical and practical guidelines and further interesting research areas.

Pathogenicity of BK virus on the urinary system

Introduction

The polyomaviruses are omnipresent in nature. The major sites of BK virus appearance are the kidney tubular epithelial cells and urinary bladder surface transitional cells.

Material and methods

A literature search according to PRISMA guidelines within the Medline database was conducted in July 2019 for articles presenting data about BK virus in urologic aspect without setting time limits, using the terms ‘BK virus’ in conjunction with transplantation, nephropathy, stenosis, cancer, bladder, prostate, kidney.

Results

The BK virus usually stays latent, however, its replication may become active in various clinical situations of impaired immunocompetence such as solid organ transplantation, bone marrow transplantation, AIDS, pregnancy, multiple sclerosis, administration of chemotherapy or biologic therapy. BK virus is associated with two main complications after transplantation: polyomavirus-associated nephropathy in kidney transplant patients and polyomavirus-associated hemorrhagic cystitis in allogeneic hematopoietic stem cell transplant patients.

Conclusions

The aim of this article was to present available data on urologic aspects of BK virus infection, its detection methods and available treatment.

Impact of extended infusional mesna prophylaxis on the incidence of BK viruria and hemorrhagic cystitis following post-transplantation cyclophosphamide and CTLA4Ig-based haploidentical transplantation

Hemorrhagic cystitis (HC) has been reported with increased frequency following post-transplantation cyclophosphamide (PTCy)-based haploidentical hematopoietic cell transplantation (HCT) along with a strong association with BK viruria. We prospectively evaluated the incidence of BK viruria and HC in 115 patients (median age 20 years, 2-65) undergoing PTCy-based haploidentical HCT with (n = 71) or without (n = 44) CTLA4Ig. HC prophylaxis consisted of a continuous infusion of mesna 30 min prior and 48 h post-PTCy. The overall incidence of BK viruria was 65.7%. None with BK viruria < 10⁴ copies/ml developed clinical symptoms (n = 65). The incidence of BK viruria ≥ 10⁴ copies/ml was 7.1% (n = 8) and 75% developed HC. The incidence of HC was 5.4% at a median of 30 days. Both BK viruria ≥ 10⁴ copies/ml and HC were strongly associated with acute GVHD (p < 0.001). A higher NRM was observed in those with BK viruria ≥ 10⁴ copies/ml, related to GVHD and its complications (41.7% vs 12.6%, p = 0.04). The incidences of acute GVHD, vis-à-vis, overall BK viruria, BK viruria ≥ 10⁴ copies/ml, and HC, tended to be lower in patients receiving CTLA4Ig. Thus, extended infusional mesna, coupled with significant reduction in alloreactivity along with possible preservation of antiviral immunity associated with the use of CTLA4Ig, was probably responsible for a much lower incidence of BK viruria and resultant HC than reported previously following PTCy-based haploidentical HCT.

Intravesicular Cidofovir in the Treatment of BK Virus-Associated Hemorrhagic Cystitis Following Hematopoietic Stem Cell Transplantation

Background: BK virus hemorrhagic cystitis (BKV-HC) is a common complication following hematopoietic stem cell transplant (HSCT); optimal management remains uncertain. Supportive care (bladder irrigation and blood transfusions) and intravenous and intravesicular cidofovir have all been used with varying success. Objective: The purpose of this study was to determine the safety and effectiveness of intravesicular cidofovir for BKV-HC following HSCT. Methods: A retrospective analysis of all HSCT patients with BKV-HC prescribed intravesicular cidofovir from 2012 to 2017. Results: 33 patients were treated for BKV-HC. The median age was 50 years (range 23-73), and 18 (55%) were male. The median HC symptom severity was 2, with a median BK urine viral load pretreatment of 100,000,000 IU/mL. Patients received a median of 2 intravesicular treatments (range 1-7) at a dosage of 5 mg/kg per instillation. In all, 19 (59%) patients demonstrated complete clinical resolution of symptoms; 9 (28%) had a partial response; and 4 (13%) had no change in symptoms. Patients with a high pretreatment BK viral load (>100 million) and high HC grade (2-4) had a lower frequency of complete remission. The main side effect of intravesicular instillation was severe bladder spasms in 4 patients (12%). Conclusion and Relevance: This is the largest study of intravesicular cidofovir treatment of BKV HC reported to date; 88% of patients with BVK-HC achieved clinical improvement of symptoms with minimal side effects. Clinical trials of intravesicular cidofovir could provide further evidence for this treatment for BKV-HC.

Complications of Stem Cell Transplantation that Affect Infections in Stem Cell Transplant Recipients, with Analogies to Patients with Hematologic Malignancies

This article discusses the complications of hematopoietic stem cell transplantion (HSCT) that affect infections in HSCT recipients, with analogies to patients with hematologic malignancies. Mucositis, with mucosal barrier disruption, is common and increases the risk of gram-positive and anaerobic bacterial, and fungal infections, and can evolve to typhlitis. Engraftment syndrome; graft-versus-host disease, hepatic sinusoidal obstruction syndrome; and posterior reversible encephalopathy syndrome can affect the infectious potential either directly from organ dysfunction or indirectly from specific treatment. Pulmonary infections can predispose to life threatening complications including diffuse alveolar hemorrhage, idiopathic pulmonary syndrome, bronchiolitis obliterans syndrome, and bronchiolitis obliterans with organizing pneumonia.

Is BK Virus-Associated Cystitis a Generalized Epithelial Disease?

BK polyomavirus-associated haemorrhagic cystitis (BKHC) is a complication after allogeneic stem cell transplantation, which can occur in 5-60% of the cases. BK viruria alone can also occur in up to 100%. BKHC can lead to severe morbidity in stem cell-transplanted patients, but data about this disease is limited. Consequently, we conducted a prospective unicentric non-interventional trial on BKHC as well as BK viruria after first adult allogeneic stem cell transplantation with a follow-up time of 1 year after inpatient treatment. Between November 2013 and December 2015, we were able to include 40 adult patients with a mean age of 52.8 years. Twenty-seven (67.5%) of these patients were male and 13 (32.5%) were female. Acute myeloid leukaemia was the most frequent underlying disease (n = 15; 37.5%). Only 1 patient developed BKHC during inpatient treatment (n = 1; 2.5%), but BK viruria was frequent (n = 11; 27.5%) during inpatient treatment as well as in the follow-up time (n = 14; 35%). Interestingly, BK viruria was significantly associated with mucositis (p = 0.038) and number of transfused platelet concentrates (p = 0.001). This unexpected association will be discussed and needs further investigation.

ECIL guidelines for the prevention, diagnosis and treatment of BK polyomavirus-associated haemorrhagic cystitis in haematopoietic stem cell transplant recipients

Objectives

To define guidelines for BK polyomavirus (BKPyV)-associated haemorrhagic cystitis (BKPyV-HC) after paediatric and adult HSCT.

Methods

Review of English literature and evidence-based recommendations by expert consensus.

Results

BKPyV-HC occurs in 8%-25% of paediatric and 7%-54% of adult recipients undergoing allogeneic HSCT. Diagnosis requires the triad of cystitis, macro-haematuria and high urine BKPyV loads >7 log10 copies/mL, and exclusion of other relevant aetiologies. BKPyV viraemia is frequent and may serve as a more specific semiquantitative follow-up marker. No randomized controlled trials are available to inform antiviral prophylaxis or treatment. However, hyper-hydration and/or bladder irrigation showed limited prophylactic value. Fluoroquinolones are not effective for prophylaxis or treatment, but rather increase antibiotic resistance. Hyperbaric oxygen or fibrin glue is marginally effective based on small case series from correspondingly equipped centres. Although cidofovir has been reported to improve and/or reduce BKPyV viraemia or viruria, the current data do not support its regular use.

Conclusions

BKPyV-HC remains a disabling unmet clinical need in HSCT that requires novel approaches supported by proper clinical trials.

Comparison of intravenous or intravesical cidofovir in the treatment of BK polyomavirus-associated hemorrhagic cystitis following adult allogeneic stem cell transplantation-A systematic review

INTRODUCTION

BK polyomavirus can lead to hemorrhagic cystitis (BKPyV-HC) in allogeneic stem cell transplantation and therefore to increased morbidity. No causal therapy has been established yet. Cidofovir (CDV) is a nucleotide analog of cytosine that is active against various DNA viruses and it has been described for therapy of BKPyV-HC using 2 admission routes: intravenous and intravesical.

METHODS

We performed a systematic review regarding the comparison of intravenous or intravesical cidofovir in the treatment of BKPyV-HC following adult allogeneic stem cell transplantation. Since there is a lack of randomized controlled trials, we considered all kinds of studies for this review. Due to heterogeneity of the data, we were not able to perform a meta-analysis, so the results are shown descriptively.

RESULTS

The literature search for primary studies yielded 232 results. Finally, 9 studies where considered which included a total of 189 adult patients with BKPyV-HC after allogeneic stem cell transplantation. We could only identify retrospective studies for this review. A total of 172 patients received intravenous CDV, 17 patients received intravesical CDV, and 2 patients received CDV in both admission routes. In 68.0% of the cases, a complete response for intravenous CDV was documented and in 88.2% for intravesical CDV. Interestingly, no kidney toxicity was mentioned in intravesical CDV. 9.3% of the intravenously treated patients had renal failure.

CONCLUSION

There is only weak evidence for the use of CDV. The intravesical admission route should be further investigated because of a good toxicity profile.

BK virus: microbiology, epidemiology, pathogenesis, clinical manifestations and treatment

Background: BK virus infection is common but is usually asymptomatic. However, it can become life threatening as severe hemorrhagic cystitis (HC) or the polyomavirus-associated nephropathy (PVAN) particularly in immune compromised and transplant recipients. Some investigators have studied the pathophysiology and there are anecdotal and uncontrolled studies of therapy with few conclusions allowing treatment guidelines. Objectives: Summarize literature review of current knowledge concerning the nature, epidemiology, pathophysiology, diagnosis and treatment of this common virus infection. Results: HC is a not uncommon and often misdiagnosed infection from BK virus. It is usually self limited but can become life threatening in immune compromised patients. PVAN threatens survival of transplanted kidneys and is difficult to differentiate from rejection without sophisticated molecular diagnostic technology. We have sufficient information for making a diagnosis of BK virus disease by using clinical, serological and molecular technology. Studies using manipulation of immunosuppression and a variety of antiviral agents, including cidofovir, leflunomide, intravenous immunoglobulin, vidarabine, fluroquinolones, have been published but most were uncontrolled reports of few cases. Cidofovir offers some promise but more must be learned before there is hope for evidence-based treatment guidelines.

Acute phase after haematopoietic stem cell transplantation

The transplantation of allogeneic or autologous haematopoietic stem cells is an established treatment for many malignant and non-malignant diseases of the bone marrow. Intensive cytoreductive regimens administered before transplantation induce prolonged and severe cytopenia of all haematopoietic lineages. Thrombocytopenia leads to an increased risk of bleeding, which may be further aggravated by consumption of plasmatic factors as a result of tumour lysis or after antibody administration. At the same time, patients after transplantation are also at increased risk of thrombotic complications. Endothelial damage induced by radio-and chemotherapy, indwelling catheters, prolonged immobilization and a high incidence of systemic infection all contribute to the frequent occurrence of thromboembolic events in this population.

This review discusses the incidence and risk factors for haemorrhagic and thrombotic complications after stem cell transplantation. Special emphasis is given to complications occurring specifically in the context of transplantation such as diffuse alveolar haemorrhage, haemorrhagic cystitis, veno-occlusive disease, and transplant associated microangiopathy.

Human Polyomaviruses: The Battle of Large and Small Tumor Antigens

About 40 years ago, the large and small tumor antigens (LT-Ag and sT-Ag) of the polyomavirus (PyVs) simian vacuolating virus 40 have been identified and characterized. To date, it is well known that all the discovered human PyVs (HPyVs) encode these 2 multifunctional and tumorigenic proteins, expressed at viral replication early stage. The 2 T-Ags are able to transform cells both in vitro and in vivo and seem to play a distinct role in the pathogenesis of some tumors in humans. In addition, they are involved in viral DNA replication, transcription, and virion assembly. This short review focuses on the structural and functional features of the HPyVs’ LT-Ag and sT-Ag, with special attention to their transforming properties.

BK Polyomavirus: Clinical Aspects, Immune Regulation, and Emerging Therapies

BK polyomavirus (BKV) causes frequent infections during childhood and establishes persistent infections within renal tubular cells and the uroepithelium, with minimal clinical implications. However, reactivation of BKV in immunocompromised individuals following renal or hematopoietic stem cell transplantation may cause serious complications, including BKV-associated nephropathy (BKVAN), ureteric stenosis, or hemorrhagic cystitis. Implementation of more potent immunosuppression and increased posttransplant surveillance has resulted in a higher incidence of BKVAN. Antiviral immunity plays a crucial role in controlling BKV replication, and our increasing knowledge about host-virus interactions has led to the development of improved diagnostic tools and clinical management strategies. Currently, there are no effective antiviral agents for BKV infection, and the mainstay of managing reactivation is reduction of immunosuppression. Development of immune-based therapies to combat BKV may provide new and exciting opportunities for the successful treatment of BKV-associated complications.

Genitourinary Tract Infections

Similarly to the general population, genitourinary tract infections are common conditions in theimmunocompromised host. They can be furthermore divided into infections of the urinary tract and genital tract infections. Transplant recipients are more likely to have infections of the urinary tract infections while persons with human immunodeficiency virus (HIV) are at higher risk for the second group of infections, especially sexually transmitted infections (STIs). Manifestations of these diseases can be associated with more complications and can be more severe. We provide an overview of manifestations, diagnosis, and management of these disorders.

Are the Polyomaviruses BK and JC Associated with Opportunistic Infections, Graft-versus-Host Disease, or Worse Outcomes in Adult Patients Receiving Their First Allogeneic Stem Cell Transplantation with Low-Dose Alemtuzumab?

BACKGROUND

The association of polyomaviruses BK and JC with other opportunistic infections and graft-versus-host disease (GvHD) in allogeneic stem cell transplantation is controversially discussed.

METHODS

We conducted a retrospective study of 64 adult patients who received their first allogeneic stem cell transplantation between March 2010 and December 2014; the follow-up time was 2 years.

RESULTS

Acute leukemia was the most frequent underlying disease (45.3%), and conditioning included myeloablative (67.2%) and nonmyeloablative protocols (32.8%). All patients received 10 mg of alemtuzumab on day -2 (20 mg in case of mismatch) as GvHD prophylaxis. Twenty-seven patients (41.5%) developed cytomegalovirus (CMV) reactivation. BKPyV-associated hemorrhagic cystitis was diagnosed in 10 patients (15.6%). Other opportunistic infections caused by viruses or protozoa occurred rarely (<10%). There was no association of BKPyV or JCPyV with CMV reactivation, Epstein-Barr virus reactivation, human herpes virus 6, or parvovirus B19 infection requiring treatment. There was a significant correlation of BKPyV-associated hemorrhagic cystitis with toxoplasmosis (p = 0.013). Additionally, there was a significant link of simultaneous BKPyV and JCPyV viruria with toxoplasmosis (p = 0.047). BKPyV and JCPyV were not associated with GvHD, relapse, or death.

CONCLUSION

We found no association of BKPyV or JCPyV with viral infections or GvHD. Only the correlation of both polyomaviruses with toxoplasmosis was significant. This is a novel and interesting finding.

Nationwide survey of BK polyomavirus associated hemorrhagic cystitis in adult allogeneic stem cell transplantation among haematologists and urologists

There are no epidemiological data on BK virus associated hemorrhagic cystitis (BKHC) in adult allogeneic stem cell transplantation in Germany available and associations with clinical conditions like GvHD are controversially discussed. Therefore, we conducted a nationwide survey among haematologists and urologists about this disease. We developed two questionnaires, one for haematologists (26 items) and one for urologists (20 items) concerning BKHC in adult allogeneic stem cell transplantation with epidemiological data and clinical implications. The survey was sent out at least three times to EBMT registered centres performing at least five transplantations a year, leading to 39 centres. The recruiting time was between January and June 2016. Total response rates were 76.9% among haematologists and 74.4% among urologists. BKHC seems to appear less frequent in this survey than it is described in the literature. Six deaths in the last 5 years due to this disease have been reported. Interestingly, haematologists as well as urologists mostly think that local therapy is most effective while 50.0% stated that there is no real effective oral or intravenous medication. Associations with other clinical conditions mentioned were heterogeneous, e.g. transplantation type, CMV reactivation, acute GvHD, nephropathy and worse clinical outcome. There was a significant discrepancy between haematologists and urologist concerning the association with acute GvHD (p = 0.004). We need prospective, multicentric clinical studies to evaluate local therapy and for developing a risk stratification model since this disease can be severe with morbidity and rarely mortality. In our opinion, this should be an interdisciplinary approach.

Studies of human polyomaviruses, with HPyV7, BKPyV, and JCPyV present in urine of allogeneic hematopoietic stem cell transplanted patients with or without hemorrhagic cystitis

BACKGROUND

BK polyomavirus (BKPyV) can cause hemorrhagic cystitis (HC) in allogeneic hematopoietic stem cell transplant (allo-HSCT) patients and polyomavirus-associated nephritis in renal transplant patients, while JC polyomavirus (JCPyV) can generate progressive multifocal leukoencephalopathy in immunocompromised individuals. Since 2007, additional human polyomaviruses (HPyVs) have been identified. In this study, we examined the urines of allo-HSCT patients for possible presence of polyomaviruses BKPyV, JCPyV, KIPyV, WUPyV, MCPyV, HPyV6, HPyV7, TSPyV, HPyV9, and HPyV10 (MWPyV).

METHODS

A total of 185 urinary samples obtained 2002-2007 from 105 allo-HSCT patients, 32/105 with HC, were tested for the above-listed HPyVs by a bead-based multiplex assay. Of these, 142 urine samples had previously been tested for BKPyV and JCPyV by nested polymerase chain reaction (PCR).

RESULTS

Aside from BKPyV and JCPyV, which dominated, HPyV7 was detected in 5 BKPyV-positive urinary samples from 1 patient. The multiplex assay was more sensitive and specific than the nested PCR. BKPyV and/or JCPyV were found in all but 1 of the previously BKPyV- or JCPyV-positive samples, although 6 previously BKPyV-positive cases were now JCPyV-positive or the reverse. Furthermore, 18/79 previously negative samples were found to be BKPyV and/or JCPyV positive, and a total of 21 double infections were found. Lastly, in 1/29 HC patients, only JCPyV was detected.

CONCLUSION

HPyV7 was found for the first time in urine of an allo-HSCT patient, and BKPyV and JCPyV were more commonly found in urine samples using the bead-based assay compared to testing by nested PCR. Finally, only JCPyV was detected in the urine of 1 HC patient.

Symptomatic BK Virus Infection Is Associated With Kidney Function Decline and Poor Overall Survival in Allogeneic Hematopoietic Stem Cell Recipients

Nephropathy due to BK virus (BKV) infection is an evolving challenge in patients undergoing hematopoietic stem cell transplantation (HSCT). We hypothesized that BKV infection was a marker of kidney function decline and a poor prognostic factor in HSCT recipients who experience this complication. In this retrospective study, we analyzed all patients who underwent their first allogeneic HSCT at our institution between 2004 and 2012. We evaluated the incidence of persistent kidney function decline, which was defined as a confirmed reduction in estimated glomerular filtration rate of at least 25% from baseline using the Chronic Kidney Disease Epidemiology equation. Cox proportional hazard regression was used to model the cause-specific hazard of kidney function decline, and the Fine-Gray method was used to account for the competing risks of death. Among 2477 recipients of a first allogeneic HSCT, BK viruria was detected in 25% (n = 629) and kidney function decline in 944 (38.1%). On multivariate analysis, after adjusting for age, sex, acute graft-versus-host disease (GVHD), chronic GVHD, preparative conditioning regimen, and graft source, BK viruria remained a significant risk factor for kidney function decline (p < 0.001). In addition, patients with BKV infection and kidney function decline experienced worse overall survival. After allogeneic HSCT, BKV infection was strongly and independently associated with subsequent kidney function decline and worse patient survival after HSCT.

Reactivation of polyomavirus in the genitourinary tract is significantly associated with severe GvHD and oral mucositis following allogeneic stem cell transplantation

PURPOSE

BK-virus and JC-virus are the most common polyomaviridae associated with hemorrhagic cystitis in the allogeneic transplant setting. Hemorrhagic cystitis and symptomatic viruria caused by these viruses are a major cause of morbidity in patients undergoing allogeneic stem cell transplantation.

METHODS

We performed a retrospective evaluation on a highly uniform study population of 73 patients receiving allogeneic stem cell transplantation. Patients were treated according to the FLAMSA-RIC-protocol, and were examined for the incidence of BK-/JC-viruria and late-onset BK-positive hemorrhagic cystitis within a two-year period.

RESULTS

The occurrence of BK-viruria was correlated with published risk factors (acute GvHD, oral mucositis, donor type, conditioning, age, gender). Thirty patients (41 %) were found to excrete either BK-virus (n = 17), JC-virus (n = 3) or both (n = 10), of whom 18 patients (60 %) developed higher-grade hemorrhagic cystitis as opposed to none in the virus-negative control group. Higher grade GvHD (grade B-D) was more common in patients with viruria (p = 0.013) and also more common in patients with manifest hemorrhagic cystitis (p = 0.048). Similarly, oral mucositis was associated both with viruria (p = 0.014) and hemorrhagic cystitis (p = 0.005). Manifest cystitis but not viruria was significantly associated with male gender (p = 0.016). No significant correlation was found with age, conditioning with busulfane vs total body irradiation or related vs unrelated donor.

CONCLUSIONS

Severe GvHD and oral mucositis are significantly associated with reactivation of polyomaviridae in the genitourinary-tract already at the level of asymptomatic viruria.

Hemorrhagic cystitis after allogeneic hematopoietic cell transplantation: risk factors, graft source and survival

Although hemorrhagic cystitis (HC) is a common complication of allogeneic hematopoietic cell transplantation (alloHCT), its risk factors and effects on survival are not well known. We evaluated HC in a large cohort (n=1321, 2003-2012) receiving alloHCT from all graft sources, including umbilical cord blood (UCB). We compared HC patients with non-HC (control) patients and examined clinical variables at HC onset and resolution. Of these 1321 patients, 219 (16.6%) developed HC at a median of 22 days after alloHCT. BK viruria was detected in 90% of 109 tested HC patients. Median duration of HC was 27 days. At the time of HC diagnosis, acute GVHD, fever, severe thrombocytopenia and steroid use were more frequent than at the time of HC resolution. In univariate analysis, male sex, age <20 years, myeloablative conditioning with cyclophosphamide and acute GVHD were associated with HC. In multivariate analysis, HC was significantly more common in males and HLA-mismatched UCB graft recipients. Severe grade HC (grade III-IV) was associated with increased treatment-related mortality but not with overall survival at 1 year. HC remains hazardous and therefore better prophylaxis, and early interventions to limit its severity are still needed.

Human polyomavirus type six in respiratory samples from hospitalized children with respiratory tract infections in Beijing, China

Background

HPyV6 is a novel human polyomavirus (HPyV), and neither its natural history nor its prevalence in human disease is well known. Therefore, the epidemiology and phylogenetic status of HPyV6 must be systematically characterized.

Methods

The VP1 gene of HPyV6 was detected with an established TaqMan real-time PCR from nasopharyngeal aspirate specimens collected from hospitalized children with respiratory tract infections. The HPyV6-positive specimens were screened for other common respiratory viruses with real-time PCR assays.

Results

The prevalence of HPyV6 was 1.7 % (15/887), and children ≤ 5 years of age accounted for 80 % (12/15) of cases. All 15 HPyV6-positive patients were coinfected with other respiratory viruses, of which influenza virus A (IFVA) (8/15, 53.3 %) and respiratory syncytial virus (7/15, 46.7 %) were most common. All 15 HPyV6-positive patients were diagnosed with lower respiratory tract infections, and their viral loads ranged from 1.38 to 182.42 copies/μl nasopharyngeal aspirate specimen. The most common symptoms were cough (100 %) and fever (86.7 %). The complete 4926-bp genome (BJ376 strain, GenBank accession number KM387421) was amplified and showed 100 % identity to HPyV6 strain 607a.

Conclusions

The prevalence of HPyV6 was 1.7 % in nasopharyngeal aspirate specimens from hospitalized children with respiratory tract infections, as analyzed by real-time PCR. Because the coinfection rate was high and the viral load low, it was not possible to establish a correlation between HPyV6 and respiratory diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-015-0390-5) contains supplementary material, which is available to authorized users.

Emerging technologies for the clinical microbiology laboratory

In this review we examine the literature related to emerging technologies that will help to reshape the clinical microbiology laboratory. These topics include nucleic acid amplification tests such as isothermal and point-of-care molecular diagnostics, multiplexed panels for syndromic diagnosis, digital PCR, next-generation sequencing, and automation of molecular tests. We also review matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and electrospray ionization (ESI) mass spectrometry methods and their role in identification of microorganisms. Lastly, we review the shift to liquid-based microbiology and the integration of partial and full laboratory automation that are beginning to impact the clinical microbiology laboratory.

BK virus-associated hemorrhagic cystitis after pediatric stem cell transplantation

Hemorrhagic cystitis is a common stem cell transplantation-related complication. The incidence of early-onset hemorrhagic cystitis, which is related to the pretransplant conditioning regimen, has decreased with the concomitant use of mesna and hyperhydration. However, late-onset hemorrhagic cystitis, which is usually caused by the BK virus, continues to develop. Although the BK virus is the most common pathogenic microorganism of poststem cell transplantation late-onset hemorrhagic cystitis, pediatricians outside the hemato-oncology and nephrology specialties tend to be unfamiliar with hemorrhagic cystitis and the BK virus. Moreover, no standard guidelines for the early diagnosis and treatment of BK virus-associated hemorrhagic cystitis after stem cell transplantation have been established. Here, we briefly introduce poststem cell transplantation BK virus-associated hemorrhagic cystitis.

BK polyomavirus reactivation after reduced-intensity double umbilical cord blood cell transplantation

Serial serum samples from 27 patients who underwent double umbilical cord blood transplantation (dUCBT) were analyzed for BK polyomavirus (BKPyV) DNA by real-time PCR and BKPyV-specific immune globulin by ELISA. Clinical data were collected on all patients. All pre-transplant sera had detectable anti-BKPyV IgG. Fifteen patients (56%) had detectable serum BKPyV DNA (median 8.9 × 10(4) copies/ml; range 4.1 × 10(3)-7.9 × 10(6) copies/ml) a median of 40 days (range, 27-733 days) after dUCBT, with highest viral loads on Day 100 assessment. The cumulative probability of developing BKPyV viremia by Day 100 was 0.52 (95% CI, 0.33-0.71). Six of 15 patients with BKPyV viremia experienced hemorrhagic cystitis by Day 100. By Day 100, there was a trend towards higher BKPyV viral loads in sera of patients with hemorrhagic cystitis than in those BKPyV viremic patients without hemorrhagic cystitis (p = 0.06). BKPyV viremia was associated with significantly higher anti-BKPyV IgM values at 6 months post-dUCBT (P = 0.003). BKPyV viremia occurs early after dUBCT and is associated with a detectable humoral immune response by 6 months post-dUBCT.

The role of CD4(+) T cells in BKV-specific T cell immunity

Reactivation of polyomavirus BK (BKV) infection represents a severe complication in kidney transplant (KTX) patients. We previously reported an association between a declining BK viral load and the reconstitution of CD4(+) T cell BKV-specific immunity in patients following kidney transplantation. However, the specific contribution of CD4(+) T cells in the regulation of BKV-replication is unknown. Nevertheless, in vitro enrichment of BKV-specific T cells and subsequent adoptive T cell transfer may improve the restoration of immune competence in KTX patients with BKV infection. To date, strategies to capture human BKV-specific T cells with the ensuing expansion to clinically useful numbers are lacking. Here, we demonstrated a comprehensive flow cytometric analysis of the BKV-specific T cell response that permits access to the majority of T cells specific for immunodominant BKV antigens. A full-spectrum evaluation of the BKV-specific T cell response was performed by stimulating peripheral blood mononuclear cells (PBMC) with a mixture of BKV immunodominant peptide pools at varying concentrations and measuring activation marker expression and cytokine secretion. We also examined the effects of co-stimulation and PBMC resting time prior to activation. We defined the narrow range of stimulation conditions that permit the capture and expansion of functional BKV-specific T cell lines. The generated BKV-specific T cell lines showed the highest specificity and functionality when the T cells were captured according to IFNγ-secretion. This study highlights the multifunctional and cytolytic BKV-specific CD4(+) T cells as a dominant population within the generated T cell product. This method offers a novel approach for the generation of BKV-specific T cell lines for adoptive immunotherapy and underscores the critical role of CD4(+) T cells in the clearance of BKV.

High burden of BK virus-associated hemorrhagic cystitis in patients undergoing allogeneic hematopoietic stem cell transplantation

BK virus (BKV) reactivation has been increasingly associated with the occurrence of late-onset hemorrhagic cystitis (HC) after allogeneic hematopoietic SCT (allo-HSCT) resulting in morbidity and sometimes mortality. We investigated the incidence, risk factors and outcome of BKV-HC in 323 consecutive adult patients undergoing allo-HSCT over a 5-year period. BK viremia values for HC staging were evaluated, as well as the medico-economic impact of the complication. Forty-three patients developed BKV-HC. In univariate analysis, young age (P=0.028), unrelated donor (P=0.0178), stem cell source (P=0.0001), HLA mismatching (P=0.0022) and BU in conditioning regimen (P=0.01) were associated with a higher risk of developing BKV-HC. In multivariate analysis, patients receiving cord blood units (CBUs) (P=0.0005) and peripheral blood stem cells (P=0.011) represented high-risk subgroups for developing BKV-HC. BK viremia was directly correlated to HC severity (P=0.011) with a 3 to 6-log peak being likely associated with grades 3 or 4 HC. No correlation was found between BKV-HC and acute graft versus host disease or mortality rate. Patients with BKV-HC required a significantly longer duration of hospitalization (P<0.0001), more RBC (P=0.0003) and platelet transfusions (P<0.0001). Over the 5-year study period, the financial cost of the complication was evaluated at \[euro]2 376 076 ($3 088 899). Strategies to prevent the occurrence of late-onset BKV-HC after allo-HSCT are urgently needed, especially in CBU and peripheral blood stem cell recipients. BK viremia correlates with the severity of the disease. Prospective studies are required to test prophylactic approaches.

Cytomegalovirus is a potential risk factor for late-onset hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation

Late-onset hemorrhagic cystitis (LOHC) is a common complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT) and is primarily associated with viral infection. We prospectively quantified cytomegalovirus (CMV), BK virus (BKV), and adenovirus in urine and plasma using Q-RT-PCR in 50 consecutive patients to define the relationship between virus and LOHC. Of the 50 patients, 21 developed LOHC at a median of 29 days (range 4-64 days), with a cumulative incidence of 42% (±7.1%). The cumulative incidence of LOHC on day 100 in patients with and without CMV viremia (prior to or at the onset of LOHC) were 56.3% (±8.9%) and 16.7% (±9.1%) (P = 0.018), respectively, and it was 59.3% (±9.8%) and 21.7% (±8.8%) in patients with and without CMV viruria (prior to or at the onset of LOHC) (P = 0.021), respectively. The cumulative incidence of LOHC was also higher in patients with a plasma BKV load increased ≥3 log10 or with a urine BKV load increased ≥4 log10 than those without the increase (P < 0.001). Only one patient with LOHC was tested positive for ADV. Both the univariate and multivariate analyses showed that CMV viremia (HR = 3.461, 95% CI: 1.005-11.922, P = 0.049) and a plasma BKV load that was increased ≥3 log10 (HR = 10.705, 95%CI: 2.469-46.420, P = 0.002) were independent risk factors for the development of LOHC. We conclude that both CMV viremia and an increase of plasma BKV are independent risk factors for LOHC. And the role of CMV viremia was firstly demonstrated.