Dataset Information

Genomic Mutations of BK Polyomavirus in Patients after Kidney Transplantation: A Cross-Sectional Study in Vietnam.

ABSTRACT:

Objectives

The purpose of this study was to identify the SNP sites and determine the BKV genotype circulating in kidney-transplant Vietnamese recipients based on the VP1 gene region.

Methods

344 samples were collected from post-kidney-transplant recipients at the 103 Vietnam Military Hospital to investigate the number of BKV infections. Positive samples with a sufficient virus concentration were analyzed by nested PCR in the VP1 region, sequencing detected genotyping and single-nucleotide polymorphism.

Results

BKV infection was determined in 214 patients (62.2%), of whom 11 (5.1%) were diagnosed with BKV-associated nephropathy. Among the 90 BKV-I strains sequenced, 89 (98.88%) were strains of I/b-1 and 1 (1.12%) was strain I/b-2. The 60 BKV-IV strains had a greater diversity of subgroups, including 40% IV/a-1, 1.66% IV/a-2, 56.68% IV/c-1, and 1.16% IV/c-2. Additionally, of 11 cases diagnosed with BKVN, seven belonged to subgroup I/b-1 (63.6%) and four to subgroup IV/c-1 (36.4%). Moreover, 22 specific SNPs that were genotype I or IV were determined in this Vietnamese population. Specifically, at position 1745, for the Vietnamese BKV-IV strains, the SNP position (A→G) appeared in 57/60 samples (95%). This causes transformation of the amino acid N→S. This SNP site can enable detection of genotype IV in Vietnam. It represents a unique evolution pattern and mutation that has not been found in other international strains.

Conclusion

The BKV-I genotype was more common than BKV-IV; however, mutations that occur on the VP1 typing region of BKV-IV strains were more frequent than in BKV-I strains.

SUBMITTER: Kien TQ

PROVIDER: S-EPMC9101345 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature

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Publications

Genomic Mutations of BK Polyomavirus in Patients after Kidney Transplantation: A Cross-Sectional Study in Vietnam.

Kien Truong Quy TQ Toan Pham Quoc PQ Nghia Phan Ba PB Van Diem Thi DT Duc Nguyen Van NV Ha Do Manh DM Dung Nguyen Thi Thuy NTT Ha Nguyen Thi Thu NTT Quyen Le Thi Bao LTB Vinh Hoang Trung HT Manh Bui Van BV Su Hoang Xuan HX Tien Tran Viet TV Thang Le Viet LV Rostaing Lionel L

Journal of clinical medicine 20220501 9

<h4>Objectives</h4>The purpose of this study was to identify the SNP sites and determine the BKV genotype circulating in kidney-transplant Vietnamese recipients based on the VP1 gene region.<h4>Methods</h4>344 samples were collected from post-kidney-transplant recipients at the 103 Vietnam Military Hospital to investigate the number of BKV infections. Positive samples with a sufficient virus concentration were analyzed by nested PCR in the VP1 region, sequencing detected genotyping and single-nu ...[more]

PMID: 35566670

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Project description:Abstract Introduction BK polyomavirus (BKPyV)‐associated nephropathy (BKPyVAN) can cause a significant risk of allograft impairment after kidney transplantation (KT). Intact BKPyV‐specific immunity is associated with viral containment. This study investigated BKPyV‐specific immunological factors among KT recipients. Methods This prospective study in a single transplant center from January 2019 to August 2019 assessed associations between clinical and immunological characteristics, with a focus on BKPyV‐cell‐specific immunity and BKPyVAN, among KT recipients aged ≥15 years. The numbers of interferon‐gamma (IFN‐γ)‐producing CD4+ T, CD8+ T, natural killer (NK), and natural killer T (NKT) cells were measured after stimulation with large T antigen and viral capsid protein 1 (VP1). Results In total, 100 KT recipients were included (mean age ± SD, 42 ± 11 years); 35% of the recipients were female patients, and 70% had received induction immunosuppressive therapy. The 1‐year cumulative incidence of high‐level BKPyV DNAuria (possible BKPyVAN) and (presumptive BKPyVAN) was 18%. Among 40 patients with immunological factor data, pre‐KT %NK cells (hazard ratio [HR], 1.258; 95% confidence interval [CI], 1.077–1.469; p = .004) and %VP1‐specific NK cells (HR, 1.209; 95% CI, 1.055–1.386; p = .006) were factors independently associated with possible and presumptive BKPyVAN. KT recipients with possible and presumptive BKPyVAN were more likely to exhibit significant mean coefficients of %NK, %VP1‐specific NK, and %NKT cells at 1 month after KT than before KT (all p < .05). Conclusion Individuals with nonspecific and VP1‐specific NK cells before KT and increasing numbers of these cells after KT may be at risk for high‐level BKPyV DNAuria and presumptive BKPyVAN. Further studies are needed to determine the utility of BKPyV‐specific innate immune surveillance in predicting the occurrence of BKPyVAN. Initial levels and post‐KT increases in NK, NKT, and VP1‐specific NK cells were greater in KT recipients who exhibited BKPyV DNAuria within 1 year after KT. BKPyV‐specific NK‐ and NKT‐cell immune surveillance could be used to identify patients at risk for post‐transplant viral reactivation.

Project description:BK polyomavirus (BKPyV) remains a significant challenge after kidney transplantation. International experts reviewed current evidence and updated recommendations according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Risk factors for BKPyV-DNAemia and biopsy-proven BKPyV-nephropathy include recipient older age, male sex, donor BKPyV-viruria, BKPyV-seropositive donor/-seronegative recipient, tacrolimus, acute rejection, and higher steroid exposure. To facilitate early intervention with limited allograft damage, all kidney transplant recipients should be screened monthly for plasma BKPyV-DNAemia loads until month 9, then every 3 mo until 2 y posttransplant (3 y for children). In resource-limited settings, urine cytology screening at similar time points can exclude BKPyV-nephropathy, and testing for plasma BKPyV-DNAemia when decoy cells are detectable. For patients with BKPyV-DNAemia loads persisting >1000 copies/mL, or exceeding 10 000 copies/mL (or equivalent), or with biopsy-proven BKPyV-nephropathy, immunosuppression should be reduced according to predefined steps targeting antiproliferative drugs, calcineurin inhibitors, or both. In adults without graft dysfunction, kidney allograft biopsy is not required unless the immunological risk is high. For children with persisting BKPyV-DNAemia, allograft biopsy may be considered even without graft dysfunction. Allograft biopsies should be interpreted in the context of all clinical and laboratory findings, including plasma BKPyV-DNAemia. Immunohistochemistry is preferred for diagnosing biopsy-proven BKPyV-nephropathy. Routine screening using the proposed strategies is cost-effective, improves clinical outcomes and quality of life. Kidney retransplantation subsequent to BKPyV-nephropathy is feasible in otherwise eligible recipients if BKPyV-DNAemia is undetectable; routine graft nephrectomy is not recommended. Current studies do not support the usage of leflunomide, cidofovir, quinolones, or IVIGs. Patients considered for experimental treatments (antivirals, vaccines, neutralizing antibodies, and adoptive T cells) should be enrolled in clinical trials.

Project description:PurposeTo construct a dynamic prediction model for BK polyomavirus (BKV) reactivation during the early period after renal transplantation and to provide a statistical basis for the identification of and intervention for high-risk populations.MethodsA retrospective study of 312 first renal allograft recipients was conducted between January 2015 and March 2022. The covariates were screened using univariable time-dependent Cox regression, and those with P<0.1 were included in the dynamic and static analyses. We constructed a prediction model for BKV reactivation from 2.5 to 8.5 months after renal transplantation using dynamic Cox regression based on the landmarking method and evaluated its performance using the area under the curve (AUC) value and Brier score. Monte-Carlo cross-validation was done to avoid overfitting. The above evaluation and validation process were repeated in the static model (Cox regression model) to compare the performance. Two patients were presented to illustrate the application of the dynamic model.ResultsWe constructed a dynamic prediction model with 18 covariates that could predict the probability of BKV reactivation from 2.5 to 8.5 months after renal transplantation. Elder age, basiliximab combined with cyclophosphamide for immune induction, acute graft rejection, higher body mass index, estimated glomerular filtration rate, urinary protein level, urinary leukocyte level, and blood neutrophil count were positively correlated with BKV reactivation, whereas male sex, higher serum albumin level, and platelet count served as protective factors. The AUC value and Brier score of the static model were 0.64 and 0.14, respectively, whereas those of the dynamic model were 0.79 ± 0.05 and 0.08 ± 0.01, respectively. In the cross-validation, the AUC values of the static and dynamic models decreased to 0.63 and 0.70 ± 0.03, respectively, whereas the Brier score changed to 0.11 and 0.09 ± 0.01, respectively.ConclusionDynamic Cox regression based on the landmarking method is effective in the assessment of the risk of BKV reactivation in the early period after renal transplantation and serves as a guide for clinical intervention.

Dataset Information

Genomic Mutations of BK Polyomavirus in Patients after Kidney Transplantation: A Cross-Sectional Study in Vietnam.

Objectives

Methods

Results

Conclusion

Publications

Genomic Mutations of BK Polyomavirus in Patients after Kidney Transplantation: A Cross-Sectional Study in Vietnam.

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