Transfusion-transmitted Virus DNA Research Articles

Higher Frequency of Transfusion-Transmitted Virus (TTV) in HIV Patients in Comparison with Healthy Blood Donors

Background: Epidemiological studies have reported commonly distributed transfusion-transmitted virus (TTV) in different populations with parental risk factors, including human immunodeficiency virus (HIV). Objectives: This study was performed to determine and compare the prevalence of TTV infection among HIV-positive patients and healthy blood donors. Patients and Methods:: A total of 186 HIV patients and 165 healthy blood donors with no markers of HIV infection were included in this study during 2004 - 2012. Semi-nested Polymerase Chain Reaction (PCR) assay was performed for the detection of TTV DNA. HBV surface antigen (HBsAg), Hepatitis C Virus Antibody (HCVAb), and CD4 were investigated in the sera of HIV-positive subjects. Aspartate transaminase (AST) and Alanine transaminase (ALT) levels were also measured. Results: The mean age of HIV-positive and healthy subjects was 39.3 and 40.5 years, respectively. In total, 182 (97.9%) subjects were male and 4 (2.1%) were female. TTV DNA was detected in 35 out of 186 HIV patients (18.8%; 95% CI, 13.2 - 24.4%). The prevalence of TTV in the HIV group was significantly higher (P = 0.027) than blood donors (11%; 95% CI, 6.2 - 15.8%). Age, marital status, unsafe sexual activity, and use of injection drugs were not significantly associated with the prevalence of TTV infection in HIV patients. Conclusions: Considering the higher frequency of TTV infection in HIV patients in comparison to healthy blood donors, HIV infection may be an important risk factor for TTV infection. In addition, the lower frequency of TTV infection in healthy individuals in comparison to HIV patients reveals the transmission of TTV infection via routes other than blood and drug injection; therefore, the effect of fecal-oral route needs to be examined in future studies.

Study the prevalence of TT virus infection in South Iranian volunteer blood donors

Exposure to blood transfusion was associated with increase in the risk of transfusion transmitted (TT) viral infection and this led to the hypothesis that TT virus may be related to undefined post-transfusion hepatitis. Therefore in this study the prevalence of TT virus DNA in volunteer blood donors in relation to Alanine transaminase (ALT) and aspartateaminotransferase (AST) levels were evaluated. In a cross sectional study the blood samples were randomly collected from 499 volunteer blood donors. The genome of TT virus infection was evaluated in studied populations by an in-house semi-nested polymerase chain reaction (PCR) protocol. Some possible risk factors of TT virus infection including: age, gender, and AST and ALT levels were collected from volunteer blood donors. TT viral DNA was detected in the serum of 66 of 499 (13.4%) volunteer blood donors. The AST and ALT had significantly higher levels in volunteer blood donors with TT viremia in comparing with uninfected population. The adolescence (p=0.219) and gender (p=0.874) were not significantly correlated with increasing the prevalence of TT viremia. The moderate prevalence of TT viremia was diagnosed in volunteer blood donors in this part of Iran for the first time. Also define a significant association between TT virus infection and elevation of liver enzymes emphasize on the importance of this viral infection in undefined hepatic disorders that should be confirmed in completed studies. Key words: Transfusion transmitted (TT) virus, alanine transaminase (ALT), aspartate aminotransferase (AST), volunteer blood donors.

Prevalence of Transfusion Transmitted Virus Infection in Hemodialysis Patients and Injection Drug Users Compared to Healthy Blood Donors in Isfahan, Iran

Introduction. The pathogenicity and transmission routes of Transfusion Transmitted Virus (TTV) remain unclear. The aim of this study was to determine the prevalence of TTV in hemodialysis patients, injecting drug users (IDUs), and healthy blood donors, in Isfahan, Iran. Method. In a case-control study, a total of 108 subjects were put into three groups namely Group I, 36 hemodialysis patients; Group II, 36 IDUs; and Group III, 36 healthy blood donors as the control group. A 5 ml blood sample was collected from each subject in an EDTA-containing tube. Samples were tested for TTV DNA by means of real-time polymerase chain reaction (PCR). Results. The mean age was 38.7 ± 14.7 years. Seventy-one subjects (66%) were male. Of the108 cases, 30 (27.8%) were TTV positive and 78 (72.2%) were TTV negative. The prevalence of TTV in IDUs [21 (58%)] was significantly higher than in the other groups [group I: 6 (17 %) and group III: 3 (8%)] (P < 0.0001). Conclusion. The prevalence of TTV in IDUs is significantly higher than in both hemodialysis patients and general population in Isfahan, Iran. It seems necessary to take serious measures to reduce the risk of TTV transmission to IDUs' close contacts and health care providers.

The prevalence of transfusion-transmitted virus (TTV) infection in patients with chronic hepatitis B and C in southwest of Iran

Transfusion-transmitted virus (TTV) is an unenveloped circular single-stranded DNA virus with a diameter of 30 to 32 nm that was first described in 1997 in Japan. TTV was detected in various populations without proven pathology, including blood donors and in patients with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV). The aim of this study was to determine the prevalence of TTV DNA in patients with chronic hepatitis B and C in southwest Iran. Viral TTV-DNA was studied in 442 samples (202 with HBV, 138 with HCV and 102 controls) collected from southwest of Iran. All the extracted serum DNA was amplified by TTV ORF1 gene specific primers using the semi nested polymerase chain reaction (PCR) technique. TTV DNA was detected in the serum of 8.9 and 10.8% patients with chronic hepatitis B and C, respectively. The prevalence of TTV-DNA in the serum of the 102 controls was 2.9%. The results showed significant relationship of TTV with HBV and HCV in patients from T test examination (P < 0.01). The prevalence of TTV-DNA in Iranian hepatitis B and C patients was rather high when compared with those of other countries. To control and prevent the distribution of TT-virus, examination of the blood and blood products seems necessary. Key words : Transfusion-transmitted virus (TTV), hepatitis C virus (HCV), hepatitis B virus (HBV), ORF1 gene, semi nested polymerase chain reaction (PCR), Iran.

TTV and HPV co-infection in cervical smears of patients with cervical lesions in littoral of Zhejiang province

To investigate the prevalence of transfusion-transmitted virus (TTV) and human papillomavirus (HPV) co-infection in cervical smears of patients with cervical lesions in littoral of Zhejiang province and analysis of transmitted route. Nested polymerase chain reaction (nPCR) was established. TTV DNA were tested by nPCR in cervical smears of 95 patients with cervical lesions and 55 healthy women, paired serum samples were available from 55 and 42 women, and their viral titer. The genotypes of 95 specimens of cervical cytology were detected with HybriMax. The phylogenetic group of TTV was determined by means of nPCR with N22 primers. The prevalence of TTV DNA in cervical smears of patients with cervical lesions and healthy women was 52.7% (29/55) and was comparable with that in paired serum sample (50%). Symptomatic women had significantly higher prevalence of TTV DNA in cervical smears (74.7%) than healthy controls (P = 0.005). The TTV DNA prevalence in patient serum samples was 51%. The phylogenetic groups of TTV serum isolates were concordant with those of TTV from cervical smears of the same subjects, and genotype was G1b. The TTV viral titer in cervical smears were 10 to 1000 times as high as in serum. The total infection rate of HPV was 98.9% in patients, and was 27.3% in healthy women. The frequently detected genotype was HPV16, 18, 33 of HSIL, and HPV6 of LSIL. The HPV positive study subjects had significantly higher TTV DNA prevalence than HPV negatives (P = 0.02). High prevalence of TTV in cervical smears suggests that sexual transmission is another mode of expansion of TTV infection among the population. The higher viral titer in cervical smears than in the respective serum samples might indicate active TTV replication in the female genital tract. Nevertheless, cooperation between TTV and HPV needs to be further investigated.

Prevalence of TT virus infection in Italian-dialysis patients

A novel DNA virus, transfusion-transmitted virus (TTV) is identified from the serum of a patient from acute hepatitis non-A-E. Few reports have been published on patients with renal disease. Patients on dialysis were at high risk of blood-borne viral infections and little is known about the prevalence of this virus in dialysis patients. In order to verify the prevalence of infection from TTV in these patients, we have examined the incidence of TTV in Italian patients with dialysis. Serum samples of 85 patients and 65 healthy individuals were examined. In order to evidence the presence of the TTV virus, a method of the seminested polymerase chain reaction (PCR) with TTV-specific primers derives from the N22 region deIl'ORF-1 of the virus has been used and products were analyzed by agarose-gel electrophoresis. All serum samples were also analyzed to markers HBV and HCV. The prevalence of TTV DNA in dialysis patients [35/85 (41.7%)] was significantly higher than in healthy population [7/65 (10.7%)]. Among TTV positive dialysis patients, HCV coinfection was present in six cases. The positivity rate for TTV-DNA tends to increase with age. Transfusion-transmitted virus had a high prevalence in Italian-dialysis patients. In our study the virus did not have an important clinical effect on patients; but remains the possibility that it may aggravate liver disease caused by HCV. However, the question of whether TTV infection might have a possible effect on dialysis patients requires further investigation in larger groups.

HCV and TTV Co-infection in Turin, Italy

To the Editor Population-based studies of patients suffering from chronic hepatitis have shown that 40–60% are associated with hepatitis C virus (HCV) infection. Long-standing hepatocyte damage and chronic inflammation can eventually lead to fibrosis, cirrhosis, and hepatocellular carcinoma [1]. The possibility of HCV co-infection with other viruses is well known. Transfusion-transmitted virus (TTV) is found worldwide and its role either in causing liver disease or in significantly increasing the severity of coexistent HCV hepatitis is doubtful. Literature data reported a prevalence of HCV/TTV co-infection between 1% and 24% [2]. In our area (Regione Piemonte, Northwest of Italy, population of 4.5 million people), this aspect has not been investigated in depth. In a prospective study, conducted in the outpatient clinic [3] and laboratory of the Gastro-Hepatology Department of Molinette Hospital, Turin, which represents the main facility of Regione Piemonte dedicated to the management of liver diseases, we analyzed the prevalence of HCV/TTV co-infection. Sera of 91 consecutive patients (59 males; mean age 48.6 ± 11.3 years) with chronic HCV hepatitis, candidates to receive standard combination antiviral therapy (interferon and ribavirin), were examined at baseline. The diagnosis of chronic hepatitis was based on histology [4] and biochemical liver function tests [5]. HCV detection was performed using polymerase chain reaction (PCR) assays (Versant 3.0; Bayer Diagnostic Corporation, Tarrytown, NY, US; lower limit of detection 615 IU/ml. COBASAMPLICOR; Roche Diagnostic Systems, Branchburg, NY, US; lower limit of detection 50 IU/ml). TTV–DNA was extracted using a phenol-chloroform method as described by Casey et al. [6]. Briefly 50 ll serum was lysed by digestion overnight at 37 C with 1.1 mg proteinase K (Eurobio) in a final volume of 350 ll lysing buffer containing 60 mM ethylenediamine tetraacetic acid (EDTA), 60 mM Hepes pH 7.0, 200 mM NaCl, and 2.2% sodium dodecyl sulfate. A first phenol–chloroform extraction was followed by a second chloroform extraction, and nucleic acids were precipitated with cold isopropanol. DNA was pelleted by centrifugation and washed with cold 70% ethanol. The pellet was allowed to dry at room temperature and subsequently resuspended in 50 ll distilled water and stored at -20 C until further processing. To determine TTV–DNA a first round of amplification followed by a seminested PCR was performed with 10 ll extracted DNA according to Okamoto et al. [7]. Primers were designed to amplify well-conserved regions of TTV genome, allowing the detection of different genotypes and subtypes of TTV. The 271-bp amplification product of second-round PCR was analyzed by agarose gel electrophoresis and ethidium bromide staining. The v test and the Fisher exact test, when required, were used for statistical analysis, and a P value of less than 0.05 was considered significant. Positivity for TTV–DNA was found in 14 out of 91 (15.3%) patients. As reported in Table 1, no significant differences were found between co-infected versus not coR. Pellicano A. Olivero M. L. Abate A. Smedile M. Rizzetto Department of Gastro-Hepatology, Molinette Hospital, Turin, Italy URL: www.rinaldopellicano.blogspot.com

Transfusion‐transmitted virus DNA in serum, tear and aqueous humour of patients undergoing cataract operation

Transfusion-transmitted virus (TTV) is a novel non-enveloped, single-stranded DNA virus with unclear pathogenesis throughout the world. Many studies were conducted to determine this virus in various body fluids and different primer sets have been tested for accurate diagnosis. This study aimed to collect data on the prevalence of TTV in serum, tear and aqueous humour of patients undergoing planned cataract surgery and to determine efficacy of three different polymerase chain reaction (PCR) techniques. A total of 72 specimens (24 each of serum, tear and aqueous humour specimens) were collected from 24 patients (11 male and 13 female) having age-related cataract. The patients did not have any other ocular pathology. TTV DNA was investigated by three different PCR methods: a seminested PCR performed with Okamato's primers, a one-step PCR performed with degenerative Takashi's primers and a commercial real-time PCR system. TTV DNA was detected in 20 (83.3%) of the 24 serum specimens by the one-step PCR and real-time PCR system. However, seminested PCR yielded a positivity rate of 25%. TTV DNA positivities of the one-step PCR and the real-time PCR system were 33.3% and 66.6% of the 24 tear specimens, respectively. Seminested PCR did not yield positive result in these specimens. From aqueous humour specimens, TTV DNA was detected in 3 (12.5%) of the 24 specimens only by the real-time PCR. TTV DNA positivity of seminested PCR was significantly low in all specimens. TTV DNA was detected in serum, tear and aqueous humour of patients undergoing cataract surgery, supporting the idea that this virus can be detected almost all of the body fluids but at different rates under various PCR conditions and primer sets. Using commercial real-time PCR significantly increased the TTV DNA positivity.

Prevalence of transfusion transmitted virus (TTV) genotypes among HCC patients in Qaluobia governorate

BackgroundTransfusion Transmitted virus (TTV) is a novel single-stranded DNA virus that was identified in patients with post-transfusion hepatitis of non-A-G type. Clinical significance of TTV infection was analyzed in Egyptian hepatocellular carcinoma (HCC) patients. The present study attempted to clarify these issues in Egypt, particularly in Qaluobia governorate, a country known for its high endemicity of liver disease and hepatotropic viruses.MethodsTTV are determined in the serum of 60 samples obtained from HCC and liver cirrhosis (LC) patients and 30 healthy individuals. TTV DNA is amplified by nested-PCR with TTV-specific mixed primers derived from the conserved open reading frame 1 (ORF1) region followed by digestion with restriction enzyme. Using the enzymes HaeIII, DraI, EcoRI and PstI, we are able to distinguish between the four TTV genotypes.ResultsThe positive rate of TTV detection was 46.7%, 40% and 36.7% among HCC, LC patients and healthy individuals respectively. The more prevalence genotype was detected in the positive serum samples was genotype 1 (35.7%) in HCC patients, (50%) in LC and (63.3%) in healthy individuals, Genotype 5 (21.4%), (25.5%) and (18.2%) in HCC, LC and healthy individuals respectively.DiscussionThis study indicates that TTV is commonly present in adult patients with HCC and LC as well as healthy individuals. The most prevalence TTV genotype is genotype 1. It seems that the infection neither contribute to the severity of liver disease no to the causation of HCC.

Molecular Detection of Transfusion Transmitted Virus Coinfection With Some Hepatotropic Viruses

A novel human DNA virus was isolated from the serum of a patient with posttransfusion hepatitis; it was named transfusion transmitted virus (TTV). To ascertain the influence of TTV (detected by polymerase chain reaction amplification of a conserved region of the viral genome) coinfection in individuals infected with hepatitis viruses (A, B, and C) and to investigate the putative role played by TTV in hepatic dysfunction in individuals with acute non-A-E hepatitis. Sixty-two patients with viral hepatitis were included in the study in addition to 18 blood donors. Viral study of 4 hepatotropic viruses (A, B, C, and E) was carried out. Study for TTV DNA was performed by nested polymerase chain reaction. The prevalence of TTV was not statistically different between hepatitis patients and blood donors, and it was not correlated to the levels of the hepatic aspartate aminotransferase and alanine aminotransferase between individuals evidencing dual infection with hepatitis B and C viruses and healthy blood donors. However, in the group of patients with viral hepatitis of unknown etiology (non-A-E), those evidencing TTV viremia had statistically significant lower levels of alanine aminotransferase (P = .03) and aspartate aminotransferase (P = .04) than those who were TTV negative. We can conclude that TTV is a frequent virus isolated from patients with various types of viral hepatitis, from cases of hepatitis without obvious viral agent, and from the healthy population. TTV has no effect on biochemical markers of associated viral hepatitis. It may be associated with a mild form of non-A-E hepatitis.

Low prevalence of transfusion transmitted virus (TTV)-like DNA sequences in cystadenolymphoma and pleomorphic adenoma of the salivary glands

Titers of transfusion transmitted virus (TTV)-like DNA in saliva samples have been reported 100-1,000 times higher than those of the corresponding sera, suggesting viral transmission by saliva droplets. The present study was conducted to determine whether TTV-like DNA sequence elements play a role in the pathogenesis of cystadenolymphoma or pleomorphic adenoma and if the parotid or the submandibular gland is a major source of TTV persistence. Sixty-two archival salivary gland samples (16 cystadenolymphomas, 13 pleomorphic adenomas, and 33 controls) and 23 corresponding saliva samples were examined using a polymerase chain reaction (PCR) for TTV DNA. All PCR products that displayed DNA bands were sequenced. Leder's stain and immunohistochemistry (anti-CD8, anti-CD20, anti-CD45R0, anti-CD68, and anti-Ki67/MiB1) were applied to detect possible changes associated with findings of TTV-like DNA sequences. Tissue displayed TTV-like DNA sequences in 8.1% (5/62; saliva: 47.8%, 11/23). Tissue that contained TTV-like DNA sequences was histologically indistinguishable from samples lacking such DNA. TTV appears to be only a bystander in cystadenolymphoma, pleomorphic adenoma, and other salivary gland affections. Neither of the glands seems to be a major source of TTV persistence.

Prevalence of transfusion‐transmitted virus infection in patients on maintenance hemodialysis from New Delhi, India

Transfusion-transmitted virus (TTV) has been reported from a number of hemodialysis (HD) units from various countries throughout the world. TTV has been associated with liver diseases, viral hepatitis B, and C. Clinical details and information regarding TTV prevalence from India are insufficient. The prevalence and clinical significance of TTV infection were studied in New Delhi, India in HD patients. Serum samples were derived from 75 patients on maintenance HD, and 75 age- and sex-matched voluntary blood donors were examined for TTV viremia by nested polymerase chain reaction (PCR) using primers derived from UTR (A) region of the TTV genome. The prevalence of TTV DNA in patients on HD (83%) was significantly (p<0.05) higher than in blood donors (43%). Clinical background including the mean age, sex, mean duration of HD, and mean alanine aminotransferase (ALT) levels did not differ significantly between TTV DNA-positive and -negative HD patients. Fifty-four (72%) TTV-positive HD patients and 7 (56%) TTV-negative HD patients had blood transfusion histories (p>0.05). Among TTV-positive patients, Hepatitis B virus (HBV) co-infection was present in 14.2% cases while hepatitis C virus (HCV) co-infection was absent. Persistent elevation of ALT levels was observed in 7(9.3%) HD patients; 3 (43%) of them were TTV positive and 4 (57%) were TTV negative (p>0.05). All 3 TTV-positive patients with elevated ALT levels were co-infected with HBV. Patients with TTV infection alone showed normal ALT levels. Prevalence of TTV infection is high in North Indian patients on maintenance HD. Also, none of the exclusively TTV DNA-positive patients had clinical or biochemical signs of liver disease. TTV seems to spread through parenteral routes. More often, TTV seems to be associated with parenterally transmitted virus HBV, indicating a parenteral mode of TTV transmission. The pathogenicity of TTV remains unclear from the present study.

Clinical features of coinfection with TTV in hepatitis C virus–infected patients undergoing hemodialysis

BACKGROUND: Transfusion-transmitted virus (TTV) was identified recently as a DNA virus associated with post-transfusion hepatitis. The significance of TTV in biochemical or histologic evidence of liver disease still remains uncertain. In this study, we investigated the frequency of TTV viremia in hepatitis C virus (HCV)–infected patients undergoing hemodialysis to determine weather TTV coinfection has any independent effect on liver enzymes abnormality. METHODS: We studied 37 HCV infected patients who were on dialysis in a dialysis center in Tehran, Iran. There were no other cofactors in patients to elevate the aminotransferase enzymes such as other kinds of hepatitis, hemochromatosis, sarcoidosis, history of recent MI, medications, etc. Sera were tested for TTV DNA by polymerase chain reaction (PCR). Alanine aminotransferase (ALT) level was measured for each patient on four continual occasions within 9 months, and the mean value was recorded in analysis. RESULTS: TTV DNA was detected in 7 patients (18.9%) who all had a prior history of transfusion. There were no significant differences in gender (p = 0.08), age (p = 0.36), and duration of dialysis (p = 0.38) between TTV positive and negative groups. Five patients (71.4%) of TTV positive patients had elevated ALT versus 19 patients (62.5%) in the other group. Therefore, ALT elevation didn't differ significantly between TTV positive and negative patients (p = 1). CONCLUSIONS: This study suggests that TTV viremia doesn't correlate with serum ALT elevation. If these patients are followed up continuously in future, it will be possible to determine weather TTV coinfection deteriorates hepatitis C course.

Increased prevalence of transfusion-transmitted virus and cross-reactivity with immunodominant epitopes of the HRES-1/p28 endogenous retroviral autoantigen in patients with systemic lupus erythematosus

Objective: Systemic lupus erythematosus (SLE) patients produce autoantibodies to HRES-1/p28, a human endogenous retrovirus-encoded nuclear protein. To identify cross-reactive viral antigens capable of triggering autoreactivity, HRES-1/p28 epitopes were mapped by SLE antibodies. Methods: Forty-four peptides overlapping HRES-1/p28 and 13 viral peptides were synthesized on cellulose membrane and tested for recognition by antibodies from 16 HRES-1 Western blot seropositive SLE patients. Transfusion-transmitted virus (TTV) was detected by gene amplification in sera of 211 SLE patients, 78 healthy SLE family members, 199 unrelated healthy donors, and 91 rheumatoid arthritis (RA) patients. Results: HRES-1/p28 residues 41–55, 121–135, and 156–170 were recognized by 12/16 (75.0%), 11/16 (68.8%), and 9/16 lupus sera (56.25%) and considered immunodominant. HRES-1/p28 residues 121–135 harbor cross-reactive epitope with retroviral peptides and the 70 K U1snRNP lupus autoantigen. HRES-1/p28 residues 41–55 and 156–170 exhibited the highest prevalence of cross-reactivity with TTV peptide ORF2a (14/16, 87%). Prevalence of TTV DNA was increased in lupus patients (120/211) with respect to healthy (66/199; P < 0.0001) or RA controls (23/91; P < 0.0001). TTV prevalence in healthy lupus relatives (40/78) was decreased with respect to lupus patients (80/121; P = 0.0184) and increased with respect to unrelated healthy donors (66/199; P = 0.0026). HRES-1/p28 Western blot reactivity was observed in 12/23 TTV PCR-negative donors and 43/58 TTV PCR-positive donors ( P < 0.0281). Conclusions: Increased prevalence of TTV and molecular mimicry with HRES-1/p28 may contribute to generation of antinuclear antibodies and pathogenesis of SLE.

Infection with transfusion-transmitted virus (TTV) in humans and other primates in Venezuela

Tranfusion-transmitted virus (TTV), a single-stranded circular DNA virus that chronically infects humans and other animals, displays a high degree of genetic diversity and was originally thought to be associated with hepatitis. The prevalences of TTV infection among different populations of humans and non-human primates from Venezuela have now been evaluated, using serum samples and three different detection tests. All three tests were PCR-based, one involving a hemi-nested PCR and primers based on the N22 open-reading-frame-1 region (N22-PCR), another employing 55 cycles with primers from the more conserved untranslated region (UTR-PCR), and the other using a hemi-nested PCR with primers from the same region (HUTR-PCR). The overall prevalences of human infection appeared much higher with the HUTR-PCR (52%) than with the N22-PCR (13%) or the UTR-PCR (5%). When the products amplified by N22-PCR from 28 human isolates of TTV were sequenced, only two genotypes of the virus were detected. The non-human sera tested came from primates kept in a zoo in north-western Venezuela. TTV DNA was detected, by HUTR-PCR, in both of the chimpanzee sera tested but not in any of the sera from the 11 New-World primates or the other 12 Old-World primates that were investigated. The results, particularly those of the HUTR-PCR, indicate that TTV infection is common in Venezuela, especially in populations, such as many Amerindian groups, who live under poor sanitary conditions. Although TTV infection may be relatively rare among non-human primates from the New World, this will have to be investigated further, using many more samples collected throughout the Americas.

Frequency of hepatitis G virus and transfusion-transmitted virus infection in type II diabetes mellitus

The hepatitis G virus (HGV) and transfusion-transmitted virus (TTV) are recently defined hepatitis viruses that the pathogenic roles in liver diseases are still not clear. It has been well known that some hepatitis virus, such as hepatitis C, might have an affinity to pancreatic islet cells. To investigate the relationship between the newly defined hepatitis viruses and diabetes mellitus (DM), we studied the prevalence of TTV and HGV in a type 2 diabetic patient population. Serum samples of 60 patients with DM and 45 healthy volunteers as control were taken. HGV RNA and TTV DNA was investigated by polymerase chain reaction. HGV was detected in none of diabetic patients (0%) and only one in control group (2.2%). However, TTV DNA was detected in 16 patients with DM (26%) and in five controls (11%). TTV was more prevalent in diabetic patients, but the difference between groups was not statistically significant (p > 0.05). These results revealed that TTV is more common in diabetic patients than in controls. At present, we don't know if this result is only a coincidence or a sign of potential association between TTV and DM. Further studies are certainly needed to elucidate a potential relationship.

Transfusion‐transmitted virus is not present in factor IX concentrates commonly used to treat haemophilia B

Transfusion-transmitted virus (TTV) is a potential cause of post-transfusion hepatitis in patients with haemophilia. Plasma-derived clotting factor concentrates currently undergo processes that are effective in removal and inactivation of viruses such as HIV, hepatitis B and C; however, their effectiveness with respect to TTV is unknown. To determine if TTV DNA is present in plasma-derived concentrates of factor IX, we tested 14 lots of Mononine and compared the results with BeneFix. Nucleic acid isolation, followed by a two-round polymerase chain reaction (PCR) and agarose gel analysis indicated that all 17 lots were negative for TTV. Although TTV may be considered an emerging pathogen, no evidence of the virus was detected in the commercially available plasma-derived concentrate of FIX most commonly used to treat haemophilia B.

Role of transfusion-transmitted virus in acute viral hepatitis and fulminant hepatic failure of unknown etiology.

The role of the newly described transfusion-transmitted virus (TTV), a circular single-stranded DNA virus, has been investigated in acute liver disease, comprising 36 patients with acute viral hepatitis (AVH) and 25 with fulminant hepatic failure (FHF), including 50 volunteer blood donors as controls. Detection of TTV DNA sequences was carried out by polymerase chain reaction (PCR) using primers derived from the UTR(A) region of the TTV genome. The clinical course and biochemical profile when infected with TTV alone or coinfected with other classical hepatotropic viruses were analyzed. All patients were first evaluated for liver function profile and for the presence of various hepatotropic viruses using serological tests and PCR in serologically negative patients. Transfusion-transmitted virus DNA was detected in 80.6% (29/36) of the AVH cases and in 76% (19/25) of the FHF cases, which were significantly higher levels (P < 0.05) than the 52% (26/50) observed in volunteer blood donors. No significant difference in symptoms, clinical course, liver function and risk factor profile between TTV-positive and TTV-negative patients could be observed in both AVH and FHF patients. TTV was found to coexist with both parenterally and non-parenterally transmitted hepatotropic viruses in similar frequency in both AVH and FHF patients. Further, there was no significant difference in the mortality rates between TTV-positive and TTV-negative FHF patients. Also, there was no difference between patients coinfected by TTV and other hepatotropic viruses and those with TTV infection alone. Thus, it appears that TTV, although it exists in a very high frequency in the Indian population, appears to have no significant etiological role in AVH and FHF.

The Study of Patients with HBV Infection and Virus of TTV Co-infection

目的 探讨输血传播病毒(TTV)与HBV混合感染的情况及其对肝脏病变程度和对HBV复制的影响.方法应用微板核酸杂交-ELISA法检测152例HBV患者血清中的TTV DNA和ELISA进行乙型肝炎相关病毒标志物检测.结果 152例HBV患者中TTV-DNA阳性23例(15.1%),其中无症状携带者、慢性肝炎、活动性肝硬化、原发性肝癌患者中的TTV-DNA检出率分别为2/18(11.1%)、8/54(14.8%)、6/40(15.0%)、7/38(18.4%),各组间无差异.在慢性肝炎、活动性肝硬化、原发性肝癌患者中,TTV-DNA阳性组与TTV-DNA阴性组各项肝功能指标改变相似.HBV和TTV混合感染组中HBeAg和抗-HBcIgM阳性率低于单纯HBV感染组(p<0.05),而血清抗-HBe阳性率则高于单纯HBV感染组.结论 TTV的混合感染似乎并不影响HBV所致的肝脏病变程度,对HBV的复制可能有一定的抑制作用。

Detection of transfusion transmitted virus DNA by real-time PCR

Little is known about the pathogenic role and the endemic situation of transfusion transmitted virus (TTV). In this study, a molecular assay for detection of TTV based on automated nucleic acid extraction and real-time PCR was developed and evaluated. The new assay includes an internal control. After optimization of the molecular assay, 103 clinical samples were studied retrospectively. All sera had been tested for anti-HCV and anti-HIV-1 antibodies earlier. The amplification efficiency was found to be 102%. When clinical specimens were tested, 79 of 103 serum samples were found to be positive for TTV. There was no significant difference between various groups of patients. The internal control was detected in all negative and weak positive samples. This molecular assay proved to be suitable for routine detection of TTV in clinical samples. Moreover, a relative statement on the TTV serum load can be done.