TT virus in peripheral blood cells from patients with human papillomavirus (HPV): investigating association with cervical carcinoma

Torque Teno Virus (TTV) presence was investigated in peripheral blood of 117 brazilian women by nested polymerase chain reaction. TTV DNA was observed in 18.6% of healthy donors and in 24.32% Human Papillomavirus (HPV) patients. TTV presence was also investigated in the HPV positive group for comparison between the cervical cancer and noncancerous patients. TTV DNA prevalence was significantly higher among the HPV positive patients with cervical cancer (57.14%) than in HPV noncancerous patients (16.67%). Thus, the presence of TTV infection could be a risk factor for cancer development in the patients presenting HPV-TTV coinfection. Further studies are required to clarify the TTV influence in HPV pathogenesis.

The high prevalence of Torque teno virus DNA in blood donors and haemodialysis patients in southern Brazil

This study investigates the frequency of Torque teno virus (TTV) infection in 150 blood donors and 77 patients requiring haemodialysis in southern Brazil. Plasma samples were screened for TTV DNA using polymerase chain reaction (PCR). The prevalences of TTV among blood donors and patients requiring haemodialysis were 73.3% and 68.8%, respectively. The presence of TTV was correlated with age in the blood donors (p = 0.024). In haemodialysis patients, no association was found between TTV infection and the demographic parameters (age, sex and education), the duration of haemodialysis or a history of blood transfusion. This study is the first to evaluate the prevalence of TTV infection in Brazilian patients requiring haemodialysis.

Clinical outcomes of Torque teno virus-infected thalassemic patients with and without hepatitis C virus infection / 대한혈액학회지

BACKGROUND: Although a marked proportion of thalassemic patients acquire Torque teno virus (TTV) through blood transfusion, its clinical importance is unclear. This study was designed to investigate the clinical importance of TTV infection in thalassemic patients with and without hepatitis C virus (HCV) co-infection in Iran. METHODS: In this case-control study, 107 thalassemic patients on chronic transfusion and 107 healthy individuals were selected. According to HCV and TTV infection status (detected by semi-nested PCR), patients were categorized into 4 groups: TTV and HCV negative, TTV positive, HCV positive, and TTV and HCV positive. Blood ferritin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in these 4 groups were assessed. RESULTS: Approximately half of the thalassemic patients (50.5%) and 27.1% of controls had TTV infection. Thalassemic patients had a greater chance of TTV infection compared to the control group with a sex-adjusted OR of 4.13 (95% CI=2.28-8.13). The increased levels of ALT, AST, and ferritin in the TTV and HCV-infected group were not significantly different from those in the TTV and HCV negative group. Co-infection with TTV and HCV did not significantly increase ALT, AST, and ferritin levels compared to infection with TTV alone. CONCLUSION: Although common in thalassemic patients, TTV infection appears to have a negligible role in increasing the severity of liver disease, even when co-infection with HCV occurs.

Total Chemical Synthesis,Assembly of Human Torque Teno Virus Genome / 中国病毒学·英文版

Torque teno virus(TTV)is a nonenveloped virus containing a single-stranded,circular DNA genome of approximately 3.8kb.We completely synthesized the 3808 nucleotides of the TTV(SANBAN isolate)genome,which contains a hairpin structure and a GC-rich region.More than 100 overlapping oligonucleotides were chemically synthesized and assembled by polymerise chain assembly reaction(PCA),and the synthesis was completed with splicing by overlap extension(SOEing).This study establishes the methodological basis of the chemical synthesis of a viral genome for use as a live attenuated vaccine or gene therapy vector.

TT Virus Detection Using Different PCR Primer Sets in Healthy and Infected Individuals with Hepatitis B or C Viruses / 대한임상미생물학회지

BACKGROUND: TT virus (TTV) infection is highly prevalent in the general population and in the patients infected with hepatitis B virus (HBV) or hepatitis C vius (HCV). The aim of the present study was to assess the positive rates of TTV DNA using different PCR primer sets in healthy and HBV or HCV-infected individuals in Korea. METHODS: TTV DNA was investigated in serum samples of 69 healthy individuals and 59 HBV-infected and 34 HCV-infected individuals by nested PCR assays using primers from N22 region, 5'-untranslated region (UTR), and 3' UTR of viral genome. RESULTS: TTV DNA was detected in 43% of total study populations using N22 primers, in 69% using 5' UTR primers and, in 64% using 3' UTR primers. No significant difference was observed in the positive rates of TTV DNA between healthy and HBV or HCV- infected individuals. CONCLUSION: The PCR assays for TTV DNA using 5' UTR primers and 3' UTR primers exhibited higher positive rates than that of the assay using N22 primers without any significant difference between healthy and HBV or HCV-infected individuals.

Distribution of TT Virus Genotypes and Genogroups in 69 Healthy and 59 Hepatitis B Virus Infected Korean Individuals / 대한진단검사의학회지

BACKGROUND: TT virus (TTV) infection is highly prevalent in general population and patients with hepatitis B virus (HBV) infection. The aim of the present study was to determine the distribution of the genotypes and genogroups of TTV in healthy and HBV-infected individuals in Korea. METHODS: Distribution of TTV genotypes and genogroups was investigated in the serum samples of 69 healthy and 59 HBV-infected individuals. PCR products of N22 region were genotyped by sequence analysis. TTV genogroups were determined by 5 different genogroup-specific PCR assays. RESULTS: Among the 20 sequenced isolates, 9 (45%) were genotype 2, 8 (40%) were genotype 1, 2 (10%) were genotype 3, and 1 (5%) was genotype 4. TTV genogroup 4 was found most frequently (52/128), followed by genogroup 3 (42/128), genogroup 1 (35/128), genogroup 5 (32/128), and genogroup 2 (1/128). Mixed infections with different genogroups were frequent. CONCLUSIONS: TTV genotype 2 and 1 are predominant genotypes. TTV genotype 3 was detected for the first time in Korea. TTV genogroups 4 and 3 were predominant genogroups. No significant difference was observed in the distribution of TTV genogroups between healthy and HBV-infected individuals.

Gene determination of transfusion transmitted virus-like mini virus / 吉林大学学报(医学版)

Objective To detect the transfusion transmitted virus-like mini virus(TLMV) sequence gene in patients with chronic hepatitis and to study the TLMV infection in population.Methods Two sets of primers in the most conservative regions of Japan strains TLMV-CBD279 and CBD231 were designed to amplify TLMV templete extracted from sera of patients with chronic hepatitis B using PCR.PCR products were cloned into pGEMR-T vector and sequenced.Results The results showed that 72%of TLMV sequence isolated in China was identical to that in Japan,suggesting that there was TLMV infection in patients with chronic hepatitis B in China.The patients with hepatitis virus C and the healthy blood donor had the highest infectious rates of TLMV.Conclusion TLMV infection exists in patients with chronic hepatitis B in China.

TT Virus (TTV) Infection in General Population, Chronic Liver Diseases, Hemodialysis, and Transfused Patients / 대한임상미생물학회지

BACKGROUND: TT virus (TTV), isolated initially from a Japanese patient with posttransfusion hepatitis of unknown etiology, was suggested to be a new causative agent of hepatitis. However, it has been found to infect both healthy and diseased individuals and numerous studies have raised questions about its pathogenic role in hepatitis. In order to study its prevalence and clinical impact on hepatitis, we assessed the frequency of TTV DNA. METHODS: Serum samples were obtained from 60 cases of the controls, 77 cases of chronic liver diseases, 44 cases of hemodialyzed patients, and 65 cases of transfused patients. TTV DNA was detected using nested polymerase chain reaction and alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatitis B surface antigen (HBsAg) were measured. RESULTS: TTV DNA was detected in 41.7% of the controls, 51.9% of patients with chronic liver diseases, 68.2% of hemodialyzed patients and 61.5% of transfused patients. Comparison between patients with or without TTV revealed no significant differences in AST, ALT, and HBsAg test results. CONCLUSION: The prevalance of TTV infection in patients with chronic liver diseases was similar to that in the controls. TTV infection was not related to abnormal liver function findings and HBsAg positivity. We found no relationship between TTV infection and chronic liver diseases.

Detection of Small Anellovirus DNA from Blood Products / 대한수혈학회지

BACKGROUND: The small anellovirus (SAV) is a new member of the genus Anellovirus infecting humans. SAV can be transmissible by transfusion. However there are no reports on SAV infections in Korea. The aim of this study was to determine the prevalence of SAV in blood products. METHODS: A total of 90 plasma samples from blood products (each 30 units of Red blood cell, whole blood, and platelet concentrate) and 30 serum samples from non-A to C hepatitis patients were tested. SAV DNA was detected using nested polymerase chain reaction (PCR). At the same time, TTV and TTMV DNA were detected using nested PCR. RESULTS: SAV DNA was detected in 34% (31/90) of blood products. TTV and TTMV DNA were detected in 66% (54/90) and 29% (26/90) of blood products, respectively. One of the three anelloviruses (SAV, TTV, TTMV) was detected in a total of 77 blood products (86%). SAV DNA was detected in 40% (12/30) of hepatitis patients. TTV and TTMV DNA were detected in 73% (22/30) and 33% (10/30) of those patients, respectively. One of the three anelloviruses (SAV, TTV, TTMV) was detected in 97% (29/30) of hepatitis patients. CONCLUSION: Blood products are frequently infected with SAV and (or) other anelloviruses (TTV/TTMV) in Korea, and can be transmissible with a high probability.

Distribution of Transfusion-transmitted Virus Genomic Groups in Blood Products / 대한진단검사의학회지

BACKGROUND: Transfusion-transmitted virus (TTV) is a small DNA virus with single-stranded, closed circular, antisense genome infecting humans. The TTV has been classified into five major genomic groups 1-5. There have been a few studies on TTV prevalence in blood donors and blood products in Korea. However there have been no reports on the TTV genomic groups in Korea. The aim of this study was to gain information on TTV genomic groups in blood products in Korea. METHODS: A total of 50 plasma samples from blood products (25 units each of red blood cell and whole blood) were tested. The samples are obtained from the segments of the blood products. TTV DNA was detected using polymerase chain reaction (PCR) with two sets of universal primers (A set and B set), and TTV genomic groups were determined using PCR with group specific primer sets. RESULTS: TTV DNA was detected in 96% (48/50) of the blood products: the TTV genomic group 3 was found the most frequently (52%, 26/50), followed by group 4 (46%, 23/50), group 1 (20%, 10/50), group 5 (10%, 5/20), and group 2 (2%, 1/50). There were seven blood products (14%) infected with TTVs but their genomic groups were not identified with group specific primer sets. Among the blood products, 44% (22/50) were infected with a unique TTV genomic group; 38% (19/50) were coinfected with TTV from 2 (28%, 14/50) or 3 (10%, 5/50) genomic groups. CONCLUSIONS: Blood products are frequently infected with TTV and all five known genomic groups are detected in Korea.

Transfusion-transmitted Virus and TTV-like Mini Virus Infection in Blood Products / 대한진단검사의학회지

BACKGROUND: Transfusion-transmitted virus (TTV) and TTV-like mini virus (TLMV) are small DNA virus with single-stranded, closed circular, antisense genome infecting man. TTV and TLMV are trans-missible by transfusion. However there had been a few study about TTV prevalence and no study about prevalence in blood donors in Korea. There has been no study about the TTV and TLMV infection in blood products in Korea. The aim of this study was to gain the prevalence of two viruses in blood products. METHODS: A total of 150 plasma samples from blood products (each 50 units of Red blood cell, whole blood, and platelet concentrate) were tested. The samples are obtained from the segments of the blood products. TTV DNA was detected using polymerase chain reaction (PCR) with two sets of primers (A set and B set) and TLMV DNA was detected using nested PCR with primer set C. RESULTS: TTV DNA was detected in 85.3% (128/150) of blood products. TLMV DNA was detected in 41.3% (62/150) of blood products. Either TTV or TLMV was detected in a total of 140 blood products (92.3%) and both TTV and TLMV were detected in 50 products (33.3%). CONCLUSIONS: The blood products are frequently infected with TTV and (or) TLMV in Korea and they can be transmissible by blood products with high probability.

Prevalence of the TT virus viremia in Patients on Hemodialysis and General Populations / 대한진단검사의학회지

BACKGROUND: The TT virus (TTV) is a recently discovered, single-stranded circular DNA virus in the serum of the patients with post-transfusion hepatitis and it is thought to be one of the causative agents of cryptogenic hepatitis. In this study, we evaluated the prevalence and clinical significance of TTV viremia in general populations and patients on hemodialysis. METHODS: Sera of 115 general populations and 69 patients on hemodialysis were examined for TTV viremia by semi-nested polymerase chain reaction using primers deduced from the N22 region. RESULTS: The TTV was detected in 26.1% (18 of 69) of the patients on hemodialysis and was not different from the 20.9% (24 of 115) prevalence in general populations. Two patients on hemodialysis that revealed biochemical evidence of acute hepatitis were the sole TTV infection without other hepatitis virus infection but the mean alanine aminotransferase level was not significantly different according to the TTV viremia. The TTV was persistently detected in the sera of eight of thirteen patients (61.5%) 12 month later without any evidence of hepatitis. CONCLUSIONS: TTV is widespread in general populations and shows similar prevalence in patients on hemodialysis. Viral persistence and nonparenteral transmission may be possible. The relationship between the TTV viremia and hepatitis was not proved.

THE INVESTIGATION OF DIFFERENT POPULATION＇S TRANSFUSION-TRANSMITTED VIRUS-DNA IN SHAANXI PROVINCE / 药物分析学报

Objective To investigate transfusion transmitted virus (TTV) infection among population of different groups in Shaanxi Province. Methods A nested polymerase chain reaction (PCR) with primers from ORF1 of TTV genome was established to detect TTV-DNA in serum of the patients. ResultsTTV-DAN was detected in the sera of 3 of 50 cases of general population(6％), 2 of 30 cases of vocational blood donors(6.7%),21 of 97 cases with Type B hepatitis (21. 6％), 9 of 35 cases of Type C hepatitis (25. 7％),and 23 of 40 cases with non-A～ non-G hepatitis (57.5 ％ ). ConclusionThere is TTV infection among general population in Shaanxi Province. TTV may be an impor- tant agent to cause non-A～non-G hepatitis. And the patients with HBV or HCV can have overlapping TTV infection.