HLA-B Bw4 alleles and HIV-1 transmission in heterosexual couples

BACKGROUND

Genetic factors may play a role in the transmission of HIV-1. Because HLA-B alleles influence HIV-1 disease progression and viral levels, they might also influence HIV-1 transmission.

OBJECTIVE

To investigate if the presence of HLA-B alleles with the Bw4 epitope in HIV-1-infected men decreased the risk of transmission to their female sex partners.

METHODS

The study comprised 304 HIV-1-infected men with hemophilia and 325 female sex partners. HLA class I genes were amplified using sequence-specific primers. Products of the polymerase chain reaction were blotted on nylon membranes and hybridized with sequence-specific oligonucleotide probes. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI) for HIV-1 infection among the women.

RESULTS

Among the 325 women, 44 (13.5%) were infected with HIV-1. HIV-1 infection in the women was associated with the HLA-B genotype of their male partner [Bw6/Bw6, 22/118 (18.6%); Bw4/Bw6, 18/154 (11.7%); Bw4/Bw4, 4/53 (7.6%)]. Compared with men who were homozygous for Bw6, men who carried Bw4 were about half as likely to have transmitted HIV-1 to their female partner (OR, 0.52; 95% CI, 0.27-0.98; P = 0.04). Transmission was higher among couples in which the man's ethnicity was other than White (OR, 2.60; 95% CI, 1.25-5.40; P = 0.01), but the association between HIV-1 transmission and HLA-B genotype was not confounded by race.

CONCLUSION

The presence of HLA-Bw4 in HIV-1-infected men was associated with a decreased risk of male-to-female HIV-1 transmission, which suggests that these alleles reduce infectivity for HIV-1.

Risk of human T-lymphotropic virus type I-associated diseases in Jamaica with common HLA types

Human T-lymphotropic virus-I (HTLV-I) causes adult T-cell leukemia/lymphoma (ATL) and HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). We postulated a higher disease risk for people with common human leukocyte antigen (HLA) types, due to a narrower immune response against viral or neoplastic antigens, compared to people with uncommon types. HLA class-I (A,B) and class-II (DRB1, DQB1) allele and haplotype frequencies in 56 ATL patients, 59 HAM/TSP patients and 190 population-based, asymptomatic HTLV-I-infected carriers were compared by logistic regression overall (score test) and with odds ratios (ORs) for common types (prevalence >50% of asymptomatic carriers) and by prevalence quartile. HTLV-I proviral load between asymptomatic carriers with common versus uncommon types was compared by t-test. ATL differed from asymptomatic carriers in overall DQB1 allele and class-I haplotype frequencies (p </=</= 0.04). ATL risk was increased significantly with common HLA-B (OR 2.25, 95% CI 1.19-4.25) and DRB1 (OR 2.11, 95% CI 1.13-3.40) alleles. Higher prevalence HLA-B alleles were associated with higher ATL risk (OR 1.14 per quartile, p(trend) = 0.02). Asymptomatic carriers with common HLA-B alleles had marginally higher HTLV-I proviral load (p = 0.057). HAM/TSP risk did not differ consistently with common HLA types. Thus, ATL risk, but not HAM/TSP risk, was increased with higher prevalence HLA-B alleles. Perhaps breadth of cellular immunity affects risk of this viral leukemia/lymphoma.

Virologic, hematologic, and immunologic risk factors for classic Kaposi sarcoma

BACKGROUND

Classic Kaposi sarcoma (CKS) is an inflammatory-mediated neoplasm that develops in the presence of KS-associated herpesvirus (KSHV) and immune perturbation. In the current study, the authors compared CKS cases with age-matched and sex-matched KSHV-seropositive controls without human immunodeficiency virus-1 infection and markers of viral control, blood counts, CD4-positive and CD8-positive lymphocytes, and serum beta-2-microglobulin and neopterin levels.

METHODS

Viral loads were detected using real-time amplification of the KSHV-K6 and EBV-pol genes, anti-K8.1 (lytic) titers were detected by enzyme-linked immunoadsorbent assay, and antilatent nuclear antigen (LANA) titers were detected using immunofluorescence. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using logistic regression adjusted for sex, age, and study site.

RESULTS

Peripheral blood mononuclear cells (PBMC) KSHV DNA detection (P < or = .0001) and high KSHV lytic (>1:1745; P < or = .0001) and latent (>1:102,400; P = .03) antibody titers were found to be positively associated with CKS risk. Antibody titers were higher in cases with lesions compared with cases without lesions (P < or =.05). The detection of Epstein-Barr virus (EBV) DNA in PBMCs was not found to be associated with CKS (P = .95). Independent of PBMC KSHV DNA, CKS risk was found to be positively associated with reduced hematocrit (<37.4%; P = .03), hemoglobin (<12g/dL; P = .04), and lymphocytes (<1000 cells/microL; P = .004), including CD4-positive (+) cells (<457 cells/microL; P = .07) and CD8+ cells (<213cells/microL; P = .04), and with increased monocytes (> or =638 cells/microL; P = .009). Nonsignificant elevations of beta-2-microglobulin and neopterin were observed among cases regardless of disease burden (P > or = .08). In a multivariate model, the CKS risk was found to be associated with PBMC KSHV DNA (OR of 2.7; 95% CI, 1.4-5.3), a high KSHV lytic antibody titer (OR of 3.7; 95% CI, 1.9-7.4), and low lymphocytes, particularly among those patients age <70 years (OR of 8.0; 95% CI, 2.7-23.7).

CONCLUSIONS

The findings of the current study appear to corroborate the specificity of KSHV and highlight the hematologic and immunologic correlates involved in the pathogenesis of CKS.

KIR/HLA pleiotropism: protection against both HIV and opportunistic infections

The compound genotype KIR3DS1/HLA-B Bw4-80I, which presumably favors natural killer cell activation, has been implicated in protection against HIV disease. We show that this genotype confers dual protection over the course of HIV disease; early direct containment of HIV viral load, and late specific defense against opportunistic infections, but not AIDS-related malignancies. The double protection of KIR3DS1/Bw4-80I in an etiologically complex disease such as AIDS, along with the disease specificity of its effects is conceptually novel and underscores the intricacy of host immunogenetics against HIV/AIDS.

Natural killer (NK) cells are part of the innate immune response which provides the first line of defense against viral infections such as HIV by production of cytokines and direct killing of infected cells. NK cells possess a variety of inhibitory and activating receptors that upon binding to their HLA class I ligands on target cells, regulate activation and inhibition of NK cell responses. A protective effect of the specific combination of the activating receptor KIR3DS1 with HLA-Bw4 alleles that have isoleucine at position 80 (HLA-B Bw4-80I) against AIDS progression was reported previously. Based on this genetic association, KIR3DS1 on NK cells was proposed to bind to HLA-B Bw4-80I on HIV-1 infected target cells, thereby signaling the NK cell to kill the target. Here we present data showing that this compound genotype also confers protection against the development of AIDS defining opportunistic infections. Interestingly, no protection against the development of AIDS defining malignancies was observed. The double protection of this compound genotype in AIDS, along with the specificity of its effects is a novel finding and underscores the complex role of host immunogenetics against HIV/AIDS.

Prevalence of conditions associated with human immunodeficiency and hepatitis virus infections among persons with haemophilia, 2001-2003

Before the mid-1980s, haemophilia often was unknowingly treated with contaminated plasma products, resulting in high rates of human immunodeficiency virus (HIV-1), hepatitis C virus (HCV) and hepatitis B virus (HBV) infections. To estimate the impact of these infections, a new cohort was established. All HCV-seropositive patients, age 13-88 years, at 52 comprehensive haemophilia treatment centres were eligible. Cross-sectional data collected during April 2001 to January 2004 (median June 2002) were analysed. Plasma HIV-1 and HCV RNA were quantified by polymerase chain reaction. Highly active antiretroviral therapy (HAART) was defined as use of at least three recommended medications. Among 2069 participants, 620 (30%) had HIV-1. Of 1955 with known HBV status, 814 (42%) had resolved HBV and 90 (4.6%) were HBV carriers. Although 80% of the HIV-1-positive participants had > or = 200 CD4+ cells microL(-1), only 59% were on HAART. HIV-1 RNA was undetectable in 23% of those not taking antiretroviral medications. Most (72%) participants had received no anti-HCV therapy. HCV RNA was detected less frequently (59%) among participants treated with standard interferon plus ribavirin (P = 0.0001) and more frequently among HIV-1-positive than HIV-1-negative participants (85% vs. 70%, P < 0.0001). HIV-1-positive participants were more likely to have pancytopenia and subclinical hepatic abnormalities, as well as persistent jaundice, hepatomegaly, splenomegaly and ascites. HAART recipients did not differ from HIV-negative participants in the prevalence of ascites. The clinical abnormalities were more prevalent with older age but were not confounded by HBV status or self-reported alcohol consumption. Eleven participants presented with or previously had hepatocellular carcinoma or non-Hodgkin lymphoma. Although prospective analysis is needed, our data reveal the scale of hepatic and haematological disease that is likely to manifest in the adult haemophilic population during the coming years unless most of them are successfully treated for HIV-1, HCV or both.

Genetic protection against hepatitis B virus conferred by CCR5Delta32: Evidence that CCR5 contributes to viral persistence

Recovery from acute hepatitis B virus (HBV) infection requires a broad, vigorous T-cell response, which is enhanced in mice when chemokine receptor 5 (CCR5) is missing. To test the hypothesis that production of a nonfunctional CCR5 (CCR5Delta32 [a functionally null allele containing a 32-bp deletion]) increases the likelihood of recovery from hepatitis B in humans, we studied 526 persons from three cohorts in which one person with HBV persistence was matched to two persons who recovered from an HBV infection. Recovery or persistence was determined prior to availability of lamivudine. We determined genotypes for CCR5Delta32 and for polymorphisms in the CCR5 promoter and in coding regions of the neighboring genes, chemokine receptor 2 (CCR2) and chemokine receptor-like 2 (CCRL2). Allele and haplotype frequencies were compared among the 190 persons with viral recovery and the 336 with persistence by use of conditional logistic regression. CCR5Delta32 reduced the risk of developing a persistent HBV infection by nearly half (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.33 to 0.83; P = 0.006). This association was virtually identical in persons with and without a concomitant human immunodeficiency virus infection. Of the nine individuals who were homozygous for the deletion, eight recovered from infection (OR, 0.25; 95% CI, 0.03 to 1.99; P = 0.19). None of the other neighboring polymorphisms examined were associated with HBV outcome. These data demonstrate a protective effect of CCR5Delta32 in recovery from an HBV infection, provide genetic epidemiological evidence for a role of CCR5 in the immune response to HBV, and suggest a potential therapeutic treatment for patients persistently infected with HBV.

Real-time PCR assay for detection and quantification of hepatitis B virus genotypes A to G

The detection and quantification of hepatitis B virus (HBV) DNA play an important role in diagnosing and monitoring HBV infection as well as assessing therapeutic response. The great variability among HBV genotypes and the enormous range of clinical HBV DNA levels present challenges for PCR-based amplification techniques. In this study, we describe the development, evaluation, and validation of a novel real-time PCR assay designed to provide accurate quantification of DNA from all eight HBV genotypes in patient plasma specimens. A computer algorithm was used to design degenerate real-time PCR primers and probes based upon a large number (n = 340) of full-length genomic sequences including HBV genotypes A to H from Europe, Africa, Asia, and North and South America. Genotype performance was tested and confirmed using 59 genotype A to G specimens from two commercially available worldwide genotype panels. This assay has a dynamic range of at least 8 log(10) without the need for specimen dilution, good clinical intra- and interassay precision, and excellent correlation with the Bayer Diagnostics VERSANT HBV DNA 3.0 (branched DNA) assay (r = 0.93). Probit analysis determined the 95% detection level was 56 IU/ml, corresponding to 11 copies per PCR well. The high sensitivity, wide linear range, good reproducibility, and genotype inclusivity, combined with a small sample volume requirement and low cost, make this novel quantitative HBV real-time PCR assay particularly well suited for application to large clinical and epidemiological studies.

Hemophilic siblings with chronic hepatitis C: Familial aggregation of spontaneous and treatment-related viral clearance

BACKGROUND & AIMS

Hemophilic siblings provide a unique population to explore the natural history of chronic hepatitis C.

METHODS

From 3993 hemophilic patients with hepatitis C, 257 sibling pairs, of which both members had evidence of hepatitis C infection, were studied to evaluate the genetic contribution to spontaneous and treatment-induced clearance of hepatitis C infection and progression of liver disease. Familial aggregation was assessed by comparing observed probabilities of concordance for these disease characteristics within sibling pairs to those expected for randomly paired hemophilic subjects. Additional measures of familial aggregation, heritability, and sibling relative risk were also calculated.

RESULTS

Among human immunodeficiency virus-negative subjects, concordance for spontaneous viral clearance was 2-fold higher in siblings compared with randomly paired subjects (8.8% vs 4.3%, respectively, P = .04). Similarly, the concordance rate for treatment-related viral clearance was over twice that among sibling pairs than among randomly paired hemophiliacs (31.3% vs 13.3%, respectively, P = ns). Heritability estimates for spontaneous and treatment-induced viral clearance were 0.24 +/- 0.14 (P = .04) and 0.43 +/- 0.42 (P = .10), respectively. The sibling relative risks for these respective characteristics were 1.6 and 1.7. Concordance for advanced liver disease was higher among siblings but did not reach statistical significance (4.0% vs 2.3%, respectively, P = ns). The heritability estimate was 0.29 +/- 0.13 (P = .02).

CONCLUSIONS

Concordance rates and heritability estimates for spontaneous and treatment-related viral clearance indicate that genetic factors have a modest influence on the outcome of hepatitis C, although shared environmental factors cannot be excluded. Investigations to map candidate disease-susceptibility genes associated with these characteristics must be approached with caution.

Consistent effects of TSG101 genetic variability on multiple outcomes of exposure to human immunodeficiency virus type 1

Tumor susceptibility gene 101 (TSG101) encodes a host cellular protein that is appropriated by human immunodeficiency virus type 1 (HIV-1) in the budding process of viral particles from infected cells. Variation in the coding or noncoding regions of the gene could potentially affect the degree of TSG101-mediated release of viral particles. While the coding regions of the gene were found to lack nonsynonymous variants, two polymorphic sites in the TSG101 5' area were identified that were associated with the rate of AIDS progression among Caucasians. These single-nucleotide polymorphisms (SNPs), located at positions -183 and +181 relative to the translation start, specify three haplotypes termed A, B, and C, which occur at frequencies of 67%, 21%, and 12%, respectively. Haplotype C is associated with relatively rapid AIDS progression, while haplotype B is associated with slower disease progression. Both effects were dominant over the intermediate haplotype A. The haplotypes also demonstrated parallel effects on the rate of CD4 T-cell depletion and viral load increase over time, as well as a possible influence on HIV-1 infection. The data raise the hypothesis that noncoding variation in TSG101 affects the efficiency of TSG101-mediated release of viral particles from infected cells, thereby altering levels of plasma viral load and subsequent disease progression.

Hodgkin lymphoma and immunodeficiency in persons with HIV/AIDS

In persons with HIV/AIDS (PWHAs), Hodgkin lymphoma (HL) risk is increased. However, HL incidence in PWHAs has unexpectedly increased since highly active antiretroviral therapy (HAART) was introduced. We linked nationwide HIV/AIDS and cancer registry data from 1980 through 2002. Immunity was assessed by CD4 T-lymphocyte counts at AIDS onset. Annual HL incidence rates were calculated for 4 through 27 months after AIDS onset. During 477 368 person years (py's) of follow-up in 317 428 persons with AIDS (PWAs), 173 HL cases occurred (36.2 per 10(5) py's). Incidence was significantly higher in 1996 to 2002 than earlier. Incidence in PWAs with 150 to 199 CD4 cells/muL was 53.7 per 10(5) py's, whereas in PWAs with fewer than 50 CD4 cells/muL, it was 20.7 per 10(5) py's (P(trend) = .002). For each HL subtype, incidence decreased with declining CD4 counts, but nodular sclerosing decreased more precipitously than mixed cellularity, thereby increasing the proportion of mixed cellularity HL seen in PWAs. We conclude that HL incidence is lower with severe immunosuppression than with moderate immunosuppression, and HAART-related improvements in CD4 counts likely explain the increasing HL incidence in PWHAS observed since 1996. With more severe immunosuppression, nodular sclerosing HL becomes infrequent, explaining the higher proportion of mixed cellularity HL found in PWAs. Pathogenesis implications are discussed.

Cohort- and time-specific associations of CTLA4 genotypes with HIV-1 disease progression

BACKGROUND

CTLA4 in the chromosome 2q33 region encodes cytotoxic T-lymphocyte (CTL) associated antigen 4, which downregulates CTL responses. We examined the relationships between common CTLA4 variants and several outcomes of HIV-1 infection in adults and adolescents.

METHODS

We studied 765 HIV-1-infected persons: 558 Caucasian seroconverters from three cohorts (MACS, ACS, and DCG) and 207 infected adolescents (mostly female) from another cohort (REACH) of mixed ethnicity. Single nucleotide polymorphisms in CTLA4 promoter (-1147C/T, -658C/T, -318C/T), coding sequence (49A/G) and the 3' untranslated region (CT60A/G) were resolved by PCR-based techniques. Repeated measures and survival analyses were used to test allelic and haplotypic associations with HIV-1 viral load (VL) and time to AIDS, respectively.

RESULTS

Individuals carrying -318T or the (-1147) T-(-318) T haplotype had elevated HIV-1 VL in MACS and REACH but reduced VL in DCG and ACS participants. Time-dependent associations of CTLA4-318T with VL were observed in MACS and REACH (P = 0.03-0.09). In Cox regression models adjusted for age and established contributory markers in CCR5 and HLA class I genes, CTLA4-318T was associated with rapid progression to AIDS in MACS (relative hazard 1.69; 95% confidence interval, 1.15-2.49; P < 0.01) as opposed to a non-significant slower disease progression in ACS and no appreciable association in DCG.

CONCLUSIONS

Association of CTLA4 genotypes with clinical and virological outcomes following HIV-1 infection appeared to vary with time and among the cohorts. Further analyses in conjunction with other biologically and positionally related genes, such as CD28 and ICOS, may help explain the disparate findings.

Trends in cancer risk among people with AIDS in the United States 1980-2002

BACKGROUND

People with AIDS have heightened cancer risk from immunosuppression. HAART has been available since 1996 and has reduced AIDS-related mortality, but there are few large-scale studies on cancer trends.

METHODS

AIDS and cancer registries in 11 US regions (1980-2002) were used to identify cancers in 375 933 people with AIDS. Cancer risk relative to the general population was measured using the standardized incidence ratio (SIR), focusing on the 2 years after AIDS onset for those with AIDS in 1990-1995 and 1996-2002 (HAART era). Time trends were assessed with Poisson regression.

RESULTS

Between 1990-1995 and 1996-2002, risk declined for the two major AIDS-defining cancers: Kaposi sarcoma [(KS) n = 5131; SIR, 22 100 and 3640, respectively; P < 0.0001] and non-Hodgkin lymphoma [(NHL) n = 3412; SIR, 53.2 and 22.6, respectively; P < 0.0001]. Declines began in the 1980s, but risk fell sharply in 1996 and was stable thereafter. Risk of cervical cancer did not change (n = 64; SIR, 4.2 and 5.3, respectively; P = 0.33). Among non-AIDS malignancies, lung cancer was most common, but risk declined between 1990-1995 and 1996-2002 (n = 344; SIR, 3.3 and 2.6, respectively; P = 0.02). Risk of Hodgkin lymphoma increased substantially over the 1990-2002 period (n = 149; SIR, 8.1 and 13.6, respectively; P = 0.003).

CONCLUSIONS

Dramatic declines in KS and NHL were temporally related to improving therapies, especially introduction of HAART, but those with AIDS remain at marked risk. Among non-AIDS-related cancers, a recent increase in Hodgkin lymphoma was observed.

Risk of breast, ovary, and uterine corpus cancers among 85,268 women with AIDS

By linking HIV/AIDS and cancer surveillance data in 12 US regions, breast and reproductive cancer risks with AIDS were compared to those in the general population. Trends in standardized incidence ratios (SIRs) were assessed by CD4 count, AIDS-relative time, and calendar time. Standardized incidence ratios were indirectly adjusted for cancer risk factors using data from AIDS cohort participants and the general population. With AIDS, 313 women developed breast cancer (SIR 0.69, 95% confidence interval (CI) 0.62–0.77), 42 developed ovary cancer (SIR 1.05, 95% CI, 0.75–1.42), and 31 developed uterine corpus cancer (SIR 0.57, 95% CI, 0.39–0.81). Uterine cancer risk was reduced significantly after age 50 (SIR 0.33). Breast cancer risk was reduced significantly both before (SIR 0.71) and after (SIR 0.66) age 50, and was lower for local or regional (SIR 0.54) than distant (SIR 0.89) disease. Breast cancer risk varied little by CD4 count (P_trend=0.47) or AIDS-relative time (P_trend=0.14) or after adjustment for established cancer risk factors. However, it increased significantly between 1980 and 2002 (P_trend=0.003), approaching the risk of the general population. We conclude that the cancer deficit reflected direct or indirect effects of HIV/AIDS and that anti-HIV therapy reduced these effects.

Genetic variation in the CCL18-CCL3-CCL4 chemokine gene cluster influences HIV Type 1 transmission and AIDS disease progression

CCL3 (MIP-1 alpha), CCL4 (MIP-1 beta), and CCL18 (DC-CK1/PARC/AMAC-1) are potent chemoattractants produced by macrophages, natural killer cells, fibroblasts, mast cells, CD4(+) T cells, and CD8(+) T cells. CCL3 and CCL4 are natural ligands for the primary human immunodeficiency virus type 1 (HIV-1) coreceptor CCR5 and are also known to activate and enhance the cytotoxicity of natural killer cells. Genomic DNAs from >3,000 participants enrolled in five United States-based natural-history cohorts with acquired immunodeficiency syndrome (AIDS) were genotyped for 21 single-nucleotide polymorphisms (SNPs) in a 47-kb interval on chromosome 17q12 containing the genes CCL3, CCL4, and CCL18. All 21 SNPs were polymorphic in African Americans (AAs), whereas 7 of the 21 had minor-allele frequencies <0.01 in European Americans (EAs). Substantial linkage disequilibrium was observed in a 37-kb interval containing 17 SNPs where many pairwise D' values exceeded 0.70 in both racial groups, but particularly in EAs. Four and three haplotype blocks were observed in AAs and EAs, respectively. Blocks were strongly correlated with each other, and common haplotype diversity within blocks was limited. Two significant associations are reported that replicate an earlier study. First, among AA members of the AIDS Link to the Intravenous Experience cohort of injection drug users, frequencies of three correlated SNPs covering 2,231 bp in CCL3 were significantly elevated among highly exposed, persistently HIV-1-uninfected individuals compared with HIV-1-infected seroconvertors (P = .02-.03). Second, seven highly correlated SNPs spanning 36 kb and containing all three genes were significantly associated with more-rapid disease progression among EAs enrolled in the Multicenter AIDS Cohort Study cohort (P = .01-.02). These results reiterate the importance of chemokine gene variation in HIV-1/AIDS pathogenesis and emphasize that localized linkage disequilibrium makes the identification of causal mutations difficult.

Associations of Classic Kaposi Sarcoma with Common Variants in Genes that Modulate Host Immunity

Classic Kaposi sarcoma (CKS) is an inflammatory-mediated neoplasm primarily caused by Kaposi sarcoma-associated herpesvirus (KSHV). Kaposi sarcoma lesions are characterized, in part, by the presence of proinflammatory cytokines and growth factors thought to regulate KSHV replication and CKS pathogenesis. Using genomic DNA extracted from 133 CKS cases and 172 KSHV-latent nuclear antigen-positive, population-based controls in Italy without HIV infection, we examined the risk of CKS associated with 28 common genetic variants in 14 immune-modulating genes. Haplotypes were estimated for IL1A, IL1B, IL4, IL8, IL8RB, IL10, IL12A, IL13, and TNF. Compared with controls, CKS risk was decreased with 1235T/-1010G-containing diplotypes of IL8RB (odds ratio, 0.49; 95% confidence interval, 0.30-0.78; P = 0.003), whereas risk was increased with diplotypes of IL13 containing the promoter region variant 98A (rs20541, alias +130; odds ratio, 1.88; 95% confidence interval, 1.15-3.08; P = 0.01) when considered in multivariate analysis. Risk estimates did not substantially vary by age, sex, incident disease, or disease burden. Our data provide preliminary evidence for variants in immune-modulating genes that could influence the risk of CKS. Among KSHV-seropositive Italians, CKS risk was associated with diplotypes of IL8RB and IL13, supporting laboratory evidence of immune-mediated pathogenesis.

Risk factors for human herpesvirus 8 seropositivity in the AIDS Cancer Cohort Study

BACKGROUND

Cigarette smoking has been associated with a decreased risk for AIDS-related and classical KS, but whether it is associated with decreased risk of human herpesvirus 8 (HHV-8) infection is unknown.

STUDY DESIGN

We evaluated factors associated with HHV-8 seropositivity in 2795 participants (132 with KS) in the National Cancer Institute AIDS Cancer Cohort, including 1621 men who have sex with men (MSM), 660 heterosexual men and 514 women. Odds ratios (OR) and 95% confidence intervals were estimated using logistic regression models.

RESULTS

Among non-KS subjects, HHV-8 seropositivity was 6%, 13% and 29% among women, heterosexual men and MSM, respectively. HHV-8 seropositivity was decreased in heavier (> or =1/2 pack/day) compared to lighter smokers among women (5% versus 8%; adjusted OR (aOR) 0.4; 95% CI 0.2-0.8) and MSM (27% versus 32%; aOR 0.7; 95% CI 0.6-1.0), but not among heterosexual men (12% versus 16%; aOR 0.7; 95% CI 0.4-1.2). HHV-8 seroprevalence was increased in heavier (> or =1 drink/day) compared to lighter consumers of alcohol among women (16% versus 4%; adjusted OR 5.2; 95% CI 2.3-12), but not among MSM (33% versus 28%; aOR 1.2; 95% CI 0.9-1.6) or heterosexual men (13% versus 13%; aOR 1.1; 95% CI 0.6-2.0). In analyses adjusted for smoking and drinking, HHV-8 seropositivity was positively associated with chlamydia infection (OR=4.3; 95% CI 1.2-13) and with marital status among women p(heterogeneity)=0.03, and with hepatitis (OR=1.6; 95% CI 1.2-2.1), gonorrhea (OR=1.5; 95% CI 1.1-1.9), genital warts (OR=1.5; 95% CI 1.1-2.0) and nitrate inhalant use (OR=1.7; 95% CI 1.3-2.3) among MSM.

CONCLUSIONS

Inverse association of HHV-8 seropositivity with cigarette smoking may indicate protective effect of tobacco smoke on HHV-8 infection, whereas positive associations with alcohol may reflect either behavioral factors or biological effects modulating susceptibility. Smoking and drinking may influence KS risk, at least in part, by altering the natural history of HHV-8 infection.

Prevalence of serologic reactivity against four strains of mouse mammary tumour virus among US women with breast cancer

Mouse mammary tumour virus (MMTV) causes breast cancer in mice, and MMTV-specific antibodies develop to high titers among mice infected as adults. Whether MMTV or a related virus infects humans is uncertain, because MMTV DNA sequences have been detected inconsistently and because serologic methods have varied widely. The current study used immunoblot and immunoprecipitation with four strains of MMTV (RIII, FM, C3H, and LA) to detect specific antibodies in 92 sera from US women with breast cancer and in masked dilutions of monoclonal hybridoma and hyperimmunised goat positive-control reagents. In these positive controls, MMTV antibodies of the expected molecular weights were detected at high titer (1 : 100 in the monoclonal reagent, 1 : 10000 in the hyperimmunised goat serum). Nearly 30% of the sera from women with breast cancer had at least one faint band on an immunoblot, but none of these matched the molecular weight of bands revealed by probing the same blot strips with the goat serum. The goat serum readily immunoprecipitated MMTV antigens from all four strains of MMTV, but MMTV antigens were not immunoprecipitated by any of the six breast cancer sera that had four or more nonspecific immunoblot bands. Thus, among women with breast cancer, we found no MMTV-specific antibodies. The upper 95% confidence limit implies that MMTV seroprevalence among breast cancer patients does not exceed 3%.

Host immunogenetics and control of human herpesvirus-8 infection

BACKGROUND

Kaposi sarcoma (KS) is primarily caused by human herpesvirus (HHV)-8 infection, and the risk is increased with high HHV-8 lytic or latent antibody titers or the detection of HHV-8 DNA in peripheral blood mononuclear cells (PBMCs). Host genes important for control of HHV-8 infection are not well characterized.

METHODS

In 172 HHV-8 latent nuclear antigen (LANA)-seropositive adults in Italy without KS, we examined correlations of common variants in host immune genes with the detection of HHV-8 DNA in PBMCs and with high lytic and latent antibody titers. Twenty-eight single-nucleotide polymorphisms in 14 genes were analyzed. We detected HHV-8 DNA in PBMCs with real-time amplification of the K6 gene, anti-K8.1 (lytic) titers with enzyme-linked immunosorbent assay, and anti-LANA (latent) titers with immunofluorescence.

RESULTS

Detection of HHV-8 DNA in PBMCs was not significantly related to any variant examined. In contrast, a 3-locus haplotype of IL4, which contains the -1098G allele (rs2243248), was overrepresented among subjects with high lytic titers (odds ratio [OR], 2.8 [95% confidence interval {CI}, 1.1-6.7]), compared with those with low titers, as was the functional promoter variant of IL6, C-236C (rs1800795) (OR, 3.7 [95% CI, 1.1-12.8]). Compared with subjects with low HHV-8 latent antibody titers, analysis of inferred haplotypes for IL12A revealed an overrepresentation of -798T/277A in subjects with high HHV-8 latent antibody titers (OR, 2.4 [95% CI, 1.1-5.2]).

CONCLUSIONS

Our observations are the first to provide preliminary evidence suggesting that common variants in key host immune genes could influence the control of HHV-8 infection.

Quantitative analysis of plasma TP53 249Ser-mutated DNA by electrospray ionization mass spectrometry

A mutation in codon 249 of the TP53 gene (249(Ser)), related to aflatoxin B(1) exposure, has previously been associated with hepatocellular carcinoma risk. Using a novel internal standard plasmid, plasma concentrations of 249(Ser)-mutated DNA were quantified by electrospray ionization mass spectrometry in 89 hepatocellular carcinoma cases, 42 cirrhotic patients, and 131 nonliver diseased control subjects, all from highly aflatoxin-exposed regions of The Gambia. The hepatocellular carcinoma cases had higher median plasma concentrations of 249(Ser) (2,800 copies/mL; interquartile range: 500-11,000) compared with either cirrhotic (500 copies/mL; interquartile range: 500-2,600) or control subjects (500 copies/mL; interquartile range: 500-2,000; P < 0.05). About half (52%) of the hepatocellular carcinoma cases had >2,500 copies of 249(Ser)/mL plasma, corresponding to the prevalence of this mutation in liver tumors in The Gambia. In comparison, only 15% of control group and 26% of cirrhotic participants exceeded this level (P < 0.05). Further subset analysis revealed a statistically significant, quantitative relation between diagnosis of hepatocellular carcinoma and levels of 249(Ser) detected at 2,501 to 10,000 copies/mL plasma (odds ratio, 3.8; 95% confidence interval, 1.3-10.9) and at >10,000 copies/mL plasma (odds ratio, 62; 95% confidence interval, 4.7-820) when compared with control subjects and after adjusting for age, gender, recruitment site, hepatitis B and C serologic status, and total DNA concentration. Levels of >10,000 copies of 249(Ser)/mL plasma were also significantly associated with the diagnosis of hepatocellular carcinoma (odds ratio, 15; 95% confidence interval, 1.6-140) when compared with cirrhotic patients. Potential applications for the quantification of 249(Ser) DNA in plasma include estimation of long-term, cumulative aflatoxin exposure and selection of appropriate high-risk individuals for targeted intervention.

High Levels of Epstein‐Barr Virus DNA in Saliva and Peripheral Blood from Ugandan Mother‐Child Pairs

In Africa, Epstein-Barr virus (EBV) is associated with Burkitt lymphoma. We measured levels of EBV DNA in saliva and buffy coats from 233 asymptomatic Ugandan children with sickle cell disease and their mothers by quantitative real-time polymerase chain reaction. EBV DNA was detected in saliva from 90% of the children (median [interquartile range [IQR]] level, 5.2 [4.2-6.0] log(10) copies/mL of saliva) and 79% of the mothers (median [IQR] level, 4.8 [3.7-5.6] log(10) copies/mL of saliva) (P < .001). EBV DNA was detected in buffy coats from 86% of the children (median [IQR] level, 2.5 [2.2-2.9] log(10) copies/1 x 10(6) peripheral white blood cells [PWBCs]) and 72% of the mothers (median [IQR] level, 2.7 [2.4-3.1] log(10) copies/1 x 10(6) PWBCs) (P = .24). Detection of EBV DNA in saliva was positively correlated with detection in buffy coats. EBV DNA was detected more frequently in saliva and buffy coats than was human herpesvirus 8 DNA. Our results indicate that EBV infection persists, with virus readily detectable in saliva and buffy coats from persons without apparent symptoms in Africa.

Antibodies to JC and BK viruses among persons with non-Hodgkin lymphoma

Two related polyomaviruses, JC virus (JCV) and BK virus (BKV), commonly cause lifelong infections in humans, with periodic reactivation manifesting as viral shedding in urine. Because JCV can infect lymphocytes and cause chromosomal damage, it is a plausible candidate to cause non-Hodgkin lymphoma (NHL). To test this hypothesis, we measured IgG antibodies to JCV and BKV capsids using a virus-like particle enzyme immunoassay in 3 separate groups of subjects. First, in a U.S. population-based case-control study of NHL (724 cases, 622 controls), we found lower JCV antibody levels in cases than controls (median optical density = 0.12 vs. 0.21, p < 0.0001); likewise, JCV seroprevalence was lower in cases (49% vs. 59%, adjusted odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.56-0.87). In contrast, BKV antibody levels did not differ between groups. Second, we found that JCV and BKV antibody levels changed little over time among 24 NHL patients receiving chemotherapy. Third, we evaluated 126 homosexual men, of whom 46 were shedding JCV and 14 were shedding BKV in urine. Antibody levels were much higher in shedders than non-shedders (JCV: median optical density = 0.67 vs. 0.07, p < 0.0001; BKV: 0.87 vs. 0.40, p = 0.003), indicating that these antibodies are a marker for viral replication. Because no deficit of BKV antibody was seen in NHL cases, and because antibody levels did not change materially with chemotherapy, we suggest that the lower levels of JCV antibody observed in NHL patients may not be due entirely to a disease or treatment effect. Additional research is needed to determine whether JCV replication is decreased in individuals with NHL and whether these findings are consistent with an etiologic role for JCV in NHL.

Hepatitis C virus load and survival among injection drug users in the United States

Persons chronically infected with hepatitis C virus (HCV), some of whom may be coinfected with HIV and human T-lymphotropic virus type II (HTLV-II), are at high risk for end-stage liver disease (ESLD). We evaluated whether ESLD death was associated with premorbid HCV RNA level or specific HCV protein antibodies among persons with or without HIV/HTLV-II coinfection in a cohort of 6,570 injection drug users who enrolled in 9 US cities between 1987 and 1991. We compared 84 ESLD descendents and 305 randomly selected cohort participants with detectable HCV RNA, stratified by sex, race, HIV, and HTLV-II strata. Relative hazard (RH) of ESLD death was derived from the proportional hazard model. Risk of ESLD death was unrelated to the intensity of antibodies against the HCV c-22(p), c-33(p), c-100(p), and NS5 proteins, individually or combined, but it increased with HCV RNA level (RH(adj) = 2.26 per log(10) IU/mL, 95% CI: 1.45-5.92). The association between HCV RNA level and ESLD death remained significant after adjustment for alcohol consumption (RH(adj) = 2.57 per log(10) IU/mL, 95% CI: 1.50-8.10). Deaths from AIDS (n = 45) and other causes (n = 43) were unrelated to HCV RNA (RH(adj)= 1.14 and 1.29 per log(10) IU/mL, respectively). HIV infection was not associated with ESLD risk in multivariate analyses adjusted for HCV RNA. Men had an increased risk of ESLD death in unadjusted analyses (RH = 1.92, 95% CI: 1.15-3.56) but not in multivariate analysis (RH(adj) = 0.98, 95% CI: 0.48-2.88). Non-black patients were at increased risk for ESLD death (RH(adj)= 2.76, 95% CI: 1.49-10.09). In conclusion, HCV RNA level is a predictor of ESLD death among persons with chronic HCV infection.

AIDS restriction HLA allotypes target distinct intervals of HIV-1 pathogenesis

An effective acquired immune response to infectious agents mediated by HLA-restricted T-cell recognition can target different stages of disease pathogenesis. We show here that three distinct HLA alleles known to alter the overall rate of AIDS progression act during distinct intervals after HIV-1 infection. The discrete timing of HLA allele influence suggests alternative functional mechanisms in immune defense against this dynamic and chronic immunosuppressive disease.

249(ser) TP53 mutation in plasma DNA, hepatitis B viral infection, and risk of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) from regions with high dietary exposure to aflatoxins and endemic for hepatitis B virus (HBV) often contain a specific mutation at codon 249 in TP53 (249(ser); AGG to AGT, Arg to Ser). This mutation is also detectable in circulating cell-free DNA from the plasma of HCC patients and healthy subjects in these regions. We have examined the joint effect of plasma 249(ser) and HBV infection in a case-control study design involving 348 control, 98 cirrhotic, and 186 HCC participants from The Gambia, West Africa, an area of high HCC incidence. The 249(ser) mutation was detected in 3.5% of controls, 15.3% of cirrhotics, and 39.8% of HCC cases (adjusted odds ratios (OR): 4.83, (95% confidence interval (CI): 1.71-13.7) for cirrhosis and 20.3 (8.19-50.0) for HCC). HBsAg positivity along with plasma 249(ser) was observed in 45/183 (24.6%) HCC cases compared to only one (0.3%) control. Risk for HCC was associated with markers of HBV alone (OR: 10.0, 95% CI: 5.16-19.6), 249(ser) alone (OR: 13.2, 95% CI: 4.99-35.0), and both markers present (OR: 399, 95% CI: 48.6-3270). These results suggest a multiplicative effect on HCC risk resulting from the mutational effect of aflatoxin on TP53, as monitored by detection of plasma 249(ser), with concomitant chronic infection with HBV.