肾移植受者BK病毒感染的检测方法及免疫抑制方案对BK病毒活化的影响

目的 探讨肾移植术后受者BK病毒感染的检测方法及免疫抑制方案对BK病毒活化的影响.方法 选择1999年1月至2007年1月问进行肾移植术的200例受者为研究对象,其中100例基础免疫抑制方案为他克莫司(FK506)十霉酚酸酯(MMF)的受者作为密切观察组;另100例基础免疫抑制方案不同、但在年龄和术后是否发生急性排斥反应方面与密切观察组受者相一致(按1:1匹配)的受者作为对照观察组.在肾移植术后平均15.3个月时,分别采集所有受者的血、尿样本,行BK病毒尿沉渣Decoy细胞计数与BK病毒DNA含量的检测.分析和比较尿Decoy细胞计数、尿BK病毒含量及血BK病毒含量之间的关系;比较两组Decoy细胞、BK病毒尿症与BK病毒血症阳性率的差异.结果 200例受者的尿Decoy细胞、BK病毒尿症与病毒血症的阳性率分别为:34.0%、36.0%和16.5%.尿Decoy细胞计数与尿BK病毒含量呈正相关(r=0.714,P＜0.001),但尿液和外周血中BK病毒含量无明显相关性(P＞0.05).密切观察组的尿Decoy细胞、BK病毒尿症与BK病毒血症的阳性率分别为49%、50%和24%,对照观察组上述指标的阳性率分别是19%、22%和9%,两组的差异有统计学意义(P＜0.01).结论 尿沉渣Decoy细胞计数方法简单、易行并敏感,可以做为BK病毒活化的指标;血、尿BK病毒DNA的检测可进一步了解病毒活化情况、筛杳BK病毒相关的移植肾肾病.FK506+MMF的组合免疫抑制方案易发生BK病毒的活化,受者术后需进行密切观察和相关的检测.     

肾移植受者BK病毒相关性肾病的临床诊断

目的 探讨肾移植受者BK病毒相关性肾病(BKVAN)的临床诊断方法 .方法 分别于肾移植术后第1、3、6、9、12个月收集90例肾移植受者血、尿标本,进行尿沉渣Decoy细胞计数与BK病毒(BKV)DNA含量的检测.应用免疫组织化学技术检测移植肾组织中的SV40-T蛋白,移植肾组织及确诊为BKVAN患者的尿沉渣中脱落的肾小管上皮细胞进行普通透射电镜观察.结果 90例肾移植受者1年内尿液Decoy细胞、BKV DNA及血浆BKV DNA阳性率分别为:42.2%(38/90)、45.6%(41/90)和22.2%(20/90);阳性者中位数水平分别为8个/10 HPF、2.60×10~5拷贝/ml和9.65×10~3拷贝/ml.确诊BKVAN 5例.结论 肾移植术后定期规律监测有关BKV活动的指标非常必要.确诊BKVAN需依靠普通病理染色与免疫组织化学染色或普通透射电子显微镜并结合临床表现.     

肾移植受者BK病毒的感染特点

目的 探讨肾移植受者BK病毒（BKV）的感染特点。 方法 于我院门诊选取肾移植术后48个月内的患者共243例作为试验组,同时选取门诊健康体检者82例作为对照组。采集上述2组的血、尿标本,行BKV尿沉渣细胞学计数与实时荧光定量PCR检测。 结果 试验组受者的尿Decoy细胞、BKV尿症与BKV血症的阳性率分别为35.4 %、36.6%和16.9%;对照组分别为4.9%、20.7%和2.9%。试验组受者的尿Decoy 细胞阳性者Decoy细胞中位数水平为6个/10 HPF,BKV DNA阳性者尿液和外周血BKV中位数水平分别为1.50×104拷贝/ml和6.87×103拷贝/ml;对照组分别为2个/10 HPF,1.10×104拷贝/ ml和2.24×103拷贝/ml。与健康者相比,肾移植术后试验组BKV DNA阳性率及水平明显升高（P < 0.01）。肾移植受者的尿液Decoy 细胞计数与尿液BKV含量呈正相关（r = 0.636,P < 0.01）;尿Decoy大量组（＞10个/10 HPF）的血BKV DNA阳性率及水平显著高于少量组（1～5个/10 HPF）（P < 0.05）。 结论　肾移植受者较健康人群易发生BKV再活化。定量尿沉渣细胞学检测简单、易行、敏感,可以作为BKV活化的指标,预测病毒尿症及病毒血症。此外,也可检测血、尿BKV DNA,以了解病毒活化情况和筛查BKV相关的移植肾肾病。     

肾移植术后BK病毒感染的危险因素分析

目的 分析肾移植术后BK病毒(BKV)感染发生的危险因素.方法 应用荧光实时定量PCR技术检测129例肾移植患者血液中BKV并行尿液细胞学检查,记录BKV-DNA阳性及阴性组患者性别、年龄、供肾冷缺血时间,术前血液透析时间、急性排斥反应、是否发生移植肾功能延迟恢复、免疫抑制剂方案、合并其他病毒感染等指标.应用二项多元逻辑回归法分析肾移植术后BKV感染发生的危险因素.结果 129例患者血中BKV-DNA阳性20例(15.5%).阴性109例(84.5%);BKV-DNA阳性患者尿细胞学检测Decoy细胞阳性15例,尿Decoy细胞阳性率与血BKV-DNA阳性率之间有明显的相关性(r=0.428,P<0.01).回归分析结果 显示:供肾冷却血时间(χ~2=9.243,95%CI:1.099～1.545,P<0.05)、患者术前透析时间(χ~2=7.599,95%CI:1.038～1.243,P<0.05)、是否为亲体供肾(χ~2=4.150,95%CI:0.012～0.070,P<0.05)为BKV感染的危险因素.结论 荧光实时定量PCR及尿细胞学检查可以作为肾移植术后BKV感染的筛查指标;供肾冷缺血时间长、术前血液透析时间长、尸体供肾均可增加患者术后BKV感染的风险.     

肾移植术后高水平BK病毒尿症危险因素分析

目的 分析肾移植术后高水平BK病毒尿症的危险因素及其对预防BK病毒相关性肾病(BKVAN)的意义.方法 回顾性分析262例保留规律随访资料的肾移植受者的临床资料.根据受者BK病毒DNA载量分为高水平BK病毒尿症组(35例)和非高水平BK病毒尿症组(227例).总结肾移植术后高水平BK病毒尿症的发生情况;采用单因素和多因...     

BK病毒血症对肾移植术后受者和移植肾功能影响临床研究

目的探究肾移植术后BK病毒(BKV)血症对受者及移植肾功能的影响。 方法回顾性分析2014年1月至2018年1月于中国科学技术大学附属第一医院接受肾移植229例受者临床资料。根据移植术后24个月内受者血清BKV最大载量,将其分为无病毒组(血清BKV持续阴性)、低病毒载量组(血清BKV最大载量≤1×10⁴ copies/mL)和高病毒载量组(血清BKV最大载量>1×10⁴ copies/mL)。以估算肾小球滤过率(eGFR)作为评价移植肾功能的指标。观察受者年龄和性别、供肾来源、供肾冷/热缺血时间、免疫抑制方案、术后3个月他克莫司血药浓度谷值、排斥反应和移植肾失功发生率以及术后24个月内eGFR。采用单因素方差分析比较3组受者年龄、供肾冷/热缺血时间、术后3个月他克莫司血药浓度谷值及术后24个月内eGFR,组间两两比较采用LSD法。采用成组t检验比较低病毒载量组与高病毒载量组受者首次检测到BKV的术后时间。采用卡方检验比较3组受者供肾来源、免疫抑制方案以及排斥反应和移植肾失功发生率。P<0.05为差异有统计学意义。 结果229例受者中28%(64/229)的受者肾移植术后血清检测到BKV,其中19%(43/229)为低病毒载量,9%(21/229)为高病毒载量。截至2018年7月,229例受者平均随访时间(44±8)个月。低病毒载量组受者术后首次检测到BKV的时间为移植后(10±8)个月,高病毒载量组为(8±6)个月,差异有统计学意义(t＝2.10,P<0.05)。无病毒组受者排斥反应发生率[24.8%(41/165)]低于低病毒载量组[60.5%(26/43)]和高病毒载量组[61.9%(13/21)](χ²＝19.82和12.42,P均<0.017)。无病毒组受者细胞排斥反应发生率[13.9%(23/165)]低于低病毒载量组[39.5%(17/43)]和高病毒载量组[42.9%(9/21)](χ²＝14.38和10.94,P均<0.017)。无病毒组受者中12例发生移植肾失功,低病毒载量组受者中2例发生移植肾失功,高病毒载量组受者中4例(3例发生BKVAN,1例病因不明确)发生移植肾失功,差异无统计学意义(χ²＝4.727,P>0.05)。高病毒载量组受者术后第3个月他克莫司血药浓度谷值高于无病毒组和低病毒载量组(P均<0.05)。高病毒载量组受者术后第3、6、12、24个月eGFR均低于无病毒组和低病毒载量组(P均<0.05)。 结论肾移植术后高BKV血症会影响肾移植受者预后及移植肾功能;而低BKV血症对移植肾功能无明显不良影响,此类受者无需调整他克莫司剂量。     

疫情常态化防控期间不规律随访对肾移植术后BK病毒再激活时的病毒载量及受者预后影响

目的 探讨在新型冠状病毒肺炎疫情常态化防控期间不规律随访对肾移植受者术后BK病毒（BKV）再激活情况及预后的影响。方法 回顾性分析363例肾移植受者的临床资料,按随访时间分为疫情前随访组与疫情期间随访组,随访期限为1年。比较疫情前随访组和疫情期间随访组的随访时间间隔,分析两组BKV感染情况,分析BKV感染进程与移植肾功能的相关性。结果 疫情前随访共计1 790例次,疫情期间随访共计2 680例次。与疫情期间随访组比较,疫情前随访组术后3个月内、3～6个月、7～12个月的随访时间间隔较短,差异均有统计学意义（均为P<0.05）。在肾移植术后1年内,疫情前随访组35例（32%）检出BKV尿症、3例（3%）检出BKV血症、1例（1%）检出BKV相关肾病（BKVAN）,疫情期间随访组53例（25%）检出BKV尿症、3例（1%）检出BKV血症、1例（1%）检出BKVAN,差异均无统计学意义（均为P>0.05）。疫情前随访组术后首次检出BKV尿症时间长于疫情期间随访组,首次再激活尿BKV载量小于疫情期间随访组,差异均有统计学意义（均为P<0.05）。首次再激活尿BKV载量与尿BK...     

两种免疫抑制方案在乙肝病毒感染的肾移植受者中的应用

目的:比较乙肝病毒感染的肾移植受者应用普乐可复(FK506)或环孢素A(CsA)为基础的两种免疫抑制方案的抗排斥疗效及肝损害情况.方法:将乙肝病毒感染的肾移植受者随机分为FK506组和CsA组,每组各20例,两组均联合应用霉酚酸酯(MMF)和泼尼松(Pred).结果:观察12个月,FK506组中有3例(15%)患者发生急性排斥,CsA组中有4例(20%)发生急性排斥,均使用甲基泼尼松龙(MP)冲击治疗后逆转,两组急性排斥发生率差异无统计学意义.FK506组中有4例(20%)出现肝损害,CsA组中有14例(70%)出现肝功能异常,两组肝功能损害发生率差异有统计学意义.结论:FK506免疫抑制效果与CsA相似,但对肝功能影响较小,适合作为乙肝病毒感染的肾移植受者首选的免疫抑制剂.     

不同免疫诱导方案下肾移植术后BK病毒感染情况分析

目的 比较同时期采用单克隆抗体免疫诱导和多克隆抗体免疫诱导治疗受者肾移植术后尿液及血液BK病毒感染的情况。方法 回顾性收集2017年1月—2019年7月于山西省第二人民医院行肾移植术共298例患者术后尿液、血液BK病毒DNA检测结果。根据免疫诱导治疗方案的不同分为单克隆抗体免疫诱导治疗组85例和多克隆抗体免疫诱导治疗组213例,比较两组BK病毒感染情况,探讨不同免疫诱导治疗方案对肾移植受者BK病毒感染的影响。结果 所有患者尿BK病毒阳性率为50.00%(149/298),血BK病毒阳性率为3.69%(11/298),肾移植术后尿BK病毒阳性率明显高于血BK病毒阳性率(P <0.01);单克隆抗体组尿BK病毒阳性率为50.59%(43/85),多克隆抗体组尿BK病毒阳性率为49.77%(106/213),差异无统计学意义(χ²=0.165,P> 0.05);单克隆抗体组血BK病毒阳性率为2.35%(2/85),多克隆抗体组血BK病毒阳性率为4.22%(9/213),差异无统计学意义(χ²=0.188,P> 0.05)。结论 单...     

肾移植术后BK病毒相关性肾病合并环孢素中毒1例报告

<正>BK病毒(BK virus,BKV)属多瘤病毒(polyomavirus)家族成员,是导致肾移植术后移植肾肾病的重要危险因素之一[1]。随着全球肾移植手术的广泛开展,由BKV感染导致移植物功能受损,进展为BK病毒性肾病(BK virus-associated nephropathy,BKVN)而导致移植肾丢失的病例报道逐渐增多[2]。国外研究报告显示,在肾移植受者中有1%~5%的人会发生BKVN,其中大约50%的受者继而发生移植肾失功,由此引起了移植     

Prospective study of polyomavirus BK replication and nephropathy in renal transplant recipients in China: a single‐center analysis of incidence,reduction in immunosuppression and clinical course

Huang G, Chen L‐Z, Qiu J, Wang C‐X, Fei J‐G, Deng S‐X, Li J, Chen G‐D, Zhang L, Fu Q, Zeng W‐T, Zhao D‐Q. Prospective study of polyomavirus BK replication and nephropathy in renal transplant recipients in China: a single‐center analysis of incidence, reduction in immunosuppression and clinical course.
Clin Transplant 2009 DOI: 10.1111/j.1399‐0012.2009.01141.x
© 2009 John Wiley & Sons A/S. Abstract: Background: BK virus (BKV)‐associated nephropathy (BKVAN) in renal transplant recipients is an important cause of renal transplant dysfunction. Our aim was to determine the kinetics of BKV load within one yr after kidney transplantation under the impact of intensive monitoring and reduction in maintenance immunosuppression, the incidence of BKVAN, and the outcome of BKVAN treatment. Methods: Urine and peripheral blood (PB) were taken from 90 renal transplant recipients for BKV cytological testing and real‐time PCR for BKV DNA at one, three, six, nine, and 12 months after transplantation and treatment. Graft biopsies and urinary sediments of recipients with BKVAN were taken to monitor viral particles by conventional transmission electron microscopy (TEM). Results: By one post‐transplant year, urinary decoy cells (median, 8/10 HPF), BKV viruria (median, 2.60 × 10⁵ copies/mL), viremia (median, 9.65 × 10³ copies/mL ) , and BKVAN occurred in 42.2%, 45.6%, 22.2%, and 5.6% of patients, respectively. The incidence of BK infection was lower in patients who received cyclosporine A (CsA) (28.9%) compared to tacrolimus (FK506) (57.7%) (p = 0.007). An increased hazard of BK infection was associated with the use of FK506 (HR 2.6, p = 0.009) relative to CsA. After reduction in immunosuppression, viremia resolved in 95%, without increased acute rejection, allograft dysfunction, or graft loss. BKVAN was diagnosed in five patients (5.6%). The treatment of immunosuppression reduction was effective (i.e., decreased the viral load and number of decoy cells, and improved graft function) in our five patients with BKVAN. Quantitative count of decoy cells (e.g., >10 per 10 HPF) as a marker of viremia and BKVAN had increased positive predictive values of 85.7% and 57.1%, respectively. Conclusions: Choice of FK506 as immunosuppressive agent is an independent risk factor affecting BKV infection. Monitoring and pre‐emptive of immunosuppression reduction were associated with resolution of viremia and showed effective in BKVAN recipients at the early stage without acute rejection or graft loss. Quantitative count of urine cytology is a very convenient, useful, and sensitive method for evaluating BKV infection in renal transplant recipients.     

肾移植术后多瘤病毒感染的临床诊断和治疗

目的 探讨肾移植术后多瘤病毒（BKV）感染的诊断方法、监测指标及初步治疗方法。方法 采集64例肾移植受者的血、尿样本，行BKV细胞学与聚合酶链反应（PCR）检测。对肾移植术后BKV感染的流行病学以及相关因素进行分析，并对BKV感染的受者进行试验性治疗。结果 64例受者的尿Decoy细胞、多瘤病毒尿症与多瘤病毒血症的阳性率分别为28．7％、17．2％和6．3％。血肌酐（Cr）升高的受者尿Decoy细胞阳性率高于血Cr稳定的受者（P=0．04）。受者的性别、年龄、诱导治疗方案、是否发生急性排斥反应以及术后肾功能恢复情况等临床因素与尿Decoy细胞、多瘤病毒尿症及多瘤病毒血症的出现无明显相关性。应用更昔洛韦试验性治疗4例BKV感染的受者，治疗2～3周后，受者的尿Decoy细胞以及血、尿BKV DNA均转为阴性。结论 血肌酐水平升高的肾移植受者易发生BKV再活化。可通过检测血BKV DNA筛查BKV相关的移植肾肾病。更昔洛韦治疗BKV具有良好的疗效，但需进一步验证。     

BKV reactivation in renal transplant recipients: diagnostic and therapeutic strategy--case reports

The Polyomaviridae family includes several viruses that are ubiquitous with specific host spectra. The human polyoma viruses BK and JC were discovered in 1971. Following primary infection, transmitted by the respiratory and probably the oral route, BK remains latent in uroepithelial cells, in B lymphocytes, or in other tissues (spleen, brain). Reactivation with asymptomatic viruria may occur in both immunocompetent subjects and immunocompromised patients. In renal transplant recipients, BKV replication may cause tubulointerstitial nephropathy (BKVAN) with increasing prevalence rates--1% in 1995, 8% in 2007--leading to the loss of the transplanted organ in 30% to 80% of cases. With the availability of diagnostic programs (decoy cells in urine, amplification of viral DNA by polymerase chain reaction (PCR) on serum and urine, real time (RT)-PCR test for mRNA VP1 urine (mRNA-VP1), and renal biopsy accompanied by reduction in immunosuppression, administration of leflunomide, cidofovir (after hydration), and N-acetylcysteine, as well as immunoglobulin by intravenous injection (IVIg), the incidence of renal loss caused by BKVAN infection has been reduced by 10% to 80%. In this study, we have described 12 patients: 6 treated with tacrolimus (FK), mycophenolate mofetil (MMF), and steroids, and 6 treated with cyclosporine or with mTOR inhibitors. Two patients from the first group showed BKVAN about 3 months posttransplantation. Early diagnosis and therapeutic intervention (cidofovir + IVIg) led to reduction in the viral load, with improvement and stabilization in renal function. Considering the high positive predictive value (98%) of mRNA VP1, it should be possible to avoid renal biopsy. The level of immunosuppression--rather than the immunosuppressive drug itself (FK and MMF)--seemed to be associated with BKV reactivation.     

Incidence of BK with Tacrolimus Versus Cyclosporine and Impact of Preemptive Immunosuppression Reduction

Our purposes were to determine the incidence of BK viruria, viremia or nephropathy with tacrolimus (FK506) versus cyclosporine (CyA) and whether intensive monitoring and discontinuation of mycophenolate (MMF) or azathioprine (AZA), upon detection of BK viremia, could prevent BK nephropathy. We randomized 200 adult renal transplant recipients to FK506 (n = 134) or CyA (n = 66). Urine and blood were collected weekly for 16 weeks and at months 5, 6, 9 and 12 and analyzed for BK by polymerase chain reaction (PCR). By 1 year, 70 patients (35%) developed viruria and 23 (11.5%) viremia; neither were affected independently by FK506, CyA, MMF or AZA. Viruria was highest with FK506-MMF (46%) and lowest with CyA-MMF (13%), p = 0.005. Viruria >/= 9.5 log(10) copies/mL was associated with a 3-fold increased risk of viremia and a 13-fold increased risk of sustained viremia. After reduction of immunosuppression, viremia resolved in 95%, without increased acute rejection, allograft dysfunction or graft loss. No BK nephropathy was observed. Choice of calcineurin inhibitor or adjuvant immunosuppression, independently, did not affect BK viruria or viremia. Viruria was highest with FK506-MMF and lowest with CyA-MMF. Monitoring and preemptive withdrawal of immunosuppression were associated with resolution of viremia and absence of BK nephropathy without acute rejection or graft loss.     

A direct association of polyomavirus BK viruria with deterioration of renal allograft function in renal transplant patients

Abstract: Background:  Polyomavirus BK virus (BKV) causes a BKV-associated nephropathy (BKVAN), frequently causing allograft dysfunction in renal transplant recipients. As BK viruria is a surrogate marker for early detection of BKVAN, the aim of this study was to clarify an association between BK viruria and allograft dysfunction in renal transplant recipients.
Methods:  One hundred and six renal transplant recipients with average 5.9-yr transplant duration received screening for quantification of BK viruria detected by real time polymerase chain reaction and were followed up for 12 months.
Results:  Twenty-six patients (25%) had detectable BK viruria. In comparison of the patients without BK viruria, more patients in the BK viruria group were treated with steroids and had a past history of acute rejection. There was no difference in sex, age, transplant duration, allograft type and previous cytomegalovirus infection. During follow-up, the patients with BK viruria had higher serum creatinine levels at the sixth, ninth and 12th month. Multiple logistic regression analysis revealed that BK viruria was the only risk factor for more than 25% or 50% rise of serum creatinine level above baseline at the end of one yr follow-up.
Conclusions:  BK viruria alone is associated with allograft dysfunction and early intervention is indicated.     

Monitoring the progress of BK virus associated nephropathy in renal transplant recipients.

BACKGROUND: Nephropathy associated with BK virus (BKVAN) has recently emerged as an important cause of allograft failure following renal transplantation. The aim of this study was to evaluate the effectiveness of laboratory markers in the follow-up of patients with BKVAN. METHODS: Serial samples from seven renal transplant recipients with biopsy proven BKVAN were studied. The median follow-up time from diagnosis was 76 weeks. Intervention after the diagnosis of BKVAN included immunosuppression dose reduction, alternative immunosuppressive agents and/or antiviral therapy with cidofovir. Serial urine samples (n = 127) were collected for electron microscopy (EM), decoy cell detection and quantitative urine BK viral load using real-time polymerase chain reaction. Serum BK viral load was also measured serially (n = 72). RESULTS: All patients showed a reduction in serum and urine viral load during the period of follow-up co-incident with the loss of decoy cells and negative urine EM. Urine samples that were negative for decoy cells or polyomavirus by EM had a urine viral load <10(6) copies/ml and a corresponding serum viral load <10(3) copies/ml. In paired serum/urine samples, there was a proportional relationship between serum and urine viral load with each urine viral load approximately 1000-fold higher than the corresponding serum level. Serum and urine viral loads that decreased to <200 and < 10(6) copies/ml, respectively, correlated with histological improvement. CONCLUSION: Negative EM and absence of decoy cells could be used as broad indicators of a response to intervention. However, measurement of BK virus DNA level provided a wider dynamic range and could be a better choice for determining the extent of viral control.     

BK Virus Infection in Thai Kidney Transplant Recipients: A Single-Center Experience

Introduction

BK virus-associated nephropathy (BKVAN) is a significant cause of allograft dysfunction and failure in kidney transplant recipients. Early detection and proper adjustment of immunosuppression is the best method for treatment of this condition and to improve long-term allograft outcome. Here, we reported the prevalence and risk factors of BK virus (BKV) infection in our population.