Low-dose cidofovir treatment of BK virus-associated hemorrhagic cystitis in recipients of hematopoietic stem cell transplant

Virus-Specific T Cells for the Treatment of Systemic Infections Following Allogeneic Hematopoietic Cell and Solid Organ Transplantation

Viral infections are a major source of morbidity and mortality in the context of immune deficiency and immunosuppression following allogeneic hematopoietic cell (allo-HCT) and solid organ transplantation (SOT). The pharmacological treatment of viral infections is challenging and often complicated by limited efficacy, the development of resistance, and intolerable side effects. A promising strategy to rapidly restore antiviral immunity is the adoptive transfer of virus-specific T cells (VST). This therapy involves the isolation and ex vivo expansion or direct selection of antigen-specific T cells from healthy seropositive donors, followed by infusion into the patient. This article provides a practical guide to VST therapy by reviewing manufacturing techniques, donor selection, and treatment indications. The safety and efficacy data of VSTs gathered in clinical trials over nearly 30 years is summarized. Current challenges and limitations are discussed, as well as opportunities for further research and development.

Posoleucel, an Allogeneic, Off-the-Shelf Multivirus-Specific T-Cell Therapy, for the Treatment of Refractory Viral Infections in the Post-HCT Setting

PURPOSE

Viral infections are a major cause of morbidity and mortality following allogeneic hematopoietic cell transplantation (allo-HCT). In the absence of safe and effective antiviral treatments, virus-specific T cells have emerged as a promising therapeutic option. Posoleucel is a multivirus-specific T-cell therapy for off-the-shelf use against six viral infections that commonly occur in allo-HCT recipients: adenovirus, BK virus (BKV), cytomegalovirus, Epstein-Barr virus, human herpes virus-6, and JC virus.

PATIENTS AND METHODS

We conducted an open-label, phase II trial to determine the feasibility and safety of posoleucel in allo-HCT recipients infected with one or more of these viruses. Infections were either unresponsive to or patients were unable to tolerate standard antiviral therapies. Fifty-eight adult and pediatric patients were enrolled and treated.

RESULTS

Posoleucel was well tolerated, with no cytokine release syndrome or other infusion-related toxicities; two patients (3.4%) developed Grade 2 and one patient (1.7%) Grade 3 GvHD during the trial. The overall response rate 6 weeks after the first posoleucel infusion was 95%, with a median plasma viral load reduction of 97%. Of the 12 patients who had two or more target viral infections identified at study entry, 10 (83%) had a clinical response for all evaluable viruses. Of the 23 patients treated for refractory BKV-associated hemorrhagic cystitis, 74% had resolution of symptoms and macroscopic hematuria by 6 weeks post-infusion.

CONCLUSIONS

In this open-label trial, treatment of refractory viral infections/disease in allo-HCT recipients with posoleucel was feasible, safe, and effective.

Daily low dose intravesical cidofovir for the treatment of BK virus associated hemorrhagic cystitis after allogeneic stem cell transplantation

INTRODUCTION

BK virus associated hemorrhagic cystitis(BKV-AHC) is a serious complication observed after allogeneic stem cell transplantation and the current therapeutic options are scarce with substantial renal side effects. Although the guidelines recommend intravenous cidofovir application with caution to nephrotoxicity, there are few studies which investigated intravesical administration and reported similar therapeutic results with less renal side effects.

METHODS

We administered low dose, daily and consecutive (75 mg/day, for 5 days) intravesical cidofovir to 25 patients with BKV-AHC that developed after (ASCT).

RESULTS

The response rate in our cohort was 92% and relapse was not encountered in 84% of the patient population during one year of follow-up. The median BK urine viral load significantly decreased from 260,000,000 IU/mL to 53,000,000 IU/mL after a week of treatment (p = 0.0001). Rise in serum creatinine was observed in 5 patients during treatment and post-treatment nephrotoxicity was seen in only 1 patient.

CONCLUSIONS

Daily low dose intravesical cidofovir might be an effective treatment option for BKV-AHC after ASCT with favorable less systemic side effects.

KIDNEY DAMAGE IN PATIENTS AFTER ALLOGENEIC STEM CELL TRANSPLANTATION

The aim of the review is to present the most common renal complications after HSCT such as acute kidney injury, chronic kidney disease glomerulopathies. HSCT is a critical therapy for many cancer patients with cancer, as well as patients with some other nonmalignant hematologic disorders and certain congenital immune deficiencies. Kidney complications after HSCT in a form of acute kidney injury is associated with significant morbidity and worse patient outcome. In addition, risk of chronic kidney disease is also increased following HSCT. It is very important to be aware, prevent, early recognize and treat renal damage to improve kidney and patient survival.

Intravesical alprostadil as a promising agent in BK virus-associated hemorrhagic cystitis: A report of a refractory case

Allogeneic stem cell transplant recipients are at risk of BK virus-associated hemorrhagic cystitis. This condition causes a significant morbidity and worsens clinical outcomes. The standard cares for BK virus-associated hemorrhagic cystitis are saline irrigation and forced diuresis. Notably, several beneficial roles are proposed for antiviral and anti-inflammatory agents against BK virus-associated hemorrhagic cystitis. However, cases who are at risk of cystectomy remain refractory. Herein, we present a 13-year-old boy with severe hematuria by passing two months from his allogeneic stem cell transplantation. The laboratory work up showed high BK viremia >1.1 ×  10⁸ copies/ml in this case's urine sample. The patient was treated with antiviral agents in combination with supportive care. Moreover, intravesical alum was administered, but no clinical benefits were achieved. Finally, intravesical alprostadil was prepared under the supervision of a pediatric clinical pharmacist. In this regard, an alprostadil solution was prepared by constitution of 250 μg alprostadil in 50 mL saline. After administrating the first dose of intravesical alprostadil, an acceptable clinical response was observed, and hematuria stopped. Of note, alprostadil induces platelet aggregation and vasoconstriction. Thus, bleeding can be controlled after the administration of intravesical alprostadil. This strategy may be associated with several side effects including bladder spasm. This study is the first report describing the special role of intravesical alprostadil in refractory cases of BK virus-associated hemorrhagic cystitis. In such refractory cases, clinicians can use intravesical alprostadil rather than invasive therapies in the treatment of BK virus-hemorrhagic cystitis.

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.

Antivirals against human polyomaviruses: Leaving no stone unturned

Human polyomaviruses (HPyVs) encompass more than 10 species infecting 30%-90% of the human population without significant illness. Proven HPyV diseases with documented histopathology affect primarily immunocompromised hosts with manifestations in brain, skin and renourinary tract such as polyomavirus-associated nephropathy (PyVAN), polyomavirus-associated haemorrhagic cystitis (PyVHC), polyomavirus-associated urothelial cancer (PyVUC), progressive multifocal leukoencephalopathy (PML), Merkel cell carcinoma (MCC), Trichodysplasia spinulosa (TS) and pruritic hyperproliferative keratinopathy. Although virus-specific immune control is the eventual goal of therapy and lasting cure, antiviral treatments are urgently needed in order to reduce or prevent HPyV diseases and thereby bridging the time needed to establish virus-specific immunity. However, the small dsDNA genome of only 5 kb of the non-enveloped HPyVs only encodes 5-7 viral proteins. Thus, HPyV replication relies heavily on host cell factors, thereby limiting both, number and type of specific virus-encoded antiviral targets. Lack of cost-effective high-throughput screening systems and relevant small animal models complicates the preclinical development. Current clinical studies are limited by small case numbers, poorly efficacious compounds and absence of proper randomized trial design. Here, we review preclinical and clinical studies that evaluated small molecules with presumed antiviral activity against HPyVs and provide an outlook regarding potential new antiviral strategies.

Effectiveness of hyperbaric oxygen therapy for virus-associated hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation

Although some studies have suggested the effectiveness of hyperbaric oxygen (HBO) therapy for hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT), the role of HBO has not been established. We compared the treatment outcomes of 8 patients with viral HC (adenovirus [ADV], n = 2; BK virus [BKV], n = 6) treated with HBO (HBO[+]) and 8 patients (ADV, n = 2; BKV, n = 6) treated with conventional therapy (HBO[−]), such as urinary catheterization and intravenous cidofovir. HBO therapy was performed at 2.1 atmospheres for 90 min/day until clinical improvement was achieved. The median number of HBO treatments was 10 (range 8–12). The median duration of HBO treatment was 19.5 days (range 10–23 days). All 8 HBO(+) patients achieved complete remission (CR) at a median of 14.5 days (range 5–25 days). Of the 8 HBO(−) patients, 5 (62.5%) obtained CR and 3 remained symptomatic for 2–6 months. The cumulative incidence of transplant-related mortality at day 100 after allogeneic HSCT was significantly higher in the HBO(−) patients than in the HBO(+) patients (14.2 vs. 0%, P < 0.05). No severe HBO-related adverse effects were observed. In conclusion, HBO is a feasible option for treating viral HC after allogeneic HSCT.

BK virus-induced nephritis and cystitis after matched unrelated donor stem cell transplantation: A case report

Currently, there is no standard therapy for a BK virus infection of the urogenital tract in immunocompromised, stem cell transplanted patients, so that early diagnosis and introduction of supportive measures have the highest response rates to date.

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.

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.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.

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.

BK Virus Associated Haemorrhagic Cystitis. A systematic review of current prevention and treatment strategies

BACKGROUND

BK virus is a major cause of late onset haemorrhagic cystitis in patients undergoing Haematopoietic Cell Transplantation (HCT). The evidence for the management of BK Virus Associated Haemorrhagic Cystitis (BKV-HC) is limited. Much of the published data consists of non-randomised case series and case reports. To our knowledge this is the first systematic review for the management of BKV-HC in both paediatric and adult populations. Our primary outcome was to examine the evidence for strategies of 1) prevention and 2) cessation of haematuria associated with BKV. Secondary outcomes were to assess the toxicity of treatment strategies and devise management recommendations for clinicians.

MATERIALS AND METHODS

We performed a systematic review of the PubMed and Central databases to evaluate the current evidence. A search protocol was prepared and registered with the PROSPERO database (CRD42017082442). The review was conducted in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement and AMSTAR (Assessing the methodological quality of systematic reviews) guidelines. Results were classified by treatment type. Qualitative analysis of included articles was performed, and grades of recommendations were devised for each treatment.

RESULTS

Of 896 titles screened, 44 articles were included for qualitative analysis. The overall quality of evidence was low. There is insufficient evidence to recommend prophylactic quinolones. 40 studies evaluated treatments for established BKV-HC. There are no high-quality comparative studies. Cidofovir is the most studied treatment but quality of evidence is low, and grade of recommendation is weak. Hyperbaric oxygen therapy, Fibrin glue, Leflunomide, Sodium Pentosan Polysulfate, Intravesical Alum and Radiological embolisation have all been described but the effectiveness of these treatments is unclear.

CONCLUSION

There remains no clear specific treatment for BKV-HC. An effective multi-disciplinary approach leading to early recognition and initiation of treatment is encouraged. The development of novel therapies followed by well-designed clinical studies are urgently needed.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

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.

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.

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.

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.

Viral-specific T-cell response in hemorrhagic cystitis after haploidentical donor stem cell transplantation

Viral hemorrhagic cystitis (HC) after hematopoietic stem cell transplantation (HSCT) can be devastating. Standard treatment modalities have not been well established, but immune reconstitution may be necessary for sustained viral clearance. We studied five pediatric patients who developed viral HC after haplo-identical HSCT. All patients developed virus-specific CD4- and CD8-positive T cells, and the emergence of these viral-specific T cells was temporally associated with successful viral clearance.

BK polyomavirus: a review of the virology, pathogenesis, clinical and laboratory features, and treatment

BK polyomavirus (BKPyV) is a non-enveloped, circular dsDNA virus with a genome of approximately 5100 base pairs. It can be divided into four major genotypes, but the effects of different genotypes on clinical disease are uncertain. Primary BKPyV infection is generally acquired asymptomatically in childhood. It establishes low-level persistence in many tissues, particularly the genitourinary tract. Reactivation can lead to severe disease including BKPyV-associated nephropathy confirmed by renal biopsy, hemorrhagic cystitis and meningoencephalitis. Nucleic acid amplification testing of blood and urine is the main diagnostic and prognostic test for BKPyV infection. The treatment of BKPyV infection has concentrated on reduction in immunosuppressive therapy. Recent studies suggest that antiviral drugs have demonstrated only modest benefit, but adoptive T-cell therapies offer potential advances.

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.

BK Virus-associated Hemorrhagic Cystitis in Patients with Allogeneic Hematopoietic Cell Transplantation: Report of Three Cases

BK viras is a human polyoma viras. It is acquired in early childhood and remains life-long latent in the genitourinary system. BK virus replication is more common in receiving immunosuppressive therapy receiving patients and transplant patients. BK virus could cause hemorrhagic cystitis in patients with allogeneic stem cell transplantation. Hemorrhagic cystitis is a serious complication of hematopoietic stem cell transplantation. Hemorrhagic cystitis could cause morbidity and long stay in the hospital. Diagnosis is more frequently determined by the presence of BK virus DNA detected with quantitative or real-time PCR testing in serum or plasma and less often in urine. The reduction of immunosuppression is effective in the treatment of BK virus infection. There are also several agents with anti-BK virus activity. Cidofovir is an active agent against a variety of DNA viruses including poliomyoma viruses and it is a cytosine nucleotide analogue. Intravenous immunoglobulin IgG (IVIG) also includes antibodies against BK and JC (John Cunningham) viruses. Hereby, we report three cases of hemorrhagic cystitis. Hemorrhagic cystitis developed in all these three cases of allogeneic stem cell transplantation due to acute myeloid leukemia (AML). BK virus were detected as the cause of hemorrhagic cystitis in these patients. Irrigation of the bladder was performed. Then levofloxacin 1 x750 mg intravenous and IVIG 0.5 gr/kg were started. But the hematuria did not decreased. In the first case, treatment with leflunomide was started, but patient died due to refractory AML and severe graft-versus-host disease after 4th day of leflunamide and levofloxacin treatments. Cidofovir treatment and the reduction of immunosuppressive treatment decreased the BK virus load and resulted symptomatic improvement in the second case. Initiation of cidofovir was planned in the third case. Administration of cidofovir together with the reduction of immunosuppression in the treatment of hemorrhagic cystitis associated with BK virus in allogeneic stem cell transplant recipients could be a good option.

BK nephropathy in the native kidneys of patients with organ transplants: Clinical spectrum of BK infection

Nephropathy secondary to BK virus, a member of the Papoviridae family of viruses, has been recognized for some time as an important cause of allograft dysfunction in renal transplant recipients. In recent times, BK nephropathy (BKN) of the native kidneys has being increasingly recognized as a cause of chronic kidney disease in patients with solid organ transplants, bone marrow transplants and in patients with other clinical entities associated with immunosuppression. In such patients renal dysfunction is often attributed to other factors including nephrotoxicity of medications used to prevent rejection of the transplanted organs. Renal biopsy is required for the diagnosis of BKN. Quantitation of the BK viral load in blood and urine are surrogate diagnostic methods. The treatment of BKN is based on reduction of the immunosuppressive medications. Several compounds have shown antiviral activity, but have not consistently shown to have beneficial effects in BKN. In addition to BKN, BK viral infection can cause severe urinary bladder cystitis, ureteritis and urinary tract obstruction as well as manifestations in other organ systems including the central nervous system, the respiratory system, the gastrointestinal system and the hematopoietic system. BK viral infection has also been implicated in tumorigenesis. The spectrum of clinical manifestations from BK infection and infection from other members of the Papoviridae family is widening. Prevention and treatment of BK infection and infections from other Papovaviruses are subjects of intense research.

Renal dysfunction following bone marrow transplantation

Acute kidney injury and long-term renal dysfunction are common problems following bone morrow transplantation (BMT) and highly related to mortality. The frequency and risk of renal dysfunction are directly related to the method of BMT, with myeloablative allogeneic BMT being associated to the highest risk followed by non-myeloablative allogeneic and myeloablative autologous BMT. The type of BMT is, thus, more important than co-factors such as advanced age, comorbidities, or high baseline serum creatinine. The causes for renal failure are multiple and include chemotherapy and high-dose radiation with fluid loss by diarrhea or vomiting, sepsis or nephrotoxic drugs such as calcineurin inhibitors and antimicrobials. Additionally, there are BMT-specific reasons for renal dysfunction including marrow infusion toxicity, hepatic veno-occlusive disease, thrombotic microangiopathy (TMA) and graft versus host disease (GvHD). Once the kidney has been damaged, the therapy depends on the underlying disease. Particularly in cases of TMA and GvHD, immunosuppressive therapy is essential. In TMA, plasma exchange therapy or eculizumab should be additionally considered if the complement system is affected. Hence, patients with these causes should preferably be referred to tertiary centers to allow early diagnosis and appropriate treatment.

BK Virus-Associated Hemorrhagic Cystitis After Allogeneic Hematopoietic Stem Cell Transplantation in the Pediatric Population

OBJECTIVE

To study the incidence, risk factors, and treatment of hemorrhagic cystitis secondary to BK-virus reactivation (HC-BKV) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the pediatric population.

METHODS

Case-control study in which all pediatric patients (0-18 years) who underwent allo-HSCT from September 2009 to January 2014 were followed.

RESULTS

Twenty-nine patients underwent an allo-HSCT. The median age was 9 years (range = 6 months to 15 years), 61% male. The primary diagnosis was acute lymphoblastic leukemia (72.4%). Six (20.7%) developed HC-BKV. In a multivariate analysis of risk factors, it was observed that the reactivation of BK virus was associated with age more than 10 years ( P = .098) and those with positive serology for Epstein-Barr virus ( P = .06). Five of the 6 patients with HC-BKV received cidofovir (CDV) at doses of 3 to 5 mg/kg/week. The treatment lasted a median of 3 cycles (range = 2-5). One of the patients (20%) developed nephrotoxicity. Of the 5 patients treated with CDV, 3 (60%) had a complete response, 1 (20%) partial response, and 1 (20%) no response.

CONCLUSION

We conclude that HC-BKV is a frequent complication after allo-HSCT. CDV therapy can be effective but controlled clinical trials are needed.

Successful treatment with intravesical cidofovir for virus-associated hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation: A case report and a review of the literature

Virus-associated hemorrhagic cystitis (VAHC) is a formidable complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The standard management of severe VAHC after allo-HSCT has not been established. Intravenous administration of cidofovir (CDV), an acyclic nucleoside analogue with broad-spectrum activity against DNA viruses, has been reported to be effective for VAHC, but it can cause severe renal toxicity. Here we report four cases who achieved clinical responses with intravesical instillation of CDV for severe VAHC after allo-HSCT. Median age was 57 years (40-63), and all were male. The underlying diseases were hematological malignancies. Three had received bone marrow transplantation, and one received cord blood transplantation twice. Conditioning regimen was myeloablative for one, and reduced-intensity for three. The viral types were BK virus and/or adenovirus. Two patients had received CDV intravenously prior to the intravesical therapy. A dose of intravesical CDV was 2-5 mg/kg. In all cases, symptoms of cystitis improved dramatically within a few days without showing any systemic adverse effects. The virological response was observed in two cases. This local therapy was effective even in the cases refractory to the intravenous CDV and a case with severe renal failure. Along with the review of literature, we propose that the intravesical instillation of CDV can be a therapeutic option for severe VAHC after allo-HSCT.

A Prospective Study on the Predictive Value of Plasma BK Virus-DNA Load for Hemorrhagic Cystitis in Pediatric Patients After Stem Cell Transplantation

BACKGROUND

In hematopoietic stem cell transplantation (HSCT), late hemorrhagic cystitis (HC) has been associated with BK virus (BKV) infection. We assessed the value of plasma BKV load in predicting HC.

METHODS

Plasma and urine BKV-DNA load were assessed prospectively in 107 pediatric patients.

RESULTS

Twenty patients developed grade II and III HC, with 100-day cumulative incidence of 18.8%. At diagnosis of HC, the median load of BKV DNA was 2.3 × 10(3) copies/mL. A plasma BKV-DNA load of 10(3) copies/mL had a sensitivity of 100% and a specificity of 86% with a negative predictive value (NPV) of 100% and a positive predictive value (PPV) of 39% for HC. A urine BKV-DNA load of >10(7) copies/mL had a sensitivity of 86% and a specificity of 60% with a NPV of 98% and a PPV of 14% for HC. A BKV load of 10(3) copies/mL on plasma was significantly associated with HC in multivariate analysis (hazard ratio [HR], 6.1; P = .0006). Patients with HC had a significantly higher risk of mortality than patients who did not have HC (HR, 2.6; P = .018).

CONCLUSIONS

The above values were used to monitor plasma BKV-DNA load, and they provided a better prediction of patients at risk of HC than urine BKV-DNA load.

Effect of Leflunomide, Cidofovir and Ciprofloxacin on replication of BKPyV in a salivary gland in vitro culture system

BK polyomavirus (BKPyV) is a known kidney tropic virus that has been detected at high levels in HIV-associated salivary gland disease (HIV-SGD), one of the most important AIDS associated oral lesions. BKPyV has been detected in HIV-SGD patient saliva and replicates in salivary gland cells in vitro. BKPyV antivirals are currently in wide use to guard against BKPyV mediated organ rejection in kidney transplant recipients. The goal of this study was to investigate the inhibitory effects of three such antiviral agents, Ciprofloxacin, Cidofovir, and Leflunomide in BKPyV infected salivary gland cells. Human salivary gland cells, and Vero cells, were infected with BKPyV, treated with antiviral drugs and assessed for BKPyV gene expression and viral replication for up to 5 days post infection. The kinetics of BKPyV replication were different in salivary gland cells compared to kidney cells. Ciprofloxacin and Cidofovir had minimal effect on metabolic activity and host cell DNA replication, however, cell toxicity was detected at the protein level with Leflunomide treatment. Ciprofloxacin decreased BKV T Ag and VP1 mRNA expression by at least 50% in both cell types, and decreased T Ag protein expression at days 3 and 4 post infection. A 2.5-4 log decrease in intracellular DNA replication and a 2-3 log decrease in progeny release were detected with Ciprofloxacin treatment. Cidofovir and Leflunomide also inhibited BKPyV gene expression and DNA replication. The three drugs diminished progeny release by 30-90% and 2- to 6-fold decreases in infectious virus were detected post drug treatment by fluorescence focus assay. Additionally, three clinical BKPyV isolates were assessed for their responses to these agents in vitro. Cidofovir and Leflunomide, but not Ciprofloxacin treatment resulted in statistically significant inhibition of BKPyV progeny release from salivary gland cells infected with HIVSGD BKPyV isolates. All three drugs decreased progeny release from cells infected with a transplant derived viral isolate. In conclusion, treatment of human salivary gland cells with each of the three drugs produced modest decreases in BKPyV genome replication. These data highlight the need for continued studies to discover more effective and less toxic drugs that inhibit BKPyV replication in salivary gland cells.

Treatment of BK virus-associated hemorrhagic cystitis with low-dose intravenous cidofovir in patients undergoing allogeneic hematopoietic cell transplantation

BACKGROUND/AIMS

BK virus (BKV) has been associated with late-onset hemorrhagic cystitis (HC) in recipients of hematopoietic stem cell transplantation (HSCT). Cidofovir has been used at higher doses (3 to 5 mg/kg/wk) with probenecid prophylaxis; however, cidofovir may result in nephrotoxicity or cytopenia at high doses.

METHODS

Allogeneic HSCT recipients with BKV-associated HC are treated with 1 mg/kg intravenous cidofovir weekly at our institution. A microbiological response was defined as at least a one log reduction in urinary BKV viral load, and a clinical response was defined as improvement in symptoms and stability or reduction in cystitis grade.

RESULTS

Eight patients received a median of 4 weekly (range, 2 to 11) doses of cidofovir. HC occurred a median 69 days (range, 16 to 311) after allogeneic HSCT. A clinical response was detected in 7/8 patients (86%), and 4/5 (80%) had a measurable microbiological response. One patient died of uncontrolled graft-versus-host disease; therefore, we could not measure the clinical response to HC treatment. One microbiological non-responder had a stable BKV viral load with clinical improvement. Only three patients showed transient grade 2 serum creatinine toxicities, which resolved after completion of concomitant calcineurin inhibitor treatment.

CONCLUSIONS

Weekly intravenous low-dose cidofovir without probenecid appears to be a safe and effective treatment option for patients with BKV-associated HC.

Infectious Complications

Infections remain a cause of significant morbidity and mortality following hematopoietic stem cell transplantation (HSCT). The conditioning regimen (chemotherapy, radiation therapy), mucosal damage, type of transplant, immune suppressive therapy, and graft-versus-host disease (GVHD) all predispose the HSCT recipient to infection. Abnormal B- and T-lymphocyte function results in impaired humoral and cellular immunity, respectively. Neutrophil function is impaired by the use of corticosteroids and other medications. Hypogammaglobulinemia and functional asplenia are common. The occurrence of infections in an individual patient varies according to the phase of the transplant process and reflects the type(s) of immune defect(s), underlying disease, endogenous host flora, exposure history, and pre-treatment infections.

Insights into the mechanism of action of cidofovir and other acyclic nucleoside phosphonates against polyoma- and papillomaviruses and non-viral induced neoplasia

Acyclic nucleoside phosphonates (ANPs) are well-known for their antiviral properties, three of them being approved for the treatment of human immunodeficiency virus infection (tenofovir), chronic hepatitis B (tenofovir and adefovir) or human cytomegalovirus retinitis (cidofovir). In addition, cidofovir is mostly used off-label for the treatment of infections caused by several DNA viruses other than cytomegalovirus, including papilloma- and polyomaviruses, which do not encode their own DNA polymerases. There is considerable interest in understanding why cidofovir is effective against these small DNA tumor viruses. Considering that papilloma- and polyomaviruses cause diseases associated either with productive infection (characterized by high production of infectious virus) or transformation (where only a limited number of viral proteins are expressed without synthesis of viral particles), it can be envisaged that cidofovir may act as antiviral and/or antiproliferative agent. The aim of this review is to discuss the advances in recent years in understanding the mode of action of ANPs as antiproliferative agents, given the fact that current data suggest that their use can be extended to the treatment of non-viral related malignancies.

Successful hyperbaric oxygen therapy for refractory BK virus-associated hemorrhagic cystitis after cord blood transplantation

BK virus-associated hemorrhagic cystitis (BKV-HC) is a common and major cause of morbidity in recipients of allogeneic hematopoietic stem cell transplantation. A 32-year-old woman developed severe BKV-HC on day 24 after cord blood transplantation (CBT). Despite supportive therapies - such as hyperhydration, forced diuresis, and urinary catheterization - macroscopic hematuria and bladder irritation persisted for over a month. Hyperbaric oxygen (HBO) therapy at 2.1 atmospheres for 90 min per day was started on day 64 after CBT. Macroscopic hematuria resolved within a week, and microscopic hematuria was no longer detectable within 2 weeks. Hematuria did not recur after 11 sessions of HBO therapy, and no significant side effects were observed during or after treatment. HBO therapy could thus be useful in controlling refractory BKV-HC after CBT.

BK Virus and Its Role in Hematopoietic Stem Cell Transplantation: Evolution of a Pathogen

We reviewed the literature regarding disease induced by BK virus (BKV) in the hematopoietic stem cell transplant (HSCT) population, particularly hemorrhagic cystitis (HC) and nephritis. The association between BKV and HC has been reported over the past four decades. BKV has been clinically implicated and widely accepted as an etiologic agent of HC and nephritis in HSCT and nephropathy in renal transplant patients. We discuss the potential benefit of early initiation of therapy in patients who fail supportive care alone as well as the different treatment strategies for HC induced by BKV. Treatments that have been used such as cidofovir and leflunomide are accompanied by risks, and the benefits are not as concrete as with other viral illness in the HSCT population.

Cellular immunotherapy for patients with reactivation of JC and BK polyomaviruses after transplantation

Immunosuppression of patients after hematopoietic stem cell or kidney transplantation potentially leads to reactivation of JC and BK polyomaviruses. In hematopoietic stem cell transplantation, the reactivation rate of BKV can be up to 60%, resulting in severe complications of the urogenital tract, particularly hemorrhagic cystitis and renal dysfunction. After kidney transplantation, BKV reactivation can cause a loss of the graft. JCV can cause progressive multifocal leukoencephalopathy, a lethal disease. Adoptive transfer of donor-derived polyomavirus-specific T cells is an attractive and promising treatment that restores virus-specific cellular immunity. Pioneering work in the early 1990s on the reconstitution of cellular immunity against cytomegalovirus and recent development in the field of monitoring and isolation of antigen-specific T cells paved the way toward a personalized T-cell therapy. Multimer technology and magnetic beads are available to produce untouched T cells in a single-step, good manufacturing practice-compliant procedure. Another exciting aspect of T-cell therapy against polyomaviruses is the fact that both JCV and BKV can be targeted simultaneously because of their high sequence homology. Finally, "designer T cells" can be redirected to recognize polyomavirus antigens with high-affinity T-cell receptors. This review summarizes the state-of-the art technologies and gives an outlook of future developments in the field.

Infectious complications of stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment for a variety of hematologic malignancies. The profound immunosuppression these patients experience adversely affects their risk of infection. This risk is much higher than in the general population and requires aggressive diagnostic and therapeutic interventions. The chapter will outline the major infections after HSCT.

The polyomavirus puzzle: is host immune response beneficial in controlling BK virus after adult hematopoietic cell transplantion?

BK virus (BKV), a ubiquitous human polyomavirus, usually does not cause disease in healthy individuals. BKV reactivation and disease can occur in immunosuppressed individuals, such as those who have undergone renal transplantation or hematopoietic cell transplantation (HCT). Clinical manifestations of BKV disease include graft dysfunction and failure in renal transplant recipients; HCT recipients frequently experience hematuria, cystitis, hemorrhagic cystitis (HC), and renal dysfunction. Studies of HCT patients have identified several risk factors for the development of BKV disease including myeloablative conditioning, acute graft-versus-host disease, and undergoing an umbilical cord blood (uCB) HCT. Although these risk factors indicate that alterations in the immune system are necessary for BKV pathogenesis in HCT patients, few studies have examined the interactions between host immune responses and viral reactivation in BKV disease. Specifically, having BKV immunoglobulin-G before HCT does not protect against BKV infection and disease after HCT. A limited number of studies have demonstrated BKV-specific cytotoxic T cells in healthy adults as well as in post-HCT patients who had experienced HC. New areas of research are required for a better understanding of this emerging infectious disease post HCT, including prospective studies examining BK viruria, viremia, and their relationship with clinical disease, a detailed analysis of urothelial histopathology, and laboratory evaluation of systemic and local cellular and humoral immune responses to BKV in patients receiving HCT from different sources, including uCB and haploidentical donors.

Diagnosis and treatment of viral diseases in recipients of allogeneic hematopoietic stem cell transplantation

Viral infections are important causes of morbidity and mortality after allogeneic stem cell hematopoietic transplantation (allo-HSCT). Although most viral infections present with asymptomatic or subclinical manifestations, viruses may result in fatal complications in severe immunocompromised recipients. Reactivation of latent viruses, such as herpesviruses, is frequent during the immunosuppression that occurs with allo-HSCT. Viruses acquired from community, such as the respiratory and gastrointestinal viruses, are also important pathogens of post-transplant viral diseases. Currently, molecular diagnostic methods have replaced or supplemented traditional methods, such as viral culture and antigen detection, in diagnosis of viral infections. The utilization of polymerase chain reaction facilitates the early diagnosis. In view of lacking efficacious agents for treatment of viral diseases, prevention of viral infections is extremely valuable. Application of prophylactic strategies including preemptive therapy reduces viral infections and diseases. Adoptive cellular therapy for restoring virus-specific immunity is a promising method in the treatment of viral diseases.

Treatment of BK virus-associated hemorrhagic cystitis in pediatric hematopoietic stem cell transplant recipients with cidofovir: a single-center experience

BACKGROUND

BK virus (BKV)-associated hemorrhagic cystitis (BKV-HC) is a severe complication after hematopoietic stem cell transplantation (HSCT). Cidofovir (CDV) has emerged as an effective agent for the treatment of BKV nephropathy, but its use for BKV-HC in pediatric HSCT recipients has not yet been established as a standard therapy.

PATIENT AND METHODS

We retrospectively investigated the efficacy and safety of CDV therapy for patients with BKV-HC at a single institution and analyzed the clinical management outcomes.

RESULTS

From April 2009 to July 2011, 12 patients developed BKV-HC at a median of 37 days after transplant (range 15-59 days). The cumulative incidence was 9% and the median peak of the urine BKV load was 2.5 × 10(10) copies/mL (range 1.4 × 10(9) -1.2 × 10(11) copies/mL). Eleven patients received intravenous CDV (5 mg/kg/dose, with probenecid), whereas 1 patient received CDV (5 mg/kg/dose, without probenecid) intravesically. The median duration of therapy was 25 days (range 9-73 days), and a median of 2 doses was given (range 1-4). A reduction of ≥ 1 log in the BKV load was found in 11 patients, while 1 patient did not have any significant change in BKV load. Clinical improvement was observed in all cases, and no HC-related death was observed. CDV-related toxicity occurred in 1 patient (8%) and spontaneously resolved.

CONCLUSIONS

CDV appears to be an effective and safe treatment for BKV-HC in pediatric HSCT recipients, but prospective trials are warranted to support its use.