Research Findings - Research on Medical Consequences of Drug Abuse and Co-Occurring Infections (HIV/AIDS, HCV)
CD4+ T Cell-dependent Reduction in Hepatitis C Virus-specific Humoral Immune Responses after HIV Infection
Human immunodeficiency virus (HIV) infection adversely affects all stages of hepatitis C virus (HCV) infection, leading to increased rates of viral persistence, higher levels of HCV viremia, and accelerated progression of HCV-related liver disease. These disease interactions may result in part from impairment of B cell function, which is CD4(+) T cell dependent. To determine the effect of HIV infection on B cell function, authors compared HCV antibody levels and specificities in 29 HCV-infected persons before and after they acquired HIV and assessed the temporal correlation of these changes with overall CD4(+) T lymphocyte counts. The pre-HIV infection HCV antibody titer was a predictor of the subsequent titer for all antigens, and decreasing CD4(+) T cell numbers was strongly associated with a decrease in anti-HCV titers for several antigens. CD4(+) T cells counts of <500 cells/mm(3) were significantly associated with lower HCV antibody end-point titers. Higher HCV end-point titers were associated with fewer years from HIV infection and, for Core antigen, current drug use. The authors conclude that HCV-specific antibody production is impaired by HIV infection, and loss of antibody production depends on CD4(+) T cell depletion. However, the decrease in titers is less significant in those who continue to actively inject drugs. Netski, D.M., Mosbruger, T., Astemborski, J., Mehta, S., Thomas, D., and Cox, A. J. Infect. Dis. 195(6), pp. 857-863, 2007.
Hepatitis C Virus Infection is Associated with Insulin Resistance Among Older Adults with or at Risk of HIV Infection
The objectives of this research was to determine the associations of hepatitis C virus (HCV) infection with insulin resistance and abnormal glucose tolerance in a cohort of older adults with or at risk of HIV infection. A cross-sectional study of 267 HIV-infected and 179 at-risk-uninfected adults without a history of diabetes mellitus was employed. HCV antibody assays and RNA levels were performed to assess HCV status. Antiretroviral use, family history of diabetes, sedentary behavior, and sociodemographic data were obtained using standardized interviews. Fasting insulin levels and oral glucose tolerance tests were performed to assess two outcomes, the homeostasis model assessment of insulin resistance and abnormal glucose tolerance [impaired glucose tolerance (IGT) or diabetes]. Of 446 participants, 265 (59%) were HCV seropositive; of these, 199 (75%) had detectable HCV-RNA levels. Insulin resistance was greater among HCV-seropositive compared with seronegative participants, adjusting for body mass index, Hispanic ethnicity, age greater than 55 years, sedentary behavior (watching television > 4h/day), HIV status, HAART, and protease inhibitor (PI) use. Ninety-eight participants (22%) had abnormal glucose tolerance (69 with IGT and 29 with diabetes). Among HIV-infected participants, 25% were on non-PI HAART and 52% were on PI HAART, but HAART and PI use were not associated with insulin resistance or abnormal glucose tolerance. Among obese participants, abnormal glucose tolerance was more common in HCV-seropositive than seronegative individuals, whereas among non-obese participants there was no association. The potential impact of HCV co-infection and obesity on glucose metabolism should be recognized in clinical care, and addressed in future research studies of HIV-infected individuals. Howard, A.A., Lo, Y., Floris-Moore, M., Klein, R.S., Fleischer, N., and Schoenbaum, E.E. AIDS. 21(5), pp. 633-641, 2007.
Body Image in Older Men With or At-risk for HIV Infection
Authors performed a cross-sectional analysis of factors associated with negative body image among 550 older men with or at-risk for HIV infection, including demographics, depression, illicit drug use, and antiretroviral therapy adherence. Overall, 31 per cent of participants reported negative body image, which was independently associated with increased BMI, self-rated fair/poor health, depression, and erectile dysfunction, but not HIV status. Screening for and treating depression, sexual dysfunction, and obesity in older men should be considered. Sharma, A., Howard, A.A., Klein, R.S., Schoenbaum, E.E., Buono, D., Webber, M.P. AIDS Care. 19(2), pp. 235-241, 2007.
Factors Affecting Reproductive Hormones in HIV-infected, Substance-using Middle-aged Women
The objective of this study was to determine whether reproductive hormone levels are affected by human immunodeficiency virus (HIV) and drug use. HIV-infected and uninfected women (N=429), median age 45, were interviewed on menstrual frequency, demographic and psychosocial characteristics, and drug use behaviors. Serum was obtained on cycle days 1 to 5 in women reporting regular menses. Premenopausal-, early menopausal, and late menopausal transition and postmenopausal stages were assigned based on menstrual history. Serum was assayed for follicle-stimulating hormone (FSH), estradiol (E2), luteinizing hormone (LH), prolactin, thyroid-stimulating hormone, and inhibin B. Body mass index, HIV serostatus, and CD4+ counts were measured. Factors associated with hormone concentrations were assessed using uni- and multivariable analyses. Hormone concentrations were compared within menstrual status categories using nonparametric comparisons of means. In this cross-sectional analysis, LH and FSH increased, and E2 and inhibin B were significantly lower in women of older age and more advanced menopausal status. Increased body mass index was strongly associated with decreased LH. Opiate use was significantly associated with lower inhibin B and E2 and increased prolactin. Poorer self-rated health was statistically significantly associated with lower LH and FSH, but increased education was associated with higher LH and FSH. Among HIV-seropositive women, opiate users had detectably lower FSH and LH than nonusers, and use of highly active antiretroviral therapy was significantly related to higher LH, FSH, and E2, whereas cocaine use was associated with lower E2. Authors conclude that age and menopausal status are strongly related to reproductive hormones. Body mass index and use of opiates, cocaine, and highly active antiretroviral therapy as well as educational attainment and perceived health can significantly modify reproductive hormones during the menopausal transition and need to be considered when interpreting hormone levels in middle-aged women. Santoro, N., Lo, Y., Moskaleva, G., Arnsten, J.H., Floris-Moore, M., Howard, A.A., Adel, G., Zeitlian, G., Schoenbaum, E.E. Menopause. 14(5), pp. 859-865, 2007.
Decreased Bone Mineral Density and Increased Fracture Risk in Aging Men With or At Risk for HIV Infection
Osteopenia has been described in HIV-infected persons, but most studies have not focused on aging men, have not included an HIV-negative comparison group with similar risks to those of the HIV-infected men, or lacked data on fracture rates. Authors analyzed bone mineral density (BMD) and incident fractures in 559 men who were >or= 49 years old with or at-risk for HIV, including 328 with and 231 without HIV infection. Median age was 55 years, 56% were black and 89% had used illicit drugs. In unadjusted analysis, BMD was lower in HIV-infected compared with HIV-uninfected men at the femoral neck (0.97 +/- 0.14 versus 1.00 +/- 0.15 g/cm; P < 0.05) and lumbar spine (1.17 +/- 0.20 versus 1.20 +/- 0.21 g/cm; P = 0.06); both differences were significant (P < 0.05) after adjusting for age, weight, race, testosterone level, and prednisone and illicit drug use. Non-black race and body weight were independently associated with BMD at both measurement sites and methadone therapy was independently associated with spine BMD. Among HIV-infected men, 87% had taken antiretrovirals and 74% had taken protease inhibitors, but their use was not associated with BMD. Among men who had at least one subsequent study visit (94%), incident fracture rates per 100 person-years differed among men with normal BMD, osteopenia and osteoporosis (1.4 versus 3.6 versus 6.5; P < 0.01). A 38% increase in fracture rate among HIV-infected men was not statistically significant. The authors conclude that HIV infection is independently associated with modestly reduced BMD in aging men, and decreased BMD is associated with increased fracture risk. Arnsten, J.H., Freeman, R., Howard, A.A., Floris-Moore, M., Lo, Y., and Klein, R.S. AIDS. 21(5), pp. 617-623, 2007.
Hepatitis C or Dual Infections of HIV and HCV Factors Affecting Serum Concentrations of Hepatitis C Virus (HCV) RNA in HCVgenotype 1-Infected Patients with Chronic Hepatitis
The serum concentration of hepatitis C virus (HCV) RNA is usually stable (4 to 8 log(10) IU/ml) in untreated patients with chronic hepatitis C. While this baseline HCV RNA concentration ([HCV RNA](BL)) is predictive of a sustained virologic response to treatment, its determinants are only partially identified. The authors therefore analyzed the baseline characteristics of 2,472 HCV genotype 1-infected patients to identify correlations with gender, age, race, weight, body mass index (BMI), HCV acquisition mode, HCV subtype, alanine aminotransferase concentration, or histopathologic changes in the liver. After separation of the data according to four [HCV RNA](BL) groups (< or =5.0, >5.0 to 5.6, >5.6 to 5.9, and >5.9 log(10) IU/ml), the authors determined that increasing [HCV RNA](BL) correlated (P < 0.05) with increasing proportions of patients who were male, >40 years of age, or heavier (a weight of >85 kg or a BMI of >27 kg/m(2)). Histologic activity index (HAI) data were available for 1,304 of these patients: increasing [HCV RNA](BL) correlated with higher fibrosis and necrosis-inflammation scores. As a continuous variable, [HCV RNA](BL) correlated with age, gender, weight (continuous or < or =85 versus >85 kg), BMI (continuous or < or =27 versus >27 kg/m(2)), subtype, fibrosis score, and necrosis-inflammation score; however, multiple-regression analysis yielded P values of <0.1 only for age, gender, BMI (< or =27 versus >27 kg/m(2)), and fibrosis score. While these findings are suggestive of a role for these factors in maintenance of the pretreatment state of HCV infection, the multiple-regression model accounted for only < or =4.6% of the [HCV RNA](BL) differences between individuals (R(2) = 0.046 for 1,304 patients with HAI scores; 0.043 for all 2,472 patients). Ticehurst, J., Hamzeh, F., Thomas, D. J. Clin. Microbiol. 45, pp. 2426-2433, 2007.
Liver Enzyme Flares and Occult Hepatitis B in Persons with Chronic Hepatitis C Infection
Occult hepatitis B (HBV) has been reported in numerous clinical settings, but it remains unclear whether occult HBV contributes to liver damage. Given that typical chronic HBV infections often have periodic flairs in viral replication and liver damage, the authors hypothesized that occult HBV may also have flares in viral replication that are associated with increased liver enzymes. Authors screened hepatitis B surface antigen negative injection drug users with untreated chronic hepatitis C viral (HCV) infection for unexplained ALT/AST flares. To further enrich for individuals with possible occult HBV flares, the authors studied those individuals whose flares were associated with IgM antibodies to hepatitis B core antigen. Serum samples were assayed for HBV DNA and serologies were performed in serum collected 6 months before, at the time, and 6 months after the flare. HCV RNA levels were also determined. Controls consisted of individuals who also had ALT/AST flares but who were negative for IgM antibodies to hepatitis B core antigen. Seven study cases and eight control cases were identified. HBV DNA was detectable during the enzyme flares in 7/7 study cases versus 3/8 controls, p=0.026. HBV DNA levels during the flare were low, averaging 1943 +/- 2341 copies/ml, but were higher in study cases versus controls, p=0.002. No change in HCV levels was associated with the flares. In this population at high risk for occult HBV, AST/ALT flares can be associated with detection of HBV DNA. These findings may link occult hepatitis B to liver injury. Kannangai, R., Vivekanandan, P., Netski, D., Mehta, S., Kirk, G.D., Thomas, D.L., Torbenson, M. J. Clin. Virol. 39(2), pp. 101-105, 2007.
Progression of Fibrosis during Chronic Hepatitis C is Associated with Rapid Virus Evolution
Hepatic fibrosis is the primary mediator of disease due to chronic infection with hepatitis C virus (HCV). HCV exists as a quasispecies in each infected individual, and longitudinal viral sequence changes may reveal viral dynamics and the selection pressures applied by the host immune system. Thus, the authors hypothesized that patterns of sequence change might reveal the immunopathogenesis of fibrosis progression. They tested this hypothesis by studying individuals enrolled in a prospective study of chronic HCV-related hepatic fibrosis with little or no fibrosis at first biopsy (stage 0 or 1) and a second planned liver biopsy sample obtained 4 years later. Serum was obtained from five individuals with fast progression (FP; defined as a >2-stage change between visits) and 10 carefully matched individuals with slow progression (SP; defined as a <2-stage change between visits). The authors sequenced multiple cloned hemigenomic cDNAs from each person spanning six genes (core through NS3). Phylogenetic analysis revealed temporal shifts in phylogenetic clustering over time, suggesting frequent quasispecies replacement rather than simple diversification. In addition, mixed infections were detected in three subjects, with coexistence in two subjects (one FP, one SP) of subtypes 1a and 1b throughout the 4-year biopsy interval. Subjects with FP had a higher rate of evolution than subjects with SP, with a preponderance of synonymous changes, suggesting purifying selection, except in hypervariable region 1, where positive selection pressure is frequently detected. Thus, in a small but carefully matched cohort the authors found evidence for rapid neutral evolution of HCV in persons with rapid progression of hepatic fibrosis, suggesting higher turnover of infected cells. Wang, X.H., Netski, D.M., Astemborski, J., Mehta, S.H., Torbenson, M.S., Thomas, D.L., and Ray, S.C. J. Virol. 81(12), pp. 6513-6522, 2007.
Evidence for a Functional RNA Element in the Hepatitis C Virus Core Gene
In the core protein-coding region of hepatitis C virus (HCV), evidence exists for both phylogenetically conserved RNA structures and a +1 alternative reading frame (ARF). To investigate its role in HCV infection, the authors introduced four stop codons into the ARF of a genotype 1a H77 molecular clone. The changes did not alter the core protein sequence, but were predicted to disrupt RNA secondary structures. An attenuated infection was established after inoculation of the mutant HCV RNA into an HCV naive chimpanzee. The acute infection was atypical with low peak viremia, minimal alanine aminotransferase elevation, and early virus control by a diverse adaptive immune response. Sequencing circulating virus revealed progressive reversions at the third and then fourth stop codon. In cell culture, RNA replication of a genome with four stop codons was severely impaired. In contrast, the revertant genome exhibited only a 5-fold reduction in replication. Genomes harboring only the first two stop codons replicated to WT levels. Similarly, reversions at stop codons 3 and 4, which improved replication, were selected with recombinant, infectious HCV in cell culture. The authors conclude that ARF-encoded proteins initiating at the polyprotein AUG are not essential for HCV replication in cell culture or in vivo. Rather, their results provide evidence for a functionally important RNA element in the ARF region. McMullan, L., Grakoui, A., Evans, M., et al. PNAS. 104(8), pp. 2879-2884, 2007.
Hepatitis C Infection is Associated with Lower Lipids and High-sensitivity C-reactive Protein in HIV-infected Men
Increased cardiovascular risk has been linked to HIV infection and combination antiretroviral therapy, but the impact of hepatitis C virus (HCV) status on indices of cardiovascular risk has not been routinely assessed in the HIV-infected population. The objective of this study was to analyze associations of HCV, HIV, and combination antiretroviral therapy with lipid levels and C-reactive protein (CRP) among older men. The authors measured fasting total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride, and high-sensitivity CRP serum levels in a cross-sectional study of 108 HIV-infected and 74 HIV-uninfected at-risk older men. One hundred ten men (60%) had detectable HCV RNA, with no difference by HIV status (p = 0.25). The majority (88%) of men with HCV infection had a history of injection drug use. Among all men, HCV infection was independently associated with lower total cholesterol (p < 0.001), LDL-C (p < 0.001), triglycerides (p = 0.01), and CRP (p = 0.001). Among HIV-infected men, HCV infection was associated with lower total cholesterol (p < 0.001), LDL-C (p < 0.001), and CRP (p = 0.004). HCV infection was associated with lower triglycerides among men on protease inhibitors (PI) (p = 0.02) and non-PI combination antiretroviral therapy (p = 0.02), but not among antiretroviral-naive men. These findings demonstrate an association of lower serum lipid and CRP levels with HCV infection and suggest that HCV status should be assessed as an important correlate of cardiovascular risk factors in studies of older men with or at risk for HIV. Floris-Moore, M., Howard, A.A., Lo, Y., Schoenbaum, E.E., Arnsten, J.H., and Klein, R.S. AIDS Patient Care STDS. 21(7), pp. 479-491, 2007.
Co-morbid Medical and Psychiatric Illness and Substance Abuse in HCV-infected and Uninfected Veterans
Comorbidities may affect the decision to treat chronic hepatitis C virus (HCV) infection. The authors undertook this study to determine the prevalence of these conditions in HCV-infected persons compared with HCV-uninfected controls. Demographic and comorbidity data were retrieved for HCV-infected and -uninfected subjects from the VA National Patient Care Database using ICD-9 codes. Logistic regression was used to determine the odds of comorbid conditions in the HCV-infected subjects. HCV-uninfected controls were identified matched on age, race/ethnicity and sex. Authors identified 126,926 HCV-infected subjects and 126,926 controls. The HCV-infected subjects had a higher prevalence of diabetes, anemia, hypertension, chronic obstructive pulmonary disease (COPD)/asthma, cirrhosis, hepatitis B and cancer, but had a lower prevalence of coronary artery disease and stroke. The prevalence of all psychiatric comorbidities and substance abuse was higher in the HCV-infected subjects. In the HCV-infected persons, the odds of being diagnosed with congestive heart failure, diabetes, anemia, hypertension, OPD/asthma, cirrhosis, hepatitis B and cancer were higher, but lower for coronary artery disease and stroke. After adjusting for alcohol and drug abuse and dependence, the odds of psychiatric illness were not higher in the HCV-infected persons. The prevalence and patterns of comorbidities in HCV-infected veterans are different from those in HCV-uninfected controls. The association between HCV and psychiatric diagnoses is at least partly attributable to alcohol and drug abuse and dependence. These factors should be taken into account when evaluating patients for treatment and designing new intervention strategies. Butt, A., Khan, U., McGinnis, K. Et al. J. Viral Hepat.14, pp. 890-896, 2007.
Impact of Hepatitis C Virus Infection and Other Comorbidities on Survival in Patients on Dialysis
The impact of hepatitis C virus (HCV) and other comorbid conditions upon survival is not well quantified in patients on dialysis. The authors identified HCV-infected and uninfected persons in the USRDS using claims data in 1997-1998 and followed until September 22, 2002 or death. They used Gray's time-varying coefficients model to examine factors associated with survival. Subjects with a renal transplant were excluded. A total of 5,737 HCV-infected and 11,228 HCV-uninfected persons were identified. HCV-infected subjects were younger (mean age 57.8 vs 65.3 years), more likely to be male (57.6%vs 49.6%) and black (54.0%vs 36.4%). They were more likely to have a diagnosis of drug (16.5%vs 4.6%) and alcohol use (14.0%vs 3.1%), and to be human immunodeficiency virus (HIV) co-infected (7.4%vs 1.8%) (all comparisons, P < 0.0005). In an adjusted Gray's time-varying coefficient model, HCV was associated with an increased risk of mortality (P < 0.0005). The hazards were highest at the time of HCV diagnosis and decreased to a stable level 2 years after diagnosis. Other factors associated with increased risk of mortality were (P < 0.0005 unless stated) HIV coinfection; diagnosis of drug use (P = 0.001); coronary artery disease (P = 0.006); stroke; diabetes as the primary cause for renal failure; peripheral vascular disease; depression and presence of anemia. HCV was associated with higher risk of death in patients on dialysis, even after adjusting for concurrent comorbidities. The risk was highest at the time of HCV diagnosis and stabilized over time. Clinical trials of HCV screening and treatment to reduce mortality in this population are warranted. Butt, A.A., Skanderson, M., McGinnis, K.A., Ahuja, T., Bryce, C.L., Barnato, A.E., and Chang, C.C. J. Viral Hepat. 14(10), pp. 688-696, 2007.
Biochemical and Virologic Parameters in Patients Co-infected with Hepatitis C and HIV Versus Patients with Hepatitis C Mono-infection
Previous studies of patients with hepatitis C virus (HCV) infection looking at the effect of human immunodeficiency virus (HIV) co-infection on biochemical parameters and HCV RNA level have shown conflicting results. Accurate characterization of the effect of HIV is important for evaluation and treatment of HCV in coinfected persons. Authors studied 315 HCV mono-infected and 75 HCV-HIV co-infected subjects to determine the effect of HIV on biochemical parameters and HCV RNA and to determine the predictors of elevated serum alanine aminotransferase (ALT) levels and HCV RNA levels. The co-infected subjects were more likely to be African-American (55% vs 26%, P<0.0005), have used injection drugs (68% vs 60%, P = 0.02), have detectable HCV RNA (84% vs 70.5%, P=0.018), have HCV RNA levels >6 log10 IU/mL (60% vs 38%, P=0.001), and have lower mean serum ALT levels (50.4 IU/mL vs 73.7 IU/mL, P=0.006). In multivariable analyses, the following factors predicted an ALT level >50 IU/mL: log10 HCV RNA (OR, 1.15; 95% CI, 1.00 to 1.32); HIV co-infection (OR, 0.48; 95% CI, 0.25-0.89); and having ever been treated for HCV (OR, 1.92; 95% CI, 1.16 to 3.18). The only significant predictor of HCV RNA level >6 log10 IU/mL was HIV co-infection (OR, 2.75; 95% CI, 1.46-5.15). Significant predictors of having a detectable HCV RNA level were female sex (OR, 3.81; 95% CI, 1.18-12.25); HIV co-infection (2.45; 95% CI, 1.14-5.26); and ever being treated for HCV (OR, 1.96; 95% CI, 1.10 to 3.48). HCV-HIV co-infected persons have higher HCV RNA levels but lower serum ALT levels than HCV mono-infected patients. Criteria for performing liver biopsy and treating HCV infection in co-infected patients may need to be revisited. Butt, A., Tsevat, J., Ahmad, J., et al., Am.J.Med.Sci. 333, pp. 271-275, 2007.
Two-step Tuberculin Skin Testing in Drug Users
To assess the utility of booster testing and to identify factors associated with a positive booster test, two-step tuberculin testing was performed in drug users recruited from methadone treatment. Participants also received a standardized interview on demographics and testing for HIV and CD4+ lymphocyte count. Of 619 enrollees completing the protocol, 174 (28%) had a positive PPD and 24 of the remaining 445 (5%) had a positive booster test. On multivariate analysis, boosting was associated with older age (adjusted odds ratio [ORadj] 2.38/decade, 95% confidence interval [CI] 1.34-4.22), history of using crack cocaine (ORadj 2.61, 95% CI 1.10-6.18) and a history of working as a home health aide (ORadj 4.23, 95% CI 1.39-12.86). Two-step tuberculin skin testing increased the proportion of participants with latent tuberculosis infection from 22% to 25%. Given the effectiveness of chemoprophylaxis, booster testing should be considered when drug users are screened for tuberculosis infection. Swaminathan, S., Schoenbaum, E., Klein, R. et al. J. Addict. Dis. 26(2), pp. 71-79, 2007.