ABSTRACT
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.
Subject(s)
Humans , 3' Untranslated Regions , 5' Untranslated Regions , DNA , Genome, Viral , Hepatitis B virus , Hepatitis B , Hepatitis C , Hepatitis , Korea , Polymerase Chain Reaction , Torque teno virusABSTRACT
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.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Amino Acid Sequence , DNA Virus Infections/diagnosis , Genotype , Hepatitis B/complications , Korea , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction/methods , Torque teno virus/classificationABSTRACT
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.
Subject(s)
Humans , Alanine Transaminase , Asian People , Aspartate Aminotransferases , DNA , Hepatitis , Hepatitis B Surface Antigens , Liver Diseases , Liver , Polymerase Chain Reaction , Prevalence , Renal Dialysis , Torque teno virusABSTRACT
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.