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1.  Relation of HLA Class I and II Supertypes with Spontaneous Clearance of Hepatitis C Virus 
Genes and immunity  2013;14(5):330-335.
Human leukocyte antigen (HLA) genotype has been associated with probability of spontaneous clearance of hepatitis C virus (HCV). However, no prior studies have examined whether this relationship may be further characterized by grouping HLA alleles according to their supertypes, defined by their binding capacities. There is debate regarding the most appropriate method to define supertypes. Therefore, previously reported HLA supertypes (46 class I and 25 class II) were assessed for their relation with HCV clearance in a population of 758 HCV-seropositive women. Two HLA class II supertypes were significant in multivariable models that included: (i) supertypes with significant or borderline associations with HCV clearance after adjustment for multiple tests, and (ii) individual HLA alleles not part of these supertypes, but associated with HCV clearance in our prior study in this population. Specifically, supertype DRB3 (prevalence ratio (PR)=0.4; p=0.004) was associated with HCV persistence while DR8 (PR=1.8; p=0.01) was associated with HCV clearance. Two individual alleles (B*57:01 and C*01:02) associated with HCV clearance in our prior study became non-significant in analysis that included supertypes while B*57:03 (PR=1.9; p=0.008) and DRB1*07:01 (PR=1.7; p=0.005) retained significance. These data provide epidemiologic support for the significance of HLA supertypes in relation to HCV clearance.
PMCID: PMC3723800  PMID: 23636221
hepatitis C virus; HLA; human leukocyte antigen; supertype
2.  Fc Gamma Receptor 3A Polymorphism and Risk for HIV-Associated Cryptococcal Disease 
mBio  2013;4(5):e00573-13.
Cryptococcus neoformans is one of the most common causes of fungal disease in HIV-infected persons, but not all of those who are infected develop cryptococcal disease (CD). Although CD4+ T cell deficiency is a risk factor for HIV-associated CD, polymorphisms of phagocytic Fc gamma receptors (FCGRs) have been linked to CD risk in HIV-uninfected persons. To investigate associations between FCGR2A 131 H/R and FCGR3A 158 F/V polymorphisms and CD risk in HIV-infected persons, we performed PCR-based genotyping on banked samples from 164 men enrolled in the Multicenter AIDS Cohort Study (MACS): 55 who were HIV infected and developed CD and a matched control group of 54 who were HIV infected and 55 who were HIV uninfected. Using additive and allelic statistical models for analysis, the high-affinity FCGR3A 158V allele was significantly associated with CD status after adjusting for race/ethnicity (odds ratio [OR], 2.1; P = 0.005), as was the FCGR3A 158 VV homozygous genotype after adjusting for race/ethnicity, rate of CD4+ T cell decline, and nadir CD4+ T cell count (OR, 21; P = 0.005). No associations between CD and FCGR2A 131 H/R polymorphism were identified. In binding studies, human IgG (hIgG)-C. neoformans complexes exhibited more binding to CHO-K1 cells expressing FCGR3A 158V than to those expressing FCGR3A 158F, and in cytotoxicity assays, natural killer (NK) cells expressing FCGR3A 158V induced more C. neoformans-infected monocyte cytotoxicity than those expressing FCGR3A 158F. Together, these results show an association between the FCGR3A 158V allele and risk for HIV-associated CD and suggest that this polymorphism could promote C. neoformans pathogenesis via increased binding of C. neoformans immune complexes, resulting in increased phagocyte cargo and/or immune activation.
HIV-associated CD4+ T cell deficiency is a sine qua non for HIV-associated cryptococcal disease (CD), but not all patients with CD4+ T cell deficiency develop CD despite serological evidence of previous infection. At present, there are no biomarkers that predict HIV-associated CD risk. The goal of our study was to understand whether Fc gamma receptor (FCGR) polymorphisms that have been shown to portend CD risk in HIV-uninfected people are associated with CD risk in HIV-infected people. Such biomarkers could identify those who would benefit most from targeted prophylaxis and/or earlier treatment, particularly in sub-Saharan Africa, where there are nearly a million cases of HIV-associated CD annually. A biomarker of risk could also identify potential candidates for immunization, should there be a vaccine for Cryptococcus neoformans.
PMCID: PMC3760251  PMID: 23982074
3.  The Relation of HLA Genotype to Hepatitis C Viral Load and Markers of Liver Fibrosis in HIV-Infected and HIV-Uninfected Women 
The Journal of Infectious Diseases  2011;203(12):1807-1814.
Background. Human leukocyte antigen (HLA) class I and II genotype is associated with clearance of hepatitis C virus (HCV) infection, but little is known regarding its relation with HCV viral load or risk of liver disease in patients with persistent HCV infection.
Methods. High-resolution HLA class I and II genotyping was conducted in a prospective cohort of 519 human immunodeficiency virus (HIV)–seropositive and 100 HIV-seronegative women with persistent HCV infection. The end points were baseline HCV viral load and 2 noninvasive indexes of liver disease, fibrosis-4 (FIB-4), and the aspartate aminotransferase to platelet ratio index (APRI), measured at baseline and prospectively.
Results. DQB1*0301 was associated with low baseline HCV load (β = −.4; 95% confidence interval [CI], −.6 to −.3; P < .00001), as well as with low odds of FIB-4–defined (odds ratio [OR], .5; 95% CI, .2–.9; P = .02) and APRI-defined liver fibrosis (OR, .5; 95% CI, .3–1.0; P = .06) at baseline and/or during follow-up. Most additional associations with HCV viral load also involved HLA class II alleles. Additional associations with FIB-4 and APRI primarily involved class I alleles, for example, the relation of B*1503 with APRI-defined fibrosis had an OR of 2.0 (95% CI, 1.0–3.7; P = .04).
Conclusions. HLA genotype may influence HCV viral load and risk of liver disease, including DQB1*0301, which was associated with HCV clearance in prior studies.
PMCID: PMC3100515  PMID: 21606539
4.  Hepatitis C Viremia Is Associated with Cytomegalovirus IgG Antibody Levels in HIV-Infected Women 
PLoS ONE  2013;8(4):e61973.
Individuals with HIV infection exhibit high cytomegalovirus (CMV) IgG levels, but there are few data regarding the association of hepatitis C virus (HCV) with the immune response against CMV.
Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART) prior to or at CMV testing.
In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 – 4.83; P = 0.004). The association of HCV RNA with CMV IgG differed by age (Pinteraction = 0.0007), with a strong association observed among women in the low and middle age tertiles (≤45.3 years of age; β = 6.21, 95% CI:3.30 – 9.11, P<0.0001) but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV) IgG levels did not affect the association between HCV and CMV.
CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients.
PMCID: PMC3629158  PMID: 23613990
5.  Specific HLA Class I and II Alleles Associated with Hepatitis C Virus Viremia 
Hepatology (Baltimore, Md.)  2010;51(5):1514-1522.
Studies of human leukocyte antigen (HLA) alleles and their relation with hepatitis C virus (HCV) viremia have had conflicting results. However, these studies have varied in size and methods, and few large studies assessed HLA class I alleles. Only one study conducted high resolution class I genotyping. The current investigation therefore involved high-resolution HLA class I and II genotyping of a large multi-racial cohort of US women with high prevalence of HCV and HIV. Our primary analyses evaluated associations between twelve HLA alleles identified through a critical review of the literature and HCV viremia in 758 HCV-seropositive women. Other alleles with >5% prevalence were also assessed; previously unreported associations were corrected for multiple comparisons. DRB1*0101 (prevalence ratio [PR] = 1.7; 95% confidence interval [CI] = 1.1–2.6), B*5701 (PR=2.0; 95% CI = 1.0–3.1), B*5703 (PR = 1.7; 95% CI = 1.0–2.5), and Cw*0102 (PR = 1.9; 95% CI = 1.0–3.0) were associated with the absence of HCV RNA (i.e., HCV clearance), while DRB1*0301 (PR = 0.4; 95% CI = 0.2–0.7) was associated with HCV RNA positivity. DQB1*0301 was also associated with the absence of HCV RNA but only among HIV-seronegative women (PR = 3.4; 95% CI = 1.2–11.8). Each of these associations was among those predicted. We additionally studied the relation of HLA alleles with HCV infection (serostatus) in women at high risk of HCV from injection drug use (IDU; N=838), but no significant relationships were observed.
HLA genotype influences host capacity to clear HCV viremia. The specific HLA associations observed in the current study are unlikely to be due to chance since they were a priori hypothesized.
PMCID: PMC2946382  PMID: 20169624
human leukocyte antigen; HIV; injection drug user; multiple comparisons; killer immunoglobulin-like receptor
6.  Not All Injection Drug Users are Created Equal: Heterogeneity of HIV, Hepatitis C Virus, and Hepatitis B Virus Infection in Georgia 
Substance use & misuse  2008;43(10):1424-1437.
Injection drug users (IDU) are widely believed to have accelerated the looming HIV/AIDS epidemic now faced by the Russian Federation and countries of the former Soviet Union. However, IDUs may be heterogeneous with regard to risk behaviors and a sub-population may be responsible for the majority of blood-borne pathogen transmission. We studied 926 adult injection drug users (IDU) from the cities of Tbilisi, Batumi, and Poti in Georgia, a small country in the Caucuses region between the Black and Caspian Seas, between 1997 and 1998. Study participants were administered a confidential questionnaire and were tested for antibody to HIV, hepatitis C virus (HCV), hepatitis B virus surface antigen (HBsAg), and hepatitis B core antibody (anti-HBc). Five (0.5%) individuals were positive for HIV, 539 (58.2%) for HCV, 67 (7.2%) for HBsAg, and 475 for (51.3%) for anti-HBc. 88.7% of the surveyed individuals reported sharing needles with others, and needle sharing with more than ten other individuals versus no sharing was a highly significant predictor (OR: 278.12, 95% CI: 77.57, 997.20) of HCV seropositivity. In adjusted analysis, individuals who usually injected stolen medical/synthetic drugs had significantly lower odds of HCV (OR: 0.38, 95% CI: 0.22, 0.68) and HBV (OR: 0.58, 95% CI: 0.37, 0.90) than individuals most commonly injecting opium. Despite some limitations, these results suggest the presence of substantial heterogeneity between different injection drug-using groups in Georgia. Identification of high risk IDU sub-populations is vital to efficiently target risk reduction programs, and to prevent confounding by risk status in large HIV/AIDS behavioral intervention and vaccine trials.
PMCID: PMC2825388  PMID: 18696377
epidemiology; HIV; hepatitis C virus; hepatitis B virus; injection drug users; heroin; synthetic drugs; Georgia; Caucasus region; former Soviet Union
7.  Risk factors and algorithms to identify hepatitis C, hepatitis B, and HIV among Georgian tuberculosis patients 
To determine prevalence, risk factors, and simple identification algorithms for HIV, hepatitis B, and hepatitis C co-infection; factors that may predispose for anti-tuberculosis therapy-induced hepatoxicity.
We recruited 300 individuals at in-patient tuberculosis hospitals in three cities in Georgia, administered a behavioral questionnaire, and tested for antibody to HIV, hepatitis C (HCV), hepatitis B core antigen (anti-HBc), and the hepatitis B surface antigen (HBsAg).
0.7% of the individuals were HIV positive, 4.3% were HBsAg positive, 8.7% were anti-HBc positive, and 12.0% were HCV positive. In multivariable analysis, a history of blood transfusion, injection drug use, and prison were significant independent risk factors for HCV, while a history of blood transfusion, injection drug use, younger age at sexual debut, and a high number of sex partners were significant risk factors for HBV. Three-questionnaire item algorithms predicted HCV serostatus 74.1% of the time and HBV serostatus 85.2% of the time.
Treatment of tuberculosis patients in resource-limited countries with concurrent epidemics of HCV, HBV, and HIV may be associated with significant hepatoxicity. Serologic screening of tuberculosis patients for HBV, HCV and HIV or using behavioral algorithms to identify patients in need of intensive monitoring during anti-tuberculosis therapy may reduce this risk.
PMCID: PMC2649965  PMID: 17644020
hepatitis C; HIV; hepatitis B; tuberculosis; hepatoxicity; Georgia; epidemiology
8.  Human Leukocyte Antigen Genotype and Risk of HIV Disease Progression before and after Initiation of Antiretroviral Therapy▿‡ 
Journal of Virology  2011;85(20):10826-10833.
While the human leukocyte antigen (HLA) genotype has been associated with the rate of HIV disease progression in untreated patients, little is known regarding these relationships in patients using highly active antiretroviral therapy (HAART). The limited data reported to date identified few HLA-HIV disease associations in patients using HAART and even occasional associations that were opposite of those found in untreated patients. We conducted high-resolution HLA class I and II genotyping in a random sample (n = 860) of HIV-seropositive women enrolled in a long-term cohort initiated in 1994. HLA-HIV disease associations before and after initiation of HAART were examined using multivariate analyses. In untreated HIV-seropositive patients, we observed many of the predicted associations, consistent with prior studies. For example, HLA-B*57 (β = −0.7; 95% confidence interval [CI] = −0.9 to −0.5; P = 5 × 10−11) and Bw4 (β = −0.2; 95% CI = −0.4 to −0.1; P = 0.009) were inversely associated with baseline HIV viral load, and B*57 was associated with a low risk of rapid CD4+ decline (odds ratio [OR] = 0.2; 95% CI = 0.1 to 0.6; P = 0.002). Conversely, in treated patients, the odds of a virological response to HAART were lower for B*57:01 (OR = 0.2; 95% CI = 0.0 to 0.9; P = 0.03), and Bw4 (OR = 0.4; 95% CI = 0.1 to 1.0; P = 0.04) was associated with low odds of an immunological response. The associations of HLA genotype with HIV disease are different and sometimes even opposite in treated and untreated patients.
PMCID: PMC3187522  PMID: 21849458
9.  Marginal and Mixed Effects Models in the Analysis of HPV Natural History Data 
Human papillomavirus (HPV) natural history has several characteristics that, at least from a statistical perspective, are not often encountered elsewhere in infectious disease and cancer research. There are, for example, multiple HPV types, and infection by each HPV type may be considered separate events. While concurrent infections are common, the prevalence, incidence, duration/persistence of each individual HPV can be separately measured. However, repeated measures involving the same subject tend to be correlated. The probability of detecting any given HPV type, for example, is greater among individuals who are currently positive for at least one other HPV type. Serial testing for HPV over time represents a second form of repeated measures. Statistical inferences that fail to take these correlations into account would be invalid. However, methods that do not use all the data would be inefficient. Marginal and mixed effects models can address these issues, but are not frequently utilized in HPV research. The current paper provides an overview of these methods, and then uses HPV data from a cohort of HIV-positive women to illustrate how they may be applied, and compare their results. The findings show the greater efficiency of these models compared with standard logistic regression and Cox models. Because mixed effects models estimate subject-specific associations, they sometimes gave much higher effect estimates than marginal models, which estimate population-averaged associations. Overall, the results demonstrate that marginal and mixed effects models are efficient for studying HPV natural history, but also highlight the importance of understanding how these models differ.
PMCID: PMC2839537  PMID: 20056635
statistical methods; cervical neoplasia; human papillomavirus; HPV; HIV; frailty models; mixed effects models; WLW models; frailty models
10.  Epidemiology of Hepatitis E Virus in the United States: Results from the Third National Health and Nutrition Examination Survey, 1988–1994 
Hepatitis E virus (HEV) is prevalent and causes disease worldwide, but its epidemiological profile is only partially understood.
We used an enzyme immunoassay to measure anti-HEV immunoglobulin G antibodies in 18,695 serum samples collected in the Third National Health and Nutrition Examination Survey. We calculated estimates of HEV seroprevalence and examined associations with putative risk factors.
The seroprevalence of HEV in the civilian noninstitutionalized United States (US) population during the period from 1988 through 1994 was 21.0% (95% confidence interval [CI], 19.0%–22.9%). Among US-born individuals, males, non-Hispanic whites, and individuals residing in the Midwest and/or in metropolitan areas had the highest seroprevalence estimates. Having a pet in the home (odds ratio [OR], 1.19 [95% CI, 1.01–1.40]) and consuming liver or other organ meats more than once per month (OR, 1.38 [95% CI, 1.01–1.88]) were significantly associated with increased odds of HEV seropositivity.
Exposure to HEV is common in the US population, although hepatitis E is rarely reported. Having pets and consuming organ meats may play a role in HEV transmission in the United States, but other mechanisms of transmission may also exist. HEV may be considered a possible etiologic agent of acute and chronic hepatitis in US patients reporting no travel history.
PMCID: PMC2762746  PMID: 19473098
11.  Aflatoxin Exposure and Viral Hepatitis in the Etiology of Liver Cirrhosis in The Gambia, West Africa 
Environmental Health Perspectives  2008;116(11):1553-1557.
Cirrhosis of the liver is thought to be a major cause of morbidity and mortality in sub-Saharan Africa, but few controlled studies on the etiology of cirrhosis have been conducted in this region.
We aimed to elucidate the association between environmental and infectious exposures and cirrhosis in The Gambia.
Ninety-seven individuals were diagnosed with cirrhosis using a validated ultrasound scoring system and were compared with 397 controls. Participants reported demographic and food frequency information. Blood samples were tested for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), hepatitis C virus (HCV) antibody, HCV RNA, and the aflatoxin-associated 249ser TP53 mutation.
HBsAg seropositivity was associated with a significant increase in risk of cirrhosis [odds ratio (OR) = 8.0; 95% confidence interval (CI), 4.4–14.7] as was the presence of HBeAg (OR = 10.3; 95% CI, 2.0–53.9) and HCV infection (OR = 3.3; 95% CI, 1.2–9.5). We present novel data that exposure to aflatoxin, as assessed both by high lifetime groundnut (peanut) intake and by the presence of the 249ser TP53 mutation in plasma, is associated with a significant increase in the risk for cirrhosis (OR = 2.8; 95% CI, 1.1–7.7 and OR = 3.8; 95% CI, 1.5–9.6, respectively). Additionally, aflatoxin and hepatitis B virus exposure appeared to interact synergistically to substantially increase the risk of cirrhosis, although this was not statistically significant.
Our results suggest that the spectrum of morbidity associated with aflatoxin exposure could include cirrhosis.
PMCID: PMC2592277  PMID: 19057710
aflatoxin; Africa; hepatitis B virus; liver cirrhosis; p53; The Gambia; ultrasound
12.  Prevalence of Hepatitis C, HIV, and Risk Behaviors for Blood-Borne Infections: A Population-Based Survey of the Adult Population of T'bilisi, Republic of Georgia 
Journal of Urban Health   2006;83(2):289-298.
Injection drug use and associated hepatitis C virus (HCV) and HIV infections are on the rise in Russia and the republics of the former Soviet Union. While small targeted studies have found widespread drug use and disease among at-risk populations, there have been few attempts to comprehensively evaluate the extent of these epidemics in general post-Soviet societies. We conducted a two-stage cluster randomized survey of the entire adult population of T'bilisi, Republic of Georgia and assessed the burden of HCV, HIV, and risk behaviors for blood-borne infections in 2,000 study participants. Of the 2,000 surveyed individuals, 162 (8.1%) had injected illicit drugs during their lifetimes. Of the individuals who had injected illicit drugs, 138 (85.2%) reported sharing needles with injection partners. HCV was found in 134 (6.7%) of the total surveyed population, but in 114 (70.4%) of those who had injected illicit drugs. We found HIV in only three (0.2%) individuals, all of whom had injected illicit drugs. Injection drug use and high-risk injection practices are very common in Georgia and may be harbingers of a large burden of HCV-associated liver diseases and a potentially serious HIV epidemic in the years to come.
PMCID: PMC2527157  PMID: 16736377
Hepatitis C virus; HIV; Injection drug use; Needle sharing; Republic of Georgia

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