Polyomavirus BK infection in blood and marrow transplant recipients

Recent Insights into the Pathogenesis, Diagnostics, and Treatment of BK Virus Infections in Children After Hematopoietic Stem Cell Transplantation

BK polyomavirus (BKPyV) is a pathogen responsible for infectious complications in hematopoietic stem cell transplant (HSCT) recipients. This review aims to give an insight into recent data about the structure and genomic organization, epidemiology, clinical manifestations, diagnosis, and current treatment options of BKPyV infections in children after HSCT. News regarding viral replication and pathogenesis include the generation of miRNA, new mechanisms of viral shedding by releasing infectious particles via extracellular vesicles, and human bladder microvascular endothelial cells probably acting as viral reservoirs enabling low-level viral replication and persistence. In studies conducted over the past five years, BKPyV hemorrhagic cystitis (BKPyV-HC) has a prevalence rate of 4 to 27% in children undergoing HSCT. Diagnostics still has unsolved dilemmas like whole blood or plasma samples as well as the standardization of molecular methods to allow for reporting in international units. In terms of treatment, new approaches have been used in the past five years, including the use of mesenchymal stem cells (MSCs), virus-specific T cells (VSTs), and recombinant human keratinocyte growth factor (rH-KGF), although the efficacy of some of these treatments has only been documented in isolated studies. This complication continues to pose a substantial clinical challenge, characterized by an absence of effective preventive and therapeutic measures.

Susceptibility to BK polyomavirus-associated hemorrhagic cystitis in children undergoing allogeneic transplant

Not available.

Advances in virus-specific T-cell therapy for polyomavirus infections: A comprehensive review

Polyomaviruses are a group of small, non-enveloped, double-stranded DNA viruses that can infect various hosts, including humans. BKPyV causes conditions such as human polyomavirus-associated nephropathy (HPyVAN), human polyomavirus-associated haemorrhagic cystitis (HPyVHC), and human polyomavirus-associated urothelial cancer (HPyVUC). JC polyomavirus (JCPyV), on the other hand, is the causative agent of progressive multifocal leukoencephalopathy (PML), a severe demyelinating disease of the central nervous system. PML primarily affects immunocompromised individuals, including those with HIV, recipients of certain immunosuppressive therapies, and transplant patients. The treatment options for HPyV infections have been limited, but recent developments in virus-specific T cell (VST) therapy have shown promise. Although VST therapy has shown potential in treating both BKPyV and JCPyV infections, several challenges remain. These include the time-consuming and costly preparation of VSTs, the need for sophisticated production facilities, and uncertainties regarding the optimal cell type and infusion frequency. To the best of our knowledge, 85 patients with haemorrhagic cystitis, 27 patients with BKPyV viremia, 2 patients with BKPyV nephritis, 14 patients with haemorrhagic cystitis and BKPyV viremia, and 32 patients with PML have been treated with VST in the literature. The overall response results were 82 complete response, 33 partial response, 35 no response, and 10 no-outcome-reported. This review underscores the importance of VST therapy as a promising treatment approach for polyomavirus infections, emphasising the need for continued research and clinical trials to refine and expand this innovative immunotherapeutic strategy.

Immune reconstitution in children after haploidentical haematopoietic stem cell transplantation

INTRODUCTION

Immune reconstitution (IR) kinetics of paediatric patients underwent haploidentical haematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PTCy) have not been extensively studied. We compared IR patterns of children receiving HSCT from haploidentical (n = 92) and HLA-matched donors (n = 36), and analysed risk factors for viral infection in these patients.

METHODS

We prospectively measured lymphocyte subset numbers before HSCT and at 1, 3, 6 and 12 months after HSCT. Blood cytomegalovirus (CMV), Epstein-Barr virus, adenovirus, BK virus (BKV) and urine adenovirus and BKV viral loads were measured at designated time points.

RESULTS

The median numbers of total T and T helper cells at 1 month were significantly lower in the haploidentical group compared with the HLA-matched group. Haploidentical HSCT recipients had significantly lower median numbers of several T cell subsets and B cells for 1 year after HSCT. The median NK cell count of the haploidentical group was lower at 1 month. BKV haemorrhagic cystitis, blood CMV and urine adenovirus reactivation were more frequently found in the haploidentical group. Post-haploidentical HSCT patients receiving anti-T lymphocyte globulin (ATG) had significantly lower median numbers of total T cells (at 1 month) and T helper cells (at 6 and 12 months) and higher rate of blood BKV reactivation compared with those without ATG.

CONCLUSION

Paediatric patients who undergo haploidentical HSCT with PTCy are likely to have delayed IR and an increased risk of viral reactivation/infection compared with HLA-matched HSCT. The addition of ATG to PTCy delayed T cell recovery and increased risk of BKV reactivation.

Purine nucleoside phosphorylase inhibition is an effective approach for the treatment of chemical hemorrhagic cystitis

Hemorrhagic cystitis may be induced by infection, radiation therapy, or medications or may be idiopathic. Along with hemorrhagic features, symptoms include urinary urgency and frequency, dysuria (painful urination), and visceral pain. Cystitis-induced visceral pain is one of the most challenging types of pain to treat, and an effective treatment would address a major unmet medical need. We assessed the efficacy of a purine nucleoside phosphorylase inhibitor, 8-aminoguanine (8-AG), for the treatment of hemorrhagic/ulcerative cystitis. Lower urinary tract (LUT) function and structure were assessed in adult Sprague-Dawley rats, treated chronically with cyclophosphamide (CYP; sacrificed day 8) and randomized to daily oral treatment with 8-AG (begun 14 days prior to CYP induction) or its vehicle. CYP-treated rats exhibited multiple abnormalities, including increased urinary frequency and neural mechanosensitivity, reduced bladder levels of inosine, urothelial inflammation/damage, and activation of spinal cord microglia, which is associated with pain hypersensitivity. 8-AG treatment of CYP-treated rats normalized all observed histological, structural, biochemical, and physiological abnormalities. In cystitis 8-AG improved function and reduced both pain and inflammation likely by increasing inosine, a tissue-protective purine metabolite. These findings demonstrate that 8-AG has translational potential for reducing pain and preventing bladder damage in cystitis-associated LUT dysfunctions.

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.

Prognostic Value of Thrombocytopenia in Myelodysplastic Syndromes After Hematopoietic Stem Cell Transplantation

Prolonged isolated thrombocytopenia (PT) is a common complication affecting the outcome of stem cell transplantation. In this study, we undertook a real-world study of 303 myelodysplastic syndrome (MDS) patients who received allogeneic hematopoietic stem cell transplantation (HSCT) between December 2007 and June 2018. 28.4% of MDS patients suffered from PT after HSCT. Survival analysis indicated that PT was associated with worse overall survival (OS) in MDS patients. The 2-year and 5-year OS in MDS patients with PT after HSCT were 49% and 47%, significantly worse than that of 68% and 60% in patients without PT (P=0.005). For RFS, patients with PT did not have an increased risk of disease relapse (P=0.964). After multivariate adjustment, PT was proved to be the independent risk factor associated with the worse OS (HR 1.49, 95% CI 1.00-2.21, P =0.048). We further analyzed risk factors associated with the occurrence of PT in MDS patients. Multiple logistic regression identified grade II-IV aGVHD, extensive chronic GVHD, hemorrhagic cystitis, and CMV activation as significant risk factors for developing PT. Among these variables, the Odds Ratio (OR) of grade II-IV aGVHD was the highest (P =0.001, OR: 2.65, 95% CI: 1.51-4.64). These data indicated the prognostic value of PT in MDS after HSCT. The identification of risk factors for PT may help improve patient management and lead to the design of effective treatment strategies.

A Clinical Review of the Different Strategies to Minimize Hemorrhagic Cystitis Associated with the Use of Post-Transplant Cyclophosphamide in an Allogeneic Transplant

Post-transplantation cyclophosphamide (PTCy) has improved hematopoietic stem cell transplantation outcomes for patients with major HLA disparities. Although PTCy in combination with calcineurin inhibitors is a successful graft-versus-host disease regimen, giving high doses of cyclophosphamide may cause hemorrhagic cystitis (HC). The strategies used to prevent HC are adapted from published data in the pre-transplantation conditioning setting. However, there is no consensus on what the optimal strategy is to prevent PTCy-associated HC. This review provides a summary of the different preventative strategies used in this setting. Based on the results published in current literature, hyperhydration is an effective preventative strategy, but it may cause fluid overload and other complications. Additionally, mesna at least 100% of the PTCy dose should be administered as a continuous infusion or frequent intermittent bolus infusion. More comparative studies between these strategies are needed to provide a definitive solution for preventing HC associated with PTCy.

Guideline for Children With Cancer Receiving General Anesthesia for Procedures and Imaging

Children with cancer and those undergoing hematopoietic stem cell transplantation frequently require anesthesia for imaging as well as diagnostic and therapeutic procedures from diagnosis through follow-up. Due to their underlying disease and side effects of chemotherapy and radiation, they are at risk for complications during this time, yet no published guideline exists for preanesthesia preparation. A comprehensive literature review served as the basis for discussions among our multidisciplinary panel of oncologists, anesthesiologists, nurse practitioners, clinical pharmacists, pediatric psychologists, surgeons and child life specialists at the Children's Hospital of Philadelphia. Due to limited literature available, this panel created an expert consensus guideline addressing anesthesia preparation for this population.

Molecular Epidemiology and Variation of the BK Polyomavirus in the Population of Central and Eastern Europe Based on the Example of Poland

The BK polyomavirus (BKPyV) is a widespread pathogen in humans. Polymorphism of the region encoding the VP1 protein of BKPyV provides the basis for classifying the virus into types and subtypes, whose frequency varies depending on geographic location. The aim of our study was to determine the frequency of BKPyV in the Polish population and to assess its variation by analysing polymorphism in the typing region. The study was conducted on 168 healthy, Polish volunteers, whose blood (plasma) and urine were sampled. The virus was detected using PCR, products, sequenced and subjected to bioinformatic analysis. In addition, viral load was assessed by qPCR. The presence of the genetic material of the BK virus was noted in 61/168 urine samples but in none of the plasma sample. Sequencing and phylogenetic analysis confirmed that the BKPyV isolates were of types I and IV, dominant in Europe (63.93% and 36.07%, respectively). All isolates from genotype I belonged to subtype Ib-2, showing polymorphism at position 1809 with a frequency of 61.54% (G1809A) and 38.46% (G1809C). To the best of our knowledge, this is the first study of this magnitude on the genetic variation of BKPyV among healthy volunteers in Poland.

Polyomavirus exerts detrimental effects on renal function in patients after lung transplantation

INTRODUCTION

Chronic kidney disease (CKD) is associated with significant morbidity and mortality after lung transplantation (LTX). Calcineurin inhibitor (CNI) nephrotoxicity is the leading cause of CKD. After kidney transplantation, polyomavirus-associated nephropathy (PyVAN) is a well-recognized problem. This study aims to evaluate the role of polyomavirus in patients after LTX.

METHODS

From January 2017 to January 2020, all lung transplant recipients who performed follow-up visits in our center were included in the study and retrospectively assessed. We measured renal function (creatinine levels before and after transplantation), JCPyV, and BKPyV load by polymerase chain reaction (PCR) in serum and urine samples after transplantation.

RESULTS

In total, 104 consecutive patients (59 males, 56.7%) with a mean age of 49.6 ± 11.1 years were identified. JCPyV was found in urine of 36 patients (34.6%) and serum of 3 patients (2.9%). BKPyV was found in urine of 40 patients (38.5%) and serum of 4 patients (3.8%), respectively. Urine evidence for JCPyV (p < 0.001, coefficient: +21.44) and BKPyV (p < 0.001, coefficient: +29.65) correlated highly with further kidney function decline.

CONCLUSION

Kidney function deterioration is associated with JCPyV and BKPyV viruria in patients after LTX. This might indicate a role of PyVAN in lung transplant recipients.

Effect of late-onset hemorrhagic cystitis on PFS after haplo-PBSCT

Introduction

This study is to investigate the effect of late-onset hemorrhagic cystitis (LOHC) on progression-free survival (PFS) of patients after haploidentical peripheral blood hematopoietic stem cell transplantation (haplo-PBSCT).

Methods

This retrospective study enrolled 74 patients with hematological malignancies treated with a myeloablative conditioning regimen and haplo-PBSCT. The effect of LOHC on PFS was studied in terms of HC occurrence, grade, disease type, duration, onset time, gender, and age.

Results

There were 28 patients with LOHC, and no case was with early-onset HC. The cumulative incidence of LOHC was 37.8% (95% CI: 26.9–48.7%). The 2-year expected PFS of 74 patients and 34 AML patients was not significantly different between LOHC patients and patients without HC (P > 0.05). Among 27 ALL patients, the 2-year expected PFS of LOHC patients was 75%, significantly higher than patients without HC (54.2%) (P < 0.05). The 2-year expected PFSs of patients with mild LOHC and severe LOHC were 69.8 and 77.8%, respectively (P > 0.05). Similarly, the onset time, duration, age, and gender of LOHC patients did not show significant effects on PFS (P > 0.05).

Conclusions

After haplo-PBSCT, LOHC has a significant effect on the PFS of ALL patients. The HC grade, duration, onset time, gender, and age have no significant effect on PFS.

The impact of orthotopic reconstruction on female sexuality and quality of life after radical cystectomy for non-malignant bladder conditions

OBJECTIVE

To review the literature on the impact on female quality of life and sexual function of orthotopic reconstruction after radical cystectomy for non-malignant bladder conditions. Radical cystectomy is commonly required to treat malignant conditions but may also be considered for the treatment of non-malignant diseases. These heterogeneous group of disorders includes interstitial cystitis, painful bladder syndrome, neurogenic bladder, haemorrhagic/ radiation cystitis, endometriosis and refractory genitourinary fistula. Treatment begins with non-invasive medical therapies but, in non-responder cases, a surgical solution should be considered. Such invasive techniques include urinary diversion and reconstructive procedures that have an impact on healthrelated quality of life, physical, social, and mental status.

MATERIALS AND METHODS

This narrative review research was done using the PubMed database up until 2020, July. All papers referring to cystectomy for benign indication were considered.

RESULTS

In comparison to other reconstructive options, orthotopic neobladder allows the restoration of a normal self-image and consequently it is the most suitable procedure when a surgical reconstruction is necessary for non-malignant conditions. However, women can face many disorders that impact on everyday life, such as voiding dysfunction or sexual activity problems.

CONCLUSIONS

Scant data is available about quality of life, sexual life and self-perception in women treated by cystectomy for benign conditions and most literature is dedicated to those indicators in cancer patients. More research is needed to understand the tolerability and the quality of life results of the female population affected by benign conditions undergoing this kind of surgical approach.

A cluster of BK polyomavirus-associated hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation

BACKGROUND

BK polyomavirus (BKV) can cause hemorrhagic cystitis (HC) in immunocompromised patients after hematopoietic stem cell transplantation (HSCT). It remains unclear whether nosocomial BKV infections occur. During a 9-month period, an increase in BKV-associated HC (BKV-HC) cases was observed at our institution.

AIM

The BKV-HC cluster population was compared with populations of HSCT patients from before and after the BKV-HC cluster to evaluate whether nosocomial BKV transmission had occurred.

METHODS

A retrospective analysis was carried out to assess the risk of patients developing BKV-HC after HSCT. The background data of the cluster patients were compared with those of the patients who underwent HSCT before or after the cluster, and the collected BKV isolates were serotyped.

RESULTS

BKV-HC involving grade ≥2 hematuria occurred in six of 15 HSCT recipients during a 9-month period. The incidence of BKV-HC was significantly higher in this period than in the other periods (p = 0.0014). There were no significant differences in the patients' background data between the cluster and non-cluster periods, including in terms of risk factors for BKV-HC. Serotype analyses of BKV revealed that the BKV detected in the urine samples from four of the six BKV-HC patients belonged to subtype Ic. The gene sequences of these four BKV exhibited >99.5% homology.

CONCLUSION

Our study suggests that nosocomial BKV infections may occur after HSCT. Although many cases of BKV-HC are caused by the reactivation of a latent virus, it is necessary to employ appropriate hygiene measures when cases of BKV-HC occur.

BK Polyomavirus-Biology, Genomic Variation and Diagnosis

The BK polyomavirus (BKPyV), a representative of the family Polyomaviridae, is widespread in the human population. While the virus does not cause significant clinical symptoms in immunocompetent individuals, it is activated in cases of immune deficiency, both pharmacological and pathological. Infection with the BKPyV is of particular importance in recipients of kidney transplants or HSC transplantation, in which it can lead to the loss of the transplanted kidney or to haemorrhagic cystitis, respectively. Four main genotypes of the virus are distinguished on the basis of molecular differentiation. The most common genotype worldwide is genotype I, with a frequency of about 80%, followed by genotype IV (about 15%), while genotypes II and III are isolated only sporadically. The distribution of the molecular variants of the virus is associated with the region of origin. BKPyV subtype Ia is most common in Africa, Ib-1 in Southeast Asia, and Ib-2 in Europe, while Ic is the most common variant in Northeast Asia. The development of molecular methods has enabled significant improvement not only in BKPyV diagnostics, but in monitoring the effectiveness of treatment as well. Amplification of viral DNA from urine by PCR (Polymerase Chain Reaction) and qPCR Quantitative Polymerase Chain Reaction) is a non-invasive method that can be used to confirm the presence of the genetic material of the virus and to determine the viral load. Sequencing techniques together with bioinformatics tools and databases can be used to determine variants of the virus, analyse their circulation in populations, identify relationships between them, and investigate the directions of evolution of the virus.

Use of high-dose mesna and hyperhydration leads to lower incidence of hemorrhagic cystitis after posttransplant cyclophosphamide-based allogeneic transplantation

Currently, there is no consensus on best practices to prevent hemorrhagic cystitis (HC) in patients receiving posttransplant cyclophosphamide (PTCy). We retrospectively reviewed 194 patients undergoing their first hematopoietic cell transplant (HCT) who received PTCy from 2014 to 2018 to describe the incidence and severity of HC, identify potential risk factors, and impact of HC on HCT outcomes. Standard HC prophylaxis was hyperhydration with forced diuresis and mesna at 320% the daily dose of PTCy. Incidence of HC was 31.4% at day +100 of HCT. Median onset of HC was 12 days with 11.5% grade 3 HC and no Grade 4 HC. Patients with chemical HC experienced earlier onset (7 days vs. 34 days, p < 0.001) with a shorter median resolution time (5 days vs. 14 days, p = 0.001) when compared to BK-associated HC. In multivariate analysis, age above 60 years (HR 4.16, p = 0.006) and myeloablative conditioning (HR 2.44, p = 0.054) were associated with higher risk for HC, but overall, HC did not affect nonrelapse mortality or overall survival. In conclusion, hyperhydration with forced diuresis combined with aggressive mesna dosing is an effective strategy in preventing severe PTCy-associated HC, subsequently preventing any negative impact on transplant outcome.

Post-allogeneic hematopoietic stem cell transplantation viral reactivations and viremias: a focused review on human herpesvirus-6, BK virus and adenovirus

Human cytomegalovirus and Epstein-Barr virus have been recognized as potential drivers of morbidity and mortality of patients undergoing allogeneic stem cell transplantation for years. Specific protocols for monitoring, prophylaxis and pre-emptive therapy are in place in many transplant settings. In this review, we focus on the next three most frequent viruses, human herpesvirus-6, BK virus and adenovirus, causing reactivation and/or viremia after allogeneic transplant, which are increasingly detected in patients in the post-transplant period owing to emerging techniques of molecular biology, recipients' characteristics, treatment modalities used for conditioning and factors related donors or stem cell source. Given the less frequent detection of an illness related to these viruses, there are often no specific protocols in place for the management of affected patients. While some patients develop significant morbidity (generally older), others may not need therapy at all (generally younger or children). Furthermore, some of the antiviral therapies used are potentially toxic. With the addition of increased risk of secondary infections, risk of graft failure or increased risk of graft-versus-host disease as well as the relationship with other post-transplant complications, the outcomes of patients with these viremias remain unsatisfactory and even long-term survivors experience increased morbidity.

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.

BK Virus Epidemiology, Risk Factors, and Clinical Outcomes: An Analysis of Hematopoietic Stem Cell Transplant Patients at Texas Children's Hospital

BACKGROUND

BK virus-associated hemorrhagic cystitis (BKV-HC) is a serious complication after hematopoietic stem cell transplantation (HSCT).

METHODS

A retrospective review was performed to determine the frequency of BKV-HC and identify risk factors and renal morbidity associated with BKV-HC in pediatric HSCT recipients at our institution.

RESULTS

A total of 314 pediatric recipients underwent allogeneic HSCT for either malignant (173, 55.1%) or nonmalignant disorders (141, 44.9%) from January 1, 2011, to December 31, 2015, with a minimum follow-up of 5 years post-HSCT. Severe BKV-HC (grades 3 and 4) was prevalent in 46 out of 67 (68.7%) recipients. Timing to presentation of severe BKV-HC (grades 3 and 4) occurred at a median of 37 days (26, 74; IQ1, IQ3) post-HSCT, with the duration of macroscopic hematuria lasting a median of 37.5 days (18, 71; IQ1, IQ3). In the first 60 days post-HSCT, peak acute kidney injury (AKI) stages 2 and 3 were seen more frequently in HSCT recipients who developed BKV-HC than those without (P = .004). Similarly, during post-HSCT days 61 to 100, peak AKI stage 3 was also more frequently seen in HSCT recipients who already developed BKV-HC prior to or during this time period than those without BKV-HC (P = .0002). Recipients who developed BKV-HC within 1 year of HSCT had more frequent mild to moderate chronic kidney disease (CKD stages 2-3) than those without BKV-HC (P = .002 and .007, respectively). On multivariate analysis, BKV-HC was associated with all-cause mortality (hazard ratio [HR]: 2.22; 95% confidence interval [CI]: 1.35-3.65). The following clinical variables were associated with time to development of HC on multivariate analysis: age (subdistribution HR [sHR] 1.11; 95% CI: 1.06-1.16) and myeloabalative conditioning regimen (sHR 4.2; 95% CI: 2.12-8.34).

CONCLUSIONS

Pediatric HSCT patients with BKV-HC experience significant morbidity and mortality. Renal morbidity, including AKI and CKD, is associated with BKV-HC.

Kidney injury and disease in patients with haematological malignancies

Acute kidney injury (AKI) is common in patients with cancer, especially in those with haematological malignancies. Kidney injury might be a direct consequence of the underlying haematological condition. For example, in the case of lymphoma infiltration or extramedullary haematopoiesis, it might be caused by a tumour product; in the case of cast nephropathy it might be due to the presence of monoclonal immunoglobulin; or it might result from tumour complications, such as hypercalcaemia. Kidney injury might also be caused by cancer treatment, as many chemotherapeutic agents are nephrotoxic. High-intensity treatments, such as high-dose chemotherapy followed by haematopoietic stem cell transplantation, not only increase the risk of infection but can also cause AKI through various mechanisms, including viral nephropathies, engraftment syndrome and sinusoidal obstruction syndrome. Some conditions, such as thrombotic microangiopathy, might also result directly from the haematological condition or the treatment. Novel immunotherapies, such as immune checkpoint inhibitors and chimeric antigen receptor T cell therapy, can also be nephrotoxic. As new therapies for haematological malignancies with increased anti-tumour efficacy and reduced toxicity are developed, the number of patients receiving these treatments will increase. Clinicians must gain a good understanding of the different mechanisms of kidney injury associated with cancer to better care for these patients.

Detection of polyomavirus microRNA-5p expression in saliva shortly after kidney transplantation

Background: MicroRNAs (miRNAs) of polyomavirus (PyV) are present in several biological fluids and are suggested to be relevant viral factors for monitoring its persistence. Aim: To evaluate the effect of an immunosuppressive regimen on the status of PyV-miRNA-5p in the oral cavity. Materials and Methods: The JCPyV, BKPyV, MCPyV miRNA-5p were investigated in paired saliva and plasma samples obtained from 23 patients before and shortly after renal-transplantation by using real-time RT-PCR. Results: Overall, within a short-time after transplantation, patients exhibited decreased numbers of leukocyte and lymphocyte as well as low levels of creatinine. During the clinical management of the patients, a significant amount of saliva samples were positive for JCPyV and BKPyV miRNA-5p (range: 26%-91%) compared to paired plasma samples (range: 9%-35%). Among the two polyomaviruses showing positive expression of miRNA-5p, BKPyV presented the highest positivity in saliva (91%) and MCPyV-miRNA-5p was constantly negative in both saliva and plasma samples. Compared to the time before transplantation, a significant reduction in the expression of JCPyV-miRNA-5p was observed in saliva samples obtained after transplantation. Conclusions: Altogether, these data suggest that additional investigations of polyomavirus miRNA-5p in saliva should be performed shortly after renal-transplantation to evaluate the potential role in early viral reactivation.

Incidence of BKV in the urine and blood samples of pediatric patients undergoing HSCT

The aims were to investigate the incidence of BKV infection and the presence of HC in pediatric patients undergoing HSCT. Twenty-four children patients (M/F: 17/7) undergoing HSCT in a single center over a period of 1 year were included in the study. The presence of BKV DNA was determined by quantitative real-time PCR in plasma and urine samples at the following times: before transplantation, twice a week until engraftment time, and weekly for + 100 days. The mean age of the patients was 7.79 ± 5.03 years, the mean follow-up time was 95.6 ± 25.9 days, and the average number of samples per patient was 15.8 ± 3.2. BKV DNA was detected in at least one urine sample in 91.6% (n: 22) and at least one plasma sample in 75% (n:18) of the patients. The median time to the first BKV DNA positivity in urine and plasma samples was 11 (range: 1-80) and 32 days (range: 2-79), respectively. The median value of BKV DNA copies in urine and plasma were 1.7 × 10⁶ (range: 2.8 × 10¹ -1.2 × 10¹⁴ ) and 1.9 × 10³ copies/mL (range: 3-2.1 × 10⁶ ), respectively. Thirteen patients (54.2%) had hematuria with BKV viruria; 8 (33.3%) patients had viremia. The median value of the BKV DNA copies in urine and plasma was 4.4 × 10⁷ (range: 65-1 × 10¹¹ ) and 2.9 × 10³ (range: 7-7.8 × 10⁴ ) copies/mL in these patients. Two (15.4%) of the 13 patients with BKV viruria and hematuria were diagnosed with BKV-related HC. BKV DNA viral load monitoring of urine and plasma in pediatric HSCT patients with a high risk for viral infections is valuable for understanding the development of BKV-related HC.

Upregulation of HLA-F expression by BK polyomavirus infection induces immune recognition by KIR3DS1-positive natural killer cells

BK polyomavirus-associated nephropathy is a common complication after kidney transplantation leading to reduced graft function or loss. The molecular pathogenesis of BK polyomavirus-induced nephropathy is not well understood. A recent study had described a protective effect of the activating natural killer cell receptor KIR3DS1 in BK polyomavirus-associated nephropathy, suggesting a role of NK cells in modulating disease progression. Using an in vitro cell culture model of human BK polyomavirus infection and kidney biopsy samples from patients with BK polyomavirus-associated nephropathy, we observed significantly increased surface expression of the ligand for KIR3DS1, HLA-F, on BK polyomavirus-infected kidney tubular cells. Upregulation of HLA-F expression resulted in significantly increased binding of KIR3DS1 to BK polyomavirus-infected cells and activation of primary KIR3DS-positive natural killer cells. Thus, our data provide a mechanism by which KIR3DS-positive natural killer cells can control BK polyomavirus infection of the kidney, and rationale for exploring HLA-F/KIR3DS1 interactions for immunotherapeutic approaches in BK polyomavirus-associated nephropathy.

Survey of BK Virus in Renal Transplant Recipients in Iran: A Systematic Review and Meta-Analysis

INTRODUCTION

BK virus (BKV) infection in renal transplant (RT) recipients can cause hemorrhagic cystitis, transient renal dysfunction, and BKV nephropathy (BKVN). The prevalence and significance of BKV in RT recipients remain to be clarified in the Iranian population. The purpose of this review is to summarize the overall prevalence of BKV infection in RT recipients from previously published studies in Iran.

METHODS

We systematically reviewed articles through a comprehensive search of the main electronic and Persian national databases up to November 2019.

RESULTS

The overall pooled prevalence of BKV infection among the Iranian population was 23% (95% CI; 15-33%). Comparing these studies revealed that the prevalence of BKV in plasma samples ranges from 3 to 40%, in renal biopsies 1-13%, and in urine samples 10-49%. Due to substantial heterogeneity among reported studies (I2 = 93%, p < 0.01), random-effect meta-analysis was performed. BKV infection rate was slightly higher in women than men (16%, p = 0.04 vs. 14%, p < 0.01, respectively). The majority of the studies employed real-time PCR (24%, I2 = 93, p < 0.01) and analyzed plasma samples alone or in combination with other types of specimens. BKV prevalence from 5 cities among the Iranian population showed a higher prevalence rate in Guilan.

CONCLUSION

Our analysis provides a preliminary estimate of the epidemiology of BKV infection in RT recipients in Iran. These results arouse a need for more epidemiological studies of BKV infection in different unanalyzed regions in Iran. Early detection of BKV in RT recipients helps timely nephropathy diagnosis and prevents graft loss.

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.

Clinical Efficacy of Intravenous Immunoglobulin for BK Polyomavirus-Associated Nephropathy After Living Kidney Transplantation

Purpose

BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) is one of the most difficult infections to be treated after kidney transplantation. Although patients with BKPyVAN usually received a reduction of immunosuppressive agents, the majority of these patients undergo the loss of the graft kidney without any effective treatment afterward. Therefore, development of more effective therapy for BKPyVAN is eagerly expected.

Patients and Methods

Among patients who underwent a kidney transplantation between January 2016 and April 2019 at our hospital, there were five cases of BKPyVAN. After the initial diagnosis, all patients discontinued administration of mycophenolate mofetil (MMF), which was not enough to diminish decoy cells in urine cytology test. Therefore, all patients received additional intravenous immunoglobulin (IVIG) (100 mg/kg/day) therapy for five days and were evaluated for the therapeutic effect of IVIG with immunohistochemical examination using re-biopsy samples of the graft kidney.

Results

After IVIG therapy, 2 cases showed negative decoy cells in urine and 3 cases showed a drastic decrease of plasma BK virus load. Importantly, simian virus (SV) 40 large T antigens diminished after IVIG administration in all cases, which degraded polyomavirus nephropathy classification.

Conclusion

Although it is difficult to treat BKPyVAN after kidney transplant, IVIG therapy was considered to a promising treatment to improve severity of BKPyVAN especially in cases that dose reduction of immunosuppressive agents was ineffective.

Rational Design of a Replication-Competent and Inheritable Magnetic Viruses for Targeting Biomedical Applications

Infection with live-attenuated vaccines always inevitably induces side effects that reduce their safety. This study suggests a concept of magnetic virus produced by genetically modifying viral surfaces with Fe₃ O₄ nanoparticles (NPs) to control their tropisms. An iron-affinity peptide is designed to be displayed on the viral surface protein (VP1) of human enterovirus type 71 (EV71), a typical nonenveloped picornavirus, as the model. The modified EV71 can self-bind with Fe₃ O₄ NPs under physiological conditions, resulting in novel EV71-Fe₃ O₄ hybrid materials. This rationally engineered EV71 with Fe₃ O₄ retains its original biological infectivity, but its tropism can be precisely controlled by magnetism. Both in vitro and in vivo experiments demonstrate that EV71-Fe₃ O₄ can infect only a desired area within the limit of the applied magnetic field, which effectively reduces its pathological damage. More importantly, this characteristic of EV71 can be inherited due to the gene-induced coassembly of viruses and NPs. This achievement provides a proof of concept in virus vaccine improvement by a combination of gene modification and material incorporation, leading to great potential for biomedical developments.

Epidemiology and clinical characteristics of viral infections in hospitalized children and adolescents with cancer in Lebanon

Background

Viral infections in children and adolescents with malignancy are commonly encountered and have a significant impact on morbidity and mortality. Studies and epidemiological data regarding viral infections in children with cancer in developing countries are lacking. This retrospective cohort study aims to assess the burden of viral infections in children and adolescents with cancer, by assessing prevalence, risk factors, as well as morbidity and mortality of common viruses over a period of 8 years.

Methods and findings

Medical records of cancer patients treated at the Children Cancer Center of Lebanon were reviewed and 155 participants under the age of 21 were identified with at least one documented viral infection during the period from July 2009 to November 2017. This subset included 136 participants with active malignancy and 19 participants with a history of cancer who underwent hematopoietic stem cell transplantation [HSCT] and were in remission; the latter group was analyzed separately. Information regarding participant characteristics, hospital course, and complications were obtained. Associations between viral infections and certain factors were assessed. In the cohort, 64% were male, 81% were Lebanese. In participants with active malignancy, 90% received chemotherapy in the 6 months preceding the viral infection episode, 11% received radiotherapy. 51% of participants were neutropenic at the time of viral detection, and 77% were lymphopenic. 17% experienced a bacterial co-infection, and 3 experienced a viral co-infection. Among 162 viral infection episodes, clinically diagnosed skin infections, mainly herpes simplex virus type 1 and varicella-zoster virus, were the most common [44% of cases]. These were followed by laboratory-proven systemic herpes infections: cytomegalovirus [14%] and Epstein-Barr virus [6%]. Respiratory viruses: influenza and respiratory syncytial virus, accounted for 9% and 4%, respectively, whereas rotavirus represented 11% and BK virus represented 3% of cases. Acute lymphocytic leukemia was the most prevalent neoplasia [57%]. Fever was the most common presenting symptom [55%] and febrile neutropenia was the reason for admission in 24% of cases. The mean length of stay was significantly longer in participants with cytomegalovirus infections and significantly lower in rotavirus infection. Admission to the ICU occurred in 9%, complications in 8%, and mortality in 5%. Participants with viral infections post-HSCT were noted to have a significantly longer length of hospital stay compared to non-HSCT participants, with no other significant differences in clinical course and outcome. The study was limited by its retrospective nature and by the late introduction and underuse of multiplex PCR panels, which may have led to underdiagnosis of viral infections.

Conclusions

Viral infections were prevalent in our sample of cancer patients and may have contributed to morbidity and mortality. Newly available viral diagnostics are likely to vastly increase the number and scope of detectable viral infections in this population. Prospective studies using multiplex PCR technology with systematic testing of patients will be more helpful in defining the burden of viral infections. Furthermore, efforts at antimicrobial stewardship would benefit from the identification of viral causes of infection and limit the unnecessary use of antibiotics in the pediatric cancer population.

BK virus encephalitis and end-stage renal disease in a child with hematopoietic stem cell transplantation

BK virus encephalitis after HSCT is uncommon. Several reports of native kidney BKVN in patients with HSCT, hematologic malignancies, human immunodeficiency virus infection, and non-renal solid organ transplantation have been described. However, an uncommon combination of BK encephalitis and ESRD of native kidneys secondary to BK virus in a child with HSCT has not been described. We report a 10-year-old boy who presented with a gradually rising serum creatinine during treatment for severe autoimmune hemolytic anemia, which he developed 9 months after receiving an allogeneic HSCT for aplastic anemia. There was no proteinuria or hematuria present. Serum BK virus load was 5 × 106  copies/mL. A renal biopsy showed evidence of BKVN. He developed fever, seizures, and confusion, and the (CSF) showed significant presence of the BK virus (1 × 106  copies/mL) along with biochemical evidence of viral encephalitis. Cerebrospinal fluid cultures were negative. Despite significant clinical symptoms and presence of BK virus in CSF, the magnetic resonance brain imaging findings were minimal. With reduction of immunosuppression, there was resolution of BK encephalitis but BKVN remained resistant to multiple anti-BK virus agents, including leflunomide and cidofovir. He eventually became dialysis-dependent and, 6 years later, received a renal transplant from his mother. This case illustrates that BK virus in severely immunocompromised HSCT recipient may lead to BK encephalitis and BKVN of native kidneys, even without hemorrhagic cystitis, leading to ESRD. Knowledge of such is important for appropriate timely evaluation and management.

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.

Fluoroquinolones for BK viral complication after transplantation: Meta-analysis

OBJECTIVES

BK polyomavirus (BKV) causes two distinct complications after transplantation, hemorrhagic cystitis (BKV-HC) after hematopoietic stem cell transplantation (HSCT), and BKV-associated nephropathy (BKVAN) after kidney transplantation (KT). Although fluoroquinolones show efficacy against BKV proliferation in vitro, the clinical effect remains uncertain; thus, we performed meta-analysis to assess its efficacy in the prophylaxis.

METHODS

Articles published before March 2020 were searched from PubMed, the Cochrane Library, ISRCTN registry, and ClinicalTrials.gov. Primary outcomes were BKV-HC after HSCT and BKVAN after KT. Secondary outcomes were BK viremia, viruria after KT, and fluoroquinolone-related adverse events.

RESULTS

Three trials with 281 patients post-HSCT and 11 trials with 1882 patients post KT were included as for prophylaxis. Fluoroquinolone prophylaxis did not show effects on BKV-HC (OR 0.54, 95% CI 0.13-2.25), BKVAN (OR 0.74, 95% CI 0.35-1.55), and BK viremia (OR 0.79, 95% CI 0.49-1.28), but significantly decreased BK viruria (OR 0.64, 95% CI 0.45-0.91). Fluoroquinolone prophylaxis was associated with the higher percentage of fluoroquinolone-resistant infection among identified bacteria (OR 2.38, 95% CI 1.16-4.88), but the incidence of fluoroquinolone-resistant infection was similar (OR 1.15, 95% CI 0.71-1.86), due to the decrease of infection itself (OR 0.52, 95% CI 0.34-0.81).

CONCLUSIONS

This meta-analysis showed that fluoroquinolones did not prevent BKV-HC after HSCT or BKVAN after KT, although the effect against BKV-HC should be further investigated by randomized controlled trials. Fluoroquinolones could reduce the rate of BK viruria to some extent but may not have clinically sufficient effects.

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.

Analysis of viruses present in urine from patients with interstitial cystitis

The question of whether some cases of interstitial cystitis may have an infectious etiology has been debated for some time. Previous studies have looked for the presence of certain specific viruses, but generally did not use the types of sensitive and unbiased approaches that are currently available. As part of the MAPP (Multidisciplinary Approach to the Study of Chronic Pelvic Pain) Research Network, we examined urine specimens from interstitial cystitis patients who provided specimens over time and also reported various symptoms at the time of urine collection. We first performed next-generation sequencing to look for the presence of viruses in urines, and detected two human polyomaviruses that are known to be excreted into urine, BKPyV and JCPyV. We were especially interested in BKPyV because it is a known cause of another bladder disease, hemorrhagic cystitis, in bone marrow transplant recipients. Further analysis of individual samples indicates a trend toward higher excretion of polyomaviruses in patients experiencing increased symptoms.

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.

Haemorrhagic cystitis, preventive and treatment interventions in patients undergoing haematopoietic stem cell transplantation: A scoping review

PURPOSE

to map (a) methodological features, (b) Haemorrhagic Cystitis (HC) preventive and treatment interventions scrutinized to date, (c) outcomes measured, and (d) trends in effectiveness as documented among Haematopoietic Stem Cell Transplanted (HSCT) adults.

METHODS

A scoping review was performed in 2018. Medline, CINAHL, and Cochrane Systematic Reviews databases were researched using "haemorrhagic cystitis", "prevention", "treatment", "prevent*" and "treat*" as search terms. Handsearching was also performed. Clinical trials, randomized controlled trials, comparative and observational studies, reviews, systematic reviews and meta-analyses published in English and concerning adults were all included.

RESULTS

Fifteen primary studies, mainly monocentric, retrospective and with a sample size <200, were identified. Seven focused on preventive (mainly continuous bladder irrigation and mesna) and eight on treatment interventions (mainly intravenous and intravesical cidofovir). The onset of micro and macrohaematuria and the clinical resolution of HC were the main measured outcomes. Positive effectiveness trends were apparent for mesna and cidofovir.

CONCLUSIONS

In HC prevention and treatment, published primary studies are sparse and further research is required with larger, multicenter, and longitudinal designs conducted at international levels, with standardized methods, interventions, outcome measures, and reported data.

Nursing Management of Haemorrhagic Cystitis in Patients Undergoing Haematopoietic Stem Cell Transplantation: a Multicentre Italian Survey

Background

Haemorrhagic cystitis (HC) is a severe complication occurring after haematopoietic stem cell transplantation (HSCT) in 13–40% of patients, caused by infectious and/or non-infectious factors that increase the in-hospital length of stay and the risk of mortality of transplanted recipients. Although different management interventions have been suggested in the literature, available knowledge on interventions performed by Italian nurses in their daily practices has not been documented to date.

Aim of the study

The aim of this study is to describe HC preventive and treatment interventions in patients undergoing HSCT as performed by Italian nurses in their daily practice.

Material and methods

A multicentre survey was conducted in 2018 by inviting all 110 Italian HSCT centres belonging to the Italian Group for Bone Marrow Transplantation (GITMO). Data collection was performed with an online questionnaire submitted to GITMO reference nurses working in each HSCT centre. Descriptive statistics were performed.

Results

A total of 38 Italian centres participated. The preventive intervention most applied in daily care was the mesna administration (n=37; 97.4%), followed by intravenous hyperhydration (n=33; 86.8%) and forced diuresis with furosemide (n=24; 63.1%). Preventive continuous bladder irrigation (CBI) was performed in 13 centres (34.2%). Transfusions of blood products (n=32; 84.2%), CBI (n=31; 81.6%) and intravenous hydration (n=28; 73.7%) were the most applied treatments, beyond the administration of analgesics (n=38; 100.0%) and antispasmodics (n=26; 68.4%).

Conclusion

A great variability both in the HC prevention and treatment interventions applied in daily practice across centres have emerged suggesting that no strong recommendations in the field are available to date. Therefore, there is a need to increase the evidence available in the field by providing methodological studies of higher quality, multicentre and prospective.

Unmanipulated haploidentical peripheral blood stem cell transplantation for patients with Philadelphia-negative acute lymphoblastic leukaemia in first complete remission

Haploidentical peripheral blood stem cell transplantation (Haplo-PBSCT) is a promising treatment option for patients with Ph-negative acute lymphoblastic leukemia (ALL). In this study, we retrospectively analyzed data from Ph-negative ALL patients who underwent haplo-PBSCT during their first complete remission (CR1), and compared the long-term outcomes between the standard-risk and high-risk patients. The 3-year probability of relapse was 7.6% and 16.7% for the standard- and high-risk group (p = .274). The 3-year probability of disease-free survival (DFS) and overall survival (OS) for the standard-risk versus high-risk groups were 84.6% versus 50% (p = .0063) and 92.3% versus 61.1% (p = .046), respectively. Univariate analysis showed that a diagnosis of high risk with fusion/mutation genes were associated with worse outcomes, which was confirmed by multivariate analysis (p = .016). In summary, haplo-PBSCT may be a promising alternative for patients with Ph-negative ALL in CR1, although the fusion/mutation genes in high-risk patients may relatively impair the long-term efficacy compared with standard-risk patients.

BK virus: Current understanding of pathogenicity and clinical disease in transplantation

BK polyomavirus (BKV) is an important cause of graft loss in renal transplant recipients that continues to pose a significant challenge to clinicians due to its frequently unpredictable onset, persistence, and the lack of effective antiviral agents or prevention strategies. This review covers our current understanding of epidemiology, viral transmission and disease progression, and treatment and prevention strategies that have been used to manage this disease.

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.

Infections in Allogeneic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has become a widely used modality of therapy for a variety of malignant and nonmalignant diseases. Despite advances in pharmacotherapy and transplantation techniques, infection remains one of the most severe and frequently encountered complications of allo-HSCT.

This chapter will address the risk factors for development of infection following allo-HSCT, including those related to the host, the conditioning regimen, and the graft, as well as the timing of opportunistic infections after allo-HSCT. The most common bacterial, viral, fungal, and parasitic infections, as well as issues surrounding their diagnostics and treatment, will be discussed. Finally, this chapter will address vaccination and other preventative strategies to be utilized when caring for patients undergoing allo-HSCT.

Role of BK polyomavirus (BKV) and Torque teno virus (TTV) in liver transplant recipients with renal impairment

PURPOSE

Renal impairment is a common complication after liver transplantation (LT). While BK polyomavirus (BKV) has been linked to renal failure in kidney transplant recipients, Torque teno virus (TTV) is a surrogate marker for immunosuppression that does not have a clear association with any human disease. The impact of BKV and TTV on renal impairment after LT is unknown.

METHODOLOGY

In this retrospective study, urine and serum samples from 136 liver transplant recipients were screened for BKV and TTV by quantitative PCR. In addition, serum was screened for BKV-specific antibodies and the VP1 typing region was sequenced for BKV genotyping. All parameters were correlated with clinical data.Results/Key findings. BK viruria was detected up to 21 years after transplantation in 16.9 % of cases. BK viraemia was detected in 8.7 % of patients with BK viruria up to 4 years after LT. BKV-specific antibodies were detected in 93.6 % of all LT recipients and correlated with BKV viral load in urine. There was no correlation between renal impairment and the detection of BK DNA in urine (OR 0.983). TTV DNA was detected in 84.6 % of serum samples and in 66.6 % of urine samples. The TTV viral load in serum correlated with the BKV viral load but had no impact on renal impairment.

CONCLUSION

Our data indicate that the detection of BKV and TTV is not a risk factor for renal impairment after LT. A correlation of TTV and BKV viral load seems to be an indicator for the immune status of the host.

Efficacy of Cidofovir in Treatment of BK Virus-Induced Hemorrhagic Cystitis in Allogeneic Hematopoietic Cell Transplant Recipients

BK virus-associated hemorrhagic cystitis (BK-HC) is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HCT), with incidences up to 70%. Cidofovir is an antiviral agent with growing evidence as a therapeutic intervention. To assess the safety profile and efficacy of intravenous and intravesical cidofovir in allo-HCT patients with BK-HC, a retrospective study was undertaken of the allo-HCT cohort who received cidofovir for symptomatic BK-HC (hematuria with BK viruria or viremia) from January 2010 until March 2017 in a single transplant center in Ontario, Canada. The primary outcome measure was a reduction in BK-HC severity (graded from 1 to 4); secondary outcomes included overall survival, BK virus titers, and the onset of acute kidney injury. Twelve allo-HCT patients received cidofovir for BK-HC, with pretreatment clinical severity of 3 (50%) or 4 (50%). Cidofovir was administered via intravenous (33%), intravesical (58%), or both modalities (8%). After a median cumulative dose of 10 mg/kg (range, 1 to 37), mean BK-HC grade decreased significantly by 1.8 (3.5 precidofovir, 1.7 postcidofovir, P < .01). Sixty-six percent of patients had at least partial response to cidofovir, with similar response rates between intravenous (66%) and intravesical (62%) administration. Sixty-seven percent of patients died, and 33% of patients experienced renal toxicity, including 2 patients receiving intravesical therapy. In this retrospective series, there was a significant reduction in BK-HC severity after cidofovir administration; most patients achieved at least partial response after cidofovir administration. Even with intravesical instillation, acute kidney injury remains a potential complication of cidofovir. Although cidofovir may be an efficacious therapy for BK-HC, albeit with potential demonstrated toxicities, further prospective trials are needed.

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.

Agnoprotein Is an Essential Egress Factor during BK Polyomavirus Infection

BK polyomavirus (BKPyV; hereafter referred to as BK) causes a lifelong chronic infection and is associated with debilitating disease in kidney transplant recipients. Despite its importance, aspects of the virus life cycle remain poorly understood. In addition to the structural proteins, the late region of the BK genome encodes for an auxiliary protein called agnoprotein. Studies on other polyomavirus agnoproteins have suggested that the protein may contribute to virion infectivity. Here, we demonstrate an essential role for agnoprotein in BK virus release. Viruses lacking agnoprotein fail to release from host cells and do not propagate to wild-type levels. Despite this, agnoprotein is not essential for virion infectivity or morphogenesis. Instead, agnoprotein expression correlates with nuclear egress of BK virions. We demonstrate that the agnoprotein binding partner α-soluble N-ethylmaleimide sensitive fusion (NSF) attachment protein (α-SNAP) is necessary for BK virion release, and siRNA knockdown of α-SNAP prevents nuclear release of wild-type BK virions. These data highlight a novel role for agnoprotein and begin to reveal the mechanism by which polyomaviruses leave an infected cell.

Infectious complications after hematopoietic stem cell transplantation: current status and future perspectives in Korea

Hematopoietic stem cell transplantation (HSCT) is a treatment for hematologic malignancies, immune deficiencies, or genetic diseases, ect. Recently, the number of HSCTs performed in Korea has increased and the outcomes have improved. However, infectious complications account for most of the morbidity and mortality after HSCT. Post-HSCT infectious complications are usually classified according to the time after HSCT: pre-engraftment, immediate post-engraftment, and late post-engraftment period. In addition, the types and risk factors of infectious complications differ according to the stem cell source, donor type, conditioning intensity, region, prophylaxis strategy, and comorbidities, such as graft-versushost disease and invasive fungal infection. In this review, we summarize infectious complications after HSCT, focusing on the Korean perspectives.