HIV/HCV co-infection: pathogenesis, clinical complications, treatment, and new therapeutic technologies.

World-wide, hepatitis C virus (HCV) accounts for approximately 130 million chronic infections, with an overall 3% prevalence. Four to 5 million persons are co-infected with HIV. It is well established that HIV has a negative impact on the natural history of HCV, including a higher rate of viral persistence, increased viral load, and more rapid progression to fibrosis, end-stage liver disease, and death. Whether HCV has a negative impact on HIV disease progression continues to be debated. However, following the introduction of effective combination antiretroviral therapy, the survival of coinfected individuals has significantly improved and HCV-associated diseases have emerged as the most important co-morbidities. In this review, we summarize the newest studies regarding the pathogenesis of HIV/HCV coinfection, including effects of coinfection on HIV disease progression, HCV-associated liver disease, the immune system, kidney and cardiovascular disease, and neurologic status; and effectiveness of current anti-HIV and HCV therapies and proposed new treatment strategies.

Long-term serologic follow-up of isolated hepatitis B core antibody in HIV-infected and HIV-uninfected women.

BACKGROUND: Isolated antibody to hepatitis B core antigen (anti-HBc) is a common serologic finding in persons infected with human immunodeficiency virus (HIV), but the outcome and clinical significance are uncertain. METHODS: We performed repeated hepatitis B virus (HBV) serologic tests on women who participated in the Women's Interagency HIV Study and who had isolated anti-HBc at study entry. RESULTS: Repeated serologic tests were performed for 322 women (282 HIV-infected and 40 HIV-uninfected) at a median of 7.5 years after study entry. Seventy-one percent of women retained isolated anti-HBc serologic status, 20% acquired antibody to hepatitis B surface antigen (anti-HBs), and 2% acquired hepatitis B surface antigen (HBsAg). In unadjusted analysis, increasing age, injection drug use, and hepatitis C viremia were negatively associated with acquisition of anti-HBs. For HIV-infected women, predictors of acquisition of anti-HBs were an increase in CD4 cell count and the use of highly active antiretroviral therapy (HAART). Receipt of drugs with activity against HBV and self-reported HBV vaccination did not predict anti-HBs acquisition. In the multivariable regression model, HAART use remained a significant predictor of anti-HBs acquisition, whereas women with hepatitis C viremia were more likely to retain isolated anti-HBc serologic status. CONCLUSIONS: Isolated anti-HBc status remained stable over time for the majority of women, especially women with chronic hepatitis C virus infection. Development of anti-HBs was predicted by HAART use and an increase in CD4 cell count. We conclude that a proportion of HIV-infected women with isolated anti-HBc have prior natural HBV infection with anti-HBs that is at an undetectable level because of immune dysfunction. Isolated anti-HBc in the presence of chronic hepatitis C virus infection may be attributable to a different phenomenon, such as dysfunctional antibody production.

Lack of evidence for human herpesvirus-8 transmission via blood transfusion in a historical US cohort.

BACKGROUND: Recent studies have found evidence of occasional human herpesvirus (HHV)-8 transmission via blood transfusion. However, because these studies were conducted outside the United States or did not have linked donor-recipient pairs, they have a limited ability to inform US blood-banking policy. METHODS: We investigated HHV-8 transmission via blood transfusion in the United States by conducting HHV-8 serologic testing among participants of the Transfusion-Transmitted Viruses Study (TTVS), who enrolled during the 1970s. RESULTS: HHV-8 seroprevalence was 2.8% (29/1023) among blood donors, 7.1% (96/1350) among transfusion recipients, 7.7% (46/599) among surgical control patients who did not receive transfusions, and 96.3% (77/80) among control patients with Kaposi sarcoma. One transfusion recipient seroconverted (0.08% [1/1259]), but this patient did not receive any HHV-8-seropositive blood units, suggesting that the infection was not related to blood transfusion. One of the surgical control patients who did not receive transfusions also seroconverted (0.18% [1/556]). Rates of seroconversion were 1.6 per 1000 person-years (95% confidence interval [CI], 0.04-8.9 per 1000 person-years) for the transfusion recipients and 3.6 per 1000 person-years (95% CI, 0.09-20.1 per 1000 person-years) for the surgical control patients who did not receive transfusions (P = .61). CONCLUSIONS: Rates of HHV-8 seroconversion in the transfusion and nontransfusion groups were not statistically different, and the historical nature of the cohort (e.g., before leukoreduction) suggests that any current transmission via blood transfusion is rare.

Factors associated with hepatitis C viremia in a large cohort of HIV-infected and -uninfected women.

BACKGROUND: Co-infection with hepatitis C virus (HCV) is common among HIV-infected women. OBJECTIVE: To further our understanding of the risk factors for HCV viremia and the predictors of HCV viral load among women. STUDY DESIGN: We investigated sociodemographic, immunologic, and virologic factors associated with presence and level of HCV viremia among 1049 HCV-seropositive women, 882 of whom were HIV-infected and 167 HIV-uninfected at their entry into the Women's Interagency HIV Study. RESULTS: Plasma HCV RNA was detected in 852 (81%) of these 1049 women (range: 1.2-7.8 log(10)copies/ml). HCV-viremic women were more likely to have an HIV RNA level >100,000 copies/ml (P=0.0004), to have reported smoking (P=0.01), or to be Black (P=0.005). They were less likely to have current or resolved hepatitis B infection. HCV RNA levels were higher in women who were >35 years old, or HIV-infected. Current smoking and history of drug use (crack/freebase cocaine, marijuana, amphetamines, or heroin) were each associated with both presence and level of viremia. CONCLUSIONS: Substance abuse counseling aimed at eliminating ongoing use of illicit drugs and tobacco may reduce clinical progression, improve response to treatment, and decrease HCV transmission by lowering levels of HCV viremia in women.

Negative-strand hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells from anti-HCV-positive/HIV-infected women.

BACKGROUND: Hepatitis C virus (HCV) has been reported to replicate in peripheral blood mononuclear cells (PBMCs), particularly in patients coinfected with HCV and human immunodeficiency virus (HIV). However, there are limited data regarding the prevalence of and the factors associated with extrahepatic replication. METHODS: The presence of negative-strand HCV RNA in PBMCs was evaluated by a strand-specific assay for 144 anti-HCV-positive/HIV-infected women enrolled in the Women's Interagency HIV Study. One to 5 PBMC samples obtained from each woman were tested. Multivariate analyses were used to assess for associations with the clinical and demographic characteristics of the women. RESULTS: Negative-strand HCV RNA was detected in 78 (25%) of 315 specimens, and, for 61 women (42%), > or = 1 specimen was found to have positive results. The presence of negative-strand HCV RNA in PBMCs was significantly positively associated with an HCV RNA plasma level of > or = 6.75 log copies/mL (P=.04) and consumption of > or = 7 alcoholic drinks per week (P=.02). It was also negatively associated with injection drug use occurring in the past 6 months (P=.03). A negative association with a CD4+ CD38+ DR+ cell percentage of > 10% and a positive association with acquired immunodeficiency syndrome were borderline significant (P=.05). CONCLUSIONS: HCV replication in PBMCs is common among HIV-coinfected women and appears to be a dynamic process related to lifestyle, virologic, and immunologic factors.

HIV-1 superinfection is not a common event.

Evidence for human immunodeficiency virus type 1 (HIV-1) superinfection was investigated among a group of four previously HIV-1 infected transfusion recipients (and the four implicated HIV-1 infected donors) identified by the Transfusion Safety Study, and two groups of 4 and 5 Brazilian injection drug users, who consistently injected themselves using shared paraphernalia. To probe these cases for possible superinfection we used heteroduplex mobility analysis (HMA) of HIV-1 tat, a technique which is a reliable for establishing epidemiologic linkages and searching for minor strains in mixed infection settings. In all these cases with established, untreated HIV-1 infections, we were unable to detect HIV-1 superinfection, even though the involved individuals were at high risk for second strain acquisition. We therefore conclude that although superinfection can occur in a few cases, it is a rare event, and the vast majority of recombinant HIV-1s characterized to date resulted from acute coinfections, rather than superinfection.

Viral and host factors in early hepatitis C virus infection.

Since 1980, the Transfusion-transmitted Viruses Study (TTVS) (1974-1980) has continued to maintain its computerized database and stored sera to enable ongoing study of new transfusion events since the 1970s. Most recently, we have used this resource to study parameters of acute hepatitis C virus (HCV) infection among 94 donor-recipient pairs in which there was transmission. In addition, frequent recipient observations permitted further characterization of the early phase of the infection's course. Donor RNA load ranged from 3.7 to 3,160,000 IU/mL. Onset of recipient viremia was judged from a total of 67 sera collected during the 4th through 8th days posttransfusion; only 2 of the 67 sera were still RNA nonreactive by that time. The recipients' latent periods to an alanine aminotransferase (ALT) elevation of > or =90 IU/L ranged from 6 to 112 days (median, 46 days) and was shorter with higher donor RNA levels. Descriptors of the recipient's illness showed several strongly positive and negative correlations. The latent period tended to be shorter in the 37% of cases that were clinically overt. Attributes of donors with genotypes 1 and non-1 and subtypes 1a and 1b did not differ significantly. Recipients with genotype 1 strains had shorter latent intervals than non-1 strains. On multivariate analysis, latent period was significantly associated (negatively) only with the highest ALT level during the first 120 days of follow-up (P = .014). In conclusion, host factors are more important determinants of acute HCV infection dynamics than virus-associated factors.

HCV viral load in anti-HCV-reactive donors and infectivity for their recipients.

BACKGROUND: An attempt has been made to determine the minimum level of HCV nucleic acid in donors associated with infection of recipients. This is important for considerations about assay sensitivity, use of minipool versus single-donation testing, and continued use of serologic testing. STUDY DESIGN AND METHODS: A total of 5387 specimens from the Transfusion-Transmitted Viruses Study in the 1970s were screened for antibody to HCV (anti-HCV). The outcome in recipients of seroreactive donations was examined for viremia and seroconversion. Present techniques for both groups included third-generation EIA, RIBA, quantitative RT-PCR assay, and transcription-mediated amplification (TMA) assay. RESULTS: A total of 156 recipients of components from 180 anti-HCV-reactive donors were identified. One-hundred seven of these were HCV-naïve before transfusion and received a single, confirmed seropositive unit; 94 (88%) became infected. Eighty-five recipients had donors whose HCV RNA level was quantifiable by RT-PCR (range, 182-3,310,000 copies/mL). Eighty-three (98%) seroconverted. Of the remaining 22, a total of 10 received units positive for HCV RNA detected only by TMA; all 10 recipients seroconverted. Of the remaining 12 recipients of anti-HCV+, TMA-negative units, 1 recipient seroconverted. CONCLUSIONS: High rates of transmission were seen at all levels of viremia, and one donor transmitted with undetectable levels in the TMA assay. Current HCV RNA testing will therefore not interdict all infectious units, even with single-donation testing, and serologic screening must be continued.