Hepatitis C virus (HCV) viremia in HIV-infected patients without HCV antibodies detectable by third-generation enzyme immunoassay

BACKGROUND: The detection of hepatitis C virus antibody (anti-HCV) by enzyme immunoassay to screen HCV infection in HIV-1-infected individuals may yield false negative results, especially in patients with advanced immunosuppression. In such cases, a diagnosis would be possible only by use of a viral RNA detection technique. Third-generation anti-HCV enzyme immunoassays seem to have superior performance compared to second-generation immunoassays in this context. METHODS: A cross-sectional study was conducted to ascertain the presence of HCV by polymerase chain reaction (PCR) in 61 HIV-1-infected patients with CD(4)(+) cell counts <200 cells/mm(3), and no detectable HCV antibodies by a third-generation enzyme immunoassay. RESULTS: Six (10%) of 61 patients tested HCV-RNA positive by PCR assay. There was one patient who seroconverted during observation. Hence, there were five patients with HCV viremia without detectable antibodies to HCV throughout the study, which represents 8.2% (95% confidence interval: 2.8-18.4) of 61 HIV-1-infected patients. All five carriers of HCV viremia had CD4 counts <100 cells/mm(3) and were diagnosed with an opportunistic disease at some stage. CONCLUSIONS: The HCV viremia and no detectable HCV antibodies by third-generation immunoassay were found only in individuals with a CD(4) count of <100 cells/mm(3). Molecular assays to detect HCV-RNA should be considered as an important tool to diagnose hepatitis C in HIV-1-infected patients with advanced immunosuppression.     

Diagnosis of hepatitis C virus (HCV) infection: diagnostic value of the anti-HCV test]

Different groups of patients were analysed for antibody to hepatitis-C-virus (anti-HCV). A high prevalence was found in individuals with parenteral exposure (chronic Non-A, Non-B hepatitis, 77.5%, drug addicts 84.5%), while blood donors had a prevalence of 0.51%, this was significantly higher in patients with chronic type B hepatitis (30%), in homosexuals (22.5%) and in patients with different types of autoimmune hepatitis (57.2%). This indicates that differential diagnosis of chronic hepatitis and indications for alpha interferon therapy is not possible by simply anti-HCV testing. Further studies are required to establish the diagnostic value of the anti-HCV test.     

Prediction of the hepatitis C viremia using immunoassay data and clinical expertise

Detection of anti-hepatitis C virus (anti-HCV) antibodies may yield a high frequency of false-positive results in people at low risk. To date, no clinical rule had been developed to predict viremia in HCV-seropositive patients. Therefore, we aimed to generate a prediction rule on the basis of clinical and serologic data, which can be used in outpatient care. We selected 114 seropositive patients without antiviral treatment or hepatitis B coinfection. Subsequently we identified independent predictors of the hepatitis C viremia by logistic regression and selected the quantitative value of the screening test for anti-HCV antibodies with the best performance in detecting viremia. Then, we combined clinical and serologic data to generate different prediction rules. Ratio of immunoassay signal strength of the sample to cut-off (S/CO) >15 had accuracy, positive predictive value (PPV) and positive likelihood ratio (LR+) of 84%, 83%, and 3.7; respectively. The rule compounded of the antecedent of blood transfusion before 1993 and S/CO >15 performed the best in prediction of viremia in all patients, with accuracy, PPV and LR+ of 71%, 88%, and 5.6; respectively. In the group of asymptomatic patients this rule improved in efficacy of prediction, with accuracy, PPV and LR+ of 79%, 91% and 12.8; respectively. In conclusion, a clinical rule is better than S/CO alone in prediction of the hepatitis C viremia. In a patient that meet the rule the probability of having viremia is high, therefore, it can be indicated directly an assay for viral load instead of other supplemental tests, thus, saving time and economic resources.     

Hepatitis C virus (HCV) specific immune responses in anti-HCV positive patients without hepatitis C viraemia

BACKGROUND/AIMS: Most patients infected with hepatitis C virus (HCV) develop chronic infection and persistent viraemia. The immune mechanisms responsible for resolution of viraemia remain poorly understood. HCV specific humoral and cellular immune responses in patients with and without viraemia were investigated. METHODS: In vitro T helper (TH) lymphocyte responses to structural and non-structural HCV proteins were determined by means of proliferative response and cytokine production in 35 anti-HCV positive/HCV RNA negative patients and in 31 patients with chronic HCV infection and persistent viraemia. Humoral responses were determined by measuring HCV specific antibody quantity and specificity. RESULTS: A TH response to two or more HCV proteins was present in 18 of 35 patients with serological viral clearance compared with just one of 31 viraemic patients (p = 0.00001). HCV specific interferon-gamma production was increased only in the former group. In contrast, the antibody levels were significantly lower and directed at fewer HCV antigens in patients with undetectable HCV RNA. CONCLUSIONS: Patients without viraemia after HCV infection frequently have strong TH lymphocyte responses of the TH1 type to multiple HCV antigens many years after the onset of infection, whereas antibody responses are less marked. These results suggest that control of HCV replication may depend on effective TH lymphocyte activation.     

The extrahepatic manifestations in hepatitis C virus (HCV) infection

The hepatitis C virus (HCV) infection could affect not only the liver, but also other tissues, organs and systems. The number of the reported in the literature extrahepatic lesions by HCV incessantly increases. A reliable association between the infections by HCV and the mixed cryoglobulinaemias, membrano-proliferative glomerulonephritis and porphyria cutanea tarda is confirmed. The participation of HCV in the pathogenesis of some diseases of the thyroid gland, the lymphocytic sialadenitis, lichen planus, diabetes mellitus, thrombocytopenia, antiphospholipid syndrome, etc., is assumed. The extrahepatic lesions by HCV are probably connected with the participation of the immune system, but they may be as well due to the replicating virus in the affected tissues, organs and systems. The pathogenetic mechanisms of the extrahepatic and autoimmune manifestations of the infection with HCV are not elucidated, which poses difficult therapeutic problems regarding the choice of interferon and/or corticosteroid hormones.     

Prevalence of hepatitis G virus (HGV) infection in an endemic area of hepatitis C virus (HCV) infection

BACKGROUND/AIMS: We investigated the prevalence of hepatitis G virus infection among inhabitants of a hepatitis C virus endemic area. METHODOLOGY: Two hundred and eighty-eight inhabitants, who underwent medical examinations for health screening, were enrolled in this epidemiological study. HGV RNA and HCV RNA were detected by polymerase chain reaction. We also examined anti-HGV envelope protein (E2) antibodies in all serum samples. RESULTS: In these 288 inhabitants, we found anti-HCV antibodies (HCV-Ab) and HCV RNA in 28.5% and 17.4%, respectively. HGV RNA and anti-HGV E2 were detected in 9 (3.1%) and 16 (5.5%), respectively. One patient was positive for both HGV RNA and anti-HGV E2. The exposure rate, expressed as the percentage of people with HGV RNA and/or anti-HGV E2, was 8.3%, which was significantly lower than the incidence of positive HCV-Ab. Of the 24 patients with HGV RNA and/or anti-HGV E2, 15 (62.5%) were positive for HCV-Ab, of those HCV RNA was detected in 9 (37.5%). Further, we found a higher prevalence of HGV exposure in patients with HCV-Ab than in those without (8.3% vs. 4.4%). CONCLUSIONS: HGV infection was not identical to the epidemic hepatitis C virus infection among inhabitants of this town, suggesting that hepatitis C virus might be less infectious than hepatitis C virus.     

A cohort study of hepatitis C virus (HCV) infection in an HCV epidemic area of Japan: age and sex-related seroprevalence of anti-HCV antibody, frequency of viremia, biochemical abnormality and histological changes

We studied the age- and sex-specific prevalence of hepatitis C virus (HCV) infection and aminotransferase abnormalities as well as histological changes in the liver associated with HCV infection. Of the eligible 3,707 inhabitants aged 6 years and older in an HCV infection epidemic area 2,382 (64.3%) were examined. The anti-HCV positivity rate was 20.7% on average and increased according to age. Age was the most potential risk indicator for anti-HCV positivity by multiple stepwise regression analysis. The HCV RNA positivity rate in females with anti-HCV was significantly lower than that in males. However, as the age of females increased, the HCV RNA positivity rate became higher. The proportion of subjects with aminotransferase abnormalities among HCV RNA-positive subjects was significantly lower in females than males. Aminotransferase abnormalities significantly increased with age in females. In subjects with abnormal aminotransferase levels, nearly half of the HCV RNA-positive females were aged 50 or older and also nearly half of the male subjects showed CAH2B or liver cirrhosis, while most of the HCV RNA-positive females younger than 50 exhibited histological findings consistent with CPH. In conclusion, age was the principal risk indicator for HCV infection in this area. Females, especially those younger than 50, both biochemically and histologically showed less severity of HCV infection than males. Gender and age might have effects on the outcome of HCV related liver disease.     

Hepatitis C viremia in patients with hepatitis C virus infection.

Sera from 103 patients were tested for hepatitis C virus RNA by nested polymerase chain reaction assay. Using primers from the highly conserved 5'-untranslated region, we detected hepatitis C virus RNA in 67 (88.2%) of 76 patients positive for antibody to hepatitis C virus by both second-generation and neutralization enzyme immunoassays. Hepatitis C virus RNA was detected in 93% of patients who had been infected for 10 yr or less and in 89% of those who had been infected for longer than 10 yr. Hepatitis C virus RNA was detected in all patients with chronic hepatitis, active cirrhosis or hepatocellular carcinoma and in 50% of those with nonspecific reactive hepatitis or inactive cirrhosis. Hepatitis C virus RNA was not detected in sera from 22 patients negative for antibody to hepatitis C virus or in 5 patients positive for antibody to hepatitis C virus by second-generation but not by neutralization enzyme immunoassay. Using primers from the less conserved nonstructural region 4, we detected hepatitis C virus RNA at a lower frequency, in 66% of patients who were positive for antibody to hepatitis C virus by both second-generation and neutralization enzyme immunoassays. The detection rate was higher in patients with frequent parenteral exposure. Our study showed that hepatitis C viremia can be detected in most patients with hepatitis C virus infection, including those with long-standing infection or advanced liver disease.     

慢性丙型肝炎病毒感染者外周血淋巴细胞增殖反应

目的　观察慢性丙型肝炎患者外周血淋巴细胞对丙型肝炎病毒（ＨＣＶ） 抗原刺激的增殖反应．方法　外周血单个核细胞（ＰＢＭＣ） 与ＨＣＶ 抗原ｃ２２ 、ｃ３３ 、ｃ１００ － ３ 、ＮＳ５ 和植物血凝素（ＰＨＡ） 分别共同孵育,加入胸腺嘧啶核苷（３ ＨＴｄＲ） ,然后收集细胞于液闪仪测定每分钟脉冲数（ｃｐｍ） ．结果　根据对不同ＨＣＶ 抗原的淋巴细胞增殖反应发现,以ｃ２２免疫原性最强,ｃ１００ － ３ 次之：淋巴细胞激活与ＨＣＶ 基因型关系不大;健康对照和慢性乙型肝炎患者对各ＨＣＶ 抗原未能显示有效的淋巴细胞增殖反应;与健康对照比较,慢性丙型肝炎和乙型肝炎患者对ＰＨＡ 刺激的淋巴细胞增殖反应降低．结论　ＨＣＶ 抗原ｃ２２ 免疫原性最强,丙型肝炎患者对ＨＣＶ 抗原的淋巴细胞增殖反应系特异性;慢性丙型肝炎和乙型肝炎患者存在抑制的细胞免疫应答．     

Clinical significance of hepatitis C virus (HCV) infection in liver transplant recipients

Hepatitis C virus (HCV) infection was studied in 60 liver transplant recipients. Antibodies to HCV were tested by both a second-generation ELISA test and a four-recombinant immunoblot assay (4-RIBA) just before the transplant and every three months thereafter. HCV RNA detection was performed by polymerase chain reaction (PCR) at least three times after the transplant in all the patients. Thirty-nine patients tested negative by ELISA before LT (group A), 14 patients tested positive by both serological tests (group B), and seven tested positive only by ELISA (group C). Posttransplant hepatitis was diagnosed in 11/14 in group B in comparison with 3/39 in group A (P<0.001) and 1/7 in group C (P<0.05). HCV RNA was detected in the sera of 14/14 patients in group B but in only 1/7 in group C and 6/39 in group A. Only 2/15 patients developed posttransplant hepatitis in the absence of HCV RNA detection. These data suggest that HCV is the major cause of hepatitis after LT. Patients HCV seropositive by RIBA test before the transplant formed a group of high-risk patients for developing viremia and hepatitis afterwards.Part of this work was presented at the XIVth International Congress of the Transplantation Society. Paris. August 1992.This work was supported by a grant from Fondo de Investigaciones Sanitarias de la Seguridad Social (FISS 92/0357).     

Compartmentalization of hepatitis C virus (HCV) during HCV/HIV coinfection

Extrahepatic replication has important implications for the transmission and treatment of hepatitis C virus (HCV). We analyzed longitudinal HCV diversity in peripheral-blood mononuclear cells (PBMCs) and serum during HCV monoinfection and HCV/HIV coinfection to determine whether distinct amino acid signatures characterized HCV replicating within PBMCs. Analysis of E1-HVR1 sequences demonstrated higher serum genetic distances among HCV/human immunodeficiency virus (HIV)-coinfected persons. Moreover, consensus PBMC sequences were rarely identical to those in the corresponding serum, suggesting divergence in these 2 compartments. Three of 5 HCV/HIV-coinfected participants showed evidence of HCV compartmentalization in PBMCs. Additionally, signature sequence analysis identified PBMC-specific amino acids in all HCV/HIV-coinfected persons. To our knowledge, this is the first study to identify specific amino acids that may distinguish HCV variants replicating in PBMCs. It is provocative to speculate that extrahepatic HCV diversity may be an important determinant of treatment response and thus warrants additional study, particularly during HCV/HIV coinfection.     

Hepatocellular carcinoma in Egyptians with and without a history of hepatitis B virus infection: association with hepatitis C virus (HCV) infection but not with (HCV) RNA level.

The aim of this study was to analyze the association of hepatocellular carcinoma (HCC) with hepatitis C virus (HCV) in Egypt, using hepatitis B virus (HBV) and hepatitis E virus (HEV) as virus controls. In addition, the association of HCC with HCV RNA levels among persons seropositive for HCV was analyzed. We compared 131 patients with proven HCC, 247 with bladder cancer, and 466 healthy hospital employees. Age, sex, and place of residence were recorded to study confounding factors. Among the healthy controls, 16% were seropositive for HCV, 21% for HBV, and 31% for HEV. When healthy controls were age-matched with HCC patients, the latter were significantly (P < 0.001) more often HCV seropositive (67%) than were the controls (30%). The seropositivity for HBV and HEV did not differ significantly in frequency between the two groups. The seropositivity for HCV was also significantly (P < 0.001) more often found in HCC patients (76%) than in BC patients (47%), with seroprevalences for HBV and HEV not differing significantly in these age-matched groups. In HBV-negative HCC and bladder cancer patients, seroprevalence for HCV was significantly (P = 0.002) higher in HCC patients (68%) than in bladder cancer patients (36%). This difference was even more pronounced (P < 0.001) in HBV-positive HCC and bladder cancer patients (78% versus 52%, respectively). Of HCV-seropositive individuals, 49% were HCV RNA positive by branched DNA assay, and of these, 96% were infected by HCV genotype 4. No correlation between HCV RNA load and seropositivity of HBV or age or disease state was found. Infection with HCV and HCV-HBV double infection, but not HBV or HEV infection alone, is strongly correlated with HCC in Egypt.     

New drugs for hepatitis C virus (HCV).

Lack of efficacy and significant side effects have severely limited the use of interferon-alpha (IFN-alpha) as the standard therapy for non-A non-B hepatitis (NANBH) caused by hepatitis C virus (HCV) and alternative, improved therapies are urgently sought. Attempts have been made to improve the potency and tolerability of IFN-alpha by adjusting dosing regimens, methods of delivery and length of treatment. Furthermore, a number of different agents have been used in combination wit IFN-alpha and, from these studies, therapeutic options have been galvanized by the synergistic effects of IFN-alpha and ribavirin. Nevertheless, the majority of patients with HCV still do not sustain lasting therapeutic benefit from this combination and continuing research is required to identify new therapeutic candidates that will have more potent antiviral activity and less severe side effects. This review focuses on the progress that has been made in this area and the prospects for new effective therapies in the near future.     

Serodiagnosis of hepatitis C virus (HCV) infection with an HCV core protein molecularly expressed by a recombinant baculovirus.

An enzyme-linked immunosorbent assay (ELISA) was developed for serological diagnosis of hepatitis C virus (HCV) infection, using HCV core protein (p22) synthesized by a recombinant baculovirus. Among 58 clinically well-defined chronic non-A, non-B hepatitis (NANBH) patients, 49 (84.5%) were positive for p22 antibody (anti-p22), whereas 42 (72.4%) were positive for C100-3 antibody (anti-C100-3), as measured by the present assay using the HCV nonstructural protein as antigen. Thirty-nine patients (67.2%) had both antibodies. No significant level of anti-p22 was detected in sera of chronic hepatitis B patients or normal blood donors. In typical post-transfusion NANBH patients, anti-p22 could be detected at, or even before, the first alanine aminotransferase peak. Anti-p22 was also detected in blood donors who were previously shown to be involved in transmitting HCV but in whose serum anti-C100-3 was not detectable. The ELISA detecting antibody to the HCV core protein expressed and properly processed in animal cells will be useful for mass screening of donor blood as well as for early diagnosis of hepatitis C.