Extended Prophylaxis With Nevirapine Does Not Affect Growth in HIV-Exposed Infants.

BACKGROUND: Effects of prolonged nevirapine prophylaxis exposure on growth among HIV-exposed uninfected (HEU) infants are unknown. This study examines the impact of extended nevirapine prophylaxis from 6 weeks to 6 months on the growth of HEU infants followed for 18 months and also identifies correlates of incident wasting, stunting, underweight, and low head circumference in the HPTN 046 trial. METHODS: Intention-to-treat analysis examined the effect of extended nevirapine exposure on: weight-for-age Z-score, length-for-age Z-score, weight-for-length Z-score, and head circumference-for-age Z-score. Multivariable linear mixed-effects and Cox proportional hazard models were used to compare growth outcomes between the study arms and identify correlates of incident adverse growth outcomes, respectively. RESULTS: Compared to placebo, extended prophylactic nevirapine given daily from 6 weeks to 6 months did not affect growth in HEU breastfeeding (BF) infants over time (treatment × time: P > 0.05). However, overall growth declined over time (time effect: P < 0.01) when compared with WHO general population norms. Male sex was associated with higher risk of all adverse growth outcomes (P < 0.05), whereas short BF duration was associated with wasting (P = 0.03). Maternal antiretroviral therapy exposure was protective against underweight (P = 0.02). Zimbabwe tended to have worse growth outcomes especially stunting, compared to South Africa, Uganda and Tanzania (P < 0.05). CONCLUSIONS: It is reassuring that prolonged exposure to nevirapine for prevention-of-mother-to-child HIV transmission does not restrict growth. However, targeted interventions are needed to improve growth outcomes among at-risk HEU infants (i.e., male sex, short BF duration, lack of maternal antiretroviral therapy exposure, and resident in Zimbabwe).

Safety and Tolerability of Maraviroc-Containing Regimens to Prevent HIV Infection in Women: A Phase 2 Randomized Trial.

BACKGROUND: Maraviroc (MVC) is a candidate drug for HIV preexposure prophylaxis (PrEP). OBJECTIVE: To assess the safety and tolerability of MVC-containing PrEP over 48 weeks in U.S. women at risk for HIV infection. DESIGN: Phase 2 randomized, controlled, double-blinded study of 4 antiretroviral regimens used as PrEP. (ClinicalTrials.gov: NCT01505114). SETTING: 12 clinical research sites of the HIV Prevention Trials Network and AIDS Clinical Trials Group. PARTICIPANTS: HIV-uninfected women reporting condomless vaginal or anal intercourse with at least 1 man with HIV infection or unknown serostatus within 90 days. INTERVENTION: MVC only, MVC-emtricitabine (FTC), MVC-tenofovir disoproxil fumarate (TDF), and TDF-FTC (control). MEASUREMENTS: At each visit, clinical and laboratory (including HIV) assessments were done. Primary outcomes were grade 3 and 4 adverse events and time to permanent discontinuation of the study regimen. All randomly assigned participants were analyzed according to their original assignment. RESULTS: Among 188 participants, 85% completed follow-up, 11% withdrew early, and 4% were lost to follow-up; 19% discontinued their regimen prematurely. The number discontinuing and the time to discontinuation did not differ among regimens. Grade 3 or 4 adverse events occurred in 5 (MVC), 13 (MVC-FTC), 9 (MVC-TDF), and 8 (TDF-FTC) participants; rates did not differ among regimens. One death (by suicide) occurred in the MVC-TDF group but was judged not to be related to study drugs. Of available plasma samples at week 48 (n = 126), 60% showed detectable drug concentrations. No new HIV infections occurred. LIMITATIONS: Participants were not necessarily at high risk for HIV infection. The regimen comprised 3 pills taken daily. The study was not powered for efficacy. CONCLUSION: Maraviroc-containing PrEP regimens were safe and well-tolerated compared with TDF-FTC in U.S. women. No new HIV infections occurred, although whether this was due to study drugs or low risk in the population is uncertain. Maraviroc-containing PrEP for women may warrant further study. PRIMARY FUNDING SOURCE: National Institutes of Health.

Phase 2 Study of the Safety and Tolerability of Maraviroc-Containing Regimens to Prevent HIV Infection in Men Who Have Sex With Men (HPTN 069/ACTG A5305).

BACKGROUND: Maraviroc (MVC) is a candidate for human immunodeficiency virus (HIV) pre-exposure prophylaxis. METHODS: Phase 2 48-week safety/tolerability study was conducted, comparing 4 regimens: MVC alone, MVC plus emtricitabine (FTC), MVC plus tenofovir disoproxil fumarate (TDF), and TDF plus FTC. Eligible participants were HIV-uninfected men and transgender women reporting condomless anal intercourse with ≥1 HIV-infected or unknown-serostatus man within 90 days. At each visit, assessments, laboratory testing, and counseling were done. Analyses were intention to treat. RESULTS: Among 406 participants, 84% completed follow-up, 7% stopped early, and 9% were lost to follow-up; 9% discontinued their regimen early. The number discontinuing and the time to discontinuation did not differ among study regimens (P = .60). Rates of grade 3-4 adverse events did not differ among regimens (P = .37). In a randomly selected subset, 77% demonstrated detectable drug concentrations at week 48. Five participants acquired HIV infection (4 MVC alone, 1 MVC + TDF; overall annualized incidence, 1.4% [95% confidence interval, .5%-3.3%], without differences by regimen; P = .32); 2 had undetectable drug concentrations at every visit, 2 had low concentrations at the seroconversion visit, and 1 had variable concentrations. CONCLUSIONS: MVC-containing regimens were safe and well tolerated compared with TDF + FTC; this study was not powered for efficacy. Among those acquiring HIV infection, drug concentrations were absent, low, or variable. MVC-containing regimens may warrant further study for pre-exposure prophylaxis. CLINICAL TRIALS REGISTRATION: NCT01505114.

Evidence of heterogeneity by race/ethnicity in genetic determinants of QT interval.

BACKGROUND: QT interval (QT) prolongation is an established risk factor for ventricular tachyarrhythmia and sudden cardiac death. Previous genome-wide association studies in populations of the European descent have identified multiple genetic loci that influence QT, but few have examined these loci in ethnically diverse populations. METHODS: Here, we examine the direction, magnitude, and precision of effect sizes for 21 previously reported SNPs from 12 QT loci, in populations of European (n = 16,398), African (n = 5,437), American Indian (n = 5,032), Hispanic (n = 1,143), and Asian (n = 932) descent as part of the Population Architecture using Genomics and Epidemiology (PAGE) study. Estimates obtained from linear regression models stratified by race/ethnicity were combined using inverse-variance weighted meta-analysis. Heterogeneity was evaluated using Cochran's Q test. RESULTS: Of 21 SNPs, 7 showed consistent direction of effect across all 5 populations, and an additional 9 had estimated effects that were consistent across 4 populations. Despite consistent direction of effect, 9 of 16 SNPs had evidence (P < 0.05) of heterogeneity by race/ethnicity. For these 9 SNPs, linkage disequilibrium plots often indicated substantial variation in linkage disequilibrium patterns among the various racial/ethnic groups, as well as possible allelic heterogeneity. CONCLUSIONS: These results emphasize the importance of analyzing racial/ethnic groups separately in genetic studies. Furthermore, they underscore the possible utility of trans-ethnic studies to pinpoint underlying casual variants influencing heritable traits such as QT.

Trans-ethnic fine-mapping of lipid loci identifies population-specific signals and allelic heterogeneity that increases the trait variance explained.

Genome-wide association studies (GWAS) have identified ~100 loci associated with blood lipid levels, but much of the trait heritability remains unexplained, and at most loci the identities of the trait-influencing variants remain unknown. We conducted a trans-ethnic fine-mapping study at 18, 22, and 18 GWAS loci on the Metabochip for their association with triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), respectively, in individuals of African American (n = 6,832), East Asian (n = 9,449), and European (n = 10,829) ancestry. We aimed to identify the variants with strongest association at each locus, identify additional and population-specific signals, refine association signals, and assess the relative significance of previously described functional variants. Among the 58 loci, 33 exhibited evidence of association at P<1 × 10(-4) in at least one ancestry group. Sequential conditional analyses revealed that ten, nine, and four loci in African Americans, Europeans, and East Asians, respectively, exhibited two or more signals. At these loci, accounting for all signals led to a 1.3- to 1.8-fold increase in the explained phenotypic variance compared to the strongest signals. Distinct signals across ancestry groups were identified at PCSK9 and APOA5. Trans-ethnic analyses narrowed the signals to smaller sets of variants at GCKR, PPP1R3B, ABO, LCAT, and ABCA1. Of 27 variants reported previously to have functional effects, 74% exhibited the strongest association at the respective signal. In conclusion, trans-ethnic high-density genotyping and analysis confirm the presence of allelic heterogeneity, allow the identification of population-specific variants, and limit the number of candidate SNPs for functional studies.

Fine-mapping and initial characterization of QT interval loci in African Americans.

The QT interval (QT) is heritable and its prolongation is a risk factor for ventricular tachyarrhythmias and sudden death. Most genetic studies of QT have examined European ancestral populations; however, the increased genetic diversity in African Americans provides opportunities to narrow association signals and identify population-specific variants. We therefore evaluated 6,670 SNPs spanning eleven previously identified QT loci in 8,644 African American participants from two Population Architecture using Genomics and Epidemiology (PAGE) studies: the Atherosclerosis Risk in Communities study and Women's Health Initiative Clinical Trial. Of the fifteen known independent QT variants at the eleven previously identified loci, six were significantly associated with QT in African American populations (P≤1.20×10(-4)): ATP1B1, PLN1, KCNQ1, NDRG4, and two NOS1AP independent signals. We also identified three population-specific signals significantly associated with QT in African Americans (P≤1.37×10(-5)): one at NOS1AP and two at ATP1B1. Linkage disequilibrium (LD) patterns in African Americans assisted in narrowing the region likely to contain the functional variants for several loci. For example, African American LD patterns showed that 0 SNPs were in LD with NOS1AP signal rs12143842, compared with European LD patterns that indicated 87 SNPs, which spanned 114.2 Kb, were in LD with rs12143842. Finally, bioinformatic-based characterization of the nine African American signals pointed to functional candidates located exclusively within non-coding regions, including predicted binding sites for transcription factors such as TBX5, which has been implicated in cardiac structure and conductance. In this detailed evaluation of QT loci, we identified several African Americans SNPs that better define the association with QT and successfully narrowed intervals surrounding established loci. These results demonstrate that the same loci influence variation in QT across multiple populations, that novel signals exist in African Americans, and that the SNPs identified as strong candidates for functional evaluation implicate gene regulatory dysfunction in QT prolongation.

Association of genetic variants and incident coronary heart disease in multiethnic cohorts: the PAGE study.

BACKGROUND: Genome-wide association studies identified several single nucleotide polymorphisms (SNP) associated with prevalent coronary heart disease (CHD), but less is known of associations with incident CHD. The association of 13 published CHD SNPs was examined in 5 ancestry groups of 4 large US prospective cohorts. METHODS AND RESULTS: The analyses included incident coronary events over an average 9.1 to 15.7 follow-up person-years in up to 26 617 white individuals (6626 events), 8018 black individuals (914 events), 1903 Hispanic individuals (113 events), 3669 American Indian individuals (595 events), and 885 Asian/Pacific Islander individuals (66 events). We used Cox proportional hazards models (with additive mode of inheritance) adjusted for age, sex, and ancestry (as needed). Nine loci were statistically associated with incident CHD events in white participants: 9p21 (rs10757278; P=4.7 × 10(-41)), 16q23.1 (rs2549513; P=0.0004), 6p24.1 (rs499818; P=0.0002), 2q36.3 (rs2943634; P=6.7 × 10(-6)), MTHFD1L (rs6922269, P=5.1 × 10(-10)), APOE (rs429358; P=2.7×10(-18)), ZNF627 (rs4804611; P=5.0 × 10(-8)), CXCL12 (rs501120; P=1.4 × 10(-6)) and LPL (rs268; P=2.7 × 10(-17)). The 9p21 region showed significant between-study heterogeneity, with larger effects in individuals age 55 years or younger and in women. Inclusion of coronary revascularization procedures among the incident CHD events introduced heterogeneity. The SNPs were not associated with CHD in black participants, and associations varied in other US minorities. CONCLUSIONS: Prospective analyses of white participants replicated several reported cross-sectional CHD-SNP associations.

Replication of breast cancer GWAS susceptibility loci in the Women's Health Initiative African American SHARe Study.

BACKGROUND: Genome-wide association studies (GWAS) have identified loci associated with risk of breast cancer. These studies have primarily been conducted in populations of European descent. To fully understand the impact of these loci, it is important to study groups with other genetic ancestries, including African American women. METHODS: We examined 22 single-nucleotide polymorphisms (SNP), previously identified in GWAS of breast cancer risk in European and Asian descent women (index SNPs), and SNPs in the surrounding regions in a study of 7,800 African American women (including 316 women with incident invasive breast cancer) from the Women's Health Initiative SNP Health Association Resource. RESULTS: Two index SNPs were associated with breast cancer: rs3803662 at 16q12.2/TOX3 (Hazard ratio [HR] for the T allele = 0.79, 95% CI: 0.67-0.92, P = 0.003) and rs10941679 at 5p12 (HR for the G allele = 1.31, 95% CI: 1.06-1.63, P = 0.014). When we expanded to regions, the 3p24.1 region showed an association with breast cancer risk (permutation based P = 0.027) and three regions (10p15.1, 10q26.13/FGFR2, and 16q12.2/TOX3) showed a trend toward association. CONCLUSION: Our findings provide evidence that some breast cancer GWAS regions may be associated with breast cancer in African American women. Larger, more comprehensive studies are needed to fully assess generalizability of published GWAS findings and to identify potential novel associations in African American populations. IMPACT: Both replication and lack of replication of published GWAS findings in other ancestral groups provides important information of the genetic etiology of this disease and may impact translation of GWAS findings to clinical and public health settings.

Fatty acid consumption and risk of fracture in the Women's Health Initiative.

BACKGROUND: Fatty acids (FAs) may be important dietary components that modulate osteoporotic fracture risk. OBJECTIVE: The objective was to examine FA intake in relation to osteoporotic fractures. DESIGN: The participants were postmenopausal women enrolled in the Women's Health Initiative (n = 137,486). Total fractures were identified by self-report; hip fractures were confirmed by medical record review. FA intake was estimated from baseline food-frequency questionnaires and standardized to total caloric intake. No data on omega-3 (n-3) FA supplements were available. Cox proportional hazard models were constructed to estimate risk of fracture. RESULTS: Higher saturated FA consumption was associated with higher hip fracture risk [quartile 4 multivariate-adjusted hazard ratio (HR): 1.31; 95% CI: 1.11, 1.55; P for trend = 0.001]. Lower total fracture risk was associated with a higher monounsaturated FA intake (quartile 3 HR: 0.94; 95% CI: 0.89, 0.98; P for trend = 0.050) and polyunsaturated FA intake (quartile 4 HR: 0.95; 95% CI: 0.90, 0.99; P for trend = 0.019). Unexpectedly, higher consumption of marine n-3 FAs was associated with greater total fracture risk (quartile 4 HR: 1.07; 95% CI: 1.02, 1.12; P for trend = 0.010), whereas a higher n-6 FA intake was associated with a lower total fracture risk (quartile 4 HR: 0.94; 95% CI: 0.89, 0.98; P for trend 0.009). CONCLUSIONS: These results suggest that saturated FA intake may significantly increase hip fracture risk, whereas monounsaturated and polyunsaturated FA intakes may decrease total fracture risk. In postmenopausal women with a low intake of marine n-3 FAs, a higher intake of n-6 FAs may modestly decrease total fracture risk. This trial was registered at clinicaltrials.gov as NCT00000611.

Placental malaria and mother-to-child transmission of human immunodeficiency virus-1.

There are few studies of the association between placental malaria (PM) and mother-to-child transmission (MTCT) of human immunodeficiency virus-1 (HIV-1), and the results of published studies are inconsistent. To determine the association between PM and MTCT of HIV-1, we performed a secondary analysis of data from a clinical trial of antibiotics to reduce chorioamnionitis. Data regarding 1,662 HIV-1-infected women with live born singleton and first-born twin infants with information regarding PM and infant HIV-1 infection status at birth were analyzed. At the time of the study, women did not have access to antiretroviral drugs for treatment of acquired immunodeficiency syndrome but had received nevirapine prophylaxis to reduce the risk of MTCT of HIV-1. Placental malaria was not associated with the infant HIV-1 infection status at birth (P = 0.67). Adjustment for maternal plasma viral load and CD4+ cell count did not change these results (odds ratio = 1.06, 95% confidence interval = 0.51-2.20, P = 0.87). Placental malaria was more likely to be related to HIV-1 infection at birth among women with low viral load at baseline (P for interaction = 0.08). In conclusion, PM was not associated with infant HIV-1 infection status at birth. The interaction of maternal plasma viral load, PM, and MTCT of HIV-1 warrants further studies.

Total lymphocyte count: not a surrogate marker for risk of death in HIV-infected Ugandan children.

OBJECTIVES: To determine the utility of total lymphocyte count (TLC) in predicting the 12-month mortality in HIV-infected Ugandan children and to correlate TLC and CD4 cell %. DESIGN: This is a retrospective data analysis of clinical and laboratory data collected prospectively on 128 HIV-infected children in the HIV Network for Prevention Trials 012 trial. METHODS: TLC and CD4 cell % measurements were obtained at birth, 14 weeks, and 12, 24, 36, 48, and 60 months of age and assessed with respect to risk of death within 12 months. RESULTS: Median TLC per microliter (CD4 cell %) was 4150 (41%) at birth, 4900 (24%) at 12 months, 4300 (19%) at 24 months, 4150 (19%) at 36 months, 4100 (18%) at 48 months, and 3800 (20%) at 60 months. The highest risk of mortality within 12 months was 34% - 37% at birth and declined to 13%-15% at 24 months regardless of TLC measurement. The correlation between CD4 cell % and TLC was extremely low overall (r = 0.01). CONCLUSIONS: The TLC did not predict a risk of progression to death within 12 months in HIV-infected Ugandan children. Therefore, TLC alone may not be a useful surrogate marker for determining those children at highest risk of death, who require antiretroviral therapy most urgently.

Nutritional indicators of adverse pregnancy outcomes and mother-to-child transmission of HIV among HIV-infected women.

BACKGROUND: Poor nutrition may be associated with mother-to-child transmission (MTCT) of HIV and other adverse pregnancy outcomes. OBJECTIVE: The objective was to examine the relation of nutritional indicators with adverse pregnancy outcomes among HIV-infected women in Tanzania, Zambia, and Malawi. DESIGN: Body mass index (BMI; in kg/m(2)) and hemoglobin concentrations at enrollment and weight change during pregnancy were prospectively related to fetal loss, neonatal death, low birth weight, preterm birth, and MTCT of HIV. RESULTS: In a multivariate analysis, having a BMI < 21.8 was significantly associated with preterm birth [odds ratio (OR): 1.82; 95% CI: 1.34, 2.46] and low birth weight (OR: 2.09; 95% CI: 1.41, 3.08). A U-shaped relation between weight change during pregnancy and preterm birth was observed. Severe anemia was significantly associated with fetal loss or stillbirth (OR: 3.67; 95% CI: 1.16, 11.66), preterm birth (OR: 2.08; 95% CI: 1.39, 3.10), low birth weight (OR: 1.76; 95% CI: 1.07, 2.90), and MTCT of HIV by the time of birth (OR: 2.26; 95% CI: 1.18, 4.34) and by 4-6 wk among those negative at birth (OR: 2.33; 95% CI: 1.15, 4.73). CONCLUSIONS: Anemia, poor weight gain during pregnancy, and low BMI in HIV-infected pregnant women are associated with increased risks of adverse infant outcomes and MTCT of HIV. Interventions that reduce the risk of wasting or anemia during pregnancy should be evaluated to determine their possible effect on the incidence of adverse pregnancy outcomes and MTCT of HIV.

Coreceptor tropism in human immunodeficiency virus type 1 subtype D: high prevalence of CXCR4 tropism and heterogeneous composition of viral populations.

In human immunodeficiency virus type 1 (HIV-1) subtype B, CXCR4 coreceptor use ranges from approximately 20% in early infection to approximately 50% in advanced disease. Coreceptor use by non-subtype B HIV is less well characterized. We studied coreceptor tropism of subtype A and D HIV-1 collected from 68 pregnant, antiretroviral drug-naive Ugandan women (HIVNET 012 trial). None of 33 subtype A or 10 A/D-recombinant viruses used the CXCR4 coreceptor. In contrast, nine (36%) of 25 subtype D viruses used both CXCR4 and CCR5 coreceptors. Clonal analyses of the nine subtype D samples with dual or mixed tropism revealed heterogeneous viral populations comprised of X4-, R5-, and dual-tropic HIV-1 variants. In five of the six samples with dual-tropic strains, V3 loop sequences of dual-tropic clones were identical to those of cocirculating R5-tropic clones, indicating the presence of CXCR4 tropism determinants outside of the V3 loop. These dual-tropic variants with R5-tropic-like V3 loops, which we designated "dual-R," use CCR5 much more efficiently than CXCR4, in contrast to dual-tropic clones with X4-tropic-like V3 loops ("dual-X"). These observations have implications for pathogenesis and treatment of subtype D-infected individuals, for the association between V3 sequence and coreceptor tropism phenotype, and for understanding potential mechanisms of evolution from exclusive CCR5 use to efficient CXCR4 use by subtype D HIV-1.

Detection of hypermethylated genes in women with and without cervical neoplasia.

BACKGROUND: DNA methylation changes are an early event in carcinogenesis and are often present in the precursor lesions of various cancers. We examined whether DNA methylation changes might be used as markers of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC). METHODS: We used methylation-specific polymerase chain reaction (PCR) to analyze promoter hypermethylation of 20 genes, selected on the basis of their role in cervical cancer, in 319 exfoliated cell samples and matched tissue biopsy specimens collected during two studies of Senegalese women with increasingly severe CIN and ICC (histology negative/atypical squamous cells of undetermined significance [ASCUS] = 142, CIN-1 = 39, CIN-2 = 23, CIN-3/carcinoma in situ [CIS] = 23, ICC = 92). Logic regression was used to determine the best set of candidate genes to use as disease markers. All statistical tests were two-sided. RESULTS: Similar promoter methylation patterns were seen in genes from exfoliated cell samples and corresponding biopsy specimens. For four genes (CDH13, DAPK1, RARB, and TWIST1), the frequency of hypermethylation increased statistically significantly with increasing severity of neoplasia present in the cervical biopsy (P<.001 for each). By using logic regression, we determined that the best panel of hypermethylated genes included DAPK1, RARB, or TWIST1. At least one of the three genes was hypermethylated in 57% of samples with CIN-3/CIS and in 74% of samples with ICC but in only 5% of samples with CIN-1 or less. The estimated specificity of the three-gene panel was 95%, and its sensitivity was 74% (95% confidence interval [CI] = 73% to 75%) for ICC and 52% (95% CI = 49% to 55%) for CIN-3/CIS. By extrapolation, we estimated that, among Senegalese women presenting to community-based clinics, detection of the DAPK1, RARB, or TWIST1 hypermethylated gene would reveal histologically confirmed CIN-3 or worse with a sensitivity of 60% (95% CI = 57% to 63%) and a specificity of 95% (95% CI = 94% to 95%). CONCLUSIONS: Aberrant promoter methylation analysis on exfoliated cell samples is a potential diagnostic tool for cervical cancer screening that potentially may be used alone or in conjunction with cytology and/or human papillomavirus testing.