Pathogenicity of BK virus on the urinary system

The molecular footprints of BK virus in the product of conception over the second and third gestational trimesters

OBJECTIVE

Prior studies have shown controversial results on the vertical transmission of BK virus (BKV). The present study aimed to assess the possibility of BKV vertical transmission from mother to fetus in the product of conception (embryo, fetuses, and/or placentas) over the three stages of pregnancy.

RESULTS

Of the 26 placental studied tissues, 6 were in the first trimester, and none of which were positive. Only one out of the 13 (7.7%) placental materials in the second trimester was positive. Only one out of 7 (14%) placental materials of the third trimester was positive. There were cases that no virus was detected in their placental but BKV was detected in their other tissues. Among 26 conceptuses, 17 (65%) were negative for BKV and 9 (34.6%) were positive, 7/13 (54%) were positive in the second, and 2/7 (29%) were positive in the third trimester fetuses. BKV was most frequently detected in the liver (eight cases), heart (three cases), and placenta (2 cases). There were cases that no virus was detected in their placental but BKV was detected in their other tissues.

BK polyomavirus: latency, reactivation, diseases and tumorigenesis

The identification of the first human polyomavirus BK (BKV) has been over half century, The previous epidemiological and phylogenetic studies suggest that BKV prevailed and co-evolved with humans, leading to high seroprevalence all over the world. In general, BKV stays latent and symptomless reactivation in healthy individuals. BKV has been mainly interlinked with BKV-associated nephropathy (BKVAN) in kidney-transplant recipients and hemorrhagic cystitis (HC) in hematopoietic stem cell transplant recipients (HSCTRs). However, the mechanisms underlying BKV latency and reactivation are not fully understood and lack of extensive debate. As Merkel cell polyomavirus (MCV) was identified as a pathogenic agent of malignant cutaneous cancer Merkel cell carcinoma (MCC) since 2008, linking BKV to tumorigenesis of urologic tumors raised concerns in the scientific community. In this review, we mainly focus on advances of mechanisms of BKV latency and reactivation, and BKV-associated diseases or tumorigenesis with systematical review of formerly published papers following the PRISMA guidelines. The potential tumorigenesis of BKV in two major types of cancers, head and neck cancer and urologic cancer, was systematically updated and discussed in depth. Besides, BKV may also play an infectious role contributing to HIV-associated salivary gland disease (HIVSGD) presentation. As more evidence indicates the key role of BKV in potential tumorigenesis, it is important to pay more attention on its etiology and pathogenicity in vitro and in vivo.

BK-Virus-Induced Hemorrhagic Cystitis in a Patient With Graft-Versus-Host Disease

The BK virus is a polyomavirus known to particularly affect transplant recipients. An important complication caused by BK virus infection in bone marrow transplant patients is hemorrhagic cystitis. We present a 31-year-old male with a history of bone marrow transplantation complicated by graft-versus-host disease (GVHD) and was diagnosed with BK virus-related hemorrhagic cystitis. He presented with gross hematuria and suprapubic and penile pain for one week. He has a significant past medical history of acute B-cell lymphocytic leukemia for which he has successfully undergone allogenic bone marrow transplantation, which was complicated by GVHD. Imaging revealed significant bladder wall thickening which prompted an evaluation for BK virus-induced hemorrhagic cystitis. A urinary specimen was sent for BK virus polymerase chain reaction (PCR) which was strongly positive, confirming the infection. He was managed supportively throughout his hospitalization and improved with symptomatic management alone. Our case demonstrates one of the main complications caused by the BK virus in allogeneic bone marrow transplant patients in the setting of GVHD and is an important differential to keep in mind when treating patients presenting with hematuria after bone marrow transplantation.

A rare case of BK virus non-hemorrhagic cystitis following lung transplant

BK virus cystitis is known to occur following hematopoietic stem cell transplant (HSCT), but few cases exist in the literature following lung transplant. Because of the rarity of this presentation, patients may have missed diagnoses and prescribed ineffective treatments. We present our case of an atypical presentation of BK virus cystitis appearing as bladder carcinoma in situ in a lung transplant patient.

Urological Cancers and Kidney Transplantation: a Literature Review

PURPOSE OF REVIEW

The aim of this review is to provide an overview of epidemiology, risk factors, and treatment of urological malignancies in renal transplant recipients (RTR).

RECENT FINDINGS

Although optimal immunosuppressive therapy and cancer management in these patients remain controversial, adherence to general guidelines is recommended. Kidney transplantation is recognized as the standard of care for the treatment of end-stage renal disease (ESRD) as it offers prolonged survival and better quality of life. In the last decades, survival of RTRs has increased as a result of improved immunosuppressive therapy; nonetheless, the risk of developing cancer is higher among RTRs compared to the general population. Urological malignancies are the second most common after hematological cancer and often have more aggressive behavior and poor prognosis.

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.

Alternative Management of a Pediatric Case of Hemorrhagic Cystitis due to BK Virus: Use of Thulium Laser Coagulation

We report on a pediatric case of hemorrhagic cystitis due to BK virus in a patient with acute lymphoblastic leukemia who had undergone bone marrow transplantation. A very large hematoma that almost completely filled the bladder was aspirated using a morcellator via suprapubic percutaneous access, and a thulium laser was then used to cauterize extensive areas of diffuse uroepithelial bleeding. This combined minimally invasive procedure was successful in clearing the bladder hematoma and achieving hemostasis.

Fingerprint Biometric System Hygiene and the Risk of COVID-19 Transmission

Biometric systems use scanners to verify the identity of human beings by measuring the patterns of their behavioral or physiological characteristics. Some biometric systems are contactless and do not require direct touch to perform these measurements; others, such as fingerprint verification systems, require the user to make direct physical contact with the scanner for a specified duration for the biometric pattern of the user to be properly read and measured. This may increase the possibility of contamination with harmful microbial pathogens or of cross-contamination of food and water by subsequent users. Physical contact also increases the likelihood of inoculation of harmful microbial pathogens into the respiratory tract, thereby triggering infectious diseases. In this viewpoint, we establish the likelihood of infectious disease transmission through touch-based fingerprint biometric devices and discuss control measures to curb the spread of infectious diseases, including COVID-19.