GB virus C/hepatitis G virus infection in Indian blood donors and high-risk groups.

The hepatitis G virus (HGV) or GB virus C (GBV-C) was discovered in 1995 as a putative agent of post-transfusion, non-A-E hepatitis. The present study was carried out with the aim to find the prevalence of this virus among various subject groups at risk for parenteral transmission as well as in healthy control subjects both individually and along with other parenterally transmitted hepatitis viruses. Of the 402 subjects tested, 6.22% were positive for the HBsAg surface antigen, 7.21% were positive for HCV RNA while only 2.24% were seen to be carriers of the HGV/GBV-C RNA. All the HGV/GBV-C positive cases were either multi-transfused thalassaemic subjects or hemodialysis patients. None of the healthy control subjects showed presence of the virus. Seven of the HGV/GBV-C positive subjects showed co-infection with one or more additional virological markers. Also, of the 9 HGV/GBV-C positive subjects, 5 showed elevated ALT levels while 4 showed elevated alkaline phosphatase levels. Overall our findings seem to indicate that HGV infections generally are asymptomatic, transient and self-limiting and the virus does not seem to show a very high prevalence among the Indian population.     

Detection of GB virus C/hepatitis G virus RNA by reverse-transcription polymerase chain reaction.

Recently, a novel RNA virus, designated GB virus C or hepatitis G virus (GBV-C/HGV) has been identified which may possibly be associated with human hepatitis. In this study, the nucleotide sequences of the partial nonstructural 5 (NS5) gene of GBV-C/HGV derived from sera of eight Chinese patients were determined. The overall degree of nucleotide conservation and the existence of regional highly conserved sequences make this part of the genome suitable for the development of diagnostic reagents. On the basis of sequence analysis, two sets of oligonucleotide primers were designed to establish a nested polymerase chain reaction (PCR) for detection of GBV-C/HGV RNA. The efficacy of three PCR methods (first, one stage PCR, second, nested PCR with primers from the NS5 region designed according to the prototype sequence and the third, our newly developed PCR) was compared in 133 Chinese patients with liver disease. The positive rates of these three methods were 8.3%, 11.3% and 18.0% respectively. The specificity of our PCR detecting system was verified by sequencing and restriction fragment length polymorphism (RFLP). In conclusion, because of the heterogeneity and geographic distribution character of GBV-C/HGV, it is necessary to assess the sequence variation among Chinese patients infected with GBV-C/HGV. This may allow to identify GBV-C/HGV RNA with high sensitivity and specificity.     

Hepatitis C virus and GB virus C/hepatitis G virus viremia in Swedish blood donors with different alanine aminotransferase levels

BACKGROUND: Hepatitis C virus (HCV) is a known blood-borne hepatotropic virus for which antibody screening of blood donors is universally practiced. The newly identified GB virus C (GBV-C) and its strain variant hepatitis G virus (HGV) are of unknown pathogenic significance, and screening of blood donors for this agent has not yet been implemented. Polymerase chain reaction (PCR) is the most sensitive method for detecting HCV viremia and is the only method presently available for the diagnosis of GBV-C/HGV infection. STUDY DESIGN AND METHODS: RNA extracts of sera from 577 anti-HCV-negative blood donors (393 with elevated alanine aminotransferase [ALT] levels, 184 with normal ALT levels) were tested with nested PCR for HCV and GBV-C/HGV directed at the 5'-noncoding regions of the two viruses. RESULTS: One donor with elevated ALT was HCV PCR positive. This donor was anti-HCV negative when recruited to the study but subsequently developed anti- HCV. Of the 19 donors with GBV-C/HGV viremia in the series as a whole, 16 belonged to the group with elevated ALT levels and 3 to the group with normal ALT levels; the group difference in prevalence was nonsignificant (4.1% [16/393] vs. 1.6% [3/184; p = 0.20]). Phylogenetic analysis showed 16 of the GBV-C/HGV isolates to be classifiable as subtype 2a and three as subtype 2b. At follow-up 3 to 5 years later, 11 of 18 donors were still viremic. CONCLUSION: There was no significant difference in GBV-C/HGV viremia in the group with elevated ALT levels and the group with normal ALT levels. The frequency and subtype distribution in the present series were similar to those in other Western countries.     

Persistent infection mechanism of GB virus C/hepatitis G virus differs from that of hepatitis C virus

OBJECTIVE: Changes in the deduced amino acid sequence of the envelope 2 (E2) region of the GB virus C/hepatitis G virus (GBV-C/HGV) were analyzed to investigate whether or not the region contributes to persistent infection with the virus. METHODS: Eight patients with acute hepatitis C and 1 patient with acute hepatitis of unknown etiology were included in the study. GBV-C/HGV RNA was detected in 6 patients, including the patient with hepatitis of unknown origin. The nucleotide sequence of the E2 region of hepatitis C virus (HCV) and GBV-C/HGV was determined by direct sequencing of polymerase chain reaction products in 5 patients with HCV infection and in 6 patients with GBV-C/HGV infection twice during the period of early infection and several months or years later in each patient. RESULTS: The mean substitution rate of the deduced amino acid sequence in the E2 region was over 100 times lower (p < 0.001) in GBV-C/HGV (0.01 +/- 0.04/month/100 sites) than in HCV (2.4 +/- 1.7/month/100 sites). The amino acid sequence of the loop domain of GBV-C/HGV-E2 did not change in any of the 6 patients. On the other hand, the sequence of the hypervariable region of HCV-E2 changed remarkably (5.9 +/- 4.3/month/100 sites). No amino acid substitution in the loop domain was observed in 7 additional patients who showed persistent GBV-C/HGV viremia for more than 2 years. CONCLUSION: These results indicate that changes in the amino acid sequence of the E2 region are not involved in the mechanism of persistent GBV-C/HGV infection.     

Prevalence of GB virus type C/hepatitis G virus RNA and of anti-E2 in individuals at high or low risk for blood-borne or sexually transmitted viruses: evidence of sexual and parenteral transmission

BACKGROUND: The first epidemiologic evidence of GB virus type C (GBV- C)/hepatitis G virus (HGV) infection showed a high prevalence of asymptomatic carriers in blood donors and in populations at risk for blood-borne viruses. However, by using only viral RNA polymerase chain reaction, those studies underestimated the true spread of GBV-C/HGV infection. The combined detection of GBV-C/HGV RNA and of anti-E2 (which reflects recovery from infection) is necessary to define accurately the prevalence of GBV-C/HGV. STUDY DESIGN AND METHODS: The presence of both anti-E2 and GBV-C/HGV RNA was searched for in 1438 serum samples collected from various groups of individuals at low or high risk for blood-borne or sexually transmitted viruses (blood donors, organ donors, unselected pregnant women, immunocompetent or immunodepressed multiply transfused patients, HIV-positive or HIV- negative homosexual men, intravenous drug addicts). RESULTS: The presence of GBV-C/HGV RNA and/or anti-E2 (exposure to GBV-C/HGV) was frequent in populations at risk for blood-borne or sexually transmitted viruses. GBV-C/HGV appeared also to be sexually transmitted, with transmission from male to female more efficient than vice versa. A particularly elevated level of exposure to GBV-C/HGV was observed in homosexual men. In immunocompetent individuals, the prevalence of anti- E2 was about twice that of GBV-C/HGV RNA, which suggests the frequency of recovery from GBV-C/HGV infection. Most of the GBV-C/HGV RNA- positive individuals had no biochemical evidence of liver damage. CONCLUSIONS: GBV-C/HGV is frequent in populations at risk for blood- borne or sexually transmitted viruses. GBV-C/HGV is not a hepatitis virus, and it seems appropriate to rename it.     

Phylogenetic analysis of hepatitis GB virus type C/hepatitis G virus in Spanish patients with chronic hepatitis B or C virus infection.

The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicase and 5'-untranslated regions from 23 Spanish patients were analyzed to assign the HGV isolates one of the proposed HGBV-C/HGV genotypes. The analysis of the evolutionary distance frequency showed that the distances among all sequences in NS3/helicase region were distributed around a single peak of 0.20, suggesting that all included sequences belonged to the same HGBV-C/HGV genotype. By contrast, in the 5'-untranslated region, all the distances corresponding to our sequences and those of the HGBV-C/HGV types 2 and 3 were distributed around a major peak of 0.03. The remaining distances corresponding to the HGBV-C/HGV type 1 sequences were distributed around a minor peak of 0.11. The phylogenetic tree and pairwise comparison of evolutionary distances among the 5'-untranslated region of the infected patients and each HGBV-C/HGV genotype demonstrated that our HGBV-C/HGV isolates belonged to subtype 2a (17/23; 78%) and 2b (5/23; 22%). No relation was found between HGBV-C/HGV subtype and hepatitis B or C virus infection.     

HCV感染者/慢性丙型肝炎患者血清HCVRNA含量、外周血淋巴细胞Fas抗原及ALT浓度的相关性

目的探讨HCV感染者/慢性丙型肝炎患者血清HCV-RNA含量、外周血淋巴细胞(PBL)Fas抗原及ALT浓度的相关性。方法对本站献血群中60例HCV感染者,50例正常者及来自本市一院56例慢性丙型肝炎患者,采用荧光定量PCR检测其HCV-RNA含量,用FACSCalibur流式细胞仪为检测外周血淋巴细胞Fas抗原,用生化自动分析仪检测ALT浓度。结果本研究116例HCV感染者/慢性丙型肝炎患者血清HCV-RNA含量与PBLFas抗原表达率、ALT异常率呈正相关(γ值分别为0.94、0.96,均P﹤0.01),但与ALT浓度无相关性γ=0.38,0.03,无统计学意义(P均>0.05),ALT浓度差异无统计学意义(均P>0.05),ALT异常率差异有统计学意义(P﹤0.05)。结论HCV感染者/慢性丙型肝炎患者血清HCV-RNA含量与外周血淋巴细胞Fas抗原呈正相关、与ALT异常率相关性显著,外周血淋巴细胞Fas抗原与ALT异常率相关性显著。     

HCV感染者/慢性丙型肝炎患者血清HCVRNA含量、外周血淋巴细胞Fas抗原及ALT浓度的相关性

目的 探讨HCV感染者/慢性丙型肝炎患者血清HCV-RNA含量、外周血淋巴细胞(PBL)Fas 抗原及ALT浓度的相关性.方法 对本站献血群中60例HCV感染者,50例正常者及来自本市一院56例慢性丙型肝炎患者,采用荧光定量PCR检测其HCV-RNA含量,用FACSCalibur流式细胞仪为检测外周血淋巴细胞Fas抗原,用生化自动分析仪检测ALT浓度.结果 本研究116例HCV感染者/慢性丙型肝炎患者血清HCV-RNA含量与PBL Fas抗原表达率、ALT异常率呈正相关(γ值分别为0.94、0.96,均P&lt;0.01),但与ALT浓度无相关性γ=0.38,0.03,无统计学意义(P&gt;0.05),ALT浓度差异无统计学意义(均P&gt;0.05).ALT异常率差异有统计学意义(P&lt;0.05).结论 HCV感染者/慢性丙型肝炎患者血清HCV-RNA含量与外周血淋巴细胞Fas抗原呈正相关、与ALT异常率相关性显著,外周血淋巴细胞Fas抗原与ALT异常率相关性显著.     

Hepatitis C virus RNA in serum of blood donors with or without elevated transaminase levels

The pattern of hepatitis C virus (HCV) viremia in blood donors who are positive for antibody to HCV (anti-HCV) according to the level of transaminase activity is unclear. A polymerase chain reaction-based HCV RNA detection method was used to study two clearly defined groups of anti-HCV-positive blood donors with repeatedly normal (n = 27) and elevated (n = 17) alanine aminotransferase (ALT) levels. HCV RNA was detected in only 4 of 27 blood donors with normal ALT values and 15 of 17 with elevated ALT values. These results indicate that anti-HCV- positive blood donors with normal ALT levels constitute a heterogeneous group, as HCV viremia is detectable in only a small proportion of cases. Polymerase chain reaction should be useful in the surveillance of anti-HCV-positive blood donors with normal ALT levels, by identifying those who might benefit from further investigation and treatment.     

Prevalence of hepatitis G virus RNA in French blood donors and recipients

BACKGROUND: Recently, cases of chronic hepatitis were linked to the presence of genomic sequences of a newly described RNA virus termed hepatitis G virus (HGV) and belonging to the Flaviviridae family. STUDY DESIGN AND METHODS: The presence of HGV RNA was searched for by polymerase chain reaction in a population of blood donors and in patients who had received multiple blood component transfusions and/or intravenous immunoglobulin (IVIG) infusions. RESULTS: Twenty-one (4.2%) of 500 donors were positive for HGV RNA as were 21 (10.7%) of 196 nonimmunosuppressed patients who had received multiple transfusions of packed red cells, 4 (8.7%) of 46 common variable immune deficiency (CVID) patients who had received only IVIG, and 22 (24.7%) of 89 bone marrow transplant (BMT) patients who had received IVIG and cellular components. The proportion of HGV-positive individuals was significantly higher in the immunosuppressed recipients (CVID and BMT patients) than in the nonimmunosuppressed patients who were multiply transfused with packed red cells (p < 0.03). The proportion of HGV- positive individuals was significantly higher in the BMT patients who had received IVIG and cellular components than in the CVID patients who had received IVIG only (p < 0.03). Eight (17.0%) of the 47 HGV-positive recipients and 48 (16.9%) of the 284 HGV-negative recipients had a serum alanine aminotransferase level higher than the upper limit of normal (nonsignificant difference). The medical history of HGV-positive donors failed to reveal a particular at-risk event. The large majority of HGV-infected patients had a normal serum alanine aminotransferase level, and the proportion of patients with elevated alanine aminotransferase was the same in HGV-positive and in HGV-negative recipients. CONCLUSION: The pathological significance of HGV infection remains unelucidated, and the classification of HGV as a new hepatitis virus was perhaps premature.     

Prevalence of hepatitis G virus RNA and antibodies to HGV envelope protein (anti-E2) in patients with liver injury in Japan]

To assess the role of hepatitis G virus (HGV) in acute and chronic liver diseases, we investigated the prevalence of HGV RNA and antibodies to HGV envelope protein (anti-E2) among patients with liver diseases diagnosed in our hospital from 1992 to 1997. Among 24 patients with acute hepatitis (HAV: 13, HBV: 2, HCV: 3, CMV: 1, non A-C: 5), only 1 patient with non A-C hepatitis (4%) were positive for HGV RNA and none was positive for anti-E2. Among 461 patients with chronic liver diseases (alcohol: 27, HBV: 74, HCV: 297, HBV + HCV: 10, non B non C: 14, autoimmune and metabolic: 39), 40 patients (alcohol: 1, HBV: 3, HCV: 33, HBV + HCV: 3) were positive for HGV RNA(9%) and 48 patients were positive for anti-E2(17%). In the patients with positive for anti-E2, only 8% were positive for HGV RNA. 98% of HGV RNA positive patients were infected with HBV or HCV, and especially 82% were infected with HCV. In patients with non A-C hepatitis, none was positive for HGV RNA, so HGV seems not to have important role in liver diseases.     

Absence of hepatitis C virus RNA in ambiguous results of mass blood screening for hepatitis C virus antibodies

The purpose of the study was to elucidate whether hepatitis C virus (HCV) RNA was present in the blood of patients from a Moscow therapeutic-and-prophylactic institution with uncertain results of a study of anti-HCV that were obtained using the algorithm developed for mass screening. The two-stage scheme of testing the serum for anti-HCV, which was obligatory in accordance with the Order of the Ministry of Health of the Russian Federation, was supplemented by a study the samples having a low optical density samples and those with controversial results in the test systems with the expanded spectrum of detectable anti-HCV, the instructions of which comprises criteria for an uncertain result. Sera with uncertain results of anti-HCV tests were assessed by two polymerase chain reaction (PCR) techniques for HCV RNA. The cDNA fragments complementary to HCV RNA were detected in the sera obtained from two elderly persons in PCR when a signal was recorded in agarose gel. The other real-time PCR failed to detect RNA in none sera with an uncertain result as to anti-HCV.