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Surveillance and impact of occult hepatitis B virus, SEN virus, and torque teno virus in Egyptian hemodialysis patients with chronic hepatitis C virus infection. Int J Infect Dis 2019; 92:13-18. [PMID: 31863879 DOI: 10.1016/j.ijid.2019.12.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/12/2019] [Accepted: 12/08/2019] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES Egypt ranks first regarding the prevalence of hepatitis C virus (HCV) infection. Many patients have concomitant diseases like kidney disorders requiring hemodialysis, a procedure carrying the hazard of transmitting other hepatitis viruses. The purpose of this study was to investigate for occult hepatitis B virus (HBV), SEN virus (SENV), and torque teno virus (TTV) among chronic HCV patients on maintenance hemodialysis to identify their impacts. METHODS A total of 325 hemodialysis patients were enrolled and divided into two groups based on HCV RNA testing results. Blood samples were collected before hemodialysis. Sera were tested for hepatitis B core antibodies (anti-HBc) and hepatitis B surface antibodies (anti-HBs) using ELISA. HBV, SENV, and TTV DNA were detected by PCR. The serum alanine aminotransferase (ALT) level was measured. RESULTS Anti-HBc and HBV DNA were detected in 73.1% and 50.8% of group 1 versus 36.4% and 22.6% of group 2. The serum ALT level was higher in group 1 than group 2. SENV was detected in 11.5% of group 1 versus 8.2% of group 2. TTV was detected in 29% of group 1 versus 27% of group 2. CONCLUSIONS There is an increased prevalence of occult HBV in our locality among chronic HCV patients undergoing hemodialysis. The existence of SENV and TTV viremia has no clinical impact.
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2
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Affiliation(s)
- F. Fabrizi
- Division of Nephrology and Dialysis, Maggiore Hospital, IRCCS, Milano - Italy
| | - P. Martin
- Division of Digestive Diseases and Dumont-UCLA Transplant Center, UCLA School of Medicine, Los Angeles, CA - USA
| | - G. Lunghi
- Institute of Hygiene and Medicine Preventive, Maggiore Hospital, IRCCS, Milano - Italy
| | - F. Locatelli
- Division of Nephrology and Dialysis, A. Manzoni Hospital, Lecco - Italy
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3
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Alavi S, Sharifi Z, Valeshabad AK, Nourbakhsh K, Shamsian BS, Arzanian MT, Safarisharari A, Navidinia M. Clinical outcomes of Torque teno virus-infected thalassemic patients with and without hepatitis C virus infection. THE KOREAN JOURNAL OF HEMATOLOGY 2011; 46:123-7. [PMID: 21747885 PMCID: PMC3128893 DOI: 10.5045/kjh.2011.46.2.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 06/09/2011] [Accepted: 06/13/2011] [Indexed: 01/03/2023]
Abstract
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.
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Affiliation(s)
- Samin Alavi
- Pediatric Hematology-Oncology Department and Pediatric Infectious Research Center, Shahid Beheshti Medical University, Mofid Childrens' Hospital, Tehran, Iran
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4
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Hu YW, Al-Moslih MI, Al Ali MT, Uzicanin S, Perkins H, Yi QL, Rahimi Khameneh S, Wu J, Brown EG. Clinical outcome of frequent exposure to Torque Teno virus (TTV) through blood transfusion in thalassemia patients with or without hepatitis C virus (HCV) infection. J Med Virol 2008; 80:365-71. [PMID: 18098140 DOI: 10.1002/jmv.21070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
As a consequence of the high prevalence of TorqueTeno virus (TTV) in blood donors, thalassemia patients frequently acquire various genotypes of this virus through therapeutic blood transfusions. At present, the clinical consequences of TTV infection remain indeterminate for these patients. Here, several hundred thalassemia patients were tested for the presence of TTV and its genotypes using a combination of PCR and clone-based DNA sequencing. Approximately 10% (12/118) of the patients aged 2-20 years remained negative for TTV including eight genotypes of SENV. Ferritin, aspartate-aminotransferase (AST) and alanine-aminotransferase (ALT) levels were invariably lower in TTV-negative patients (P = 0.02, <0.01, and 0.06, respectively) than in TTV-positive patients. Patients with TTV-HCV co-infection showed elevated ferritin and ALT levels compared with patients with TTV infection alone (P < 0.02 and P < 0.01). AST and ALT levels were within the normal range for all TTV-negative patients, whereas abnormal levels of AST and ALT were seen in a significant proportion of TTV-positive patients (30.7% and 33.6%, respectively) and patients with TTV-HCV co-infections (70.0% and 56.6%, respectively). Only TTV-positive patients (28.0%) and patients with TTV-HCV co-infections (36.3%) had hyper-ferritin levels (> or =3,000 ng/ml). The genotype(s) of TTV responsible for the liver dysfunction could not be determined. However, high levels of AST and ALT were found to be correlated with detection of a higher number of TTV genotypes in the patients. The data suggests that frequent and persistent TTV infection through blood transfusion is associated with hepatic dysfunction and/or damage in transfusion dependent thalassemia patients.
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Affiliation(s)
- Yu-Wen Hu
- Canadian Blood Services, Ottawa, Ontario, Canada.
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5
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Tarrass F, Koenig JL, Leroy F, Mackaya L, Colomb H. [Transfusion-transmitted virus (TTV) and renal failure]. Nephrol Ther 2006; 2:176-82. [PMID: 16966062 DOI: 10.1016/j.nephro.2006.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Revised: 05/15/2006] [Accepted: 06/26/2006] [Indexed: 01/06/2023]
Abstract
In 1997, a new DNA virus, designated TTV "Transfusion Transmitted Virus", was isolated and seemed to be associated with non A-G post-transfusion hepatitis. The virus infects mainly patients at risk for parenteral exposure and hence, prone to develop chronic liver disease, as well as healthy populations worldwide. Few reports, however, have been published on the epidemiology and potential significance of TTV infection in patients with renal disease. This paper reviews, characterization of the virus, the history of its discovery, taxonomy and identification. Current status of TTV infection in patients with renal diseases are also summarised.
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Affiliation(s)
- Faissal Tarrass
- Service d'hémodialyse, hôpitaux Drôme-Nord (Site de Romans), BP 1002, route du Tain, 26100 Romans-sur-Isère, France.
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6
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Irshad M, Joshi YK, Sharma Y, Dhar I. Transfusion transmitted virus: A review on its molecular characteristics and role in medicine. World J Gastroenterol 2006; 12:5122-34. [PMID: 16937521 PMCID: PMC4088008 DOI: 10.3748/wjg.v12.i32.5122] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The present review gives an updated overview of transfusion transmitted virus (TTV), a novel agent, in relation to its molecular characteristics, epidemiological features, modes of transmission, tissue tropism, pathogenesis, role in various diseases and its eradication from the body. TTV, a DNA virus, is a single stranded, non-enveloped, 3.8 kb long DNA virus with a small and covalently closed circular genome comprising 3852 bases. It was tentatively designated Circinoviridae virus. TTV genome sequence is heterogeneous and reveals the existence of six different genotypes and several subtypes. TTV has been reported to transmit not only via parenteral routes, but also via alternate routes. This virus has been detected in different non-human primates as well. At present, TTV is detected by polymerase chain reaction (PCR) with no other available diagnostic assays. It shows its presence globally and was detected in high percent populations of healthy persons as well as in various disease groups. Initially it was supposed to have strong association with liver disease; however, there is little evidence to show its liver tropism and contribution in causing liver diseases. It shows high prevalence in hemodialysis patients, pointing towards its significance in renal diseases. In addition, TTV is associated with several infectious and non-infectious diseases. Although its exact pathogenesis is not yet clear, TTV virus possibly resides and multiplies in bone marrow cells and peripheral blood mononuclear cells (PBMCs). Recently, attempts have been made to eradicate this virus with interferon treatment. More information is still needed to extricate various mysteries related to TTV.
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Affiliation(s)
- M Irshad
- Clinical Biochemistry Division, Department of Laboratory Medicine, PO Box -4938, A I I M S, New Delhi-110029, India.
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7
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Chattopadhyay S, Rao S, Das BC, Singh NP, Kar P. Prevalence of transfusion-transmitted virus infection in patients on maintenance hemodialysis from New Delhi, India. Hemodial Int 2005; 9:362-6. [PMID: 16219056 DOI: 10.1111/j.1542-4758.2005.01154.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
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.
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Affiliation(s)
- Saket Chattopadhyay
- PCR-Hepatitis Laboratory, Department of Medicine, Maulana Azad Medical College, New Delhi, India
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Boysen T, Christensen JK, Madsen CD, Eugen-Olsen J, Christensen LS, Møller-Sørensen H, Weber A, Ladefoged SD, Krogsgaard K. Presence and significance of TT virus in Danish patients on maintenance hemodialysis. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 2003; 37:259-64. [PMID: 12775287 DOI: 10.1080/00365590310008163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVES To determine the prevalence of TT virus (TTV) in a population of Danish hemodialysis patients and evaluate possible relations between TTV infection and elevated levels of C-reactive protein (CRP) and hypo-response to treatment with erythropoietin (EPO). MATERIAL AND METHODS Patients on maintenance hemodialysis at a single center were invited to participate. Demographic and clinical data were registered. Blood samples for virological and routine biochemical tests were drawn simultaneously. TTV DNA was detected using polymerase chain reaction (PCR). TTV viral load was estimated by means of semi-quantitative PCR. All patients were tested for hepatitis B, hepatitis C and GB virus C. RESULTS Of 252 patients, 204 (80.9%) gave their written informed consent to participate in the study. The prevalence of TTV was 68% and 50% of TTV-positive patients had a high TTV viral load. TTV-positive patients were significantly older than TTV-negative patients (p = 0.011). No relations were found between TTV infection and elevated levels of alanine aminotransferase (ALT) or CRP or hypo-response to EPO treatment. The mean hemoglobin concentration was 11.24 +/- 1.48 g/dl. Patients with a high TTV viral load had a lower level of hemoglobin (10.86 +/- 1.47 g/dl) than the others (p = 0.01). This trend suggested a positive relation between TTV infection and the number of blood transfusions. A restriction fragment length polymorphism assay suggested that patients were infected with different TTV strains. CONCLUSIONS TTV is common in patients on maintenance hemodialysis. The presence of TTV is associated with increasing age. Patients with a high TTV viral load had lower levels of hemoglobin than the others. TTV infection is not related to elevated levels of ALT or CRP or to hypo-response to EPO treatment.
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Affiliation(s)
- Trine Boysen
- Clinical Research Unit, Hvidovre University Hospital, Denmark
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Dai CY, Yu ML, Chuang WL, Sung MH, Lin ZY, Chen SC, Hsieh MY, Wang LY, Tsai JF, Chang WY. Epidemiology and clinical significance of chronic hepatitis-related viruses infection in hemodialysis patients from Taiwan. Nephron Clin Pract 2002; 90:148-53. [PMID: 11818698 DOI: 10.1159/000049035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS A novel DNA virus which was designated TT virus (TTV) in 1997 was considered a possible hepatitis-related virus, like hepatitis C (HCV), hepatitis B (HBV) and GB virus C/hepatitis G viruses (GBV-C/HGV). In the present study, the molecular epidemiology and clinical significance of TTV, GBV-C/HGV and HCV infection in hemodialysis patients from Taiwan are investigated. METHODS Sera of 85 patients on maintenance hemodialysis were tested for alanine aminotransferase (ALT), hepatitis B surface antigen (HBsAg), second-generation HCV antibody (anti-HCV), anti-envelope protein 2 antibody (anti-E2) and RNA of GBV-C/HGV, HCV RNA and TTV DNA. Sera of patients with positive TTV DNA, GBV-C/HGV RNA or HCV RNA were tested for viruses 2 years later. RESULTS Seven (8.2%) 29 (34.1%), 21 (24.7%), 12 (14.1%) and 9 (10.6%) hemodialysis patients were positive for HBsAg, Anti-HCV, HCV RNA, GBV-C/HGV RNA and anti-E2, respectively. TTV DNA was positive in 46 (54.1%) patients. Neither clinical nor virological factors were associated with TTV viremia. The ALT level was significantly elevated in HCV RNA-positive individuals than -negative ones (34.5 vs. 12.5%, p < 0.05). TTV DNA, GBV-C/HGV RNA and HCV RNA remained detectable in sera of 31 (86.1%), 6 (50%) and 21 (100%) patients collected 2 years after first diagnosis of viremia. CONCLUSION Among Taiwanese hemodialysis patients, TTV infection is highly prevalent. No clinical or virological factor was observed to be significantly associated with TTV infection. The ALT abnormality was mainly attributable to HCV but not TTV infection in Taiwanese hemodialysis patients.
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Affiliation(s)
- Chia-Yen Dai
- Hepatobiliary Division, Department of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan/ROC
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10
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Valtuille R, Frankel F, Gómez F, Moretto H, Fay F, Rendo P, Lef L, Fernández J. The role of transfusion-transmitted virus in patients undergoing hemodialysis. J Clin Gastroenterol 2002; 34:86-8. [PMID: 11743253 DOI: 10.1097/00004836-200201000-00017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
GOALS To study transfusion-transmitted virus (TTV) infection in 75 patients on hemodialysis and examine its relationship with age, sex, duration of dialysis, history of transfusion, and chronic elevation of alanine aminotransferase (ALT) levels. STUDY Serum TTV was analyzed by polymerase chain reaction (PCR), TTV genotypes by restriction fragment length polymorphism, and hepatitis C virus (HCV) RNA by PCR. RESULTS Transfusion-transmitted virus was detected in 32 patients (42.7%). Transfusion-transmitted virus genotypes were as follows: G1 in 16 patients; G2, 3; G3, 1; G4, 2; G2-G5, 6; and unclassified, 4. Mean duration of dialysis was 37 +/- 32 months for TTV-positive patients and 43 +/- 37 months for TTV-negative patients (not significant). Twenty-seven (84%) TTV-positive patients and 27 (63%) TTV-negative patients had a history of transfusions ( p = 0.04). Chronic ALT elevation was observed in 9 patients; 5 of them were TTV-positive (16%) and 4 were TTV-negative (9%) (not significant). Four (40%) HCV RNA-positive patients and 5 (8%) HCV RNA-negative patients had chronic ALT elevation ( p = 0.003). Three TTV-positive patients with chronic ALT elevation were also infected with HCV. The two patients with isolated TTV infection did not have another clinical feature to explain their ALT elevation. CONCLUSIONS Transfusion-transmitted virus had a high prevalence in the patients on hemodialysis; genotype G1 accounts for half of the cases. Transfusion-transmitted virus infection depends on the transfusional antecedent but not on the duration of dialysis. Chronic ALT elevation is significantly associated with HCV infection but not TTV infection. However, TTV could be a causative agent of chronic ALT elevation in some patients.
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Affiliation(s)
- Rodolfo Valtuille
- RTC, Monte Grande, CDM, Bio Sidus, Department of Clinical Research, Buenos Aires, Argentina
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Maggi F, Fornai C, Zaccaro L, Morrica A, Vatteroni ML, Isola P, Marchi S, Ricchiuti A, Pistello M, Bendinelli M. TT virus (TTV) loads associated with different peripheral blood cell types and evidence for TTV replication in activated mononuclear cells. J Med Virol 2001; 64:190-4. [PMID: 11360252 DOI: 10.1002/jmv.1035] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
TT virus (TTV) loads associated with the peripheral blood cells of seven patients known to carry the virus in plasma were investigated by real-time PCR. Whereas red cells/platelets were uniformly negative, six and four patients yielded positive peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes, respectively, but viral titres were generally low. Fractionation of PBMCs into monocyte- and B, T4, and T8 lymphocyte-enriched subpopulations showed no pattern in the viral loads that might suggest the preferential association of TTV to one or more specific cell types. TTV-negative PBMCs absorbed measurable amounts of virus when incubated with infected plasma at 4 degrees C. Furthermore, cultures of TTV-negative phytohaemagglutinin-stimulated PBMCs exposed in vitro to virus-positive plasma and faecal extracts released considerable levels of infectious TTV into the supernatant fluid and the same was true for TTV-positive stimulated PBMCs. These results indicate that, whereas freshly harvested resting PBMCs seem to produce little, if any TTV, stimulated PBMCs actively replicate the virus.
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Affiliation(s)
- F Maggi
- Virology Section and Retrovirus Centre, Department of Biomedicine, University of Pisa, Via San Zeno 37, I-56127 Pisa, Italy
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Huang LY, Oystein Jonassen T, Hungnes O, Grinde B. High prevalence of TT virus-related DNA (90%) and diverse viral genotypes in Norwegian blood donors. J Med Virol 2001; 64:381-6. [PMID: 11424130 DOI: 10.1002/jmv.1062] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Early estimates of the prevalence of TTV viremia in healthy adults of developed countries were in the order of 1--10 %, while similar estimates in Third World countries were considerably higher. Using three different PCRs, TTV-related DNA was detected in serum from 180 out of the 201 Norwegian blood donors tested, indicating that these viruses are almost universally present in adults. Sequence analysis revealed heterogeneity similar to what is found world-wide. The data suggest that the previous discrepancy in prevalences might be related to a lower serum concentration of virus in developed countries. The high prevalence adds evidence to the benign nature of the virus.
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Affiliation(s)
- L Y Huang
- Department of Virology, National Institute of Public Health, Oslo, Norway
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Abstract
Patients with chronic renal failure are predisposed to infections. Infections in end-stage renal disease patients are caused by immunosuppressive effects of uremia. Patients with renal failure on dialysis have impaired host defenses and may develop infections related to vascular access. This article reviews the infectious complications related to chronic renal failure in dialysis.
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Affiliation(s)
- V R Minnaganti
- State University of New York School of Medicine, Stony Brook, New York, USA
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Touinssi M, Gallian P, Biagini P, Attoui H, Vialettes B, Berland Y, Tamalet C, Dhiver C, Ravaux I, De Micco P, De Lamballerie X. TT virus infection: prevalence of elevated viraemia and arguments for the immune control of viral load. J Clin Virol 2001; 21:135-41. [PMID: 11378494 DOI: 10.1016/s1386-6532(01)00157-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The most recent polymerase chain reaction (PCR) detection protocols for the TT virus (TTV) permit one to identify the presence of viral DNA in the serum of a majority of healthy individuals, in the absence of any particular risk factor. This is in contrast with previous epidemiological studies that reported a higher prevalence of TTV infection in populations such as haemodialysis patients (HD), haemophiliacs, intravenous drug users or diabetics. OBJECTIVES To show that these discrepant results were due to the different sensitivity (number of viral copies detected) of the detection protocols used in initial and more recent epidemiological studies. STUDY DESIGN AND RESULTS We designed a standardised primary PCR assay that detects only viraemia >5x10(3) to 5x10(4) copies/ml for genotypes 1, 2 and 3, and compared the results of this test with those of a nested PCR assay which is 100-fold more sensitive. Viraemia >5x10(3) to 5x10(4) copies/ml were statistically more frequent in HD patients (54.3%), diabetics (54.7%), and HIV-infected patients with CD4 cells <200/mm(3) (69%) than in blood donors (37%) or HIV-infected patients with CD4 cells >500/mm(3) (33%). CONCLUSIONS These data suggest a possible relationship between the prevalence of elevated viral loads and the level of immunocompetence of the populations studied, and therefore that of an immune control of TTV viraemia. This corroborates previous findings showing that the stimulation of the immune system by an interferon treatment was able to clear TTV viraemia.
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Affiliation(s)
- M Touinssi
- Unité des Virus Emergents, Laboratoire de Virologie Moléculaire, Tropicale et Transfusionnelle, Faculté de Médecine de Marseille, Boulevard Jean Moulin, 13385 Marseille cedex 05, France
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15
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Schröter M, Feucht HH, Zöllner B, Schäfer P, Laufs R. Prevalence of a novel DNA virus (TTV) among patients on maintenance hemodialysis. Nephron Clin Pract 2001; 87:139-42. [PMID: 11244308 DOI: 10.1159/000045902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS A recently detected DNA virus (TTV) has been assumed to be responsible for posttransfusion hepatitis in humans. Until now it is unclear whether patients on maintenance hemodialysis are at increased risk of acquiring TTV. METHODS Serum samples derived from 143 chronically hemodialyzed patients were examined for TTV viremia by nested PCR. All serum specimens were also investigated for viremia and for the presence of antibodies of hepatitis C virus (HCV) and GB virus C/hepatitis G virus (GBV-C/HGV) by PCR and serological assays, respectively. RESULTS The prevalence of TTV was determined to be 18.8% (n = 27), for HCV a prevalence of 15.4% (n = 22) and for GBV-C/HGV of 8.4% (n = 12) could be demonstrated. Parallel infection by TTV and HCV was detected in only 1.4% (n = 2) of the patients. In no serum sample could TTV and GBV-C/HGV be detected in parallel. None of the solely TTV-viremic individuals had clinical or biochemical signs of liver disease. CONCLUSION From our data we conclude that TTV viremia is widespread among hemodialysis patients and can be detected in 18.8%. Since no viremic patient had clinical or biochemical signs of liver disease, the hepatitis-inducing capacity of TTV remains unclear.
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Affiliation(s)
- M Schröter
- Institut für Medizinische Mikrobiologie und Immunologie, Universitäts-Krankenhaus Eppendorf, Hamburg, Deutschland
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Bendinelli M, Pistello M, Maggi F, Fornai C, Freer G, Vatteroni ML. Molecular properties, biology, and clinical implications of TT virus, a recently identified widespread infectious agent of humans. Clin Microbiol Rev 2001; 14:98-113. [PMID: 11148004 PMCID: PMC88963 DOI: 10.1128/cmr.14.1.98-113.2001] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
TT virus (TTV) was first described in 1997 by representational difference analysis of sera from non-A to non-G posttransfusion hepatitis patients and hence intensively investigated as a possible addition to the list of hepatitis-inducing viruses. The TTV genome is a covalently closed single-stranded DNA of approximately 3.8 kb with a number of characteristics typical of animal circoviruses, especially the chicken anemia virus. TTV is genetically highly heterogeneous, which has led investigators to group isolates into numerous genotypes and subtypes and has limited the sensitivity of many PCR assays used for virus detection. The most remarkable feature of TTV is the extraordinarily high prevalence of chronic viremia in apparently healthy people, up to nearly 100% in some countries. The original hypothesis that it might be an important cause of cryptogenic hepatitis has not been borne out, although the possibility that it may produce liver damage under specific circumstances has not been excluded. The virus has not yet been etiologically linked to any other human disease. Thus, TTV should be considered an orphan virus.
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Affiliation(s)
- M Bendinelli
- Virology Section, Department of Biomedicine and Retrovirus Center, University of Pisa, Pisa, Italy.
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L�pez-Alcorocho JM, Barril G, Ortiz-Movilla N, Traver JA, Bartolom� J, Sanz P, Selgas R, Carre�o V. Prevalence of hepatitis B, hepatitis C, GB virus C/hepatitis G and TT viruses in predialysis and hemodialysis patients. J Med Virol 2001. [DOI: 10.1002/1096-9071(20000201)63:2<103::aid-jmv1003>3.0.co;2-e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The safety of the blood supply is critical to many parts of modern medicine. In a time when prescriber's and the public's expectations are increasing, it is essential that transfusion services globally ensure the safety of the blood supply. There are, however, many threats to this safety, one being the appearance of new infectious agents. Such agents may be truly 'novel', or may be existing agents, known but not routinely screened for, posing a new or increased threat. However, before an agent is considered to be a true threat to blood safety it must be well characterized, and evidence must be presented that (i) transfusion transmission is a significant route of spread, and (ii) the agent causes significant clinical disease. If either of these criteria are not met, the question has to be asked as to whether the agent is truly a threat to blood safety.
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Affiliation(s)
- A D Kitchen
- Department of Transfusion Microbiology, National Blood Service, Colindale Avenue, London, NW9 5BG, UK
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Campo N, Brizzolara R, Sinelli N, Torre F, Russo R, Deferrari G, Picciotto A. TT virus infection in haemodialysis patients. Nephrol Dial Transplant 2000; 15:1823-6. [PMID: 11071972 DOI: 10.1093/ndt/15.11.1823] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The recent discovery of a new parenterally transmitted DNA virus called TT virus (TTV) led us to investigate its prevalence in haemodialysis patients, a high-risk group for blood-borne infection, and to evaluate its role in liver disease. Moreover, we compared the TTV prevalence with the prevalence of other hepatitis virus coinfections. METHODS Serum samples of 78 patients on maintenance haemodialysis were tested for TTV-DNA, hepatitis G virus (HGV)-RNA, anti-E2, anti-hepatitis C virus (HCV) and HCV-RNA. TTV-DNA was detected by semi-nested PCR using the primers from open reading frame 1 (ORF). HGV-RNA was detected by PCR using specific primers for the NS3 and the 5'-UTR genome regions while anti-E2 were checked by an enzyme immunological test. Anti-HCV was tested by the second generation Chiron RIBA HCV test system. HCV-RNA was evaluated by nested PCR with primers directed to the highly conserved 5' non-coding region of the HCV genome. RESULTS TTV prevalence in our patients was 19% (15/78) while the prevalence of HCV and HGV infection proved to be 20 and 15.4%, respectively. Among TTV positive patients HGV co-infection was present in five cases (33%), HCV in six cases (39.9%), while HBV co-infection was not present in any of the patients. Only three patients proved positive for all three viruses. ALT levels were normal in most cases (13/15; 86%). In particular, patients with TTV infection alone showed normal ALT levels and HCV coinfection was found in the two patients with moderate ALT increases. CONCLUSIONS TTV prevalence in haemodialysed patients is significant though the real clinical impact is still unclear. However, we must keep in mind that the epidemiological relevance of TTV infection is probably underestimated due to the impossibility in detecting the corresponding antibody.
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Affiliation(s)
- N Campo
- Department of Internal Medicine, Gastroenterology Unit, University of Genoa, Genoa, Italy
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