BACKGROUND Polyomavirus-associated nephropathy is a leading cause of kidney allograft failure. Therapeutic options are limited and prompt reduction of the net state of immunosuppression represents the mainstay of trea...BACKGROUND Polyomavirus-associated nephropathy is a leading cause of kidney allograft failure. Therapeutic options are limited and prompt reduction of the net state of immunosuppression represents the mainstay of treatment. More recent application of aggressive screening and management protocols for BK-virus infection after renal transplantation has shown encouraging results. Nevertheless,long-term outcome for patients with BK-viremia and nephropathy remains obscure. Risk factors for BK-virus infection are also unclear.AIM To investigate incidence, risk factors, and outcome of BK-virus infection after kidney transplantation.METHODS This single-centre observational study with a median follow up of 57(31-80) mo comprises 629 consecutive adult patients who underwent kidney transplantation between 2007 and 2013. Data were prospectively recorded and annually reviewed until 2016. Recipients were periodically screened for BK-virus by plasmaquantitative polymerized chain reaction. Patients with BK viral load ≥ 1000 copies/mL were diagnosed BK-viremia and underwent histological assessment to rule out nephropathy. In case of BK-viremia, immunosuppression was minimized according to a prespecified protocol. The following outcomes were evaluated: patient survival, overall graft survival, graft failure considering death as a competing risk, 30-d-event-censored graft failure, response to treatment,rejection, renal function, urologic complications, opportunistic infections, newonset diabetes after transplantation, and malignancies. We used a multivariable model to analyse risk factors for BK-viremia and nephropathy.RESULTS BK-viremia was detected in 9.5% recipients. Initial viral load was high(≥ 10000 copies/mL) in 66.7% and low(< 10000 copies/mL) in 33.3% of these patients.Polyomavirus-associated nephropathy was diagnosed in 6.5% of the study population. Patients with high initial viral load were more likely to experience sustained viremia(95% vs 25%, P < 0.00001), nephropathy(92.5% vs 15%, P <0.00001), and polyomavirus-related graft loss(27.5% vs 0%, P = 0.0108) than recipients with low initial viral load. Comparison between recipients with or without BK-viremia showed that the proportion of patients with Afro-Caribbean ethnicity(33.3% vs 16.5%, P = 0.0024), panel-reactive antibody ≥ 50%(30% vs14.6%, P = 0.0047), human leukocyte antigen(HLA) mismatching > 4(26.7% vs13.4%, P = 0.0110), and rejection within thirty days of transplant(21.7% vs 9.5%; P= 0.0073) was higher in the viremic group. Five-year patient and overall graft survival rates for patients with or without BK-viremia were similar. However,viremic recipients showed higher 5-year crude cumulative(22.5% vs 12.2%, P =0.0270) and 30-d-event-censored(22.5% vs 7.1%, P = 0.001) incidences of graft failure than control. In the viremic group we also observed higher proportions of recipients with 5-year estimated glomerular filtration rate < 30 mL/min than the group without viremia: 45% vs 27%(P = 0.0064). Urologic complications were comparable between the two groups. Response to treatment was complete in55%, partial in 26.7%, and absent in 18.3% patients. The nephropathy group showed higher 5-year crude cumulative and 30-d-event-censored incidences of graft failure than control: 29.1% vs 12.1%(P = 0.008) and 29.1% vs 7.2%(P <0.001), respectively. Our multivariable model demonstrated that Afro-Caribbean ethnicity, panel-reactive antibody > 50%, HLA mismatching > 4, and rejection were independent risk factors for BK-virus viremia whereas cytomegalovirus prophylaxis was protective.CONCLUSION Current treatment of BK-virus infection offers sub-optimal results. Initial viremia is a valuable parameter to detect patients at increased risk of nephropathy. Panelreactive antibody > 50% and Afro-Caribbean ethnicity are independent predictors of BK-virus infection whereas cytomegalovirus prophylaxis has a protective effect.展开更多
VP1是人多瘤病毒BK株的主要结构蛋白,使用重组杆状病毒表达系统在体外表达 VP1 可以形成病毒样颗粒(VLP)。为了探讨VP1的C末端阳电荷残基R 281, R 285, K 288, R 290, R 292, K 293, R 294,和 K297 对VLP形成和其结合DNA的影响,我们分...VP1是人多瘤病毒BK株的主要结构蛋白,使用重组杆状病毒表达系统在体外表达 VP1 可以形成病毒样颗粒(VLP)。为了探讨VP1的C末端阳电荷残基R 281, R 285, K 288, R 290, R 292, K 293, R 294,和 K297 对VLP形成和其结合DNA的影响,我们分别改变将阳电荷残基变成丙氨酸,然后表达 VP1 蛋白。结果发现用丙氨酸替代K 288,R 290,R 292,K 293,R 294后仍能形成VLP, 但与野毒株相比,在 VLP分泌以及衣壳蛋白与细胞DNA的结合方面有差异。有趣的是,R 281被丙氨酸取代后仅在细胞中形成少量的 VLP,而 R 285 被丙氨酸取代后不能形成VLP。该研究证实阳电荷氨基酸残基 R 281 和 R 285 是形成 VLP所必须的,K 288、R 290、R 292、K 293、R 294和K 297则影响VLP和DNA的结合。展开更多
Viral infections have been considered as a major cause of morbidity and mortality after kidney transplantation in pediatric cohort.Children are at high risk of acquiring virus-related complications due to immunologica...Viral infections have been considered as a major cause of morbidity and mortality after kidney transplantation in pediatric cohort.Children are at high risk of acquiring virus-related complications due to immunological immaturity and the enhanced alloreactivity risk that led to maintenance of high immunosuppressive regimes.Hence,prevention,early detection,and prompt treatment of such infections are of paramount importance.Among all viral infections,herpes viruses(herpes simplex virus,varicella zoster virus,Epstein-Barr virus,cytomegalovirus),hepatitis B and C viruses,BK polyomavirus,and respiratory viruses(respiratory syncytial virus,parainfluenza virus,influenza virus and adenovirus)are common in kidney transplant recipients.These viruses can cause systemic disease or allograft dysfunction affecting the clinical outcome.Recent advances in technology and antiviral therapy have improved management strategies in screening,monitoring,adoption of prophylactic or preemptive therapy and precise treatment in the immunocompromised host,with significant impact on the outcome.This review discusses the etiology,screening and monitoring,diagnosis,prevention,and treatment of common viral infections in pediatric renal transplant recipients.展开更多
BK病毒（BK V ）是人类多瘤病毒的一个亚群，有很高的隐性感染率，研究显示全球超过80％的人口BK V血清学阳性。随着移植后强效免疫抑制剂的使用，BK V感染正成为移植肾失活的重要原因。据统计，约1％～10％的肾移植受者在免疫抑制状态...BK病毒（BK V ）是人类多瘤病毒的一个亚群，有很高的隐性感染率，研究显示全球超过80％的人口BK V血清学阳性。随着移植后强效免疫抑制剂的使用，BK V感染正成为移植肾失活的重要原因。据统计，约1％～10％的肾移植受者在免疫抑制状态下，可因BKV激活而引起BKV肾病（BKVN），而BKVN可引起约45％的远期移植肾失活。由于目前缺乏明确有效的抗病毒药物，早期监测病毒载量、减少免疫抑制剂对控制BKVN、保留移植肾功能至关重要。本文就肾移植相关的BKV感染概况及BKVN的诊断、治疗进展进行综述。展开更多
Polyomavirus BK(BKV) infects up to 90% of the general population. After primary infection, occurring early during childhood, a state of non-replicative infection is established in the reno-urinary tract, without compl...Polyomavirus BK(BKV) infects up to 90% of the general population. After primary infection, occurring early during childhood, a state of non-replicative infection is established in the reno-urinary tract, without complications for immunocompetent hosts. In immunocompromised individuals, particularly transplanted patients, asymptomatic BKV viremia and/or viruria can be observed. Renal grafts may also be sources of infection as BKV prefers kidneys rather than other solid organs for transplantation such as the liver. The mechanism behind the higher incidence of BKV infection in kidney transplant patients, compared to liver or heart transplantation, is unclear and the prevalence of BKV infection in non-renal solid organ transplants has not been yet thoroughly investigated. We evaluated the prevalence of Polyomavirus BK infection among liver transplant recipients. A Pub Med search was conducted using the terms BKV infection AND liver transplant recipients; BKV AND non-renal solid organ transplant*; BKV infection AND immunosuppression; the search was limited to title/abstract and English-language articles published from 2000, to March 2015. Eleven relevant studies suggest that the prevalence of BKV viruria and/or viremia among liver transplant recipients is less than that reported in kidney or heart transplant recipients, except when chronic kidney disease(CKD) is present at the same time. Data also suggest that viruric and viremic patients have higher levels of serum creatinine than BKV negative patients. Moreover, no specific immunosuppressive drugs are associated with the onset of BKV nephropathy. The comorbidity of transplantation and CKD could play a major role in promoting BKV replication.展开更多
AIM: To describe the clinicopathologic features of concurrent polyomavirus nephropathy(PVN) and endarteritis due to rejection in renal allografts.METHODS: We searched our electronic records database for cases with tra...AIM: To describe the clinicopathologic features of concurrent polyomavirus nephropathy(PVN) and endarteritis due to rejection in renal allografts.METHODS: We searched our electronic records database for cases with transplant kidney biopsies demonstrating features of both PVN and acute rejection(AR). PVN was defined by the presence of typical viral cytopathic effect on routine sections and positive polyomavirus SV40 large-T antigen immunohistochemistry. AR was identified by endarteritis(v1 by Banff criteria). All cases were subjected to chart review in order to determine clinical presentation, treatment course and outcomes. Outcomes were recorded with a length of follow-up of at least one year or time to nephrectomy. RESULTS: Of 94 renal allograft recipients who developed PVN over an 11-year period at our institution, we identified 7(7.4%) with viral cytopathic changes, SV40 large T antigen staining, and endarteritis in the same biopsy specimen, indicative of concurrent PVN and AR. Four arose after reduction of immunosuppression(IS)(for treatment of PVN in 3 and tuberculosis in 1), and 3 patients had no decrease of IS before developing simultaneous concurrent disease. Treatment consisted of reduced oral IS and leflunomide for PVN, and antirejection therapy. Three of 4 patients who developed endarteritis in the setting of reduced IS lost their grafts to rejection. All 3 patients with simultaneous PVN and endarteritis cleared viremia and were stable at 1 year of follow up. Patients with endarteritis and PVN arising in a background of reduced IS had more severe rejection and poorer outcome.CONCLUSION: Concurrent PVN and endarteritis may be more frequent than is currently appreciated and may occur with or without prior reduction of IS.展开更多
AIM To evaluate incidence, risk factors and treatment outcome of BK polyomavirus nephropathy(BKVN) in a cohort of renal transplant recipients in the Auckland region without a formal BK polyomavirus(BKV) surveillance p...AIM To evaluate incidence, risk factors and treatment outcome of BK polyomavirus nephropathy(BKVN) in a cohort of renal transplant recipients in the Auckland region without a formal BK polyomavirus(BKV) surveillance programme.METHODS A cohort of 226 patients who received their renal transplants from 2006 to 2012 was retrospectively reviewed.RESULTS Seventy-six recipients(33.6%) had a BK viral load(BKVL) test and 9 patients(3.9%) developed BKVN. Cold ischaemia time(HR = 1.18, 95%CI: 1.04-1.35) was found to be a risk factor for BKVN. Four recipients with BKVN had complete resolution of their BKV infection; 1 recipient had BKVL less than 625 copies/mL; 3 recipients had BKVL more than 1000 copies/mL and 1 had graft failure from BKVN. BKVN has a negative impact on graft function [median estimated glomerular filtration rate(eG FR) 22.5(IQR 18.5-53.0) mL /min per 1.73 m^2, P = 0.015), but no statistically significant difference(P = 0.374) in renal allograft function was found among negative BK viraemia group [median e GFR 60.0(IQR 48.5-74.2) mL /min per 1.73 m^2), positive BK viraemia without BKVN group [median eG FR 55.0(IQR 47.0-76.0) mL /min per 1.73 m^2] and unknown BKV status group [median eG FR 54.0(IQR 43.8-71.0) mL /min per 1.73 m^2]. The incidence and treatment outcomes of BKVN were similar to some centres with BKV surveillance programmes.CONCLUSION Recipients with BVKN have poorer graft function. Although active surveillance for BKV has been shown to be effective in reducing incidence of BKVN, it should be tailored specifically to that transplant centre based on its epidemiology and outcomes of BKVN, particularly in centres with limited resources.展开更多
文摘BACKGROUND Polyomavirus-associated nephropathy is a leading cause of kidney allograft failure. Therapeutic options are limited and prompt reduction of the net state of immunosuppression represents the mainstay of treatment. More recent application of aggressive screening and management protocols for BK-virus infection after renal transplantation has shown encouraging results. Nevertheless,long-term outcome for patients with BK-viremia and nephropathy remains obscure. Risk factors for BK-virus infection are also unclear.AIM To investigate incidence, risk factors, and outcome of BK-virus infection after kidney transplantation.METHODS This single-centre observational study with a median follow up of 57(31-80) mo comprises 629 consecutive adult patients who underwent kidney transplantation between 2007 and 2013. Data were prospectively recorded and annually reviewed until 2016. Recipients were periodically screened for BK-virus by plasmaquantitative polymerized chain reaction. Patients with BK viral load ≥ 1000 copies/mL were diagnosed BK-viremia and underwent histological assessment to rule out nephropathy. In case of BK-viremia, immunosuppression was minimized according to a prespecified protocol. The following outcomes were evaluated: patient survival, overall graft survival, graft failure considering death as a competing risk, 30-d-event-censored graft failure, response to treatment,rejection, renal function, urologic complications, opportunistic infections, newonset diabetes after transplantation, and malignancies. We used a multivariable model to analyse risk factors for BK-viremia and nephropathy.RESULTS BK-viremia was detected in 9.5% recipients. Initial viral load was high(≥ 10000 copies/mL) in 66.7% and low(< 10000 copies/mL) in 33.3% of these patients.Polyomavirus-associated nephropathy was diagnosed in 6.5% of the study population. Patients with high initial viral load were more likely to experience sustained viremia(95% vs 25%, P < 0.00001), nephropathy(92.5% vs 15%, P <0.00001), and polyomavirus-related graft loss(27.5% vs 0%, P = 0.0108) than recipients with low initial viral load. Comparison between recipients with or without BK-viremia showed that the proportion of patients with Afro-Caribbean ethnicity(33.3% vs 16.5%, P = 0.0024), panel-reactive antibody ≥ 50%(30% vs14.6%, P = 0.0047), human leukocyte antigen(HLA) mismatching > 4(26.7% vs13.4%, P = 0.0110), and rejection within thirty days of transplant(21.7% vs 9.5%; P= 0.0073) was higher in the viremic group. Five-year patient and overall graft survival rates for patients with or without BK-viremia were similar. However,viremic recipients showed higher 5-year crude cumulative(22.5% vs 12.2%, P =0.0270) and 30-d-event-censored(22.5% vs 7.1%, P = 0.001) incidences of graft failure than control. In the viremic group we also observed higher proportions of recipients with 5-year estimated glomerular filtration rate < 30 mL/min than the group without viremia: 45% vs 27%(P = 0.0064). Urologic complications were comparable between the two groups. Response to treatment was complete in55%, partial in 26.7%, and absent in 18.3% patients. The nephropathy group showed higher 5-year crude cumulative and 30-d-event-censored incidences of graft failure than control: 29.1% vs 12.1%(P = 0.008) and 29.1% vs 7.2%(P <0.001), respectively. Our multivariable model demonstrated that Afro-Caribbean ethnicity, panel-reactive antibody > 50%, HLA mismatching > 4, and rejection were independent risk factors for BK-virus viremia whereas cytomegalovirus prophylaxis was protective.CONCLUSION Current treatment of BK-virus infection offers sub-optimal results. Initial viremia is a valuable parameter to detect patients at increased risk of nephropathy. Panelreactive antibody > 50% and Afro-Caribbean ethnicity are independent predictors of BK-virus infection whereas cytomegalovirus prophylaxis has a protective effect.
文摘VP1是人多瘤病毒BK株的主要结构蛋白,使用重组杆状病毒表达系统在体外表达 VP1 可以形成病毒样颗粒(VLP)。为了探讨VP1的C末端阳电荷残基R 281, R 285, K 288, R 290, R 292, K 293, R 294,和 K297 对VLP形成和其结合DNA的影响,我们分别改变将阳电荷残基变成丙氨酸,然后表达 VP1 蛋白。结果发现用丙氨酸替代K 288,R 290,R 292,K 293,R 294后仍能形成VLP, 但与野毒株相比,在 VLP分泌以及衣壳蛋白与细胞DNA的结合方面有差异。有趣的是,R 281被丙氨酸取代后仅在细胞中形成少量的 VLP,而 R 285 被丙氨酸取代后不能形成VLP。该研究证实阳电荷氨基酸残基 R 281 和 R 285 是形成 VLP所必须的,K 288、R 290、R 292、K 293、R 294和K 297则影响VLP和DNA的结合。
文摘Viral infections have been considered as a major cause of morbidity and mortality after kidney transplantation in pediatric cohort.Children are at high risk of acquiring virus-related complications due to immunological immaturity and the enhanced alloreactivity risk that led to maintenance of high immunosuppressive regimes.Hence,prevention,early detection,and prompt treatment of such infections are of paramount importance.Among all viral infections,herpes viruses(herpes simplex virus,varicella zoster virus,Epstein-Barr virus,cytomegalovirus),hepatitis B and C viruses,BK polyomavirus,and respiratory viruses(respiratory syncytial virus,parainfluenza virus,influenza virus and adenovirus)are common in kidney transplant recipients.These viruses can cause systemic disease or allograft dysfunction affecting the clinical outcome.Recent advances in technology and antiviral therapy have improved management strategies in screening,monitoring,adoption of prophylactic or preemptive therapy and precise treatment in the immunocompromised host,with significant impact on the outcome.This review discusses the etiology,screening and monitoring,diagnosis,prevention,and treatment of common viral infections in pediatric renal transplant recipients.
文摘BK病毒（BK V ）是人类多瘤病毒的一个亚群，有很高的隐性感染率，研究显示全球超过80％的人口BK V血清学阳性。随着移植后强效免疫抑制剂的使用，BK V感染正成为移植肾失活的重要原因。据统计，约1％～10％的肾移植受者在免疫抑制状态下，可因BKV激活而引起BKV肾病（BKVN），而BKVN可引起约45％的远期移植肾失活。由于目前缺乏明确有效的抗病毒药物，早期监测病毒载量、减少免疫抑制剂对控制BKVN、保留移植肾功能至关重要。本文就肾移植相关的BKV感染概况及BKVN的诊断、治疗进展进行综述。
文摘Polyomavirus BK(BKV) infects up to 90% of the general population. After primary infection, occurring early during childhood, a state of non-replicative infection is established in the reno-urinary tract, without complications for immunocompetent hosts. In immunocompromised individuals, particularly transplanted patients, asymptomatic BKV viremia and/or viruria can be observed. Renal grafts may also be sources of infection as BKV prefers kidneys rather than other solid organs for transplantation such as the liver. The mechanism behind the higher incidence of BKV infection in kidney transplant patients, compared to liver or heart transplantation, is unclear and the prevalence of BKV infection in non-renal solid organ transplants has not been yet thoroughly investigated. We evaluated the prevalence of Polyomavirus BK infection among liver transplant recipients. A Pub Med search was conducted using the terms BKV infection AND liver transplant recipients; BKV AND non-renal solid organ transplant*; BKV infection AND immunosuppression; the search was limited to title/abstract and English-language articles published from 2000, to March 2015. Eleven relevant studies suggest that the prevalence of BKV viruria and/or viremia among liver transplant recipients is less than that reported in kidney or heart transplant recipients, except when chronic kidney disease(CKD) is present at the same time. Data also suggest that viruric and viremic patients have higher levels of serum creatinine than BKV negative patients. Moreover, no specific immunosuppressive drugs are associated with the onset of BKV nephropathy. The comorbidity of transplantation and CKD could play a major role in promoting BKV replication.
文摘AIM: To describe the clinicopathologic features of concurrent polyomavirus nephropathy(PVN) and endarteritis due to rejection in renal allografts.METHODS: We searched our electronic records database for cases with transplant kidney biopsies demonstrating features of both PVN and acute rejection(AR). PVN was defined by the presence of typical viral cytopathic effect on routine sections and positive polyomavirus SV40 large-T antigen immunohistochemistry. AR was identified by endarteritis(v1 by Banff criteria). All cases were subjected to chart review in order to determine clinical presentation, treatment course and outcomes. Outcomes were recorded with a length of follow-up of at least one year or time to nephrectomy. RESULTS: Of 94 renal allograft recipients who developed PVN over an 11-year period at our institution, we identified 7(7.4%) with viral cytopathic changes, SV40 large T antigen staining, and endarteritis in the same biopsy specimen, indicative of concurrent PVN and AR. Four arose after reduction of immunosuppression(IS)(for treatment of PVN in 3 and tuberculosis in 1), and 3 patients had no decrease of IS before developing simultaneous concurrent disease. Treatment consisted of reduced oral IS and leflunomide for PVN, and antirejection therapy. Three of 4 patients who developed endarteritis in the setting of reduced IS lost their grafts to rejection. All 3 patients with simultaneous PVN and endarteritis cleared viremia and were stable at 1 year of follow up. Patients with endarteritis and PVN arising in a background of reduced IS had more severe rejection and poorer outcome.CONCLUSION: Concurrent PVN and endarteritis may be more frequent than is currently appreciated and may occur with or without prior reduction of IS.
文摘AIM To evaluate incidence, risk factors and treatment outcome of BK polyomavirus nephropathy(BKVN) in a cohort of renal transplant recipients in the Auckland region without a formal BK polyomavirus(BKV) surveillance programme.METHODS A cohort of 226 patients who received their renal transplants from 2006 to 2012 was retrospectively reviewed.RESULTS Seventy-six recipients(33.6%) had a BK viral load(BKVL) test and 9 patients(3.9%) developed BKVN. Cold ischaemia time(HR = 1.18, 95%CI: 1.04-1.35) was found to be a risk factor for BKVN. Four recipients with BKVN had complete resolution of their BKV infection; 1 recipient had BKVL less than 625 copies/mL; 3 recipients had BKVL more than 1000 copies/mL and 1 had graft failure from BKVN. BKVN has a negative impact on graft function [median estimated glomerular filtration rate(eG FR) 22.5(IQR 18.5-53.0) mL /min per 1.73 m^2, P = 0.015), but no statistically significant difference(P = 0.374) in renal allograft function was found among negative BK viraemia group [median e GFR 60.0(IQR 48.5-74.2) mL /min per 1.73 m^2), positive BK viraemia without BKVN group [median eG FR 55.0(IQR 47.0-76.0) mL /min per 1.73 m^2] and unknown BKV status group [median eG FR 54.0(IQR 43.8-71.0) mL /min per 1.73 m^2]. The incidence and treatment outcomes of BKVN were similar to some centres with BKV surveillance programmes.CONCLUSION Recipients with BVKN have poorer graft function. Although active surveillance for BKV has been shown to be effective in reducing incidence of BKVN, it should be tailored specifically to that transplant centre based on its epidemiology and outcomes of BKVN, particularly in centres with limited resources.
