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BACKGROUND: This study was designed to investigate the association between donor-derived cell-free DNA (dd-cfDNA) and renal allograft injuries. METHODS: This single-center study enrolled 113 adult kidney transplant recipients with kidney biopsies. Plasma and urine dd-cfDNA was detected by target region capture sequencing. RESULTS: Plasma dd-cfDNA fraction was increased in multiple types of injuries, but most significantly in antibody-mediated rejection. Plasma dd-cfDNA fraction in isolated antibody-mediated rejection (1.94%, IQR: 1.15%, 2.33%) was higher than in T cell-mediated rejection (0.55%, IQR: 0.50%, 0.73%, P = 0.002) and negative biopsies (0.58%, IQR: 0.42%, 0.78%, P < 0.001), but lower than in mixed rejection (2.49%, IQR: 1.16%, 4.90%, P = 0.342). Increased urine dd-cfDNA concentration was associated with several types of injury, but most significantly with BK polyomavirus-associated nephropathy. Urine dd-cfDNA concentration in BK polyomavirus-associated nephropathy (12.22â ng/mL, IQR: 6.53â ng/mL, 31.66â ng/mL) was respectively higher than that in T cell-mediated rejection (5.24â ng/mL, IQR: 3.22â ng/mL, 6.99 ng/mL, P = 0.001), borderline change (3.93â ng/mL, IQR: 2.45â ng/mL, 6.30â ng/mL, P < 0.001), and negative biopsies (3.09â ng/mL, IQR: 1.94â ng/mL, 5.05â ng/mL, P < 0.001). Plasma dd-cfDNA fraction was positively associated with glomerulitis (r = 0.365, P < 0.001) and peri-tubular capillaritis (r = 0.344, P < 0.001), while urine dd-cfDNA concentration correlated with tubulitis (r = 0.302, P = 0.002). CONCLUSIONS: Both plasma and urine dd-cfDNA are sensitive markers for renal allograft injuries. The interpretation of a specific disease by dd-cfDNA should be combined with other clinical indicators.
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Ácidos Nucleicos Livres , Rejeição de Enxerto , Transplante de Rim , Adulto , Aloenxertos , Anticorpos , Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/urina , Rejeição de Enxerto/diagnóstico , Humanos , Rim , Doadores de TecidosRESUMO
BACKGROUND: The purpose of this study was to investigate the effect of BK polyomavirus (BKPyV infection of glomerular parietal epithelial cells (GPECs) on graft outcome in kidney transplant recipients with BKPyV-associated nephropathy (BKPyVAN). METHODS: A total of 152 kidney transplant recipients with BKPyVAN were divided into 31 with (GPEC-positive group) and 121 without (GPEC-negative group) BKPyV-infected GPECs. Clinicopathological characteristics and allograft survival were compared between the groups. RESULTS: The GPEC-positive group had more patients with advanced-stage BKPyVAN than the GPEC-negative group (P < .001). At the last follow-up, the GPEC-positive group had a significantly higher serum creatinine level than the GPEC-negative group. The graft loss rate in the GPEC-positive group was higher than that in the GPEC-negative group (32.3% vs 12.4%; P = .008). Kaplan-Meier analysis showed that the graft survival rate in the GPEC-positive group was lower than that in the GPEC-negative group (log-rank test, P = .004). Multivariate Cox regression analysis demonstrated that BKPyV infection of GPECs was an independent risk factor for graft survival (hazard ratio, 3.54; 95% confidence interval, 1.43-8.76; P = .006). CONCLUSIONS: GPEC infection in patients with BKPyVAN indicates more-severe pathological damage and a rapid decline in renal function. BKPyV infection of GPECs is an independent risk factor for allograft loss.
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Vírus BK , Rejeição de Enxerto , Glomérulos Renais , Transplante de Rim/efeitos adversos , Infecções por Polyomavirus , Infecções Tumorais por Vírus , Adulto , Feminino , Rejeição de Enxerto/patologia , Rejeição de Enxerto/virologia , Humanos , Rim/patologia , Rim/virologia , Nefropatias/patologia , Nefropatias/virologia , Glomérulos Renais/citologia , Glomérulos Renais/patologia , Glomérulos Renais/virologia , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Camellia oleifera is expected to provide alternative aglycone to synthesize some saponins similar to that from Schima superba with inhibitory activity against Magnaporthe oryzae. Eight theasapogenol galactosides were synthesized via protection of adjacent hydroxyl groups by a benzylidene for regioselective glycosylation in the multi-hydroxyl sapogenin. Water soluble galactose chain connected far from liposoluble end was a key group in inhibiting the growth of M. oryzea unless theasapogenol was modified by two galactosyl groups or by one galactosyl group and one benzylidene group. The amphoteric characteristics of saponin such as saccharide group number, distance between bipolar groups play an important role in inhibiting mycelium growth of M. oryzae.
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Galactosídeos/isolamento & purificação , Galactosídeos/farmacologia , Magnaporthe/efeitos dos fármacos , Saponinas/síntese química , Theaceae/química , Camellia/química , Galactosídeos/química , Estrutura Molecular , Saponinas/química , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Co-infection of JC polyomavirus (JCPyV) and BK polyomavirus (BKPyV) is uncommon in kidney transplant recipients, and the prognosis is unclear. This study aimed to investigate the effect of concurrent JCPyV-DNAemia on graft outcomes in BKPyV-infected kidney transplant recipients with polyomavirus-associated nephropathy (PyVAN). METHODS: A total of 140 kidney transplant recipients with BKPyV replication and PyVAN, 122 without concurrent JCPyV-DNAemia and 18 with JCPyV-DNAemia were included in the analysis. Least absolute shrinkage and selection operator regression analysis and multivariate Cox regression analysis were used to identify prognostic factors for graft survival. A nomogram for predicting graft survival was created and evaluated. RESULTS: The median tubulitis score in the JCPyV-DNAemia-positive group was higher than in JCPyV-DNAemia-negative group ( P â =â 0.048). At last follow-up, the graft loss rate in the JCPyV-DNAemia-positive group was higher than in the JCPyV-DNAemia-negative group (50% versus 25.4%; P â =â 0.031). Kaplan-Meier analysis showed that the graft survival rate in the JCPyV-DNAemia-positive group was lower than in the JCPyV-DNAemia-negative group ( P â =â 0.003). Least absolute shrinkage and selection operator regression and multivariate Cox regression analysis demonstrated that concurrent JCPyV-DNAemia was an independent risk factor for graft survival (hazard ratioâ =â 4.808; 95% confidence interval: 2.096-11.03; P â <â 0.001). The nomogram displayed favorable discrimination (C-index = 0.839), concordance, and clinical applicability in predicting graft survival. CONCLUSIONS: Concurrent JCPyV-DNAemia is associated with a worse graft outcome in BKPyV-infected kidney transplant recipients with PyVAN.
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DNA Viral , Sobrevivência de Enxerto , Transplante de Rim , Infecções por Polyomavirus , Humanos , Transplante de Rim/efeitos adversos , Transplante de Rim/mortalidade , Feminino , Masculino , Pessoa de Meia-Idade , Infecções por Polyomavirus/virologia , Infecções por Polyomavirus/diagnóstico , Adulto , DNA Viral/sangue , Estudos Retrospectivos , Vírus BK/patogenicidade , Fatores de Risco , Nefropatias/cirurgia , Nefropatias/virologia , Nefropatias/mortalidade , Nefropatias/diagnóstico , Infecções Tumorais por Vírus/virologia , Infecções Tumorais por Vírus/diagnóstico , Infecções Tumorais por Vírus/mortalidade , Resultado do Tratamento , Coinfecção , Nomogramas , Rejeição de Enxerto/virologia , IdosoRESUMO
Objective: This study aimed to explore the molecular mechanism of cytoplasmic vacuolation caused by BK polyomavirus (BKPyV) and thus search for potential target for drug repurposing. Methods: Morphological features of BK polyomavirus-associated nephropathy (BKPyVAN) were studied under light and electron microscopes. Microarray datasets GSE75693, GSE47199, and GSE72925 were integrated by ComBat, and differentially expressed genes (DEGs) were analyzed using limma. Furthermore, the endoplasmic reticulum (ER)-related genes obtained from GenCLiP 2.0 were intersected with DEGs. GO and KEGG enrichment pathways were performed with intersection genes by R package clusterProfiler. The single-cell RNA sequencing (scRNA-seq) from a BKPyVAN recipient was analyzed with a dataset (GSE140989) downloaded from Gene Expression Omnibus (GEO) as control for gene set variation analysis (GSVA). Immunohistochemistry and electron microscopy of kidney sections from drug-induced ERS mouse models were performed to explore the association of ERS and renal tubular vacuolation. Protein-protein interaction (PPI) network of the intersection genes was constructed to identify hub target. AutoDock was used to screen Food and Drug Administration (FDA)-approved drugs that potentially targeted hub gene. Results: Light and electron microscopes exhibited obvious intranuclear inclusions, vacuoles, and virus particles in BKPyV-infected renal tubular cells. Transcriptome analysis revealed 629 DEGs between samples of BKPyVAN and stable transplanted kidneys, of which 16 were ER-associated genes. GO analysis with the intersection genes illustrated that ERS-related pathways were significantly involved, and KEGG analysis showed a prominent enrichment of MAPK, Toll-like receptor, and chemokine signaling pathways. GSVA analysis of the proximal tubule revealed similar pathways enrichment. An electron microscope image of the kidney from ERS mouse models showed an obvious renal tubular vacuolation with prominent activation of ERS markers verified by immunohistochemistry. Furthermore, DDIT3 was identified as the hub gene based on PPI analysis, and ZINCOOOOO1531009 (Risedronate) was indicated to be a potential drug for DDIT3. Conclusion: ERS was involved in renal tubular cytoplasmic vacuolation in BKPyVAN recipients. Risedronate was screened as a potential drug for BKPyVAN by targeting DDIT3.
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Vírus BK , Transplante de Rim , Infecções por Polyomavirus , Animais , Vírus BK/genética , Estresse do Retículo Endoplasmático/genética , Camundongos , Infecções por Polyomavirus/etiologia , Ácido Risedrônico , Estados UnidosRESUMO
Background: BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) causes renal allograft dysfunction and graft loss. However, the mechanism of BKPyV replication after kidney transplantation is unclear. Clinical studies have demonstrated that immunosuppressants and renal ischemia-reperfusion injury (IRI) are risk factors for BKPyV infection. Studying the pathogenic mechanism of BKPyV is limited by the inability of BKPyV to infect the animal. Mouse polyomavirus (MPyV) is a close homolog of BKPyV. We used a model of MPyV infection to investigate the core genes and underlying mechanism of IRI and immunosuppressants to promote polyomavirus replication. Materials and Methods: One-day-old male C57BL/6 mice were intraperitoneally injected with MPyV. At week 9 post-infection, all mice were randomly divided into IRI, immunosuppressant, and control groups and treated accordingly. IRI was established by clamping the left renal pedicle. Subsequently, kidney specimens were collected for detecting MPyV DNA, histopathological observation, and high-throughput RNA sequencing. Weighted gene correlation network analysis (WGCNA), protein-protein interaction network analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to screen for core genes and common signaling pathways involved in promoting MPyV replication by IRI and immunosuppressants. Results: After primary infection, MPyV established persistent infection in kidneys and subsequently was significantly increased by IRI or immunosuppressant treatment individually. In the IRI group, viral loads peaked on day 3 in the left kidney, which were significantly higher than those in the right kidney and the control group. In the immunosuppressant group, viral loads in the left kidney were significantly increased on day 3, which were significantly higher than those in the control group. Protein-protein interaction network analysis and WGCNA screened complement C3, epidermal growth factor receptor (EGFR), and FN1 as core genes. Pathway enrichment analysis based on the IRI- or immunosuppressant-related genes selected by WGCNA indicated that the NF-κB signaling pathway was the main pathway involved in promoting MPyV replication. The core genes were further confirmed using published datasets GSE47199 and GSE75693 in human polyomavirus-associated nephropathy. Conclusions: Our study demonstrated that IRI and immunosuppressants promote polyomavirus replication through common molecular mechanisms. In future studies, knockdown or specific inhibition of C3, EGFR, FN1, and NF-κB signaling pathway will further validate their critical roles in promoting polyomavirus replication.
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Vírus BK , Transplante de Rim , Nefrite Intersticial , Infecções por Polyomavirus , Polyomavirus , Traumatismo por Reperfusão , Animais , Vírus BK/fisiologia , Receptores ErbB , Feminino , Humanos , Imunossupressores/efeitos adversos , Transplante de Rim/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B , Nefrite Intersticial/complicações , Polyomavirus/genética , Traumatismo por Reperfusão/tratamento farmacológicoRESUMO
BACKGROUND: The positive predictive value (PPV) of urinary decoy cells for diagnosing BK polyomavirus associated-nephropathy (BKPyVAN) is low. This study was designed to increase the PPV of urinary decoy cells for diagnosing BKPyVAN in kidney transplant recipients. METHODS: A total of 105 urine sediment samples from 105 patients with positive BK viruria and decoy cells were evaluated by automatic double-immunostaining with anti-HGD (a renal tubular marker) antibody + anti-SV40-T antibody or anti-S100P (an urothelial marker) antibody + anti-SV40-T antibody. RESULTS: Of the 105 patients, 76 (72.4%) had both HGD(+)/SV40-T(+) cells and S100P(+)/SV40-T(+) cells (group A), 24 (22.9%) had only S100P(+)/SV40-T(+) cells (group B), and 5 (4.6%) had only S100P(-)/HGD(-)/SV40-T(+) cells (group C). Seventy patients in group A (92.1%), 3 patients in group B (12.5%), and no patients in group C were diagnosed with BKPyVAN. The area under the ROC curve of predicting BKPyVAN by decoy cells was 0.531 (0.431-0.630), with an optimal cut-off value of 29 (per 10 high power field), a sensitivity of 45.8% (95% CI: 34.0-58.0%), and a specificity of 68.8% (95% CI: 50.0-83.9%). Besides, the area under the ROC curve of predicting BKPyVAN by plasma BKPyV load was 0.735 (95% CI: 0.632-0.822), with an optimal cut-off value of 1,000 copies/mL, a sensitivity of 61.1% (95% CI: 48.9-72.4%) and a specificity of 84.2% (95% CI: 60.4-96.6%). In contrast, the PPV, negative predictive value, sensitivity, and specificity of HGD(+)/SV40-T(+) cells for diagnosing BKPyVAN were 92.1% [95% confidence interval (CI): 83.0-96.7%], 89.7% (95% CI: 71.5-97.3%), 95.9% (95% CI: 87.7-98.9%), and 81.3% (95% CI: 63.0-92.1%) respectively. CONCLUSIONS: Double-immunostaining with anti-HGD or anti-S100P and anti-SV40-T antibodies helps to identify the origin of decoy cells and diagnose BKPyVAN.
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BACKGROUND: BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) is an important cause of dysfunction and failure of renal transplants. This study aimed to assess the diagnostic performance of morning urine specific gravity (MUSG) in diagnosing BKPyVAN in kidney transplant recipients. METHODS: A total of 87 patients, including 27 with BKPyVAN, 22 with isolated BKPyV viruria, 18 with T cell-mediated rejection (TCMR), and 20 with stable graft function, were enrolled in the First Affiliated Hospital of Sun Yat-Sen University from March 2015 to February 2017. MUSG at biopsy and during a follow-up period of 24 months after biopsy was collected and analyzed. Receiver operating characteristic (ROC) curve analysis was used to determine the ability of MUSG to discriminate BKPyVAN. RESULTS: At biopsy, the MUSG of BKPyVAN group (1.008â±â0.003) was significantly lower than that of isolated BK viruria group (1.013â±â0.004, Pâ<â0.001), TCMR group (1.011â±â0.003, Pâ=â0.027), and control group (1.014â±â0.006, Pâ<â0.001). There was no significant difference in MUSG among the isolated BK viruria group, TCMR group, and control group (Pâ=â0.253). In BKPyVAN group, the timing and trend of MUSG elevate were consistent with the timing and trend of the decline of viral load in urine and plasma, reaching a statistical difference at 3 months after treatment (1.012â±â0.003, Pâ<â0.001) compared with values at diagnosis. ROC analysis indicated that the optimal cut-off value of MUSG for diagnosis of BKPyVAN was 1.009, with an area under the ROC curve (AUC) of 0.803 (95% confidence interval [CI]: 0.721-0.937). For differentiating BKPyVAN and TCMR, the optimal MUSG cut-off value was 1.010, with an AUC of 0.811 (95% CI: 0.687-0.934). CONCLUSION: Combined detection of MUSG and BKPyV viruria is valuable for predicting BKPyVAN and distinguishing BKPyVAN from TCMR in renal transplant recipients.
Assuntos
Vírus BK/patogenicidade , Transplante de Rim/efeitos adversos , Infecções por Polyomavirus/urina , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Gravidade Específica , TransplantadosRESUMO
BACKGROUND: This study aimed to investigate the pathological characteristics of BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) with glomerular involvement in kidney transplant recipients. METHODS: Forty-four patients with glomerular BKPyV infection were retrospectively included for analysis. Immunohistochemical (IHC) staining was performed on paraffin sections using monoclonal mouse anti-SV40 large T antigen antibody. RESULTS: In BKPyV-infected glomeruli, the glomerular parietal epithelial cells (GPECs) were swollen, hyperchromatic, and enlarged, with an increased nuclear to cytoplasm (N/C) ratio and smudgy basophilic intra-nuclear viral inclusions. IHC staining revealed the distribution of BKPyV involvement in GPECs, podocytes, and shedding cells within Bowman's space. Notably, BKPyV affected GPEC proliferation and caused crescent formation (7 biopsies, 15.9%). Three biopsies exhibited fibrous crescents and the absence of viral inclusions. The other 4 biopsies exhibited cellular and fibro-cellular crescents, with viral cytopathic changes and positive IHC staining in the proliferative GPECs. Electron microscopy showed viral particles in both GPECs and podocytes. BKPyV-infected GPECs were degenerative, with mitochondrial swelling, endoplasmic reticulum expansion, and multi-layered membranous structure formation. Twelve (27.3%) patients received repeat biopsies within 1.6 to 39.5 months (median: 13.5 months), but none revealed persistent glomerular BKPyV infection. CONCLUSIONS: Distinct glomerular changes in BKPyVAN biopsies should raise the possibility of glomerular involvement.
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Background: Studies have shown that plasma donor-derived cell-free DNA (dd-cfDNA) can predict renal allograft antibody-mediated rejection. This study was performed to evaluate the value of urine dd-cfDNA concentration and dd-cfDNA fraction (%) for discriminating BK polyomavirus-associated nephropathy (BKPyVAN) in kidney transplant recipients with urinary BK polyomavirus (BKPyV) infection. Methods: In this retrospective single-center observational study, we enrolled kidney transplant recipients who were diagnosed with urine BKPyV infection between August 2018 and May 2019 at the First Affiliated Hospital of Sun Yat-sen University. Urine dd-cfDNA was measured by using a novel target region capture sequencing methodology. The pathological diagnosis of BKPyVAN was confirmed by anti-SV40-T immunohistochemical staining and classified using the American Society for Transplantation schema. Receiver operating characteristic curve analysis was used to investigate the relations of urine dd-cfDNA and dd-cfDNA% to intrarenal allograft BKPyV infection states. Results: In total, 93 patients were enrolled, including 40 cases of proven BKPyVAN, seven cases of probable BKPyVAN, 23 cases of possible BKPyVAN, and 23 cases of resolving BKPyVAN. Urine dd-cfDNA level in proven BKPyVAN (22.09 ± 21.27 ng/ml) was comparable to that in probable BKPyVAN (15.64 ± 6.73 ng/ml, P = 0.434) but was significantly higher than that in possible BKPyVAN (5.60 ± 3.53 ng/ml) and resolving BKPyVAN (5.30 ± 3.34 ng/ml) (both Ps < 0.05). Urine dd-cfDNA% of proven BKPyVAN (0.71 ± 0.21) was lower than that of probable BKPyVAN (0.91 ± 0.04, P < 0.001), but was significantly higher than that of possible BKPyVAN (0.56 ± 0.30) and resolving BKPyVAN (0.46 ± 0.28) (both Ps < 0.05). For distinguishing biopsy-proven BKPyVAN from biopsy-excluded BKPyVAN, the discrimination capacity of urine dd-cfDNA (AUC: 0.842, 95% CI: 0.735, 0.918) was superior to that of plasma BKPyV DNA load (AUC: 0.660, 95% CI: 0.537, 0.769) with 0.181 (95% CI: 0.043, 0.319) difference between areas under ROC curves (P = 0.010). Conclusion: The elevated urine dd-cfDNA level may help discriminate BKPyVAN in kidney transplant recipients with BKPyV viruria.
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Vírus BK/genética , Ácidos Nucleicos Livres/urina , DNA Viral/urina , Nefropatias/diagnóstico , Transplante de Rim/efeitos adversos , Infecções por Polyomavirus/diagnóstico , Infecções Tumorais por Vírus/diagnóstico , Infecções Urinárias/diagnóstico , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Nefropatias/urina , Nefropatias/virologia , Masculino , Pessoa de Meia-Idade , Infecções por Polyomavirus/urina , Infecções por Polyomavirus/virologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Resultado do Tratamento , Infecções Tumorais por Vírus/urina , Infecções Tumorais por Vírus/virologia , Urinálise , Infecções Urinárias/urina , Infecções Urinárias/virologia , Carga ViralRESUMO
Background: The extent and depth of BK polyomavirus (BKPyV) infection in renal allograft correlate with prognosis. This study was designed to evaluate the value of urinary sediment double-immunostaining for predicting BKPyV infection in proximal tubular epithelium. Materials and methods: A total of 76 urine sediment cell blocks, as well as the corresponding transplanted kidney tissues with BK polyomavirus associated-nephropathy (BKPyVAN), were evaluated by automatic double-immunostaining with anti-58-kDa Golgi protein (58K, a proximal renal tubular marker) + anti-SV40-T and anti-homogentisate 1, 2-dioxygenase (HGD, a renal tubular marker) + anti-SV40-T. Results: Immunohistochemical staining demonstrated that 58K was expressed in proximal tubular epithelium but not in distal tubular epithelium or transitional epithelium. Of the 76 patients, 28 (36.8%) had urinary 58K(+)/SV40-T(+) cells and HGD(+)/SV40-T(+) cells, 41 (53.9%) had only HGD(+)/SV40-T(+) cells, one (1.3%) had only 58K(+)/SV40-T(+) cells, and six (7.9%) had only 58K(-)/HGD(-)/SV40-T(+) cells. The presence of urinary 58K(+)/SV40-T(+) cells was correlated with BKPyV infection in proximal tubular epithelium (P < 0.001, r = 0.806). The mean extent of SV40-T staining was significantly more extensive in patients with urinary 58K(+)/SV40-T(+) cells than those without urinary 58K(+)/SV40-T(+) cells (21.4 vs. 12.0%, P < 0.001). The positive predictive value, negative predictive value, sensitivity, and specificity of urinary 58K(+)/SV40-T(+) cells for predicting BKPyV infection in proximal tubular epithelium were 89.7% (95% CI: 71.5-97.3%), 91.5% (95% CI: 78.7-97.2%), 86.7% (95% CI: 68.4-95.6%), and 93.5% (95% CI: 81.1-98.3%), respectively. Conclusion: Urinary sediment double-immunostaining with anti-58K and anti-SV40-T is valuable for predicting the extent and depth of BKPyV infection in renal allograft.
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Aloenxertos/imunologia , Vírus BK/fisiologia , Rejeição de Enxerto/imunologia , Transplante de Rim , Túbulos Renais Proximais/patologia , Infecções por Polyomavirus/imunologia , Urotélio/patologia , Adulto , Aloenxertos/virologia , Estudos Transversais , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplantados , Urina/citologiaRESUMO
BACKGROUND: BK virus-associated nephropathy (BKVN) is an important cause of chronic allograft dysfunction. The objective of our study was to evaluate the prognosis of BKVN. METHODS: We retrospectively reviewed the data of 133 renal transplant recipients with BKVN treated at the First Affiliated Hospital of Sun Yat-Sen University between July 2007 and July 2017. BK viral loads, graft function, and pathologic indexes were compared between initial diagnosis and last follow-up. RESULTS: After a mean follow-up period of 14.4 (range, 0.3-109.6) months after diagnosis of BKVN, BK viruria, and BK viremia become negative in 19.5% and 90.2% of patients, respectively. The mean estimated glomerular filtration rate (eGFR) at last follow-up was lower than at diagnosis of BKVN (18.3â±â9.2 vs. 32.8â±â20.6âmL·min·1.73âm, tâ=â7.426, Pâ<â0.001). Eight (6.0%) patients developed acute rejection after reducing immunosuppression. At last follow-up, the eGFR was significantly lower in patients with subsequent rejection than those without (21.6â±â9.8 vs. 33.5â±â20.9âmL·min·1.73âm, tâ=â3.034, Pâ=â0.011). In 65 repeat biopsies, SV40-T antigen staining remained positive in 40 patients and became negative in the other 20 patients. The eGFR (42.6â±â14.3 vs. 26.5â±â12.3âmL·min·1.73âm), urine viral loads (median, 1.3â×â10vs. 1.4â×â10âcopies/mL), and plasma viral load (median, 0 vs. 0âcopies/mL) were all significantly lower in patients with negative SV40-T antigen staining than those with persistent BK involvement (all, Pâ<â0.05). Five (3.8%) recipients lost their graft at diagnosis of BKVN, and 13 (9.8%) lost their graft during the follow-up period. The 1-, 3-, and 5-year graft survival rates after diagnosis of BKVN were 99.2%, 90.7%, and 85.7%, respectively. Higher pathologic stage correlated with lower allograft survival rate (χâ=â6.341, Pâ=â0.042). CONCLUSION: Secondary rejection and persistent histologic infection in BKVN lead to poor prognosis.
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Vírus BK , Sobrevivência de Enxerto , Nefropatias/complicações , Transplante de Rim/efeitos adversos , Infecções por Polyomavirus/complicações , Adolescente , Adulto , Idoso , Criança , Feminino , Taxa de Filtração Glomerular , Rejeição de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Carga Viral , Viremia/complicações , Adulto JovemRESUMO
Background: There is no effective therapy for BK virus (BKV) nephropathy (BKVN). Cyclosporine A (CsA) has a lower immunosuppressive effect than tacrolimus. In vitro studies have shown that CsA inhibits BKV replication. The present study aimed to evaluate the effectiveness of switching from tacrolimus to low-dose CsA in renal transplant recipients with BKVN. Methods: Twenty-four patients diagnosed with BKVN between January 2015 and December 2016 were included. Tacrolimus was switched to low-dose CsA, and patients were followed for 24 months. Primary end points were BKV clearance in blood and graft. Secondary end points were urine specific gravity, serum creatinine, and graft loss. Results: The viremia in all patients cleared at a mean of 2.7 ± 2.0 months after switching to CsA. Urine specific gravity at 3 months after switching to CsA increased significantly compared with that at diagnosis (P=0.002). The timing and trend of urine specific gravity increase was consistent with the timing and trend of blood and urine viral load decrease. Repeated biopsies at a median of 11.2 months (range: 9.1-12.5 months) after switching to CsA showed that 8 patients (42.1%) were negative for BKV, and 11 patients (58.9%) had a decrease in BKV load (P<0.001). There was no statistical difference in the serum creatinine level between the time of diagnosis and 24 months of CsA therapy (P=0.963). The graft survival rate was 100%. Only two patients (8.3%) suffered from acute rejection. Conclusion: Switching from tacrolimus to low-dose CsA may be an effective therapy for BKVN.