Torque teno virus among dialysis and renal-transplant patients

Patients who undergo dialysis treatment or a renal transplant have a high risk of blood-borne viral infections, including the Torque teno virus (TTV). This study identified the presence of TTV and its genome groups in blood samples from 118 patients in dialysis and 50 renal-transplant recipients. The research was conducted in a hospital in the city of Maringá, state of Paraná. The viral DNA, obtained from whole blood, was identified by using two nested Polymerase Chain Reactions (PCR). The frequencies of TTV were 17% and 36% in dialysis patients using the methodology proposed by Nishizawa et al. (1997) and Devalle and Niel (2004), respectively, and 10% and 54% among renal-transplant patients. There was no statistically significant association between the frequency of the pathogen and the variables: gender, time in dialysis, time since transplant, blood transfusions, and the concomitant presence of hepatitis B, for either the dialysis patients or the renal-transplant recipients. Among dialysis patients and renal-transplant recipients, genogroup 5 was predominant (48% and 66% respectively), followed by genogroup 4 (37% and 48%) and genogroup 1 (23% and 25%). Genogroup 2 was present in both groups of patients. Some patients had several genogroups, but 46% of the dialysis patients and 51% of the renal-transplant recipients had only a single genogroup. This study showed a high prevalence of TTV in dialysis patients and renal-transplant recipients.

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.

Molecular epidemiology and genotyping of TT virus isolated from Saudi blood donors and hepatitis patients

In Saudi Arabia, the epidemiology and clinical significnance of Torque Teno virus [TTV] infection alone and in patients with hepatitis virus infections have not been determined in a single study. In this paper, we molecularly investigated the rate and genotypes of TTV infection among Saudi Arabian blood donors and patients with viral hepatitis. The effect of TTV coinfection on viral hepatitis was also examined. DNA was extracted from the sera of 200 healthy blood volunteers, 45 hepatitis B virus patients, 100 hepatitis C virus patients, 19 hepatitis G virus patients, and 56 non-A-G hepatitis patients. TTV DNA was amplified using primers derived from the ORF1 and 5'UTR regions. The alanine aminotransferase [ALT] level was determined for each specimen. Sequencing of ORF1 amplicons was carried out to investigate TTV genotypes. Using primers derived from ORF1 and 5'UTR, TTV DNA was detected in 5.5% and 50.5%, respectively, of healthy blood donors, in 2.2% and 88.8% in hepatitis B patients, in 2.0% and 70% of hepatitis C patients, in 15.8% and 100% of hepatitis G patients, in 5.4% and 12.5% of non-A-G hepatitis patients and in 4.8% and 56.4% overall. No detrimental effect of TTV coinfection in viral hepatitis patients was noted. An overall prevalence of 4.8% and 56.4% was established. Phylogenetic analysis indicated that the most common genotype of TTV among Saudis is 2c. The rate of TTV infection among Saudi Arabians seems to be lower than that stated in previous reports on Saudi Arabia and in some other countries. The virus does not seem to worsen the status of those who are suffering from viral hepatitis infection