Current status of Merkel cell carcinoma: Epidemiology, pathogenesis and prognostic factors.

Merkel cell carcinoma (MCC) is an extremely rare cutaneous neuroendocrine cancer, with an incidence approximately 40 times lower than that of malignant melanoma; however, its significantly inferior survival rate compared to melanoma establishes MCC as the most lethal form of skin cancer. In recent years, a substantial body of literature has demonstrated a gradual increase in the incidence of MCC. Although the two factors that contribute to MCC, ultraviolet radiation and Merkel cell polyomavirus infection, have been well established, the specific pathogenesis of this disease remains unclear. Additionally, considering the high lethality and recurrence rates of MCC, as well as the absence of specific antitumor drugs, it is crucial to elucidate the factors that can accurately predict patients' outcomes. In this review, we summarized the significant advancements in the epidemiological characteristics, pathogenesis, and the factors that influence patient prognosis of MCC to enhance clinical practices and public health efforts.

Neoplastic and non-neoplastic diseases associated with feline leukaemia virus (FeLV) in cats in southern Brazil.

The objective of this study was to categorise diseases associated with FeLV infection in cats. A total of 154 cats were submitted to necropsy, histopathology exam and anti-FeLV immunohistochemistry (IHC), and 83 (50.9 %) were IHC FeLV-positive. The cats age means of 4.1 years, including 3.6 % kittens, 34.9 % junior, 37.4 % prime, 18.1 % mature, 2.4 % senior, 3.6 % unknown age. Neoplastic diseases were most prevalent with leukaemia and lymphoma being most predominant, followed by viral diseases, bacterial, trauma, degenerative, intoxications, parasitic, malformation and others. FeLV+ cats were 5.73 times more likely to be diagnosed with neoplasms than other diseases. The odds ratio (OR) of FeLV+ cats developing leukaemia (OR = 7.75) and lymphoma (OR = 6.75) was higher than other neoplasms. FeLV infection was more prevalent in the mixed breed, junior to prime, male, with neoplastic diseases, including leukaemia and lymphoma. Therefore, understanding the diseases associated with FeLV is of paramount importance in Brazil due to its high prevalence, and it may encourage the implementation of prophylactic measures to reduce its dissemination.

Association of polyomavirus infection with lung cancer: A systematic review and meta-analysis.

AIM: The objective of this study was to investigate the pooled prevalence and possible association between polyomavirus infection and lung cancer. METHODS: A systematic publication search was conducted by identifying relevant cross-sectional and case-control studies from major online databases. Heterogeneity, OR, and corresponding 95 % CI were applied to all studies through meta-analysis and forest plot. Random effects models were used to calculate the overall pooled prevalence. Visual inspection of a funnel plot plotting the log-transformed OR and its associated standard error of the log (OR) was combined with the Begg and Egger test to examine the presence and influence of publication bias. Analyzes were performed using Stata software v.14.1. RESULTS: 23 articles (33 datasets) were included in the meta-analysis, of which 14 datasets were case/control and the rest were cross-sectional studies. The pooled polyomavirus infection rate in lung cancer patients was 0.06 % (0.02-0.11 %). In subgroup analysis, the pooled prevalence of JCV, MCPyV, KI, SV40, BKV, WU, MU, and STL was 21 %, 7 %, 6 %, 2 %, 0 %, 0 %, 0 %, and 0 % respectively. An association has been found between polyomavirus infection and lung cancer [summary OR 6.33 (95 % CI (1.76-22.77); I2=67.45 %)]. The subgroup analysis, based on the virus type, showed a strong association between MCPyV and lung cancer [summary OR 13.61 (95 % CI 2.41-76.59; I2=40.0 %)]. despite the high prevalence of JCV DNA in lung cancer tissue, analysis of case-control studies showed that JCV is not associated with lung cancer and does not increase the risk of lung cancer. CONCLUSION: This study showed a significant association between polyomaviruses infection with lung cancer. The results also revealed a pooled prevalence of 6 % for polyomaviruses in lung tumor patients. Altogether, the findings of the present work suggest that Merkel cell polyomavirus infection is a potential risk factor for lung cancer.

Human papillomavirus and Merkel cell polyomavirus in Korean patients with nonsmall cell lung cancer: Evaluation and genetic variability of the noncoding control region.

Human papillomavirus (HPV) is an important causative factor of cervical cancer and is associated with nonsmall cell lung cancer (NSCLC). Merkel cell polyomavirus (MCPyV) is a rare and highly fatal cutaneous virus that can cause Merkel cell carcinoma (MCC). Although coinfection with oncogenic HPV and MCPyV may increase cancer risk, a definitive etiological link has not been established. Recently, genomic variation and genetic diversity in the MCPyV noncoding control region (NCCR) among ethnic groups has been reported. The current study aimed to provide accurate prevalence information on HPV and MCPyV infection/coinfection in NSCLC patients and to evaluate and confirm Korean MCPyV NCCR variant genotypes and sequences. DNA from 150 NSCLC tissues and 150 adjacent control tissues was assessed via polymerase chain reaction (PCR) targeting regions of the large T antigen (LT-ag), viral capsid protein 1 (VP1), and NCCR. MCPyV was detected in 22.7% (34 of 150) of NSCLC tissues and 8.0% (12 of 150) of adjacent tissues from Korean patients. The incidence rates of HPV with and without MCPyV were 26.5% (nine of 34) and 12.9% (15 of 116). The MCPyV NCCR genotype prevalence in Korean patients was 21.3% (32 of 150) for subtype I and 6% (nine of 150) for subtype IIc. Subtype I, a predominant East Asian strain containing 25 bp tandem repeats, was most common in the MCPyV NCCR data set. Our results confirm that coinfection with other tumor-associated viruses is not associated with NSCLC. Although the role of NCCR rearrangements in MCPyV infection remains unknown, future studies are warranted to determine the associations of MCPyV NCCR sequence rearrangements with specific diseases.

High rates of anal Merkel Cell Polyomavirus and HPV co-infection among people living with HIV.

Knowledge of Human Polyomavirus (HPyV) infection in the anal area and its association with sexually transmitted infections such as Human Papillomavirus (HPV) and Human Immunodeficiency Virus (HIV) remains limited. Therefore, anal specimens from 150 individuals of both sexes were analyzed for screening purposes. HPV DNA was found in 50.7% of cases, with a predominance of high-risk (HR) genotypes. HPyV DNA was found in 39.3% of samples, with Merkel Cell Polyomavirus (MCPyV) being the most common, with a higher viral load than JCPyV and BKPyV. In addition, MCPyV viral load increased in people living with HIV (PLWH) with HPV infection (p < 0.0001).

Analysis of BK Virus Infection in Children After Hematopoietic Cell Transplantation: A Retrospective Single-center Study.

BACKGROUND: BK virus (BKV) is one of the most common causes of hemorrhagic cystitis (HC) in children undergoing hematopoietic stem cell transplantation (HSCT). Viruses can be found in urine and serum of immunocompromised patients. OBJECTIVE: This study aimed to evaluate the incidence, clinical course, and risk factors for BKV infection in children undergoing HSCT. METHODS: Retrospectively analyzed children who underwent HSCT at Beijing Children's Hospital, Capital Medical University from June 2020 to June 2022. Data related to the clinical manifestations, engraftment, and prognosis were extracted from medical records. Patients were divided into the case group and the control group, according to the BKV infection or not after HSCT. RESULTS: A total of 149 patients were enrolled in this study, and 61 (40.9%) patients developed BKV infection after HSCT. Among the 61 patients, BKV load was detected in all patients in urine samples and 22 patients in blood samples. The median value of BKV DNA copies in urine and plasma were 9.50×10 7 (5.37×10 2 to 6.84×10 9 ) copies/mL and 2.97×10 3 (9.96×10 2 to 3.58×10 8 ) copies/mL, respectively. The median time from beginning of the conditioning regimen to BKV infection was 23 (0 to 273) days, and the first positive time of urinary BKV was earlier than that of blood (13.5 d [0.0 to 123.0 d] vs. 30.5 d [7.0 to 165.0 d], P =0.003). Among the patients with BKV infection, 36 (59.0%) patients met the diagnosis of hemorrhagic cystitis (HC), and the incidence was higher than that in the control group ( P <0.001). Similarly, 15 (24.6%) patients developed renal function damage in the case group and the proportion was higher than that in the control group. The median follow-up was 5.67 (0.03 to 24.90) months, and there was no significant difference in 1-year overall survival rate between the case group and the control group (84.2%±5.7% vs. 95.3%±2.3%, P =0.688), but the incidence of TA-TMA/VOD (31.1%) and diffuse alveolar hemorrhage (9.8%) in the case group was higher than that in the control group ( P =0.002 and 0.038, respectively). Multivariate analysis showed that age above 5 years old (OR=9.039, 95% CI: 3.561-24.333, P <0.001) and use of MMF (OR=2.708, 95% CI: 1.041-7.044, P <0.05) were independent risk factors for BKV infection after HSCT. CONCLUSION: Among children after HSCT, the incidence of BKV infection was high and BKV infection was associated with an increased incidence of TA-TMA/VOD and diffuse alveolar hemorrhage. Patients older than 5 years of age at the time of HSCT and treated with MMF were more likely to develop BKV infection.

Biopsy-proven BK virus nephropathy in renal transplant recipients: A multi-central study from Turkey (BK-TURK STUDY).

AIM: BK polyomavirus infection is a challenging complication of renal transplantation. The management is not standardized and is based on reports from transplantation centers' experiences, usually with small sample sizes. Therefore, we aimed to present our countrywide experience with BK virus nephropathy (BKVN) in renal transplant recipients. MATERIALS AND METHODS: Our study was carried out with the participation of 30 transplantation centers from all regions of Turkey. Only cases with allograft biopsy-proven BKVN were included in the study. RESULTS: 13,857 patients from 30 transplantation centers were screened, and 207 BK nephropathy cases were included. The mean age was 46.4 ±  13.1 years, and 146 (70.5%) patients were male. The mean time to diagnosis of BK nephropathy was 15.8 ± 22.2 months after transplantation. At diagnosis, the mean creatinine level was 1.8 ±  0.7 mg/dL, and the mean estimated glomerular filtration rate was 45.8 ± 19.6 mL/min/1.73m2. In addition to dose reduction or discontinuation of immunosuppressive drugs, 18 patients were treated with cidofovir, 11 patients with leflunomide, 17 patients with quinolones, 15 patients with intravenous immunoglobulin (IVIG), 5 patients with cidofovir plus IVIG, and 12 patients with leflunomide plus IVIG. None of the patients receiving leflunomide or leflunomide plus IVIG had allograft loss. During follow-up, allograft loss occurred in 32 (15%) out of 207 patients with BK nephropathy. CONCLUSION: BKVN is still a frequent cause of allograft loss in kidney transplantation and is not fully elucidated. The results of our study suggest that leflunomide treatment is associated with more favorable allograft outcomes.

Incidence and Outcomes of BK Virus Nephropathy in Kidney Transplant Recipients With Steroid-Free Maintenance Immunosuppression.

BACKGROUND: BK virus nephropathy (BKVN) is a significant complication in kidney transplant recipients, resulting in graft dysfunction and potentially leading to graft loss. This study aims to investigate the incidence and outcomes of BKVN in kidney transplant recipients receiving steroid-free maintenance immunosuppression in a Latin -American cohort. METHODS: Case series study of BKVN among kidney transplant recipients who underwent transplantation between 2008 and 2023. The primary outcome was graft loss caused by BKVN, excluding death with function. Secondary outcomes included graft function and acute rejection episodes. The statistical analysis involved descriptive statistics and the Kaplan-Meier (K-M) method to plot the overall probabilities of not initiating dialysis. RESULTS: During the 15-year period, 2236 kidney transplants were performed, BKVN was histologically diagnosed in 38 kidney recipients and 33 cases were analyzed. Median age was 50 years and men were 48.5% of patients. A total of 45.4% of BKVN occurred within the first 12 months of transplant. The incidence of BKVN was 1.6% but it varied by era. The rate of graft loss was 75.7% (25 cases). The K-M graft survival probability at 6 months and 12 months after diagnosis of BKVN was 38.3% (95% CI 24.7-59.4) and 22.3% (95% CI 11.7-42.8), respectively. CONCLUSION: BKVN affected 1.6% of transplant recipients and it was associated with high-rate of graft loss. We observed that significant graft disfunction at the time of diagnosis resulted in worse outcomes with a reduced probability of graft survival.

Case-control study: Unveiling human polyomaviruses and papillomavirus in Egyptian colorectal cancer patients.

BACKGROUND: Colorectal cancer (CRC) is a cancer type that is thought to be influenced by human papillomaviruses (HPVs) and human polyomaviruses (HPyVs). In Egypt, CRC ranks as the 7th most common cancer, accounting for 3.47% of male cancers and 3% of female cancers. However, there is currently a lack of information regarding the presence of PyVs and HPVs co-infection specifically in CRC cases in Egypt. Therefore, the aim of this study was to investigate the occurrence of HPVs and HPyVs (JCPyV, BKPyV, and SV40) infections, as well as co-infections, among CRC patients in Egypt. Additionally, the study aimed to assess any potential association between these viral infections and tumor stages. METHODS: In the present study, we analyzed a total of 51 tissue samples obtained from Egyptian CRC patients, along with 19 polyps' samples. Our investigation focused on the detection and genotyping of HPyVs using Real-Time PCR. Additionally, we employed real-time PCR for the detection of HPVs, and for their genotyping, we utilized a combination of PCR amplification followed by sequencing. RESULTS: In our study, we found evidence of HPyVs infection in the CRC patients, specifically SV40 (25.5%) and BKPyV (19.6%). However, JCPyV was not detected in the samples that were examined. Additionally, we discovered that HPV was present in 43.1% of the CRC patients. When considering viral co-infections, 19.6% of the CRC samples showed coexistence of multiple viruses, while no co-infections were found in the polyps samples. Importantly, we observed a significant correlation between the presence of HPVs and advanced colorectal tumor grades B2 and D. CONCLUSION: Our findings provide valuable data for the detection of oncogenic viruses in colorectal cancer (CRC) and underscore the association of viral co-infections with advanced tumor stages. However, further research with larger cohorts is necessary to validate these findings and strengthen their significance in the field of CRC.

Molecular epidemiology and risk factors associated with BK and JC polyomavirus urinary shedding after kidney allograft.

Polyomaviruses BK (BKPyV) and JC (JCPyV), belonging to the Polyomaviridae, are responsible for human pathologies. In kidney transplant recipients, BKPyV replication can lead to irreversible nephron damage whereas JCPyV replication remains asymptomatic. Concomitant replication is rare and potential competition between the infections has been described. The aim of this retrospective case-control study was to describe the molecular epidemiology and risk factors associated with BKPyV and JCPyV replication in a cohort of kidney transplant recipients. In total, 655 urine samples from 460 patients were tested for BKPyV and JCPyV DNA. Positive samples were submitted to strain genotyping. Demographic and clinical characteristics were also compared. Isolated JCPyV and BKPyV was found in 16.5% and 23.3% of patients, respectively; co-replication was rare (3.9%). BKPyV strains Ib-2, Ib-1, and IVc-2 were the most prevalent. JCPyV strains mostly belonged to genotypes 4 and 1B. During follow-up, JCPyV shedding significantly reduced the risk of BKPyV DNAuria, with an odds ratio of 0.57 (95% confidence interval: 0.35-0.99), and was associated with better prognosis than BKPyV replication, based on the estimated glomerular filtration rate. Molecular epidemiology of BKPyV and JCPyV strains in our region was similar to previous studies. This study suggests that JCPyV is benign and appears to limit damaging BKPyV replication. JCPyV DNAuria screening could thus be a useful strategy to predict BKPyV-related outcomes.

Association Study of Pleural Mesothelioma and Oncogenic Simian Virus 40 in the Crocidolite-Contaminated Area of Dayao County, Yunnan Province, Southwest China.

Background: In Dayao County, Chuxiong Yi Autonomous Prefecture, Yunnan Province, Southwest China, 5% of the surface is scattered with blue asbestos, which has a high incidence of pleural mesothelioma (PMe). Simian virus 40 (SV40) is a small circular double-stranded DNA polyomavirus that can cause malignant transformation of normal cells of various human and animal tissue types and promote tumor growth. In this study, we investigate whether oncogenic SV40 is associated with the occurrence of PMe in the crocidolite-contaminated area of Dayao County, Yunnan Province, Southwest China. Methods: Tumor tissues from 51 patients with PMe (40 of whom had a history of asbestos exposure) and pleural tissues from 12 non-PMe patients (including diseases such as pulmonary maculopathy and pulmonary tuberculosis) were collected. Three pairs of low-contamination risk primers (SVINT, SVfor2, and SVTA1) were used to detect the gene fragment of SV40 large T antigen (T-Ag) by polymerase chain reaction (PCR). The presence of SV40 T-Ag in PMe tumor tissues and PMe cell lines was detected by Western blotting and immunohistochemical staining with SV40-related antibodies (PAb 101 and PAb 416). Results: PCR, Western blotting, and immunohistochemical staining results showed that the Met5A cell line was positive for SV40 and contained the SV40 T-Ag gene and protein. In contrast, the various PMe cell lines NCI-H28, NCI-H2052, and NCI-H2452 were negative for SV40. PCR was negative for all three sets of low-contamination risk primers in 12 non-PMe tissues and 51 PMe tissues. SV40 T-Ag was not detected in 12 non-PMe tissues or 51 PMe tissues by immunohistochemical staining. Conclusion: Our data suggest that the occurrence of PMe in the crocidolite-contaminated area of Yunnan Province may not be related to SV40 infection and that crocidolite exposure may be the main cause of PMe. The Clinical Trial Registration number: 2020-YXLL20.

Avian Polyomavirus Among Psittacine Birds in Iran: Molecular Detection Rate and Associated Risk Factors.

Avian polyomavirus (APV) infection causes various health problems in psittacine species, including death. The present study was conducted to investigate the prevalence of APV among psittacine birds in Iran. We also aimed to evaluate the impact of age, sex, species, season, and origin of the birds on the prevalence of APV. This study investigated the presence of APV among 1050 individual birds from 7 psittacine species over a 1-year period in Iran, namely, green-cheeked parakeets (Pyrrhura molinae), rosy-faced lovebirds (Agapornis roseicollis), monk parakeets (Myiopsitta monachus), sun conures (Aratinga solstitialis), Senegal parrots (Poicephalus senegalus), cockatiels (Nymphicus hollandicus), and grey parrots (Psittacus erithacus). The overall prevalence of APV in all studied species was 25% (263/1050, 95% confidence interval [CI]: 22.5-27.8). Results of the study showed that age and the season of the year were 2 important determinant factors in the prevalence of APV in psittacine birds. Young psittacine birds <6 months old were 2.94 (95% CI: 1.19-7.27) times more likely to be infected with APV than birds >1 year old, and there was a significant interaction between season and species in the multivariate analysis. In the winter season, rosy-faced lovebirds and green-cheeked parakeets were 15.6 (95% CI: 4.20-57.95) and 4.76 (95% CI: 1.4-16.21) times more likely to be infected with APV than in other seasons, respectively. This is the first report on the detection rate of APV in psittacine birds in Iran.

Impact of BK polyomavirus viremia on the outcomes of allogeneic hematopoietic stem cell transplantation.

Although it is known that BK polyomavirus (BKPyV) causes hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT), the clinical significance of BKPyV viremia has not been fully evaluated. We retrospectively analyzed the results of quantitative polymerase chain reaction (PCR) evaluations for detecting BKPyV in the whole blood samples of patients undergoing allogeneic HSCT during the period from January 2010 to June 2020 at a single institute, Tokyo Medical and Dental University. BKPyV was detected in the blood of 28 of the 107 evaluated patients, and the cumulative incidence of was 27.9% (95%CI: 20.2-37.9%). HC due to BKPyV developed in four of the 28 patients with BKPyV viremia (14.3%) and in two of the 79 patients without it (2.5%; P < 0.05). BKPyV viremia itself did not affect the patients' post-transplant estimated glomerular filtration rate (eGFR), but BKPyV viremia with a high viral load was significantly associated with decreased eGFR values (P < 0.05). BKPyV viremia was also associated with significantly lower progression-free survival at 3 years (35.1% [95%CI: 17.8-53.1%] vs. 60.4% [95%CI: 48.4-70.5], P < 0.05). Our findings demonstrated that BKPyV viremia was associated with onset of HC, an early decline of renal function, and poorer survival after allogeneic HSCT. Further studies are needed to test these results and elucidate the mechanisms of renal dysfunction associated with BKPyV viremia.

Prevalence of BK and JC Polyomaviruses among Patients with Breast Cancer.

INTRODUCTION: Breast cancer, a pervasive invasive carcinoma among women globally, afflicts approximately 12% of women worldwide. Previous studies have indicated that certain viruses, including oncogenic viruses such as polyomaviruses BK and JC, may play a role in the development of breast cancer. In light of this, the present study endeavors to assess the incidence of BKV and JCV virus in breast cancer patients. MATERIALS AND METHODS: One hundred formalin-fixed paraffin-embedded tissue samples were procured and subjected to deparaffinize by xylene, followed by DNA extraction through the phenol-chloroform methodology. Detection and genotyping of BKV and JCV were carried out utilizing specific primers via PCR analysis. RESULTS: Merely 2 out of 100 (2%) ductal carcinoma in situ with grade 2 specimens exhibited positivity for BK virus genotype IV, whereas JC virus DNA was not discerned across all the samples. DISCUSSION: The findings of the current investigation demonstrate that there was an absence of JC virus detection in the breast biopsy. Additionally, a small fraction of patients diagnosed with ductal carcinoma exhibited a low prevalence of genotype IV polyomavirus BK at a rate of 2%. However, in order to gain a more comprehensive understanding of the incidence of BKV and JCV in breast cancer, a substantial number of breast samples must undergo investigation.

Experimental infection of domestic turkeys with lymphoproliferative disease virus of North American origin.

Lymphoproliferative disease virus (LPDV) was first documented in wild turkeys in North America in 2009. LPDV infection is often subclinical but can manifest as lymphoid proliferation or round cell neoplasia. Despite high prevalence across many sampled areas corresponding to declining populations of wild turkeys, knowledge regarding LPDV pathogenesis, risk factors for disease development, and associated impacts on population dynamics are unknown. To understand transmission, viral shedding, and tissue tropism, we inoculated 21 domestic turkeys via the oral cavity, crop, nasal cavity, subcutis, or coelomic cavity. For 12 weeks, oropharyngeal swabs, cloacal swabs, and whole blood were collected weekly. At 1 week postinoculation, 3 turkeys (3/21; 14%) had detectable LPDV proviral DNA in blood by polymerase chain reaction, and 10 developed DNAemia (50%; 10/20) by 12 weeks. LPDV proviral DNA was intermittently detected in oropharyngeal and cloacal swabs. Splenomegaly was the most consistent gross finding in DNAemic birds (8/11; 73%). Lymphoid hyperplasia in the spleen was the most significant microscopic finding (9/11; 82%). Three turkeys (3/11; 27%) developed round cell neoplasia characterized by sheets of pleomorphic, round to polygonal cells in the adrenal gland, bone marrow, skin, small intestine, and/or spleen. LPDV was detected in the spleen and bone marrow from all turkeys with DNAemia and all neoplasms. Our study establishes that infection and disease with North American LPDV from wild turkeys can be experimentally reproduced in domestic turkeys, laying the groundwork for future investigations into LPDV pathogenesis, development of diagnostic techniques, and understanding the impacts of LPDV on wild turkey populations.

Incidence of postoperative cytomegalovirus and BK-polyoma virus infections and graft loss in ABO-incompatible renal transplant recipients: a multicenter retrospective study.

OBJECTIVES: The current study aimed to examine the incidence of perioperative infections and graft viability in ABO-compatible and ABO-incompatible renal transplant recipients. METHODS: We included 643 living donor renal transplant recipients registered in the Michinoku Renal Transplant Network from 1998 to 2021. Patients were divided into the ABO-compatible and ABO-incompatible kidney transplantation groups. We compared the characteristics of the two groups and evaluated the incidence of postoperative viral infections (cytomegalovirus and BK virus), graft loss-free survival, and overall survival between the two groups. RESULTS: Of 643 patients, 485 (75%) and 158 (25%) were ABO-compatible and ABO-incompatible renal transplant recipients, respectively. Postoperative viral infections, rituximab use, and plasma exchange were significantly more common in ABO-incompatible than in ABO-compatible transplant recipients. However, there were no significant differences in terms of other background characteristics. The ABO-incompatible group was more likely to develop viral infections than the ABO-compatible group. Graft loss-free survival and overall survival did not significantly differ between the two groups. According to the multivariate Cox regression analysis, ABO compatibility was not significantly associated with graft loss-free survival and overall survival. CONCLUSION: Although the incidence of postoperative viral infections in ABO-incompatible renal transplant recipients increased, there was no significant difference in terms of rejection events, graft loss-free survival, and overall survival.

The Relationship between Acute Rejection, Hemoglobin Level, and BK Virus Infection Among Renal Transplant Recipients.

BACKGROUND: This study aimed to explore the risk factors for BK virus (BKV) infection in renal transplant recipients (RTRs) routinely treated with tacrolimus. METHODS: Forty-two cases with BKV infections and 51 patients without BKV infections were enrolled in the study. Eighty-seven healthy individuals and 77 patients undergoing dialysis were randomly included as controls. A logistic regression model was used to analyze potential variables in order to evaluate factors related to BKV infection in the renal transplant recipients. RESULTS: The number of individuals with acute rejection in BKV positive RTRs is significantly higher than that in BKV negative RTRs. Hemoglobin levels in BKV positive RTRs were significantly lower than those in BKV negative RTRs (109.61 ± 20.11 vs. 130.16 ± 26.297, p < 0.001). There was a positive correlation between tacrolimus levels and hemoglobin concentration in RTRs (r = 0.329, p = 0.023). The results of a multivariate regression analysis indicated that a history of acute rejection (OR = 4.157, p = 0.031) and low hemoglobin (OR = 0.963, p < 0.001) were risk factors for BKV infection. CONCLUSIONS: Acute rejection and low hemoglobin were risk factors for BKV infection after renal transplantation.

Risk factors for BK virus-associated hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation: A systematic review and meta-analysis.

OBJECTIVE AND BACKGROUND: BK virus-associated hemorrhagic cystitis (BKV-HC) is an intractable complication leading to higher mortality and prolonged hospitalization among allogeneic hematopoietic stem cell transplantation (allo-HCT) recipients. Therefore, identifying the potential risk factors of BKV-HC after allo-HCT is crucial to improve prognosis and for early prevention. However, the risk factors for BKV-HC remain debatable. Therefore, we conducted a systematic review and meta-analysis to identify the risk factors for BKV-HC, for early prevention of the occurrence of BKV-HC and to improve the quality of life and prognosis of allo-HCT recipients. METHODS: We searched relevant studies from PubMed, EMBASE, and the Cochrane Library up to February 2023. The odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) of all risk factors were calculated to evaluate their effects on the occurrence of BKV-HC. RESULTS: Overall, 11 studies involving 2556 allo-HCT recipients were included in this meta-analysis. All included studies were retrospective and published between 2013 and 2022. We found that male sex (OR = 1.32; 95% CI, 1.07-1.62; p = .009, I2  = 34%), haploidentical donor (OR = 1.84; 95% CI, 1.18-2.87; p = .007, I2  = 23%), myeloablative conditioning (OR = 1.76; 95% CI, 1.36-2.28; p < .0001, I2  = 45%), acute graft versus host disease (aGVHD) (OR = 2.73; 95% CI, 2.02-3.69; p < .0001, I2  = 46%), chronic graft versus host disease (cGVHD) (OR = 1.71; 95% CI, 1.12-2.60; p = .01, I2  = 0%), and cytomegalovirus (CMV) reactivation (OR = 3.13; 95% CI, 1.12-8.78; p = .03, I2  = 79%) were significantly associated with BKV-HC in the univariable analysis. CONCLUSIONS: Our meta-analysis indicated that male sex, haploidentical donor, myeloablative conditioning, aGVHD, cGVHD, and CMV reactivation were potential risk factors for BKV-HC.

BK polyomavirus DNAemia in pancreas transplant recipients compared to pancreas-kidney recipients.

BACKGROUND: BK polyomavirus (BKV) infection is a common complication of kidney transplantation. While BKV has been described in non-kidney transplant recipients, data are limited regarding its epidemiology and outcomes in pancreas transplant recipients. METHODS: We conducted a retrospective cohort study of adults who underwent pancreas transplantation from 2010-2020. The primary outcome was BKV DNAemia. Secondary outcomes were estimated glomerular filtration rate (eGFR) reduction by 30%, eGFR < 30 mL/min/1.73 m2 , endstage kidney disease, and pancreas allograft failure. Cox regression with time-dependent variables was utilized. RESULTS: Four hundred and sixty-six patients were analyzed, including 74, 46, and 346 with pancreas transplant alone (PTA), pancreas-after-kidney, or simultaneous pancreas-kidney transplants, respectively. PTA recipients experienced a lower incidence of BKV DNAemia (8.8% vs. 32.9%; p < .001) and shorter duration of DNAemia (median 28.0 vs. 84.5 days). No PTA recipients with BKV DNAemia underwent kidney biopsy or developed endstage kidney disease. Lymphopenia, non-PTA transplantation, and older age were associated with BKV DNAemia, which itself was associated with pancreas allograft failure (adjusted hazard ratio 2.14, 95% confidence interval 1.27-3.60; p = .004). Among PTA recipients, BKV DNAemia was not associated with eGFR reduction or eGFR < 30 mL/min/1.73 m2 . CONCLUSIONS: BKV DNAemia was common among PTA recipients, though lower than a comparable group of pancreas-kidney recipients. However, BKV DNAemia was not associated with adverse native kidney outcomes and no PTA recipients developed endstage kidney disease. Conversely, BKV DNAemia was associated with pancreas allograft failure. Further studies are needed to estimate the rate of BKV nephropathy in this population, and further evaluate long-term kidney outcomes.

Human polyomavirus 9 as a potential threat in kidney transplant recipients; lessons from BKPyV.

As a therapeutic method, kidney transplantation significantly improved the life quality and prognosis of patients with the end-stage renal disease. Since a key element in stable kidney transplantation is continuous therapy with immunosuppressive agents, an inhibited immune response makes patients vulnerable to opportunistic viral and bacterial infections. Polyomavirus (PyV), from the Polyomaviridae family, includes a well-known BK virus (BKPyV) and less publicized human polyomavirus 9 (HPyV9). Both these viruses may inflict significant damage to kidney transplants because of their high prevalence and pathogenesis. While a great body of knowledge was accumulated about the BKPyV-caused nephropathy, much less information is about the potential threat from the HPyV9-caused damage to kidney transplants. The current review provides a glimpse of general information about the PyV-associated nephropathy with a special focus on the role of the HPyV9 in pathogenesis of nephropathy in kidney transplants.