The association of Torque Teno viral load with CMV and BKV infection in pediatric and adolescent kidney transplant patients.

BACKGROUND: Long-term allograft and patient survival after kidney transplantation (KTX) depends on the balance between over- and under-immunosuppression (IS). High levels of IS predispose to opportunistic infections. Plasma load of Torque Teno Virus (TTV), a non-pathogenic highly prevalent Annellovirus, is associated with its hosts immune status, especially after solid organ transplantation. OBJECTIVES: To investigate the association of plasma TTV load and opportunistic viral infections after pediatric KTX. STUDY DESIGN: This retrospective study includes all pediatric KTX patients followed at the Medical University of Vienna 2014-2020. PCR for Cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), and TTV was performed every 4-8 weeks at routine follow-up visits. RESULTS: 71 pediatric KTX patients were followed with TTV measurements for a median of 2.7 years. TTV plasma load was associated with CMV DNAemia at the next visit with an OR of 2.37 (95 % CI 1.15-4.87; p = 0.03) after adjustment for time after KTX and recipient age. For a cut-off of 7.68 log10 c/mL TTV a sensitivity of 100 %, a specificity of 61 %, a NPV 100 %, and a PPV of 46 % to detect CMV DNAemia at the next visit was calculated. TTV plasma loads were also associated with BKV DNAuria and BKV DNAemia at the next visit, but not with EBV DNAemia. CONCLUSIONS: This is the first study to analyse associations between TTV plasma loads and opportunistic viral infections in pediatric KTX. We were able to present a TTV cut-off for the prediction of clinically relevant CMV DNAemia that might be useful in clinical care.

Better detection of Torque teno virus in children with leukemia by metagenomic sequencing than by quantitative PCR.

Torque teno virus (TTV) is a group of chronically persisting viruses with a short circular DNA genome. TTV demonstrates a wide sequence diversity and a large majority of humans are chronically infected by one or more types of TTV. As TTV is ubiquitous, and viral replication correlates with immune status, TTV has been studied as a marker to assess global functional immune competence in transplant recipients. Most studies of the prevalence, amounts, and variation in TTV have been performed using PCR assays. We here present a comparison of the most frequently used quantitative PCR (qPCR) assay for TTV with shotgun metagenomic sequencing for detection and characterization of TTV in a cohort of pediatric cancer patients. The results show that TTV is more common than the qPCR assays indicate, and analysis of the TTV genome sequences indicate that a qPCR with primers and probe designed on a conserved region of the TTV genome may fail to detect some of the TTV strains found in this study.

Herpes DNAemia and TTV Viraemia in Intensive Care Unit Critically Ill Patients: A Single-Centre Prospective Longitudinal Study.

Introduction: We analysed blood DNAemia of TTV and four herpesviruses (CMV, EBV, HHV6, and HSV-1) in the REAnimation Low Immune Status Marker (REALISM) cohort of critically ill patients who had presented with either sepsis, burns, severe trauma, or major surgery. The aim was to identify common features related to virus and injury-associated pathologies and specific features linking one or several viruses to a particular pathological context. Methods: Overall and individual viral DNAemia were measured over a month using quantitative PCR assays from the 377 patients in the REALISM cohort. These patients were characterised by clinical outcomes [severity scores, mortality, Intensive Care Unit (ICU)-acquired infection (IAI)] and 48 parameters defining their host response after injury (cell populations, immune functional assays, and biomarkers). Association between viraemic event and clinical outcomes or immune markers was assessed using χ2-test or exact Fisher's test for qualitative variables and Wilcoxon test for continuous variables. Results: The cumulative incidence of viral DNAemia increased from below 4% at ICU admission to 35% for each herpesvirus during the first month. EBV, HSV1, HHV6, and CMV were detected in 18%, 12%, 10%, and 9% of patients, respectively. The incidence of high TTV viraemia (>10,000 copies/ml) increased from 11% to 15% during the same period. Herpesvirus viraemia was associated with severity at admission; CMV and HHV6 viraemia correlated with mortality during the first week and over the month. The presence of individual herpesvirus during the first month was significantly associated (p < 0.001) with the occurrence of IAI, whilst herpesvirus DNAemia coupled with high TTV viraemia during the very first week was associated with IAI. Herpesvirus viraemia was associated with a lasting exacerbated host immune response, with concurrent profound immune suppression and hyper inflammation, and delayed return to immune homeostasis. The percentage of patients presenting with herpesvirus DNAemia was significantly higher in sepsis than in all other groups. Primary infection in the hospital and high IL10 levels might favour EBV and CMV reactivation. Conclusion: In this cohort of ICU patients, phenotypic differences were observed between TTV and herpesviruses DNAemia. The higher prevalence of herpesvirus DNAemia in sepsis hints at further studies that may enable a better in vivo understanding of host determinants of herpesvirus viral reactivation. Furthermore, our data suggest that EBV and TTV may be useful as additional markers to predict clinical deterioration in ICU patients.

Elevated levels of Merkel cell polyoma virus in the anophthalmic conjunctiva.

The human ocular surface hosts a paucibacterial resident microbiome and virome. The factors contributing to homeostasis of this mucosal community are presently unknown. To determine the impact of ocular enucleation and prosthesis placement on the ocular surface microbiome, we sampled conjunctival swabs from 20 anophthalmic and 20 fellow-eye intact conjunctiva. DNA was extracted and subjected to quantitative 16S rDNA PCR, biome representational karyotyping (BRiSK), and quantitative PCR (qPCR) confirmation of specific organisms. 16S ribosomal qPCR revealed equivalent bacterial loads between conditions. Biome representational in silico karyotyping (BRiSK) demonstrated comparable bacterial fauna between anophthalmic and intact conjunctiva. Both torque teno virus and Merkel cell polyoma virus (MCPyV) were detected frequently in healthy and anophthalmic conjunctiva. By qPCR, MCPyV was detected in 19/20 anophthalmic samples compared with 5/20 fellow eyes. MCPyV copy number averaged 891 copies/ng in anophthalmic conjunctiva compared with 193 copies/ng in fellow eyes (p < 0.001). These results suggest that enucleation and prosthesis placement affect the ocular surface flora, particularly for the resident virome. As MCPyV has been shown to be the etiologic cause of Merkel cell carcinoma, understanding the mechanisms by which the ocular surface regulates this virus may have clinical importance.

Torque Teno Virus load in lung cancer patients correlates with age but not with tumor stage.

BACKGROUND: Torque teno virus (TTV) is a ubiquitous non-pathogenic virus, which is suppressed in immunological healthy individuals but replicates in immune compromised patients. Thus, TTV load is a suitable biomarker for monitoring the immunosuppression also in lung transplant recipients. Since little is known about the changes of TTV load in lung cancer patients, we analyzed TTV plasma DNA levels in lung cancer patients and its perioperative changes after lung cancer surgery. MATERIAL AND METHODS: Patients with lung cancer and non-malignant nodules as control group were included prospectively. TTV DNA levels were measured by quantiative PCR using DNA isolated from patients plasma and correlated with routine circulating biomarkers and clinicopathological variables. RESULTS: 47 patients (early stage lung cancer n = 30, stage IV lung cancer n = 10, non-malignant nodules n = 7) were included. TTV DNA levels were not detected in seven patients (15%). There was no significant difference between the stage IV cases and the preoperative TTV plasma DNA levels in patients with early stage lung cancer or non-malignant nodules (p = 0.627). While gender, tumor stage and tumor histology showed no correlation with TTV load patients below 65 years of age had a significantly lower TTV load then older patients (p = 0.022). Regarding routine blood based biomarkers, LDH activity was significantly higher in patients with stage IV lung cancer (p = 0.043), however, TTV load showed no correlation with LDH activity, albumin, hemoglobin, CRP or WBC. Comparing the preoperative, postoperative and discharge day TTV load, no unequivocal pattern in the kinetics were. CONCLUSION: Our study suggest that lung cancer has no stage dependent impact on TTV plasma DNA levels and confirms that elderly patients have a significantly higher TTV load. Furthermore, we found no uniform perioperative changes during early stage lung cancer resection on plasma TTV DNA levels.

Pigeon adenovirus and pigeon torque teno virus associated with acute multifocal hepatic necrosis in pigeons in Queensland, Australia.

In 2018, an outbreak resulting in deaths of 28 breeding pigeons was reported north of Brisbane, Australia. The affected birds had runny nasal discharge and poor body condition. Two birds were submitted to Biosecurity Sciences Laboratory, Brisbane, for investigation. A range of diagnostic tests excluded a number of known pathogens, and no virus was isolated in cell culture. Histopathological examination revealed severe acute multifocal necrosis in the liver with eosinophilic intranuclear inclusions in hepatocytes and Kupffer cells. High-throughput sequencing (HTS) revealed full-length sequences for pigeon adenovirus 1 (PiAd-A) and pigeon torque teno virus (PTTV). This report indicates concomitant PiAd-1and PTTV infections in Australian pigeons.

Torque Teno Virus Viral Load as a Marker of Immune Function in Allogeneic Haematopoietic Stem Cell Transplantation Recipients.

Torque teno virus (TTV) has been proposed as a surrogate biomarker of T-cell function in allogeneic-haematopoietic-stem-cell transplantation (allo-HSCT). Conflicting data exists regarding the value of TTV to assess the degree of immunosuppression. The aim of the present study was to investigate the correlation between TTV viral load and immune function. Using samples from a prospective cohort composed of healthy-volunteers (HV) and allo-HSCT recipients at 6 months post-transplantation, we assessed the correlation between TTV viraemia and immune cell counts or T-cell proliferation capacity post-phytohaemagglutinin stimulation. TTV viraemia was detected in 68% of HV (n = 80) and 100% of allo-HSCT recipients (n = 41; p < 0.001); it was significantly higher in allo-HSCT recipients (3.9 vs. 2.1 Log copies/mL, p < 0.001). There was no correlation between T-cell function and CD3+T-cell count (rho: 0.002) suggesting that T-cell count can normalise without full functional recovery. Furthermore, no significant correlation was observed between TTV viraemia and absolute total/subset lymphocyte counts (rho: <0.13). The highest correlation was observed between TTV viral load and T-cell proliferation capacity (rho: -0.39). We therefore report an inverse correlation between T-cell function and TTV viraemia that is independent of T-cell count. Monitoring of TTV viraemia could be a fast suitable option to objectively assess the competence of immune function in at-risk populations.

Torquetenovirus viremia for early prediction of graft rejection after kidney transplantation.

OBJECTIVES: New biomarkers reflecting the degree of immunosuppression in transplant recipients are needed to provide an optimal personalized balance between rejection and infection risks. METHODS: For this purpose, we investigated TTV viremia dynamics in 66 kidney transplant recipients followed up for two years after transplantation, in relation to BK virus infection and graft rejection. RESULTS: After transplantation, TTV viremia rose by ≥2 log10 copies/mL from baseline to month 3, then declined by ≥1 log10 copies/mL thereafter. Higher TTV viremia was associated with recipients of a deceased donor, a lower count of CD8+ T cells and a higher BKV viremia. Importantly, TTV loads were significantly lower in KTR who would later display graft rejection; indeed, patients with TTV viremia lower than 3.4 log10 copies/mL at transplantation or lower than 4.2 log10 copies/mL at month 1 had a higher risk of developing graft rejection in the two following years (hazard ratio (HR) at D0 = 7.30, p = 0.0007 and HR at M1 = 6.16, p = 0.001). CONCLUSIONS: TTV viremia measurement at early times post transplantation predicts graft rejection and would represent a useful tool to improve kidney transplant monitoring.

Kinetics of Alphatorquevirus plasma DNAemia at late times after allogeneic hematopoietic stem cell transplantation.

Torque teno virus (TTV) plasma DNA load has been consistently shown to be a surrogate biomarker of immunosuppression in solid organ transplant recipients. It is uncertain whether it may behave similarly in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). Here, we characterized the dynamics of TTV DNAemia in patients undergoing T-cell replete allo-SCT at late times after transplantation (> day + 100). This retrospective single-center observational study included 33 allo-HSCT patients. Plasma TTV DNA loads were quantified by real-time PCR before initiating the conditioning regimen and at different time points after transplant. Absolute lymphocyte counts (ALC) were measured by flow cytometry. Overall, TTV DNA load increased steadily after engraftment, reaching a peak by day + 90; afterwards, it remained relatively constant until day + 210. TTV DNA loads measured within days + 120 and + 210 correlated inversely with paired ALC, while both parameters did correlate directly within days + 20 and + 60. The median TTV DNA area under a curve between days + 90 and + 210 [(AUC)90-210] was significantly higher in patients who received corticosteroids within this time frame for treatment of graft versus host disease (either acute, chronic or both) than in controls (P = 0.025). In summary, TTV DNA load may mirror the degree of immunosuppression at late times after allo-HSCT.

Kinetics of Torque Teno Virus-DNA Plasma Load Predict Rejection in Lung Transplant Recipients.

BACKGROUND: Lung transplantation is the only therapeutic option in end-stage lung diseases; however, survival after transplantation is limited by acute and chronic rejection or infectious events being results of inappropriate immunosuppression. Torque Teno Viruses (TTVs) are ubiquitous DNA viruses in humans but not found to be causative for any disease. However, some reports suggest that TTV-DNA levels reflect the grade of immunosuppression with higher levels being found in more immunosuppressed individuals. METHODS: We investigated the TTV-DNA levels in 34 lung transplant recipients within their first year after transplantation by quantitative real-time polymerase chain reaction. Clinical data were extracted from charts. RESULTS: In accordance with previous results TTV-DNA levels increase after lung transplantation reaching a steady state after 3 months. The TTV-DNA levels were not correlated with immunosuppressive trough levels and a selective increase was not observed with other DNA viruses. In steady state TTV-DNA levels were significantly higher in patients with infectious complications compared to the group of patients without. Additionally, TTV-DNA levels decreased significantly before biopsy-proven rejection. Sensitivity of a 10-fold decrease in TTV-DNA levels for a subsequent rejection episode was 0.74 with a specificity of 0.99. CONCLUSIONS: In summary, TTV-DNA might be used as an additional tool to monitor immunosuppression in lung transplant recipients. Higher TTV-DNA levels reflect more intense immunosuppression, whereas the TTV-DNA kinetic (ie, decrease of TTV-DNA levels) indicate rejection.

Torque Teno Virus Is Associated With the State of Immune Suppression Early After Liver Transplantation.

The development of noninvasive biomarkers that reflect the state of immunosuppression (IS) remains an unmet need in liver transplantation (LT). Torque Teno virus (TTV) is a highly prevalent, nonpathogenic DNA virus whose plasma levels may be associated with the immune status of the host. The aim of this study was to assess the role of TTV as a biomarker of IS in LT recipients. TTV DNA in plasma was quantified by real-time polymerase chain reaction at different time points during the first year after transplant in a prospectively followed cohort of 63 de novo LT recipients, and any correlation between TTV DNA and biopsy-proven acute cellular rejection (ACR) and opportunistic infections was then evaluated. In addition, TTV DNA was studied in 10 longterm LT recipients in monotherapy with tacrolimus, 10 tolerant recipients, and 10 healthy controls. TTV was detected in the plasma of all patients. Among the 63 LT recipients, 20 episodes of ACR were diagnosed, and there were 28 opportunistic infections, 26 of them being cytomegalovirus (CMV) infections. TTV viremia was significantly lower during ACR (4.41 versus 5.95 log10 copies/mL; P = 0.002) and significantly higher during CMV infections (5.79 versus 6.59 log10 copies/mL; P = 0.009). The area under the receiver operating characteristic curve of TTV viral load for the diagnosis of moderate ACR was 0.869, with a sensitivity and negative predictive value of 100%, respectively, for a cutoff point of 4.75 log10 copies/mL. There were no statistically significant differences in TTV DNA in either longterm or tolerant patients and healthy controls. In conclusion, plasma TTV DNA levels are associated with immune-related events after LT and could constitute a potential biomarker of the state of IS during the first months after transplant.

Role of BK polyomavirus (BKV) and Torque teno virus (TTV) in liver transplant recipients with renal impairment.

PURPOSE: Renal impairment is a common complication after liver transplantation (LT). While BK polyomavirus (BKV) has been linked to renal failure in kidney transplant recipients, Torque teno virus (TTV) is a surrogate marker for immunosuppression that does not have a clear association with any human disease. The impact of BKV and TTV on renal impairment after LT is unknown. METHODOLOGY: In this retrospective study, urine and serum samples from 136 liver transplant recipients were screened for BKV and TTV by quantitative PCR. In addition, serum was screened for BKV-specific antibodies and the VP1 typing region was sequenced for BKV genotyping. All parameters were correlated with clinical data.Results/Key findings. BK viruria was detected up to 21 years after transplantation in 16.9 % of cases. BK viraemia was detected in 8.7 % of patients with BK viruria up to 4 years after LT. BKV-specific antibodies were detected in 93.6 % of all LT recipients and correlated with BKV viral load in urine. There was no correlation between renal impairment and the detection of BK DNA in urine (OR 0.983). TTV DNA was detected in 84.6 % of serum samples and in 66.6 % of urine samples. The TTV viral load in serum correlated with the BKV viral load but had no impact on renal impairment. CONCLUSION: Our data indicate that the detection of BKV and TTV is not a risk factor for renal impairment after LT. A correlation of TTV and BKV viral load seems to be an indicator for the immune status of the host.

Kinetics of torque teno virus DNA load in saliva and plasma following allogeneic hematopoietic stem cell transplantation.

Plasma torque teno virus (TTV) DNA load directly correlates with the degree of T-cell immune reconstitution early after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, the kinetics of oral TTV DNA shedding was examined to assess whether quantitation of TTV DNA load in saliva may either replace or complement that in plasma for predicting lymphocyte (ALC) reconstitution after engraftment. This prospective observational study enrolled 38 nonconsecutive allo-HSCT recipients. Saliva and plasma specimens were collected at baseline (pretransplant) and at around days +30, +50, and +90 after allo-HSCT. TTV DNA was quantitated in both specimen types by real-time PCR. ALCs were measured by cytometry. A total of 104 paired saliva and plasma specimens were available for TTV PCR analyses. TTV DNA was detected more frequently in saliva than in plasma specimens at all time points (overall, 94.2% vs 86.5%). Increasing levels of TTV DNA were seen in both specimen types from day +30 to day +90 after transplantation. Overall, TTV DNA loads were significantly higher in saliva than in plasma specimens (P = .0002) and correlated significantly (P ≤ .0001). A direct correlation between TTV DNA loads in saliva and plasma and ALCs was observed after engraftment (P = .034 and P = .002, respectively). Future studies should be aimed at determining whether monitoring of oral TTV DNA shedding may be of any utility for inference of immune reconstitution after allo-HSCT.

Prevalence of occult hepatitis B virus infection and Torque teno virus infection and their association with hepatocellular carcinoma in chronic hepatitis C patients.

BACKGROUND: The role of occult hepatitis B virus (HBV) infection and Torque teno virus (TTV) infection in the development of hepatocellular carcinoma (HCC) in chronic hepatitis C patients is still uncertain. AIM: The aim of the present study was to investigate the prevalence and significance of OBI and TTV infection, and to examine the genetic diversity of these viruses, in chronic hepatitis C patients with and without HCC. METHODS: Sera from 151 hepatitis C virus (HCV)-infected patients (49 patients with HCC and 102 without HCC) negative for HBV surface antigen (HBsAg) were tested for the presence of OBI and TTV infection by semi-nested and group-specific multiplex PCR assays, respectively. Nucleotide sequencing of HBV S region was further performed. RESULTS: OBI and TTV infection were detected in 5 (3.3%) and 68 (45%) patients, respectively. HBV isolates were classified into genotypes A (4/5, 80%) and D (1/5, 20%), and no HBsAg escape mutation was observed. TTV phylogenetic group 3 was the most prevalent among both HCC and non-HCC patients. OBI and TTV infection were significantly more frequent in patients with HCC than patients without HCC (p=0.003, and p=0.009, respectively). Moreover, TTV infection was associated with HCC (OR=2.23, 95%CI=1.04-4.80, p=0.040), independently of liver cirrhosis. CONCLUSIONS: A low prevalence of OBI was observed in patients with HCV-related chronic liver disease, and TTV infection was an independent factor associated with the occurrence of HCC. Whether TTV influences the progression of liver disease in chronic hepatitis C patients remains to be elucidated.

Dynamics of Torque Teno virus viremia could predict risk of complications after allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an established treatment option for several hematological diseases. However, the first year post-transplantation is often complicated by infections and graft-versus-host disease (GVHD). Improvements in immunological monitoring could reduce such post-transplant complications. Torque Teno virus (TTV), a chronically persisting DNA virus, is reported to be a marker for immune function in immunocompromised patients. In the present study, the TTV kinetics were analyzed to investigate the potential role of TTV viremia as immune-competence read-out after allo-HSCT. Twenty-three monocentric allo-HSCT recipients were retrospectively tested for TTV-DNA in whole blood at given day post-transplant. Dynamics of TTV viremia was analyzed with respect to episodes of non-TTV viral reactivations (CMV, EBV, and BKPyV), acute GVHD, and recovery of immune cells. Recipients affected by persisting viral infections and/or GVHD during the first 100 days after allo-HSCT showed a significantly higher median TTV load at day +30 than patients with a less complicated clinical course (p = 0.005). This was also associated with a total lymphocyte count <5.5E+08 cells/L in this high-risk group (p = 0.039). These findings suggest that TTV could represent an additional parameter to identify patients at higher risk for complications in the first 100 days following allo-HSCT. Prospective studies, including the monitoring of lymphocyte subsets, are required to define the potential use of TTV in immunological monitoring after allo-HSCT.

Development of an Immunoassay for Detection of Torque Teno Virus (TTV) Antibodies Using the N22 Expression Product from TTV Genotype 2.

AIMS: This study describes an immunoassay to detect anti-torque teno virus (TTV) antibodies using a peptide obtained from expression of the N22 region of TTV genotype 2. METHODS: The N22 region (∼500 bp) of TTV genotype 2 was cloned in a pET-28a(+) vector and expressed in ZYM-5052 autoinduction medium. Following metal affinity chromatography, a purified polypeptide was used as an antigen for the development of an immunoassay to detect anti-TTV antibodies in human sera. RESULTS: Recombinant protein (∼25-kDa) was obtained after 24 h of incubation at 25°C in ZYM-5052 autoinduction medium. A blot assay developed using this polypeptide as an antigen and TTV-positive sera as the primary antibody produced a distinct spot on the nitrocellulose membrane. Serum samples from 36 of 42 patients with renal disease and 29 of 48 patients with liver diseases produced a positive signal using this immunoassay. Simultaneously, 18 of 48 healthy controls were also detected to be positive for anti-TTV antibodies. These results were found to be comparable with TTV detection using PCR, and the assay showed a high sensitivity and specificity (i.e., 97.44 and 91.67%, respectively). Moreover, this assay could detect TTV infection irrespectively of the genotype, including cases of mixed infection. CONCLUSION: The present immunoassay using the N22 expression product may be used as an alternative to PCR to detect TTV infection in large populations.

Detection and Phylogenetic Analysis of Torque Teno Virus in Salivary and Tumor Biopsy Samples from Head and Neck Carcinoma Patients.

OBJECTIVES: Because torque teno virus (TTV) has been implicated in tumorigenesis as a cocarcinogen, we studied TTV prevalence in saliva and biopsy samples from head and neck cancer (HNCC) patients, patients with premalignant lesions of oral cancer, and controls. We also wished to determine the TTV genotypes in HNCC patients. METHODS: A seminested polymerase chain reaction (PCR) amplifying the N22 region of the TTV genome, as well as direct sequencing of PCR fragments, was used. RESULTS: TTV prevalence was higher in HNCC patients (saliva: 27/71, 38%; tumor biopsy: 22/74, 30%) than in controls (saliva: 8/56, 14%; oral mucosa: 1/19, 5%). TTV prevalence was also high in patients with premalignant lesions of oral carcinoma (saliva: 9/18, 50%; biopsy: 5/21, 24%). By phylogenetic analysis, TTV belonging mostly to genotypes 1 and 2 was found in HNCC patients. In most of the cases, identical TTV strains were present in the biopsy and salivary sample of the same HNCC patient. In addition, the same TTV strain was detected in 2 laryngeal carcinoma biopsies obtained from 2 independent patients. CONCLUSIONS: Our data are compatible with the idea that TTV might act as a cocarcinogen in certain cases of HNCC. Alternatively, HNCC may facilitate either TTV replication or TTV entry into the saliva.

A diverse virome in kidney transplant patients contains multiple viral subtypes with distinct polymorphisms.

Recent studies have established that the human urine contains a complex microbiome, including a virome about which little is known. Following immunosuppression in kidney transplant patients, BK polyomavirus (BKV) has been shown to induce nephropathy (BKVN), decreasing graft survival. In this study we investigated the urine virome profile of BKV+ and BKV- kidney transplant recipients. Virus-like particles were stained to confirm the presence of VLP in the urine samples. Metagenomic DNA was purified, and the virome profile was analyzed using metagenomic shotgun sequencing. While the BK virus was predominant in the BKV+ group, it was also found in the BKV- group patients. Additional viruses were also detected in all patients, notably including JC virus (JCV) and Torque teno virus (TTV) and interestingly, we detected multiple subtypes of the BKV, JCV and TTV. Analysis of the BKV subtypes showed that nucleotide polymorphisms were detected in the VP1, VP2 and Large T Antigen proteins, suggesting potential functional effects for enhanced pathogenicity. Our results demonstrate a complex urinary virome in kidney transplant patients with multiple viruses with several distinct subtypes warranting further analysis of virus subtypes in immunosuppressed hosts.

Probable transfusion-transmitted Zika virus in Brazil.

BACKGROUND: Zika virus (ZIKV) is an emerging arthropod-borne flavivirus transmitted by Aedes mosquitoes. Recent commentaries regarding ZIKV routes of transmission describe a potential transmission by transfusion. Herein, we report a probable case of transfusion-transmitted ZIKV infection through a platelet transfusion that was detected from postdonation information. CASE REPORT: A blood donor made a voluntary telephone report to the blood donor facility 3 days after donation and informed the facility of a febrile illness (fever, malaise, and headaches). Due to the ongoing dengue epidemic, the initial clinical investigation included dengue among other possible diagnoses. The serology and molecular laboratory results excluded dengue infection. However, stored samples from the donation were positive for ZIKV on reverse transcription-polymerase chain reaction (RT-PCR) analysis. A retrospective investigation demonstrated that the platelet concentrate, which was part of a pool, had been transfused after a liver transplantation. A physician had evaluated the patient 4 days after surgery. Laboratory investigation showed enzyme-linked immunosorbent assay results that were negative for dengue immunoglobulin M antibodies; however, the results were positive for hemagglutination inhibition antibodies against flavivirus. ZIKV RT-PCR and virus isolation analyses in cell cultures from recipient serum were both positive. The sequencing confirmed ZIKV in the donor and patient samples. Ten partial nucleotide sequences from the ZIKV strain that were detected in the donor were aligned and compared with the ZIKV genome detected in the recipient, revealing a 99.8% homology between the two strains. CONCLUSIONS: This is a case of probable transmission of ZIKV through blood transfusion. The patient had been transfused with the blood product from an infected donor, most likely in the incubation period after ZIKV infection but prior to clinical disease onset. This report emphasizes the importance of postdonation information and recipient investigations during outbreaks of potentially blood-borne infections.

Detection of SENV Virus in Healthy, Hepatitis B- and Hepatitis C-Infected Individuals in Yazd Province, Iran.

BACKGROUND: SEN virus (SENV) is the latest virus proposed as a cause of unknown hepatitis cases. Among nine detected genotypes of the virus, genotypes D and H are more frequent in hepatitis cases of unknown origin. The aim of this study was to determine the frequency of SENV-D and SENV-H genotypes in the sera of healthy individuals and hepatitis B and C patients. METHODS: Totally, 200 serum samples from healthy individuals as well as 50 hepatitis B and 50 hepatitis C patients were collected. Anti-HCV (hepatitis C virus), anti-human immunodeficiency virus, hepatitis B surface antigen and anti-HBV (hepatitis B virus) core antigen were detected, and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. Viral DNA was subjected to nested PCR. Fisher's exact and unpaired ANOVA tests were used for statistical analyses. RESULTS: SENV was detected in 90%, 66%, and 46% of the healthy individuals HBV and HCV-positive individuals, respectively. The frequency of SENV and its two genotypes were significantly lower in hepatitis B and hepatitis C patients (P<0.01). Also, the frequency of SENV-H was higher than SENV-D in all studied groups. In SENV-positive HBV patients, the level of ALT and AST enzymes were significantly less than SENV-negative patients (P<0.05). It was the same for SENV-H-negative and -positive cases. CONCLUSIONS: The levels of liver enzymes were significantly lower in HBV patients co-infected with SENV compared to HBV patients (P<0.05), indicating a positive impact of the virus in liver pathology by decreasing liver damage and thus decreasing the liver enzymes.