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.

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 associatednephropathy (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

ObjectiveThis study aimed to explore the molecular mechanism of cytoplasmic vacuolation caused by BK polyomavirus (BKPyV) and thus search for potential target for drug repurposing.MethodsMorphological 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.ResultsLight 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.ConclusionERS was involved in renal tubular cytoplasmic vacuolation in BKPyVAN recipients. Risedronate was screened as a potential drug for BKPyVAN by targeting DDIT3.

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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BK polyomavirus (BKPyV) infection is the main factor affecting the prognosis of kidney transplant recipients, as no antiviral agent is yet available. A better understanding of the renal-cell-type tropism of BKPyV can serve to develop new treatment strategies. In this study, the single-cell transcriptomic analysis demonstrated that the ranking of BKPyV tropism for the kidney was proximal tubule cells (PT), collecting duct cells (CD), and glomerular endothelial cells (GEC) according to the signature of renal cell type and immune microenvironment. In normal kidneys, we found that BKPyV infection-related transcription factors P65 and CEBPB were PT-specific transcription factors, and PT showed higher glycolysis/gluconeogenesis activities than CD and GEC. Furthermore, in the BKPyV-infected kidneys, the percentage of late viral transcripts in PT was significantly higher than in CD and GEC. In addition, PT had the smallest cell–cell interactions with immune cells compared to CD and GEC in both normal and BKPyV-infected kidneys. Subsequently, we indirectly demonstrated the ranking of BKPyV tropism via the clinical observation of sequential biopsies. Together, our results provided in-depth insights into the renal cell-type tropism of BKPyV in vivo at single-cell resolution and proposed a novel antiviral target.

Background: Fatigue is a usual occurrence in tumor patients during illness and treatment, patients with cancer related fatigue (CRF) showed signs of fatigue after tumor development, and not only in patients with advanced process, and still a evidently subjective fatigue even after effective symptomatic treatment. Methods: In this study, two metastasis models of BALB/c mice were established by subcutaneous and intraperitoneal inoculation of tumor cells, and a series of quantitative description and qualitative prediction techniques were adopted to investigate the effects of subcutaneous and intraperitoneal tumorigenesis on the life of mice, After 21 days periods, all mice were tested for several aspects of CRF: (1) size of tumor volume; (2) behavioral detection of fatigue; (3) liver, kidney function and lipid levels; (4) organ indices; (5) pathological and electron microscopic observation of gastrocnemius and quadriceps muscles; and (6) determination of oxidative stress indices in gastrocnemius.Results: Compared with normal mice, the fatigue level significantly increased in both models mice, and tumor growth was accompanied by significant fatigue in the organism and might be related to decrease of skeletal muscle mass, destruction of muscle structure, and disorders of skeletal muscle metabolism. Different analyses were performed on the two models, and it was found that the fatigue level was more severe in the abdominal transfer model compared with the subcutaneous transplantation tumor model. HGB and HCT decreased significantly, liver and kidney function were more severely impaired, gastrocnemius muscle area was more reduced, and oxidative damage of gastrocnemius muscle was higher. Conclusion: This study provides a comprehensive description of the main processes that cause fatigue due to tumor itself and provides a standard and reliable animal model for further pharmacological or pharmacodynamic studies.

Previous studies showed physical activity had benefits for older adults’ life satisfaction, but the mechanism was unclear. This study aimed to investigate whether older adults with more physical activity had better functional fitness and life satisfaction, and whether functional fitness mediated the relationship between physical activity and life satisfaction. A cross-sectional study design was employed, and 623 older adults (73.71 ± 5.91 years) were recruited. Physical activity, functional fitness, life satisfaction, and demographic characteristics were collected. Compared with older adults with low physical activity, those with high (B = 0.41, p = 0.025) and moderate (B = 0.40, p = 0.041) physical activity had better life satisfaction; those with high physical activity had better lower limb muscle strength (B = 1.71, p = 0.001), upper (B = 2.91, p = 0.032) and lower (B = 3.12, p = 0.006) limb flexibility, cardiorespiratory endurance (B = 6.65, p = 0.008), and dynamic balance ability (B = −1.12, p < 0.001). Functional fitness did not mediate the relationship between physical activity and life satisfaction. Promoting physical activity may be useful for increasing older adults’ functional fitness and life satisfaction, but the effects on functional fitness only occurred at a high level of physical activity, and the effect of physical activity on life satisfaction was not mediated by functional fitness.