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Boan P, Hewison C, Swaminathan R, Irish A, Warr K, Sinniah R, Pryce TM, Flexman J. Optimal use of plasma and urine BK viral loads for screening and predicting BK nephropathy. BMC Infect Dis 2016; 16:342. [PMID: 27448566 PMCID: PMC4957298 DOI: 10.1186/s12879-016-1652-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/07/2016] [Indexed: 01/01/2023] Open
Abstract
Background BK virus is a polyoma virus causing renal allograft nephropathy. Reduction of immunosuppression with the early recognition of significant BK viral loads in urine and plasma can effectively prevent BKV associated nephropathy (BKVN), however the optimal compartment and frequency of BK viral load measurement post renal transplantation are undetermined. Our purpose was to examine time to detection and viral loads in urine compared to plasma, and establish viral load cut-offs associated with histological BKVN. Methods We performed a retrospective analysis of the BKV screening frequency and compartment(s) of 277 adult renal transplant recipients (RTR). Results BKVN was histologically diagnosed in 17 (6.1 %) RTR. In cases where both urine and plasma were tested fortnightly for 6 months (n = 53), BKV was detected in the urine 29 days earlier than plasma. Fortnightly (n = 72) versus 3-monthly (n = 78) testing demonstrated that BKV was detected in the urine significantly earlier (median 63 versus 97 days, p = 0.001) and at a lower level (median 3.27 versus 6.71 log10 c/mL, p < 0.001) with more frequent testing, but this difference was not evident in plasma first detection (80 versus 95 days, p = 0.536) or first positive viral load (3.18 versus 3.30 log10 c/mL, p = 0.603). The optimum cut-off BK viral load for histological diagnosis of BKVN was 4.10 log10 c/mL for the first positive urine, 3.79 log10 c/mL for the first positive plasma, 9.24 log10 c/mL for the peak urine, and 4.53 log10 c/mL for the peak plasma. Conclusions Frequent urinary BK viral load screening for the prevention of BKVN is suggested due to its high sensitivity and earlier detection.
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Affiliation(s)
- Peter Boan
- Departments of Microbiology and Infectious Diseases, PathWest Laboratory Medicine WA and Fiona Stanley Hospital, Level 1, Path Block, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia.
| | - Christopher Hewison
- Department of Microbiology, PathWest Laboratory Medicine WA, Level 1, Path Block, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia
| | - Ramyasuda Swaminathan
- Renal Transplant Unit, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia
| | - Ashley Irish
- Renal Transplant Unit, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia
| | - Kevin Warr
- Renal Transplant Unit, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia
| | - Rajalingam Sinniah
- Department of Histopathology, Royal Perth Hospital, GPO Box X2214, Perth, 6000, Western Australia, Australia
| | - Todd M Pryce
- Department of Microbiology, PathWest Laboratory Medicine WA, Level 1, Path Block, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia
| | - James Flexman
- Department of Microbiology, PathWest Laboratory Medicine WA, Level 1, Path Block, Fiona Stanley Hospital, 102-118 Murdoch Dve, Murdoch, Perth, 6150, Western Australia, Australia
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Akpinar E, Ciancio G, Sageshima J, Chen L, Guerra G, Kupin W, Roth D, Ruiz P, Burke G. BK virus nephropathy after simultaneous pancreas-kidney transplantation. Clin Transplant 2011; 24:801-6. [PMID: 20088913 DOI: 10.1111/j.1399-0012.2009.01204.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND BK virus nephropathy (BKVN) was reported in up to 7.5% of patients after simultaneous pancreas-kidney transplantation (SPK). Its management by reduction in immunosuppression might pre-dispose to pancreatic graft loss. METHODS A retrospective analysis of 178 SPK recipients was performed. All patients received thymoglobulin, daclizumab and a maintenance of low-dose steroids, tacrolimus, and either sirolimus or mycophenolate. RESULTS Two (1.1%) patients were identified with BKVN. Time of diagnosis was 22 and 45 months after transplant. Both patients had superimposed calcineurin toxicity in their graft biopsies. Immunosuppression was reduced in both patients, and leflunomide (LEF) was used in one patient. Concurrent kidney rejection episodes were treated with steroid pulses in both patients. One kidney graft improved with a last estimated glomerular filtration rate (GFR) of 43 mL/min, and another kidney graft showed limited improvement with a last GFR of 30 mL/min. Pancreatic graft function remained excellent in both patients as assessed by serum c-peptide, glycosylated hemoglobin, amylase-lipase, and urine amylase levels. CONCLUSION Low incidence of BKVN was observed in our SPK series. Reduction in immunosuppression and sometimes LEF can be effective. The underlying mechanism of stable pancreatic allograft function despite ongoing kidney rejection warrants further investigation.
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Affiliation(s)
- Edip Akpinar
- Division of Transplantation, Departments of Surgery and Pathology, The Lillian Jean Kaplan Renal Transplant Center, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, USA
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Bechert CJ, Schnadig VJ, Payne DA, Dong J. Monitoring of BK viral load in renal allograft recipients by real-time PCR assays. Am J Clin Pathol 2010; 133:242-50. [PMID: 20093233 DOI: 10.1309/ajcp63vdfckcruul] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BK virus (BKV) is a nonenveloped, double-stranded DNA virus of the polyomavirus family that primarily affects immunocompromised people. BKV may cause nephropathy in renal transplant recipients receiving immunosuppressive therapy, resulting in renal dysfunction and, possibly, graft loss. Monitoring of BK viral load in urine and blood has been used as a surrogate marker of BKV nephropathy (BKVN). Although real-time polymerase chain reaction (PCR) is the method of choice, currently there is no US Food and Drug Administration-approved or standardized BK viral load assay. Different PCR assays vary significantly in sample types, DNA extraction method, PCR primers and probes, and reference materials used to generate a standard curve. These differences can affect the accuracy, specificity, and dynamic ranges of various real-time PCR assays. These analytic differences cause difficulty in comparing test results, making it impossible to establish universal standardized cutoff values that correlate with clinical manifestations of BKVN. In this review, we summarize real-time PCR assays used for managing BKVN.
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