The infection process of BK virus in transplant recipients after renal transplantation / 中华泌尿外科杂志

Objective To investigate the characteristics and manifestations of the different stages of BK virus infection in the recipients after renal transplantation.Methods A retrospective survey from January 2015 to December 2016 was done in our hospital.A total 135 recipients were included and accepted BK virus detection in 1,3,6,9,12,15 months respectively after renal transplantation.The prevalence of decoy cell,BK virus DNA load in urine and BK virus DNA load in blood was 56 cases (41.5％),9 cases (43.7％) and 30 cases (22.2％),5 cases of BK vims nephropathy confirmed by pathological biopsy (3.7％).At the same time,51 cases (37.8％) were combined with decoy cells and virus DNA load in urine.Positive decoy cells and negative BK virus DNA load in urine was 5 cases,and Positive BK virus DNA load in urine and negative decoy cells was 8 cases.The recipients were divided into positive group of urine decoy cell,positive group of urinary BK virus DNA load,and positive group of blood BK virus DNA load.Statistical correlation analysis was conducted on the laboratory test results of the 3 groups.Results The positive group of blood BK virus DNA load were detected the high level urine decoy cell count [median of 23/10HPF(2-48/10HPF)] and high level of urinary BK virus DNA load [4.52 × 106 copies/ml (6.51 × 103-7.89 × 109 copies/ml)],significantly higher than the positive group of decoy cells [8/10HPF(2-40/10HPF)] and the positive group of urine BK virus DNA load [4.56 × 105 copies/ml(5.62 × 103-7.89 ×109 copies/ml)] (P ＜ 0.05).The decoy cell count and urine DNA load has a significant linear correlation in viruria recipients,and the urinary BK DNA load and blood BK virus DNA load has the same significant 0.939 and 0.702 in 3 months,0.969 and 0.910 in 6 months,0.782 and 0.766 in 9 months,0.898 and 0.615 in 12 months after renal transplantation.Conclusions There is a linear correlation between decoy cell in urine,viruria and viremia,suggesting that the infection of BK virus in kidney transplant recipients is a continuous process.linear correlation in viremia recipients(P ＜ 0.05).The correlation coefficients at different time points were

Urinary Decoy Cell Grading and Its Clinical Implications

BACKGROUND: Examination of urine for decoy cells (DCs) is a useful screening test for polyomavirus (PV) activation. We explored the significance of the amount of DCs in persistent shedding, PV nephropathy and acute rejection. METHODS: A case-controlled study was performed in 88 renal allograft patients who had DCs detected at least once in four or more urine samples. RESULTS: Fifty one patients were classified into the high-grade shedding group (HG) and 37 patients into the low-grade shedding group (LG) according to DC shedding (> or =10 or or =10 DCs/10 HPF is associated with sustained shedding, polymerase chain reaction positivity and PV nephropathy, but not a predictor of acute rejection.

Urinary Decoy Cell Grading and Its Clinical Implications

BACKGROUND: Examination of urine for decoy cells (DCs) is a useful screening test for polyomavirus (PV) activation. We explored the significance of the amount of DCs in persistent shedding, PV nephropathy and acute rejection. METHODS: A case-controlled study was performed in 88 renal allograft patients who had DCs detected at least once in four or more urine samples. RESULTS: Fifty one patients were classified into the high-grade shedding group (HG) and 37 patients into the low-grade shedding group (LG) according to DC shedding (> or =10 or or =10 DCs/10 HPF is associated with sustained shedding, polymerase chain reaction positivity and PV nephropathy, but not a predictor of acute rejection.

BK virus infection in renal transplant recipients: Diagnosis and risk factors analysis / 第二军医大学学报

Objective: To investigate the incidence of BK virus infection in renal transplant recipients and to analyze the risk factors of BKV infection. Methods: The urine samples and peripheral blood samples of 63 renal transplant recipients were collected at 1, 2, 3, 4, 6 and 8 months after transplantation. A real-time fluorescent PCR procedure was used to detect BK virus DNA in the samples and the samples were divided into the following 3 groups according to the detection outcomes: UV+PV+ group (BKV DNA positive in both urine and blood samples), UV- PV- group (BKV DNA positive in urine but negative in blood samples), and UV- PV- group (BKV DNA negative in both urine and blood samples). Urinary sediment smears of patients were checked for decoy cells and the decoy cells were subjected to cytological immunostaining. Renal graft biopsy was performed when a sample was highly suspected of BKVAN by its clinical manifestations. The age, cold ischemia time, hematodialysis duration, immunosuppressive agents, panel reactive antibody, and other clinical parameters were compared between the 3 groups and a Logistic regression was performed to analyze the risk factors of BK virus infection. Results: There were 19 (30.1%) patients in UV+ PV- group, 9(14.3%)in UV-PV+ group,and 35 in UV-PV- group. The median time for the first detection of BK virus was 4 months in UV-PV- group and 3 months in UV+ PV+ group. Decoy cells were detected in 39.7% of the 63 patients and the positive rate of decoy cell immunostaining was 54.3%. One patient showed no BDVAN manifestation in renal biopsy. Logistic regression found that the cold ischemia time was significantly related to the BKV DNA infection (P=0.048; OR=1.151), but not to other parameters (P=0.069). Conclusion: Real-time fluorescent quantitative PCR is a good way for detection of BKV infection after renal transplantation. The peak time for BKV shedding is 3-4 months after transplantation. Cold ischemia time may be one of the risk factors of BKV infection, and immunosupressive regiment may has no obvious influence on BK virus infection.

Immunologic Control for Polyomavirus Infection after Kidney Transplantation / 대한이식학회지

Purpose: The purposes of this study were to compare the relative efficacy of urine decoy cell (UDC) and polymerase chain reaction (PCR) for the polyomavirus infection (PVI), and to search the efficacy of preemptive immunologic control for PVI in earlier stage before irreversible graft injury. Methods: Between Mar. 2003 to Sep. 2005, 265 patients were monitored for the PVI after kidney transplantation. Of the 265 patients, the results of preemptive immunologic modifications were searched among 222 recipients who had the complete data. Results: Of the total 222 patients, 75 patients (33.8%) were positive for UDCs in at least one examination. Overall cumulative incidence of PVI was 32.9%. According to the episode of acute rejection, the one year incidences of PVI were 51.4% and 29.5% in recipients with and without the episode of acute rejection, respectively (P=0.0047). Using decoy cells as a marker of PV viruria, cytology has a sensitivity of 57.1% and negative predictive value of 74.1%. The specificity and positive predictive value for viruria (not viral nephropathy) are 67.2% and 48.8%. False-negative results occurred in samples with suboptimal cellularity, and a low viral load. Three cases of PV nephropathy (PVN) were documented. From January 2001 to December 2002, when we did not prospectively monitor UDCs, 7 cases of PVN were documented among the 116 recipients. Conclusion: The combination test of UDC and PV PCR should be considered as screening test for PVI due to low positive predictive value of UDC. The modulation of net immunosuppression based on UDC values and PV viral loads may reduce the development of PVN.

Prospective Monitoring of Urine Decoy Cell after Kidney Transplantation / 대한이식학회지

PURPOSE: To find the incidence and risk factors for polyomavirus (PV) infection, we monitored urine decoy cell (UDC) after renal transplantation. METHODS: From March 2003 to September 2004, 142 de novo renal recipients were prospectively monitored for UDC at post-transplant 1, 3, 6, 9, 12 months. According to the number of UDC in Cytospin, patients were divided into 3 groups: A (0), B (1~9) and C (> or =10). We decreased immunosuppression (IS) when group C status persisted for more than 1 month or more than 4 UDC was continuously detected for more than 3 months. Differences in demographics and clinical characteristics among the groups were compared. RESULTS: Forty four (31%) patients were found to have positive UDC at least at one examination (30 in group B and 14 in C). The number of patients with positive UDC at postoperative 1, 3, 6, 9, 12 months were 10 (22.7%), 14 (31.8%), 17 (38.6%), 27 (61.3%), 20 (45.4%) respectively with a highest at 9 months. One PV nephropathy was documented by renal biopsy. During the period from January 2001 to December 2002 when we did not prospectively monitor UDC, 7 PV nephropathy cases were documented among 116 recipients. Tacrolimus (Tac) and episode of acute rejection (AR) were significant risk factor for positive UDC (P=0.036, 0.010, respectively). Cumulative incidence of PV infection was significantly different by the use of Tac and episode of AR (P=0.03, 0.013, respectively). CONCLUSION: Use of Tac and episode of AR were risk factor for positive UDC and PV infection. Modulation of IS by the result of UDC monitoring could decrease the development of PV nephropathy after renal transplantation.