BK Virus Infection and Its Effect on Renal Function in Pediatric Liver-Transplant Recipients: A Cross-Sectional, Longitudinal, Prospective Study

Hemorrhagic Cystitis in a Liver Transplant Recipient Secondary to BK Virus

The association between BK virus infection and hemorrhagic cystitis (HC) in hematopoietic stem cell transplant (HSCT) recipients is well established. However, BK virus-associated HC has not been described in liver transplant (LT) recipients. We present a case of BK virus-associated HC in a LT recipient. Our patient presented with worsening liver function tests 2 years after transplantation and was found to have acute cellular rejection. He was treated with increased immunosuppression and subsequently developed hematuria. He was eventually diagnosed with BK virus-associated HC.

The association between polyomavirus BK strains and BKV viruria in liver transplant recipients

BK virus (BKV) is a polyomavirus that cause of allograft dysfunction among kidney transplant recipients. The role of BKV infection in non-renal solid organ transplant recipients is not well understood neither for the relationship between various BKV strains with occurrence of BKV viral viruria. This study aimed to understand the prevalence of BKV infection and identified of BKV various strains in the urine of liver transplant recipients. There was not significant difference of renal outcome between high BKV viruria and low BKV viruria in the liver transplant recipients. The WW-non-coding control region (NCCR) BKV detected in urine was associated with higher urinary BKV load, whereas the Dunlop-NCCR BKV was detected in the urine of low urinary BKV load. An in vitro cultivation system demonstrated that WW-BKV strain exhibiting the higher viral DNA replication efficiency and higher BKV load. Altogether, this is the first study to demonstrate the impact of BKV strains on the occurrence of BK viruria in the liver transplant recipients.

BK polyoma virus infection and renal disease in non-renal solid organ transplantation

BK virus (BKV) is a non-enveloped DNA virus of the polyomaviridae family that causes an interstitial nephritis in immunosuppressed patients. BKV nephropathy is now a leading cause of chronic kidney disease and early allograft failure following kidney transplantation. It is also known to cause renal disease with a progressive decline in kidney function in non-renal solid organ transplant (NRSOT) recipients, although the disease may not be recognized nor its impact appreciated in this patient population. In this report, we review the existing literature to highlight our current understanding of its incidence in NRSOT populations, the approaches to diagnosis and the potential treatment options.

Monitoring the BK virus in liver transplant recipients: a prospective observational study

OBJECTIVES

Because of the controversy regarding the effects of BK virus on nonrenal solid-organ transplant, we detected the BK virus via different methods and its effect on clinical findings, liver and kidney functions, and graft dysfunction in liver transplant recipients.

MATERIALS AND METHODS

This prospective cohort study comprised patients over the age of 18, who consecutively received liver transplant from January 1 to December 31, 2011. The patients were examined once, every 2 weeks, for the first 3 months after transplant. Clinical findings were evaluated on each examination; blood and urine samples were collected, BK virus DNA was assessed with real-time polymerase chain reaction, and the presence of decoy cells (which are epithelial cells with large nuclei and large basophilic inclusions) in the urine was investigated. Patients were followed-up for 1 year to see if rejection occurred.

RESULTS

Five of 39 patients (12.8%) showed BK viremia; 11 patients (28.2%) showed BK viruria, and 13 (33.3%) showed decoy cells. No statistically significant differences were found between BK virus positive and negative groups, respecting demographic variables, kidney and liver functions, and graft survival. BK virus DNA positivity in blood was the standard, while decoy cell assessment in urine and BK virus polymerase chain reaction test sensitivity in urine was 40%.

CONCLUSIONS

No matter the method used to detect BK virus in the urine, the negativity of the tests is more valuable than their positivity. Although no statistically significant difference was found between the groups, we concluded that BK virus is a factor that should be considered when unexplained deterioration in kidney and liver function tests is observed in liver transplant recipients. Prospective studies with larger numbers of patients are warranted.

Adoptive T-cell immunotherapy from third-party donors: characterization of donors and set up of a T-cell donor registry

Infection with and reactivation of human cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus (ADV) are frequent and severe complications in immunocompromised recipients after hematopoietic stem cell transplantation (HSCT) or solid organ transplantation (SOT). These serious adverse events are associated with significant morbidity and mortality. Donor lymphocyte infusions (DLIs) are often used to treat both viral infections and leukemia relapses after transplantation but are associated with potentially life-threatening graft-versus-host disease (GvHD). Adoptive immunotherapy with virus-specific cytotoxic effector T cells (CTLs) derived from seropositive donors can rapidly reconstitute antiviral immunity after HSCT and organ transplantation. Therefore, it can effectively prevent the clinical manifestation of these viruses with no significant acute toxicity or increased risk of GvHD. In conditions, where patients receiving an allogeneic cord blood (CB) transplant or a transplant from a virus-seronegative donor and since donor blood is generally not available for solid organ recipients, allogeneic third party T-cell donors would offer an alternative option. Recent studies showed that during granulocyte colony-stimulating factor (G-CSF) mobilization, the functional activity of antiviral memory T cells is impaired for a long period. This finding suggests that even stem cell donors may not be the best source of T cells. Under these circumstances, partially human leukocyte antigen (HLA)-matched virus-specific CTLs from healthy seropositive individuals may be a promising option. Therefore, frequency assessments of virus-specific memory T cells in HLA-typed healthy donors as well as in HSCT/SOT donors using a high throughput T-cell assay were performed over a period of 4 years at Hannover Medical School. This chapter will address the relevance and potential of a third-party T-cell donor registry and will discuss its clinical implication for adoptive T-cell immunotherapy.

BK polyoma virus nephropathy in the native kidney

BACKGROUND

While BK polyoma virus nephropathy (PVN) is a well-recognized cause of renal allograft dysfunction, PVN of native kidneys is likely under-recognized.

METHODS

We present the pathologic features, risk factors and outcomes of eight cases of PVN in native kidneys.

RESULTS

The cohort included eight males aged 16-73 years (mean 47.4) with an immunocompromised state (mean duration 3.15 years) attributable to: hematologic malignancies (n = 6), for which three had undergone bone marrow transplant; lung transplant (n = 1) and combined tuberculosis and diabetes (n = 1). Seven patients were receiving specific immunosuppressive therapies. Patients were biopsied for acute kidney injury (AKI) with rise in mean creatinine levels from baseline 1.6 to 2.8 mg/dL. Pathology showed BK PVN with characteristic intranuclear inclusions staining positive for SV40 T antigen and negative for JC virus (JCV), with positive serum and/or urine PCR for BK virus. One patient had focal medullary JCV co-infection. Two patients also had renal infiltration by chronic lymphocytic leukemia (CLL). Six patients received specific therapy directed to PVN (cidofovir or leflunomide). Follow-up ranged from 2 to 20 (mean 10) months. Despite marked decrease in serum BK viral copy numbers, creatinine continued to rise in six cases (mean 3.7 mg/dL in four, requiring dialysis in two) and three patients died of malignancy, opportunistic infection or renal failure. Advanced histologic stage of PVN, ineffective antiviral therapy, co-morbidities and persistent immunocompromised state likely contributed to the poor outcomes.

CONCLUSION

A high level of suspicion in immunocompromised patients is needed to diagnose PVN in an early stage that may respond more favorably to antiviral therapy.