Different strategies of reducing non-viral nucleic acid of meta-virome in plasma: a comparative study / 中国输血杂志

【Objective】 To explore the influence of common methods of reducing non-viral nucleic acid on the abundance of plasma virus group. 【Methods】 Three kinds of library construction, five kinds of centrifugation conditions, two kinds of filters, four kinds of enzymes and four concentrations of chloroform were used to treat plasma samples added quantitatively 2.16 mL of pseudorabies virus(PRV) and 2.16 mL of porcine parvovirus(PPV). A total of 21.6 mL of plasma samples were processed, including 54 samples. Subsequently, nucleic acid was extracted, mitochondrial DNA(mtDNA) and two viruses were quantitated, the library of the next generation sequencing was constructed, Illumina NovaSeq 6000 was used for the next generation sequencing. The sequencing data were compared with Kraken Py 2.0 software, and the species annotation analysis was conducted. The corresponding species classification information of each segment was obtained to analyze the impact of different reducing non-viral nucleic acid methods on the relative abundance of microorganisms and two indicator viruses. 【Results】 After sequencing by Illumina NovaSeq 6000, 306.27 GB raw data and 193.17 GB clean data were obtained, with Q20>90%, Q30>85%, Error Rate of 0.03%, and average GC Content of 45.02%. The DNA library construction process significantly increased the proportion of microbial sequences and the PRV abundance [(91.8±0.5)%](P<0.05); RNA library construction and combined library construction can increase the abundance of Pestivirus, an RNA virus, and the PRV abundance was(17.7±3.3)% and(8.1±1.5)% respectively. The Ct value of mtDNA was increased and the proportion of human sequence decreased to less than(89.5±1)%, while the proportion of microbial sequence increased to (2.4±0.03)% after treatment of five centrifugation conditions(P<0.05); After centrifugation at 4℃, 100 g, 30 min, the PRV abundance was increased to (40.6±6)%, and centrifugation at 4℃, 4 000 g, 45 min reduced the PRV abundance to (4.1±0.01)%(P<0.05). Both of 0.22-μm filter and 0.45-μm filter increased the Ct value of mtDNA to above 25.56±0.13, decreased the proportion of human sequence to less than (86.1±0.6)%, increased the proportion of microbial sequence to (3.1±0.1)% and (3.4±0.2)%, and decreased the PRV abundance to (1.6±0.3)% and (4.1±0.7)%(P<0.05), while there was no statistical difference in the effect on PPV concentration and abundance. DNase Ⅰ and Benzonase increased the Ct value of PPV to 25.65±0.06 and 25.36±0.45, decreased the proportion of human sequence to (81.7±5.6)% and (72.8±6.7)%, and increased the proportion of microbial sequence and PRV abundance to (11.0±4.1)% and (16.1±4.7)%, (55.8±2.3)% and (39.0±8.9)%, respectively(P<0 05); After treatment with RNase A, the Ct value of PRV increased to 25.20±0.11, and the human sequence proportion decreased to (85.4±5.6)%(P<0 05); Lysozyme had no effect on removing non-viral nucleic acid. The chloroform of 1%, 5%, 10% and 20% increased Ct value of PRV and mtDNA to no less than 27.17±0.21 and 25.68±0.04; Only 10% chloroform increased the proportion of microbial sequences to (3.1±1.2)%(P<0.05); The abundance of PRV with 1% and 5% chloroform treatment was increased to (48.7±13.3)% and (42.1±5.5)%(P<0.05), while 10% and 20% chloroform reduced PRV abundance to (1.0±0.5)% and (3.4±2.8)%(P<0.05). There was no statistical difference in the effect of chloroform with four contents on PPV abundance. 【Conclusion】 Centrifugation at 4℃, 5 000 g, 10 min is suitable for increasing the overall abundance of virus, and centrifugation at 4℃, 100 g, 30 min is suitable for increasing the content of virus similar to PRV. 0.45-μm filter, DNase Ⅰ, Benzonase and low concentration chloroform can effectively reduce the proportion of non-viral nucleic acid sequence in plasma to increase the abundance of the indicated virus group. Thus, the enrichment effect of plasma meta-virome is closely related to the nature of the virus, and the appropriate virus enrichment method should be selected according to the research purpose to establish the corresponding enrichment strategy.

Viral Infections and Systemic Lupus Erythematosus: New Players in an Old Story.

A causal link between viral infections and autoimmunity has been studied for a long time and the role of some viruses in the induction or exacerbation of systemic lupus erythematosus (SLE) in genetically predisposed patients has been proved. The strength of the association between different viral agents and SLE is variable. Epstein-Barr virus (EBV), parvovirus B19 (B19V), and human endogenous retroviruses (HERVs) are involved in SLE pathogenesis, whereas other viruses such as Cytomegalovirus (CMV) probably play a less prominent role. However, the mechanisms of viral-host interactions and the impact of viruses on disease course have yet to be elucidated. In addition to classical mechanisms of viral-triggered autoimmunity, such as molecular mimicry and epitope spreading, there has been a growing appreciation of the role of direct activation of innate response by viral nucleic acids and epigenetic modulation of interferon-related immune response. The latter is especially important for HERVs, which may represent the molecular link between environmental triggers and critical immune genes. Virus-specific proteins modulating interaction with the host immune system have been characterized especially for Epstein-Barr virus and explain immune evasion, persistent infection and self-reactive B-cell "immortalization". Knowledge has also been expanding on key viral proteins of B19-V and CMV and their possible association with specific phenotypes such as antiphospholipid syndrome. This progress may pave the way to new therapeutic perspectives, including the use of known or new antiviral drugs, postviral immune response modulation and innate immunity inhibition. We herein describe the state-of-the-art knowledge on the role of viral infections in SLE, with a focus on their mechanisms of action and potential therapeutic targets.

The seroprevalence of parvovirus B19 antibody in blood donors at the National Blood Transfusion Center in Kinshasa.

BACKGROUND: Human parvovirus B19 (PVB19) is a cosmopolitan DNA virus transmissible parenterally by blood transfusion. Therefore, the risk of transmission through asymptomatic blood donors should be considered and appropriately managed worldwide. PVB19 screening of blood and blood products for transfusion is not done routinely in the Democratic Republic of Congo (DRC). The main objective of this study was to determine the seroprevalence of PVB19 infection in healthy eligible blood donors in Kinshasa, capital of the DRC, located in the western part of the DRC, and the association of infection with the sociodemographic characteristics of blood donors. MATERIALS AND METHODS: A total of 360 whole blood donors who attended the National Center of Blood Transfusion were examined for anti-PVB19 IgG and IgM antibodies by using enzyme-linked immunosorbent assay kits. Sociodemographic information was collected on the blood donors. All statistical analyses were performed with SPSS 21. RESULTS: Among the study group, 289 men and 52 women were infected with PVB19. The mean age was 32.7 ± 9.8 years, 48.6% of donors were positive only for PVB19 IgG antibodies while 40.8% were positive for both IgG and IgM antibodies. In addition, 5.3% were positive only for PVB19 IgM antibodies and so were considered as a potential group of PVB19 transfusion-transmission. PVB19 seropositivity was significantly associated with sex, with a higher prevalence in men. In multivariate analysis, male sex and Tshangu district have emerged as major factors associated to PVB19 seropositivity. CONCLUSIONS: This research showed that recipients of blood and blood products in Kinshasa are at a high risk (5.3%) of transfusion-transmitted PVB19 infection. Therefore, the implementation of PVB19 nucleic acid testing assays capable of detecting all PVB19 genotypes and discard donations with high titer PVB19 DNA for blood products seems to be necessary.

Torque teno virus dynamics during the first year of life.

BACKGROUND: Torque teno virus is a small chronically persisting circular negative ssDNA virus reaching near 100% prevalence. It is reported to be a marker for immune function in immunocompromised patients. The possibility of vertical maternal-fetal transmission remains controversial but incidence rate of TTV DNA in children increased with age. TTV dynamics well studied for allogeneic hematopoietic stem cell transplantation as a predictor of post-transplant complications but there is no viral proliferation kinetics data for other patient groups or healthy individuals. The aim of this study was to determine TTV dynamics during the first year of life of healthy infants. METHODS: Ninety eight clinically healthy breastfeeding infants (1-12 months of age) were analyzed by quantitative PCR for the whole blood TTV load with the test sensitivity of about 1000 viral copies per milliliter of blood (total number of samples including repeatedly tested infants was 109). RESULTS: 67% of all analyzed samples were TTV-positive demonstrating significant positive correlation between age and TTV load (r = 0.81, p < 0.01). CONCLUSIONS: This is the first study to suggest that viral load increases during the first year of life reaching a plateau after 6 months with strong proliferation for the first 60 days. Our data well correlates with TTV dynamics in patients following allogeneic hematopoietic stem cell transplantation.

Transplacental transmission of torque teno virus.

BACKGROUND: TTV has been detected in almost every human tissue type or body fluid reaching near 100% prevalence. Several studies report mother-to-child postnatal transmission of TTV in infancy but the risk of transplacental transmission of TTV is still unclear. METHODS: The blood and plasma collected postpartum from 100 mother-child pairs were analyzed using TTV-specific qPCR. Samples were collected from the peripheral vein of the mother and the umbilical cord. RESULTS: Eighty four percent of pregnant women were TTV positive (median titers: 8 × 104 copies/mL; range: 103 - 3 × 107). The TTV load in plasma was approximately 100 times lower than in whole blood. TTV was not detected in any of cord blood samples. CONCLUSIONS: Our data demonstrate the lack of transplacental transmission of TTV (or effective prenatal inhibition of viral proliferation). The presence of the virus in infants may be associated with mother-to-child transmission through breast feeding or other routes of transmission.

Zika Virus and the Blood Supply: What Do We Know?

Zika virus (ZIKV), a mosquito-borne Flavivirus and emerging infectious disease, is the focus of an international public health emergency after its rapid spread through the Americas and the Caribbean. Although most ZIKV infections are subclinical or characterized by mild febrile illness, ZIKV has been implicated in severe complications, most notably microcephaly in babies born to incident infected mothers during pregnancy. As yet, the extent to which ZIKV is transfusion transmissible remains undefined. Nonetheless, a high prevalence of asymptomatic infection during outbreaks, the demonstration of ZIKV in blood donors, and 4 possible cases of transfusion-transmitted ZIKV in Brazil have raised concern for risk to the blood supply. Consequently, a proactive response is underway by blood collection agencies, regulatory bodies, national funding agencies, and industry alike. Mitigation strategies differ between endemic and nonendemic areas. In the continental United States, the American Association of Blood Banks and Food and Drug Administration guidelines recommend travel-based deferral for those returning from affected areas, and nucleic acid testing is being initiated under an investigational new drug application in Puerto Rico and selected areas of the United States. Options are less clear for countries where autochthonous vector-borne transmission is active. The burden of Zika falls in low-resource countries where high cost and technical barriers associated with testing and pathogen reduction pose barriers to implementation. Additional strategies include maintaining selective inventory for high-risk recipients (eg, pregnant women). We review the available data as of July 2016 on ZIKV in relation to the blood supply including risk, mitigation strategies, and barriers to implementation in addition to the research that is needed to address current uncertainty.

The Prevalence of SEN Virus and Occult Hepatitis B (OBI) Virus Infection Among Blood Donors in Ahvaz City.

BACKGROUND: The SEN virus (SENV) is a prevalent blood borne pathogen that has a worldwide incidence. SENV is comprised of eight genotypes; genotypes H and D are frequently associated with the pathogenesis of non-A - E hepatitis and post-transfusion hepatitis in blood donors and hepatitis patients. So far, no SENV pathogenesis has been reported in the liver biopsies of SENV carriers, but the frequency of SENV and its related genotypes requires further molecular epidemiology studies in different regions of the world. Occult hepatitis B infection (OBI) is another global public health problem that is primarily transmitted via blood transfusions. Therefore, the identification of OBI among blood donors is key to preventing the spread of this disease. The relationship between SENV and OBI requires further evaluation. OBJECTIVES: The aim of this study was to determine the prevalence of SENV-D and SENV-H in blood donors in Ahvaz city with a particular focus on co-infection with OBI. PATIENTS AND METHODS: This study had a cross-sectional design and included 184 healthy consecutive blood donors who visited a blood transfusion center in Ahvaz city from October-November 2013. The sera of all blood donors negative for HBsAg, anti-HCV antibody, and anti-HIV antibody were tested for SENV-D and SENV-H using nested polymerase chain reaction (PCR). In addition, tests for HBV DNA (PCR), HBcIgG (ELISA), liver function (aspartate transaminase and alanine transaminase), and alkaline phosphatase were carried out. RESULTS: Liver function tests in the healthy blood donors were within the normal range. The incidence rates of SENV-D and SENV-H in the 184 total blood donors were 10 (5.4%) (95% confidence interval (CI): 2.1% - 9.0%) and 32 (17.4%) cases (95% CI: 12.0% - 23.0%), respectively. SENV-H/D co-infection occurred in 2 (1.1%) patients. The sera of 8/184 (4.3%) were positive for anti-HBc antibody but negative for HBV DNA. CONCLUSIONS: Regardless of the presence of nonpathogenic SENV, 44/184 (24%) blood donors tested positive for both SENV-D and SENV-H. Although 4.3% of blood donors were positive for HBcIgG but negative for HBV DNA, the presence of OBI cannot be ruled out unless their liver biopsies show negative for HBV DNA.

The prevalence of HTLV-1 and its Co-Infection with HCV, HBV and HIV in Hemophilic patients.

BACKGROUND AND OBJECTIVE: Blood-borne infections, such as the HIV virus and hepatitis B and C, are major problems in patients receiving blood products. Here we examined the prevalence of HTLV-1, HCV, HBV, and HIV in hemophilic patients. METHODS: A cross-sectional study on 108 hemophilic patients (101 males and 7 females) involved detection of HBV, HCV, HIV and HTLV-1 infections using immunoassays for HBsAg, hepatitis B core antibodies (anti-HBc), hepatitis C antibodies (anti-HCV), HIV antibodies (anti-HIV) and Anti-HTLV-1. Real-time PCR was used to measure HCV RNA, and HCV genotyping was performed by direct sequencing of the 5' noncoding region. RESULTS: Hemophilia A was reported in 93 (86%) patients with severe symptoms in 8 cases. The seroprevalence of anti-HCV and anti-HTLV-1 antibodies was 20% and 3% respectively. One patient with severe hemophilia had a HCV/HTLV-1 co-infection. HCV-RNA was detected in 82% of patients. In terms of genotyping prevalence was 56% HCV genotype 3a, 39% HCV genotype 1a, and 6% HCV genotype2. Anti HIV and HBsAg were not detected in any patient. HTLV1 prevalence was higher, HCV lower in South Khorasan than other regions in Iran or elsewhere. CONCLUSION: Management of transfusion of blood and blood products should account for the underlying prevalence of infectious agents.

Is transfusion-transmitted dengue fever a potential public health threat?

Dengue is an arboviruses due to single-stranded enveloped ribonucleic acid viruses, named dengue viruses (DENV), that include four serotypes and are mainly transmitted via the bite of mosquitoes of the genus Aedes (A. aegypti and A. albopictus). The distribution of the disease was historically limited to intertropical areas; however, during the last thirty years, the perimeter of the disease extended considerably and temperate areas are now at risk of outbreaks. The present global burden of dengue is considerable: 2.5 billion people over more than 100 countries are concerned; 50 to 100 million infections occur every year, with a number of fatal cases of approximately 20000. Although frequently asymptomatic or limited to a mild fever, dengue is responsible for severe cases mainly consecutive to the occurrence of hemorrhagic complications that can lead to shock and death, notably in children from poor-resource settings. The place of DENV as a transfusion-transmitted pathogen has been recognized only in 2008. At the present time, only five cases of transfusion-transmitted dengue, including one case of dengue hemorrhagic fever, have been formerly documented. This review provides a general overview of dengue, its viruses and their vectors. It replaces the disease in the context of other viral diseases transmitted by arthropods. It discusses the threat of dengue on the supply of blood products in endemic and non endemic areas. Finally, it describes the specific and non specific measures available for improving the security of blood products with regards to this emerging risk. Interestingly, in 2009, the American Association of Blood Banks placed DENV in the highest category of emerging infectious agents for their potential impact on transfusion recipient safety for the next years in North America.

Optimization of influencing factors of nucleic acid adsorption onto silica-coated magnetic particles: application to viral nucleic acid extraction from serum.

We present a detailed study of nucleic acid adsorption onto silica-coated magnetic particles in the presence of guanidinium thiocyanate, and extraction of nucleic acid from two important transfusion-transmitted viruses using these particles. Silica-coated magnetic particles were prepared by encapsulating Fe3O4 nanoparticles with tetraethylorthosilicate (TEOS) hydrolysis. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and vibrating sample magnetometer (VSM) were used for particle characterization. The results indicate that silica-coated magnetic particles are spheroid with a narrow hydrodynamic size distribution of about 500nm. VSM data indicates that these particles display paramagnetic behavior with saturation magnetization of about 30emu/g. The adsorption capacities were evaluated with DNA from salmon sperm and RNA of Escherichia coli strain JM109 in the presence of guanidinium thiocyanate. The maximum of adsorption is up to 10.6mg DNA or 7.7mg RNA per 1g of silica-coated magnetic particles with 4M guanidinium thiocyanate (GTC) at pH 5.5 without adding ethanol. The influencing factors were analyzed in term of the adsorption of nucleic acids onto silica-coated magnetic particles. The adsorption capacity in acidic condition is found to be larger than that in alkaline condition and increases with adding equivalent volume of ethanol. A simple method was therefore established to extract nucleic acids of two important transfusion-transmitted viruses from serum and compared with the commercial kits. The results indicate that the extraction method based on silica-coated magnetic particles can be adapted to rapidly and facilely isolate viral nucleic acid for diagnosis of viral infection from serum within 30min, irrespective of genome compositions of virus.

Recent insights on risk factors of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a disease prevalent in many populations worldwide. It initiates many economic and health problems in management modalities and leads to increasing mortality rates. Worldwide, trials have attempted to discover specific early markers for detection and prediction of the disease, hoping to set a more precise strategy for liver cancer prevention. Unfortunately, many economic, cultural and disciplinary levels contribute to confounding preventive strategies. Many risk factors contribute to predisposition to HCC, which can present individually or simultaneously. Previous articles discussed many risk factors for hepatocellular carcinogenesis; however, most of them didn't consider collectively the most recent data relating to causes. In this article, the pathogenesis and risk factors of HCC are discussed. Most of the intermediary steps of HCC involve molecular and transcriptional events leading to hepatocyte malignant transformation. These steps are mainly triggered by hepatitis B, C or transfusion-transmitted virus, either alone, or with other factors. Diabetes seems to be a major contributing risk factor. Schistosomiasis, a blood infestation, mostly affects Nile basin inhabitants leading to bladder, renal and hepatic cancers. Alcoholism, food and water pollutants and some drugs can also lead to HCC. Additionally, some hereditary diseases, as hemochromatosis, α-1-antitrypsin deficiency and tyrosinaemia are known to lead to the development of HCC, if not well managed.

The clinical epidemiologic characteristics of patients infected with hepatitis C virus post blood transfusion in Shanghai area / 中华传染病杂志

Objective To investigate the clinical epidemiologic characteristics of patients with hepatitis C virus(HCV)infection post blood transfusion.Methods The polymerase chain reaction (PCR)and enzyme linked immunosorbent assay(ELlSA)were used to detect HCV RNA and antiHCV,respectively.Analysis was performed for patients' age distribution,cause of primary diseases,exposure years,ingredient and amount of transfusion,incubation period and liver function damage.The statistical processing were performed with chi-square test,t-test and correlation analysis.Results HCV RNA levels were higher than 3.0 log10 copy/mL in 85.3%infected patients with a median of 5.99log10 copy/mL,among which 19.7%patients showed viral load 3.0 to 4.0 log10 copy/mL and 69.9%showed 5.0 to 6.0 log10 copy/mL.Eighty-one point six percent(40/49)of infected persons were confirmed as HCV RNA positive by HCV RNA qualitative analysis,while 99.7%(383/384)patientswere detected as anti-HCV positive by serological test.The sensitivity of serological test was higher than both HCV RNA quantitative and qualitative assays(F=57.138,P=0.000;F=63.149,P=0.000,respectively).HCV infection post blood transfusion was more common in people of 30 to 60years old.Most cases(84.4%)got the first time exposure during 1990 to 1994.More than 10%cases had primary disease as obstetrics, orthopedics or gastrointestinal tract hemorrhage. Eighty percent received whole blood product transfusion.The mean interval between transfusion and clinical diagnosis was (86.0±54.6 ) months. Eighty nine percent of infected patients had liver function damage, while most of them showed elevated alanine aminotransferase (ALT) with no more than 5 upper limits of normal (ULN). Conclusions Post transfusion HCV infection mainly happened in adulthood. Infected patients usually have liver function damage with elevated ALT with no more than 5 ULN and medium HCV RNA levels.

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.

DNA Sequence Features of Transfusion Transmitted Virus in Neonatal Infection / 实用儿科临床杂志

Objective To analyze the mutations in nucleotide sequences of transfusion transmitted virus(TTV) in neonatal infection.Methods Neonatal serum TTV-DNA was detected by a nested PCR technique.Fifteen Chinese neonates with positive TTV-DNA were diagnosed as TTV infection.ORF1 sequences of TTV-DNA from these neonates were determined.Results Homology of Chinese TTV(C01-C15) and Japanese TTV(N22)isolated ranged from 87.1%-97.7% at nucleotide level,but there were point mutations in Chinese TTV,such as GG→TT in locus 112 and 113,TTATC→CCTAT in locus 236-240.Conclusions Chinese and Japanese TTV isolated had the same genotype.Some gene mutations may increase the TTV pathogen,and result in neonatal hepatitis syndrome or hyperbilirubinemia.

Prevalence and Genotypes of Transfusion-Transmitted Virus in Children with Hepatitis and Normal Control / 대한소아소화기영양학회지

PURPOSE: Transfusion transmitted virus (TTV) is a newly discovered virus and to date the contribution of TTV to liver disease remains unclear. Little is known about the frequency of TTV infection in children in Korea. The purpose of this study was to investigate the prevalence and genotypic distribution of TTV carried by healthy children and patients with hepatitis in Korea. METHODS: Eighty eight of healthy children and three groups of patients with hepatitis-14 patients with chronic hepatitis B, 12 patients with chronic hepatitis C and 25 patients with hepatitis of unknown etiology-were tested. TTV DNA was detected by semi-nested PCR using primer sets generated from N-22 region and from 5' noncoding region (NCR) of the viral genome. PCR products derived from 8 patients with hepatitis and from 11 healthy children were sequenced and a phylogenetic tree was constructed. RESULTS: TTV was found by PCR with N22 primer in 11.3% of healthy children, 28.5% of children with hepatitis B, 25% of children with hepatitis C, 24% of children with hepatitis of unknown etiology. TTV DNA was found by PCR with 5'NCR primer in 32.9% of healthy children, 71.4% of patients with chronic hepatitis B, in 50% of patients with hepatitis C and in 48% of patients with hepatitis of unknown etiology. TLMV DNA was found in 48.9% of healthy children, 21.4% of patients with hepatitis B, 16.6% of patients with hepatitis C, 40% of patients with hepatitis of unknown etiology. Among the sequenced isolates, 10(52%) belonged to genotype 1 (G1) and others belonged to genotype 2 (G2) or genotype 3 (G3). Among the G1 sequences, 7 were grouped as G1a. CONCLUSION: TTV infection was common in healthy children and in patients with hepatitis. But, the prevalence of TTV DNA by 5'NCR primer was relatively high in patients with hepatitis B and there may be some association between TTV and hepatitis B virus infection. G1 was the major genotype of the studied population.

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.

The Prevalence of Transfusion-Transmitted Virus Infection in Children / 소아과

PURPOSE: Transfusion-transmitted virus(TTV) is an newly described nonenveloped human virus, with a circular, negative stranded DNA genome. Although a high prevalence of TTV infection in the normal population has been demonstrated, there is a still possibility of association with hepatitis according to the genotype of TTV. The aim of this study is to investigate the prevalence of TTV infection in Korean children. METHODS: Nested polymerase chain reaction(PCR) using priner sets generated from the noncoding region(NCR) of the viral genome was done in 105 children without liver disease, aged 0-15 years. We performed a second set of PCR using N22 primer in 88 children after the first set of PCR. RESULTS: The TTV DNA was detectable in 36(34%) of 105 children without hepatitis by 5'NCR primer. The prevalence of TTV varied with age:<1 y,16%(4/25); 1-3 y, 44%(15/31); 4-6 y, 31%(5/ 16); 7-9 y, 25%(3/12); 10-15 y, 14%(3/21). By using N22 primers, the prevalence of TTV DNA in children without hepatitis was 11.3%(11/88):<1 y 8%(2/25); 1-3 y, 13.7%(4/29); 4-6 y, 6.2%(1/16); 7-9 y, 33.3%(2/6); 10-14 y, 8.2%(1/12). CONCLUSION: Our result showed a high prevalence of TTV infection, varying with age, in Korean children. Further evaluation of genotypes of TTV in patients with hepatitis and normal children is needed.

Transfusion Transmitted Virus Hepatitis in Neonates and Curative Effects of Genciclovir / 实用儿科临床杂志

Objective To investigate the pathogenicity of transfusion transmitted virus (TTV) infection and assess the effect of genciclovir on TTV.Methods Serum TTV-DNA from 968 neonates was detected by a nested polymerase chain reaction technique and electropherosis. Alanine aminotrans ferase (ALT) and direct bilirubin (DB) were assayed in neonates with positive TTV-DNA.Genciclovir[10 mg/(kg?d)]was used to treat neonates with TTV-induced hepatitis.Results Among 968 neonates, 38 had positive TTV-DNA (4.0%). All neonates with positive TTV-DNA had normal serum levels of ALT and DB [(24.8?12.0) U/L and (17.6?6.8) ?mo l/L] 3 days after birth;But an elevated ALT and DB level [(95.5?16.4) U/L and (58.2?10.4) ?mol/L] occurred in 15 of them 2 weeks after birth,and were diagnosed as TTV-induced hepatitis.These patients had hypersomnia,jaundice and anorexia. Serum ALT and DB levels recovered to normal range one week after genciclovir therapy in 11 patients,so did the other 4 patients after 2 weeks therapy with genciclovir. Serum TTV-DNAs in all patients became negative 2 weeks after genciclovir therapy.Conclusion TTV infection exists in the neonates, and may be one of important causes of neonatal hepatitis.genciclovir might have a good anti-TTV effect.

Transfusion transmitted virus infection in the neonates / 中华传染病杂志

Objective To investigate the relationship between transfusion transmitted virus (TTV)infection and neonatal hyperbilirubinemia,the effect of TTV infection on the liver function, and analyse the feature of nucleotide sequences in TTV ORF1.Methods Serum TTV DNA,which were from 58 neonates with high direct bilirubin(DB,including 5 with hepatitis Syndrome),92 ones with high indirect bilirubin(IB),and 85 normal ones,was detected using a nested polymerase chain reaction technique(nPCR),electropherosis and sequence analyse,and serum alanine amniotransferase (ALT)was determined in all neonates.Results In DB neonates,TTV DNA were detected in 7 neo- nates(12.1%,including 3 neonates with hepatitis syndrome);in IB and normal ones,1 neonate had positive TTV DNA(1.1% and 1.25),respectively.Even if there were point mutations in Guangdong's TTV,the homology of Guangdong's TTV(GD1-9)and Japanese TTV(N22)ranged from 87.1%～97.8% at nucleotide level.Conclusion TTV infection may be one of important pathogenesis resulting in neonatal hyperbilirubinemia and liver damage in such patients.Guangdong's and Japanese TTV isolates had the same genotype,some gene mutations maybe increase the pathogenicity in TTV.

Gene quasispecies analysis of transfusion transmitted virus DNA in two patients with transfusion transmitted virus infection / 中国医师杂志

Objective To investigate gene variation and the relationship between gene variation and pathogenicity of transfusion transmitted virus(TTV).Methods The TTV DNA in the serum sample from a blood donor(BD) and a chronic non-A-G severe hepatitis(CSH) patient with TTV infection was amplified by using PCR.The purified PCR product was cloned and 10 clones from each case were sequenced.The sequences were compared among different clones and analyzed by Phylogentic tree.Results There were two different TTV strains in the BD and seven different TTV strains in the chronic non-A-G severe hepatitis patient.The TTV clones in the BD were of G1a subtype and those of the CSH were of G1a and G1b subtype.Conclusion Gene variant of TTV was much more complicated in the CSH patients than that in the BD ones.