Risk of Kaposi sarcoma during the first months on combination antiretroviral therapy

OBJECTIVE

To determine whether incident AIDS-defining Kaposi sarcoma or Pneumocystis jiroveci pneumonia (PJP) is associated with combination antiretroviral therapy (cART) initiation.

DESIGN

Compare risk for Kaposi sarcoma and PJP by time on cART and CD4 reconstitution.

METHODS

: In the FHDH-ANRS CO4 cohort (N = 66 369), Kaposi sarcoma (N = 1811) and PJP (N = 1718) incidence rates were computed by demographic and HIV strata. Crude and adjusted relative risk (RR) with 95% confidence intervals (CIs) following cART initiation were calculated by Poisson regression with untreated patients during 1996-2009 as reference. CD4 cell counts were compared by Wilcoxon rank sum tests.

RESULTS

The risk of Kaposi sarcoma was very high during months 1-3 on cART (N = 160, RRCrude 3.94, 95% CI 3.26-4.76), which was incompletely attenuated by adjustment for demographics and contemporaneous CD4 cell count (RRAdj 1.25, 95% CI 1.02-1.53). Corresponding PJP risk was minimally elevated (N = 84, RRCrude 1.80, 95% CI 1.42-2.30) and markedly reduced with adjustment on the same variables and PJP prophylaxis (RRAdj 0.52, CI 0.41-0.67). HIV load had no added effect. Median CD4 cell count at cART initiation was much lower in patients with incident Kaposi sarcoma (82 cells/μl) or PJP (61 cells/μl) within 3 months than in those who did not develop these conditions (>250 cells/μl). Notably, median CD4 cell count change was +44 cells/μl per month with incident Kaposi sarcoma within 3 months of cART initiation versus 0 cells/μl per month with incident PJP (P = 0.0003).

CONCLUSION

Failure of CD4 cell count reconstitution during months 1-3 on cART fully accounted for incident PJP. In contrast, there were 1.6 additional Kaposi sarcoma cases per 1000 person-years during months 1-3 on cART, suggesting that immune reconstitution may contribute to the risk for AIDS-defining Kaposi sarcoma.

Genome-wide association study of spontaneous resolution of hepatitis C virus infection: data from multiple cohorts

Chinese translation

BACKGROUND

Hepatitis C virus (HCV) infections occur worldwide and either spontaneously resolve or persist and markedly increase the person's lifetime risk for cirrhosis and hepatocellular carcinoma. Although HCV persistence occurs more often in persons of African ancestry and persons with genetic variants near interleukin-28B (IL-28B), the genetic basis is not well-understood.

OBJECTIVE

To evaluate the host genetic basis for spontaneous resolution of HCV infection.

DESIGN

2-stage, genome-wide association study.

SETTING

13 international multicenter study sites.

PATIENTS

919 persons with serum HCV antibodies but no HCV RNA (spontaneous resolution) and 1482 persons with serum HCV antibodies and HCV RNA (persistence).

MEASUREMENTS

Frequencies of 792 721 single nucleotide polymorphisms (SNPs).

RESULTS

Differences in allele frequencies between persons with spontaneous resolution and persistence were identified on chromosomes 19q13.13 and 6p21.32. On chromosome 19, allele frequency differences localized near IL-28B and included rs12979860 (overall per-allele OR, 0.45; P = 2.17 × 10-30) and 10 additional SNPs spanning 55 000 base pairs. On chromosome 6, allele frequency differences localized near genes for HLA class II and included rs4273729 (overall per-allele OR, 0.59; P = 1.71 × 10-16) near DQB1*03:01 and an additional 116 SNPs spanning 1 090 000 base pairs. The associations in chromosomes 19 and 6 were independent and additive and explain an estimated 14.9% (95% CI, 8.5% to 22.6%) and 15.8% (CI, 4.4% to 31.0%) of the variation in HCV resolution in persons of European and African ancestry, respectively. Replication of the chromosome 6 SNP, rs4272729, in an additional 745 persons confirmed the findings (P = 0.015).

LIMITATION

Epigenetic effects were not studied.

CONCLUSION

IL-28B and HLA class II are independently associated with spontaneous resolution of HCV infection, and SNPs marking IL-28B and DQB1*03:01 may explain approximately 15% of spontaneous resolution of HCV infection.

Predictive accuracy of the Veterans Aging Cohort Study index for mortality with HIV infection: a North American cross cohort analysis

BACKGROUND

By supplementing an index composed of HIV biomarkers and age (restricted index) with measures of organ injury, the Veterans Aging Cohort Study (VACS) index more completely reflects risk of mortality. We compare the accuracy of the VACS and restricted indices (1) among subjects outside the Veterans Affairs Healthcare System, (2) more than 1-5 years of prior exposure to antiretroviral therapy (ART), and (3) within important patient subgroups.

METHODS

We used data from 13 cohorts in the North American AIDS Cohort Collaboration (n = 10, 835) limiting analyses to HIV-infected subjects with at least 12 months exposure to ART. Variables included demographic, laboratory (CD4 count, HIV-1 RNA, hemoglobin, platelets, aspartate and alanine transaminase, creatinine, and hepatitis C status), and survival. We used C-statistics and net reclassification improvement (NRI) to test discrimination varying prior ART exposure from 1 to 5 years. We then combined Veterans Affairs Healthcare System (n = 5066) and North American AIDS Cohort Collaboration data, fit a parametric survival model, and compared predicted to observed mortality by cohort, gender, age, race, and HIV-1 RNA level.

RESULTS

Mean follow-up was 3.3 years (655 deaths). Compared with the restricted index, the VACS index showed greater discrimination (C-statistics: 0.77 vs. 0.74; NRI: 12%; P < 0.0001). NRI was highest among those with HIV-1 RNA <500 copies per milliliter (25%) and age ≥50 years (20%). Predictions were similar to observed mortality among all subgroups.

CONCLUSIONS

VACS index scores discriminate risk and translate into accurate mortality estimates over 1-5 years of exposure to ART and for diverse patient subgroups from North American.

A genome-wide association study of resistance to HIV infection in highly exposed uninfected individuals with hemophilia A

Human genetic variation contributes to differences in susceptibility to HIV-1 infection. To search for novel host resistance factors, we performed a genome-wide association study (GWAS) in hemophilia patients highly exposed to potentially contaminated factor VIII infusions. Individuals with hemophilia A and a documented history of factor VIII infusions before the introduction of viral inactivation procedures (1979-1984) were recruited from 36 hemophilia treatment centers (HTCs), and their genome-wide genetic variants were compared with those from matched HIV-infected individuals. Homozygous carriers of known CCR5 resistance mutations were excluded. Single nucleotide polymorphisms (SNPs) and inferred copy number variants (CNVs) were tested using logistic regression. In addition, we performed a pathway enrichment analysis, a heritability analysis, and a search for epistatic interactions with CCR5 Δ32 heterozygosity. A total of 560 HIV-uninfected cases were recruited: 36 (6.4%) were homozygous for CCR5 Δ32 or m303. After quality control and SNP imputation, we tested 1 081 435 SNPs and 3686 CNVs for association with HIV-1 serostatus in 431 cases and 765 HIV-infected controls. No SNP or CNV reached genome-wide significance. The additional analyses did not reveal any strong genetic effect. Highly exposed, yet uninfected hemophiliacs form an ideal study group to investigate host resistance factors. Using a genome-wide approach, we did not detect any significant associations between SNPs and HIV-1 susceptibility, indicating that common genetic variants of major effect are unlikely to explain the observed resistance phenotype in this population.

The association between cancer and amyotrophic lateral sclerosis

OBJECTIVE

Increasing evidence suggests that some neurodegenerative disorders, such as Parkinson's disease, are inversely related to cancer. Few epidemiologic studies have examined the relationship between cancer and amyotrophic lateral sclerosis (ALS), another major neurodegenerative disease. This study addresses that gap.

METHODS

Using data from 16 population-based cancer registries of the Surveillance, Epidemiology, and End Results (SEER) Program of the U.S. National Cancer Institute and death certificates, we followed 2.7 million cancer survivors who were diagnosed between 1973 and 2007, and who survived at least 1 year following cancer diagnosis. The standardized mortality ratio (SMR) of observed to expected ALS deaths in cancer survivors was calculated.

RESULTS

A total of 1,216 ALS deaths were reported among 1 year survivors of cancer over 16.6 million person-years of follow-up. ALS mortality was not significantly associated with the incidence of total cancers [SMR = 1.00 (95 % confidence interval (CI), 0.95-1.06)]. There was, however, a significantly elevated risk of ALS death among survivors of melanoma [SMR = 1.49 (95 % (CI), 1.17-1.85)] and of tongue cancer [SMR = 2.57 (95 % CI, 1.41-4.32)], and a significantly reduced ALS death risk among prostate cancer survivors [SMR = 0.86 (95 % CI, 0.76-0.96)].

CONCLUSIONS

Cancer at certain sites may be related to risk of ALS death. Possible biologic factors linking ALS to these cancers are discussed. Future studies should attempt to confirm these associations using incident ALS outcomes. Establishing relationships between cancer and neurodegenerative diseases, such as ALS, opens new opportunities for understanding related pathophysiologic and therapeutic possibilities for these diseases.

Fecal microbial determinants of fecal and systemic estrogens and estrogen metabolites: a cross-sectional study

Background

High systemic estrogen levels contribute to breast cancer risk for postmenopausal women, whereas low levels contribute to osteoporosis risk. Except for obesity, determinants of non-ovarian systemic estrogen levels are undefined. We sought to identify members and functions of the intestinal microbial community associated with estrogen levels via enterohepatic recirculation.

Methods

Fifty-one epidemiologists at the National Institutes of Health, including 25 men, 7 postmenopausal women, and 19 premenopausal women, provided urine and aliquots of feces, using methods proven to yield accurate and reproducible results. Estradiol, estrone, 13 estrogen metabolites (EM), and their sum (total estrogens) were quantified in urine and feces by liquid chromatography/tandem mass spectrometry. In feces, β-glucuronidase and β-glucosidase activities were determined by realtime kinetics, and microbiome diversity and taxonomy were estimated by pyrosequencing 16S rRNA amplicons. Pearson correlations were computed for each log_e estrogen level, log_e enzymatic activity level, and microbiome alpha diversity estimate. For the 55 taxa with mean relative abundance of at least 0.1%, ordinal levels were created [zero, low (below median of detected sequences), high] and compared to log_e estrogens, β-glucuronidase and β-glucosidase enzymatic activity levels by linear regression. Significance was based on two-sided tests with α=0.05.

Results

In men and postmenopausal women, levels of total urinary estrogens (as well as most individual EM) were very strongly and directly associated with all measures of fecal microbiome richness and alpha diversity (R≥0.50, P≤0.003). These non-ovarian systemic estrogens also were strongly and significantly associated with fecal Clostridia taxa, including non-Clostridiales and three genera in the Ruminococcaceae family (R=0.57−0.70, P=0.03−0.002). Estrone, but not other EM, in urine correlated significantly with functional activity of fecal β-glucuronidase (R=0.36, P=0.04). In contrast, fecal β-glucuronidase correlated inversely with fecal total estrogens, both conjugated and deconjugated (R≤-0.47, P≤0.01). Premenopausal female estrogen levels, which were collected across menstrual cycles and thus highly variable, were completely unrelated to fecal microbiome and enzyme parameters (P≥0.6).

Conclusions

Intestinal microbial richness and functions, including but not limited to β-glucuronidase, influence levels of non-ovarian estrogens via enterohepatic circulation. Thus, the gut microbial community likely affects the risk for estrogen-related conditions in older adults. Understanding how Clostridia taxa relate to systemic estrogens may identify targets for interventions.

Trial registration

Not applicable.

Opportunistic intestinal infections and risk of colorectal cancer among people with AIDS

Because mucosal inflammation contributes to colorectal carcinogenesis, we studied the impact of intestinal infections on risk of this malignancy among people with AIDS (PWA). Using the population-based HIV/AIDS Cancer Match, which includes approximately half of all PWA in the United States, the cancer registries ascertained colorectal cancers (ICD-O3 codes C180-C189, C199, C209, and C260). During 4-120 months after AIDS onset, risk of cancer occurring after AIDS-defining intestinal infections (considered as time-dependent exposures) was estimated with hazard ratios (HR) and 95% confidence intervals (CI) calculated by Cox regression. Analyses included cancers overall and by histology and anatomic site. After excluding 118 squamous cell rectal cancers (possible anal cancers), we analyzed 320 incident colorectal cancer cases that occurred among 471,909 PWA. Colorectal cancer risk was marginally elevated following cryptosporidiosis (HR=2.08, 95% CI=0.93-4.70, p=0.08) and mucocutaneous herpes (HR=1.69, 95% CI=0.97-2.95, p=0.07) but not with Pneumocystis pneumonia (HR=0.79, 95% CI=0.57-1.10). Cryptosporidiosis was associated with rare colon squamous cell carcinoma [N=8, HR=13, 95% CI=1.5-110] and uncommon histologies [HR=4.4, 95% CI=1.1-18, p=0.04], but it was not associated with colorectal adenocarcinoma (N=269, HR=1.3, 95% CI=0.4-3.9, p=0.70). Mucocutaneous herpes was associated with colon squamous cell carcinoma (HR=13, 95% CI=2.4-67, p=0.003) but not with colorectal adenocarcinoma (HR=1.3, 95% CI=0.6-2.6, p=0.52) or uncommon histologies (HR=2.5, 95% CI=0.8-8.2, p=0.13). Colon squamous cell carcinoma risk was significantly elevated among PWA who had cryptosporidiosis or mucocutaneous herpes. These findings might suggest that HPV or inflammation from other infection may contribute to carcinogenesis.

Impact of highly effective antiretroviral therapy on the risk for Hodgkin lymphoma among people with human immunodeficiency virus infection

PURPOSE OF REVIEW

To estimate the impact of highly effective antiretroviral therapy (ART) on the incidence and prognosis of Hodgkin lymphoma among people with human immunodeficiency virus infection or AIDS (PWHA).

RECENT FINDINGS

Age-adjusted incidence of Hodgkin lymphoma in PWHA is unchanged and is still five-fold to fifteen-fold higher than in the general population. Aging of the PWHA population with ART may account for increasing numbers of Hodgkin lymphoma cases. CD4 cell count has a complex relationship to Hodgkin lymphoma risk in PWHA. Depending on the time of measurement, Hodgkin lymphoma risk is highest with 50-249 CD4 cells/μl, and falling CD4 count on ART may be a harbinger of Hodgkin lymphoma onset. HIV load appears irrelevant to Hodgkin lymphoma. For obscure reasons, Hodgkin lymphoma risk may be elevated soon after starting ART, but the risk is probably modestly reduced with 6 or more months on ART. For PWHA who develop Hodgkin lymphoma, ART and ABVD chemotherapy can be administered safely, with one recent study demonstrating equivalent outcomes for HIV-positive and HIV-negative Hodgkin lymphoma patients.

SUMMARY

Vigilance for Hodgkin lymphoma is needed for immune-deficient PWHA, including those on ART. ART with opportunistic infection prophylaxis enables the delivery of effective chemotherapy for Hodgkin lymphoma, leading to a good prognosis.

Free light chains and the risk of AIDS-defining opportunistic infections in HIV-infected individuals

BACKGROUND

The relevance of B-cell dysfunction for progression to AIDS among human immunodeficiency virus (HIV)-infected individuals has not been clearly defined. We evaluated the association between circulating κ and λ free light chains (FLCs), which are markers of B-cell dysfunction, and risk of developing an AIDS-defining opportunistic infection in HIV-infected men.

METHODS

The study included 252 case patients with clinical AIDS and 252 HIV-infected controls from the Multicenter Hemophilia Cohort Study I. Case patients were matched to controls on birth date, specimen type, blood sample collection date, and CD4 cell count. Levels of κ and λ FLCs were measured in serum or plasma collected 0-2.5 years before selection. Elevated FLC levels (κ or λ, above the upper limit of normal) were classified as polyclonal (normal κ-λ ratio) or monoclonal (abnormally skewed κ-λ ratio). We used conditional logistic regression to estimate odds ratios (ORs) for AIDS.

RESULTS

FLC levels were higher in case patients than in controls, for κ (median, 4.03 vs 2.98 mg/dL) and λ (3.77 vs 2.42 mg/dL) FLCs. Compared with normal levels, above-normal FLC levels were associated with AIDS (OR, 3.13 [95% confidence interval (CI), 1.78-5.49] for κ and 3.47 [2.31-5.20] for λ FLCs), and the association with AIDS was strengthened with increasing κ and λ FLC levels (P trends < .0001). Polyclonal FLC elevation was associated with a 4-fold increase in the risk of AIDS (OR, 3.85; 95% CI, 1.97-7.54), but monoclonal FLC elevation was not associated with AIDS.

CONCLUSIONS

Circulating FLCs are associated with elevated risk of AIDS in HIV-infected individuals. Polyclonal B-cell dysfunction may contribute to HIV-related immune suppression and predispose to clinical AIDS events.

Assessment of the human faecal microbiota: I. Measurement and reproducibility of selected enzymatic activities

BACKGROUND

The intestinal microbial community has major effects on human health, but optimal research methods are unsettled. To facilitate epidemiologic and clinical research, we sought to optimize conditions and to assess reproducibility of selected core functions of the distal gut microbiota, β-glucuronidase and β-glucosidase bioactivities.

METHODS AND RESULTS

A colorimetric kinetic method was optimized and used to quantify activities of β-glucuronidase and β-glucosidase in human faeces. Enzyme detection was optimal with neutral pH, snap freezing in liquid nitrogen and rapid thawing to 37 °C before protein extraction. Enzymatic stability was assessed by delayed freezing for 2-48 h to mimic field settings. Activities decayed approximately 20% within 2 h and 40% within 4 h at room temperature. To formally assess reproducibility, 51 volunteers (25 men; mean age 39) used two devices to self-collect and rapidly chill four replicates of a stool. Devices were compared for mean enzymatic activities and intraclass correlation coefficients (ICC) in paired replicates of the self-collected specimens. Reproducibility was excellent with both devices for β-glucuronidase (ICC 0·92). The larger collection device had significantly higher reproducibility for β-glucosidase (ICC 0·92 vs. 0·76, P < 0·0001) and higher mean activities for both enzymes (P < 0·0001).

CONCLUSIONS

Optimal measurement of these core activities of the microbiota required a sufficient quantity of rapidly chilled or frozen specimens collected in phosphate buffered saline at pH7·0. Application of these methods to clinical and epidemiologic research could provide insights on how the intestinal microbiota affects human health.

Increased levels of circulating cytokines with HIV-related immunosuppression

Cytokines may contribute to the severity of CD4 cell depletion with human immunodeficiency virus (HIV) infection, but quantitative relationships are not well defined. Serum and plasma from 181 HIV-infected individuals were tested with Millipore 30-plex Luminex cytokine assays. Within-individual correlations among cytokines were summarized by two-dimensional hierarchical cluster analysis. Associations with age, sex, race, CD4 count, and HIV viral load were determined with linear regression models. Tests for statistical significance were corrected for multiple comparisons, using a false discovery rate of 0.1. African-Americans had significantly higher levels than whites of six cytokines (IL-2, IL-5, IL-7, IL-15, fractalkine, and IFN-γ), and lower levels of MCP-1. Females had higher fractalkine levels than males. Age was not associated with levels of any cytokine. Six cytokines, including the T-helper (Th) type 1 cytokine IL-15, the Th2 cytokines IL-1ra and IL-10, the chemokines fractalkine and MCP-1, and the growth factor G-CSF were each inversely associated with CD4 count; no cytokine was directly associated with CD4 count. Fractalkine was directly associated with HIV viral load, adjusted for CD4 count. Cytokines clustered by primary function (e.g., Th1, Th2, proinflammatory, chemokines, or growth factors) whereas individuals clustered according to cytokine levels (generally high, intermediate, or low) had significantly different CD4 counts [medians (interquartile range) of 60 (17-162), 131 (62-321), and 155 (44-467), respectively; p<0.0001]. CD4 deficiency is associated with generalized increases in cytokines of various functions. Racial differences in cytokine response to HIV infection could contribute to disparities in disease progression.

Assessment of the human faecal microbiota: II. Reproducibility and associations of 16S rRNA pyrosequences

BACKGROUND

We conducted a pilot study of reproducibility and associations of microbial diversity and composition in faecal microbial DNA.

METHODS AND RESULTS

Participants (25 men and 26 women, aged 17-65 years) provided questionnaire data and multiple samples of one stool collected with two Polymedco and two Sarstedt devices preloaded with RNAlater. 16S rRNA genes in each faecal DNA aliquot were amplified, sequenced (Roche/454 Life Sciences) and assigned to taxa. Devices were compared for ease of use and reproducibility [intraclass correlation coefficient (ICC)] between duplicate aliquots on diversity and taxonomic assignment. Associations were tested by linear regression. Both collection devices were easy to use. Both alpha diversity (Shannon index) and beta diversity (UniFrac) were higher between than within duplicates (P ≤ 10(-8) ) and did not differ significantly by device (P ≥ 0·62). Reproducibility was good (ICC≥0·77) for alpha diversity and taxonomic assignment to the most abundant phyla, Firmicutes and Bacteroidetes (71·5% and 25·0% of sequences, respectively), but reproducibility was low (ICC≤0·48) for less abundant taxa. Alpha diversity was lower with nonantibiotic prescription medication (P = 0·02), with younger age (P = 0·03) and marginally with higher body mass index (P = 0·08).

CONCLUSIONS

With sampling from various parts of a stool, both devices provided good reproducibility on overall microbial diversity and classification for the major phyla, but not for minor phyla. Implementation of these methods should provide insights into how broad microbial parameters, but not necessarily rare microbes, affect risk of various conditions.

Immunoglobulin M seropositivity for Toscana virus in a random population sample in Sicily

OBJECTIVES

High Toscana virus (TOSV) antibody seropositivity rates have been documented in the last decade, especially in the Mediterranean area. It is unclear if these rates are associated with a recent or past exposure to the virus. This is of importance, as primary infection can cause neurologic complications, especially in adults. The aim of the present study was to assess the current active TOSV circulation in western Sicily.

METHODS

A cross-sectional seroprevalence study was conducted on 271 individuals aged 4-92 years, sampled from the general population of a small city. Each participant completed a self-administered questionnaire and provided serum, which was analyzed for the presence of specific anti-TOSV IgM and IgG.

RESULTS

Anti-TOSV IgM was detected in eight (3.0%) participants, of whom only three had anti-TOSV IgG. The prevalence of anti-TOSV IgM was highest in subjects aged 25-34 and 35-44 years (7.1% and 4.8%, respectively). All subjects positive for anti-TOSV IgM were resident in the suburban area.

CONCLUSIONS

The detection of IgM documented the circulation of TOSV, a Phlebovirus, in a random population sample of Sicilian adults. The highest risk of TOSV seroconversion in subjects living in the suburbs appears to suggest a high density of TOSV vectors in peri-urban areas.

Association of fecal microbial diversity and taxonomy with selected enzymatic functions

Few microbial functions have been compared to a comprehensive survey of the human fecal microbiome. We evaluated determinants of fecal microbial β-glucuronidase and β-glucosidase activities, focusing especially on associations with microbial alpha and beta diversity and taxonomy. We enrolled 51 healthy volunteers (26 female, mean age 39) who provided questionnaire data and multiple aliquots of a stool, from which proteins were extracted to quantify β-glucuronidase and β-glucosidase activities, and DNA was extracted to amplify and pyrosequence 16S rRNA gene sequences to classify and quantify microbiome diversity and taxonomy. Fecal β-glucuronidase was elevated with weight loss of at least 5 lb. (P = 0.03), whereas β-glucosidase was marginally reduced in the four vegetarians (P = 0.06). Both enzymes were correlated directly with microbiome richness and alpha diversity measures, directly with the abundance of four Firmicutes Clostridia genera, and inversely with the abundance of two other genera (Firmicutes Lactobacillales Streptococcus and Bacteroidetes Rikenellaceae Alistipes) (all P = 0.05–0.0001). Beta diversity reflected the taxonomic associations. These observations suggest that these enzymatic functions are performed by particular taxa and that diversity indices may serve as surrogates of bacterial functions. Independent validation and deeper understanding of these associations are needed, particularly to characterize functions and pathways that may be amenable to manipulation.

A novel variant marking HLA-DP expression levels predicts recovery from hepatitis B virus infection

Variants near the HLA-DP gene show the strongest genome-wide association with chronic hepatitis B virus (HBV) infection and HBV recovery/persistence in Asians. To test the effect of the HLA-DP region on outcomes to HBV infection, we sequenced the polymorphic HLA-DPB1 and DPA1 coding exons and the corresponding 3' untranslated regions (3'UTRs) in 662 individuals of European-American and African-American ancestry. The genome-wide association study (GWAS) variant (rs9277535; 550A/G) in the 3'UTR of the HLA-DPB1 gene that associated most significantly with chronic hepatitis B and outcomes to HBV infection in Asians had a marginal effect on HBV recovery in our European- and African-American samples (odds ratio [OR] = 0.39, P = 0.01, combined ethnic groups). However, we identified a novel variant in the HLA-DPB1 3'UTR region, 496A/G (rs9277534), which associated very significantly with HBV recovery in both European and African-American populations (OR = 0.37, P = 0.0001, combined ethnic groups). The 496A/G variant distinguishes the most protective HLA-DPB1 allele (DPB1*04:01) from the most susceptible (DPB1*01:01), whereas 550A/G does not. 496A/G has a stronger effect than any individual HLA-DPB1 or DPA1 allele and any other HLA alleles that showed an association with HBV recovery in our European-American cohort. The 496GG genotype, which confers recessive susceptibility to HBV persistence, also associates in a recessive manner with significantly higher levels of HLA-DP surface protein and transcript level expression in healthy donors, suggesting that differences in expression of HLA-DP may increase the risk of persistent HBV infection.

Abstract 5489: Feasibility study of gut microbiome collection in randomly sampled women

Systemic estrogen level strongly determines risk for postmenopausal breast cancer (BC). We hypothesize that differences in hormone metabolism by the gut microbiota may contribute to BC risk by modulating enterohepatic circulation of estrogens. We conducted a study to determine the feasibility of enrolling healthy postmenopausal members of Kaiser Permanente Colorado (KPCO) in a fecal microbiome study. With electronic medical records, we created a pool of potentially eligible women aged 55-69 who recently had a negative screening mammogram. We excluded those with any hormone prescription in the prior 12 months, an antibiotic prescription in the prior 6 months, or history of cancer, inflammatory bowel disease or other conditions likely to affect fecal microbiota. A packet (invitation letter, informed consent form, information pamphlet, and opt-out postcard) was sent to 250 randomly sampled women. Women who have not returned the postcard are contacted by KPCO research staff to determine interest in participating, verify eligibility, and obtain verbal informed consent. Consented participants were mailed a second packet with a self-administered risk factor questionnaire, link to an on-line diet questionnaire, collection kit for urine (to measure 15 estrogens) and stool specimens, and shipping instructions to the laboratory. Enrollees have spent an estimated 1-2 hours completing all recruitment and data collection components. To date, 60 (24%) have enrolled, 70 (28%) refused (most via the opt-out card), and the remainder are pending phone contact. As shown in the table, the enrolled women are similar to the total sample; slightly more of them are non-Hispanic white, and they are more likely to have a history of breast biopsy. These data demonstrate that we can successfully recruit an apparently representative sample of women into a microbiome study.

Seroprevalence of and risk factors for Toscana and Sicilian virus infection in a sample population of Sicily (Italy)

OBJECTIVE

The present study aimed to assess seroprevalence of and risk factors for Toscana (TOSV) and Sicilian (SFSV) virus infections in a sample of Sicilian subjects.

METHODS

A cross-sectional seroepidemiological study was conducted on 271 individuals. Each participant completed a self-administrated questionnaire and provided a serum sample which was analyzed for the presence of IgG specific anti-TOSV and anti-SFSV viruses.

RESULTS

Overall, 90 subjects (33.2%) were positive for TOSV IgG, 25 (9.2%) were positive for SFSV IgG and 11 (4%) were positive for both the viruses. A higher risk for TOSV seropositivity was found in participants who were older (adjOR = 1.02 per year; 95% CI = 1.01-1.03), having a pet living outdoors (adjOR = 2.62; 95% CI = 1.42-4.83) and being obese (adjOR = 2.37; 95% CI = 1.06-5.30).

CONCLUSIONS

TOSV seroprevalence appears to be relatively high in Sicilian general population, especially in older adults, representing a potential public health concern. The observations that seropositivity for TOSV was not significantly associated with SFSV seropositivity, and none of the risk factors associated with TOSV were associated with SFSV seem to suggest that these two phleboviruses may have different ecology and transmission pathways.

Risk of anal cancer in HIV-infected and HIV-uninfected individuals in North America

BACKGROUND

Anal cancer is one of the most common cancers affecting individuals infected with human immunodeficiency virus (HIV), although few have evaluated rates separately for men who have sex with men (MSM), other men, and women. There are also conflicting data regarding calendar trends.

METHODS

In a study involving 13 cohorts from North America with follow-up between 1996 and 2007, we compared anal cancer incidence rates among 34 189 HIV-infected (55% MSM, 19% other men, 26% women) and 114 260 HIV-uninfected individuals (90% men).

RESULTS

Among men, the unadjusted anal cancer incidence rates per 100 000 person-years were 131 for HIV-infected MSM, 46 for other HIV-infected men, and 2 for HIV-uninfected men, corresponding to demographically adjusted rate ratios (RRs) of 80.3 (95% confidence interval [CI], 42.7-151.1) for HIV-infected MSM and 26.7 (95% CI, 11.5-61.7) for other HIV-infected men compared with HIV-uninfected men. HIV-infected women had an anal cancer rate of 30/100 000 person-years, and no cases were observed for HIV-uninfected women. In a multivariable Poisson regression model, among HIV-infected individuals, the risk was higher for MSM compared with other men (RR, 3.3; 95% CI, 1.8-6.0), but no difference was observed comparing women with other men (RR, 1.0; 95% CI, 0.5-2.2). In comparison with the period 2000-2003, HIV-infected individuals had an adjusted RR of 0.5 (95% CI, .3-.9) in 1996-1999 and 0.9 (95% CI, .6-1.2) in 2004-2007.

CONCLUSIONS

Anal cancer rates were substantially higher for HIV-infected MSM, other men, and women compared with HIV-uninfected individuals, suggesting a need for universal prevention efforts. Rates increased after the early antiretroviral therapy era and then plateaued.

A whole-genome analysis of premature termination codons

We sequenced the genomes of ten unrelated individuals and identified heterozygous stop codon-gain variants in protein-coding genes: we then sequenced their transcriptomes and assessed the expression levels of the stop codon-gain alleles. An ANOVA showed statistically significant differences between their expression levels (p=4×10(-16)). This difference was almost entirely accounted for by whether the stop codon-gain variant had a second, non-protein-truncating function in or near an alternate transcript: stop codon-gains without alternate functions were generally not found in the cDNA (p=3×10(-5)). Additionally, stop codon-gain variants in two intronless genes were not expressed, an unexpected outcome given previous studies. In this study, stop codon-gain variants were either well expressed in all individuals or were never expressed. Our finding that stop codon-gain variants were generally expressed only when they had an alternate function suggests that most naturally occurring stop codon-gain variants in protein-coding genes are either not transcribed or have their transcripts destroyed.

Risk factors for tuberculosis after highly active antiretroviral therapy initiation in the United States and Canada: implications for tuberculosis screening

BACKGROUND

Screening for tuberculosis prior to highly active antiretroviral therapy (HAART) initiation is not routinely performed in low-incidence settings. Identifying factors associated with developing tuberculosis after HAART initiation could focus screening efforts.

METHODS

Sixteen cohorts in the United States and Canada contributed data on persons infected with human immunodeficiency virus (HIV) who initiated HAART December 1995-August 2009. Parametric survival models identified factors associated with tuberculosis occurrence.

RESULTS

Of 37845 persons in the study, 145 were diagnosed with tuberculosis after HAART initiation. Tuberculosis risk was highest in the first 3 months of HAART (20 cases; 215 cases per 100000 person-years; 95% confidence interval [CI]: 131-333 per 100000 person-years). In a multivariate Weibull proportional hazards model, baseline CD4+ lymphocyte count <200, black race, other nonwhite race, Hispanic ethnicity, and history of injection drug use were independently associated with tuberculosis risk. In addition, in a piece-wise Weibull model, increased baseline HIV-1 RNA was associated with increased tuberculosis risk in the first 3 months; male sex tended to be associated with increased risk.

CONCLUSIONS

Screening for active tuberculosis prior to HAART initiation should be targeted to persons with baseline CD4 <200 lymphocytes/mm³ or increased HIV-1 RNA, persons of nonwhite race or Hispanic ethnicity, history of injection drug use, and possibly male sex.

Role of exonic variation in chemokine receptor genes on AIDS: CCRL2 F167Y association with pneumocystis pneumonia

Chromosome 3p21-22 harbors two clusters of chemokine receptor genes, several of which serve as major or minor coreceptors of HIV-1. Although the genetic association of CCR5 and CCR2 variants with HIV-1 pathogenesis is well known, the role of variation in other nearby chemokine receptor genes remain unresolved. We genotyped exonic single nucleotide polymorphisms (SNPs) in chemokine receptor genes: CCR3, CCRL2, and CXCR6 (at 3p21) and CCR8 and CX3CR1 (at 3p22), the majority of which were non-synonymous. The individual SNPs were tested for their effects on disease progression and outcomes in five treatment-naïve HIV-1/AIDS natural history cohorts. In addition to the known CCR5 and CCR2 associations, significant associations were identified for CCR3, CCR8, and CCRL2 on progression to AIDS. A multivariate survival analysis pointed to a previously undetected association of a non-conservative amino acid change F167Y in CCRL2 with AIDS progression: 167F is associated with accelerated progression to AIDS (RH = 1.90, P = 0.002, corrected). Further analysis indicated that CCRL2-167F was specifically associated with more rapid development of pneumocystis pneumonia (PCP) (RH = 2.84, 95% CI 1.28-6.31) among four major AIDS-defining conditions. Considering the newly defined role of CCRL2 in lung dendritic cell trafficking, this atypical chemokine receptor may affect PCP through immune regulation and inducing inflammation.

KIR2DL2 enhances protective and detrimental HLA class I-mediated immunity in chronic viral infection

Killer cell immunoglobulin-like receptors (KIRs) influence both innate and adaptive immunity. But while the role of KIRs in NK-mediated innate immunity is well-documented, the impact of KIRs on the T cell response in human disease is not known. Here we test the hypothesis that an individual's KIR genotype affects the efficiency of their HLA class I-mediated antiviral immune response and the outcome of viral infection. We show that, in two unrelated viral infections, hepatitis C virus and human T lymphotropic virus type 1, possession of the KIR2DL2 gene enhanced both protective and detrimental HLA class I-restricted anti-viral immunity. These results reveal a novel role for inhibitory KIRs. We conclude that inhibitory KIRs, in synergy with T cells, are a major determinant of the outcome of persistent viral infection.