Ashley L. Buchanan

Barriers to Medication Adherence in HIV-Infected Children and Youth Based on Self- and Caregiver Report

OBJECTIVE: Nonadherence to antiretroviral therapy among children/youth with HIV often is associated with disease progression. This study examined the agreement between child and caregiver perceptions of barriers to adherence and factors associated with these barriers. METHODS: Children/youth with perinatally acquired HIV and their parents/caregivers (n = 120 dyads) completed a questionnaire about 19 potential barriers to adherence to the child’s antiretroviral therapy regimen. Agreement between the 2 reports was measured via the kappa statistic. Factors associated with the barriers were assessed by using multiple logistic regression. RESULTS: Of the 120 children, 55% were African American, 54% were boys, and the average age was 12.8 years. The most frequently reported barrier by either the caregiver or youth was “forgot.” There were varying degrees of agreement between child and caregiver on the following barriers: “forgot,” “taste,” “child was away from home,” “child refused,” and “child felt good.” Children who knew their HIV status were more likely to report logistical barriers, such as scheduling issues. Children with a biological parent as their caregiver were more likely to report regimen or fear of disclosure as a barrier. CONCLUSIONS: Lack of agreement was observed for more than half of the studied barriers, indicating discrepancies between children’s and caregivers’ perceptions of factors that influence medication-taking. The findings suggest a need for interventions that involve both child and caregiver in the tasks of remembering when to administer the child’s medications, sustaining adherence, and appropriately transitioning medication responsibility to the youth.

Language Impairment in Children Perinatally Infected with HIV Compared to Children Who Were HIV-Exposed and Uninfected

Objective: To investigate the risk for language impairment (LI) in children perinatally infected or exposed to HIV. Methods: We evaluated the prevalence of LI in 7- to 16-year-old children with perinatal HIV infection (HIV+) compared with HIV-exposed and uninfected children, using a comprehensive standardized language test (Clinical Evaluation of Language Functioning-Fourth Edition [CELF-4]). LI was classified as primary LI (Pri-LI) (monolingual English exposure and no cognitive or hearing impairment), concurrent LI (Con-LI) (cognitive or hearing impairment), or no LI. Associations of demographic, caregiver, HIV disease, and antiretroviral treatment factors with LI category were evaluated using univariate and multivariable logistic regression models. Results: Of the 468 children with language assessments, 184 (39%) had LI. No difference was observed by HIV infection status for overall LI or for Pri-LI or Con-LI; mean (SD) CELF-4 scores were 88.5 (18.4) for HIV+ versus 87.5 (17.9) for HIV-exposed and uninfected children. After adjustment, black children had higher odds of Pri-LI versus no LI (adjusted odds ratio [aOR] = 2.43, p = .03). Children who were black, Hispanic, had a caregiver with low education or low intelligence quotient, or a nonbiological parent as caregiver had higher odds of Con-LI versus no LI. Among HIV+ children, viral load >400 copies/mL (aOR = 3.04, p < .001), Centers for Disease Control and Prevention Class C (aOR = 2.19, p = .02), and antiretroviral treatment initiation <6 months of age (aOR = 2.12, p = .02) were associated with higher odds of Con-LI versus no LI. Conclusions: Children perinatally exposed to HIV are at high risk for LI, but such risk was not increased for youth with HIV. Risk factors differed for Pri-LI and Con-LI.

HIV viremia and incidence of non-Hodgkin lymphoma in patients successfully treated with antiretroviral therapy

BACKGROUND The incidence of non-Hodgkin lymphoma (NHL) in human immunodeficiency virus (HIV)-infected patients remains high despite treatment with antiretroviral therapy (ART). METHODS We evaluated NHL incidence in HIV-infected patients followed in the Centers for AIDS Research Network of Integrated Clinical Systems who started combination ART and achieved suppression of HIV. We estimated the hazard ratio for NHL by time-varying HIV viremia categories, accounting for time-varying CD4 cell count using marginal structural models. RESULTS We observed 37 incident NHL diagnoses during 21 607 person-years of follow-up in 6036 patients (incidence rate, 171 per 100 000 person-years; 95% confidence interval [CI], 124-236). NHL incidence was high even among patients with nadir CD4 cell count >200 cells/µL (140 per 100 000 person-years [95% CI, 80-247]). Compared with ≤50 copies/mL, hazard ratios (HRs) for NHL were higher among those with HIV viremia of 51-500 copies/mL (HR current = 1.66 [95% CI, .70-3.94]; HR 3-month lagged = 2.10 [95% CI, .84-5.22]; and HR 6-month lagged = 1.46 [95% CI, .60-3.60]) and >500 copies/mL (HR current = 2.39 [95% CI, .92-6.21]; HR 3-month lagged = 3.56 [95% CI, 1.21-10.49]; and HR 6-month lagged = 2.50 [95% CI, .91-6.84]). Current HIV RNA as a continuous variable was also associated with NHL (HR = 1.42 per log10 copies/mL [95% CI, 1.05-1.92]). CONCLUSIONS Our findings demonstrate a high incidence of NHL among HIV-infected patients on ART and suggest a role of HIV viremia in the pathogenesis of NHL. Earlier initiation of potent ART and maximal continuous suppression of HIV viremia may further reduce NHL risk.

Evaluation of risk for late language emergence after in utero antiretroviral drug exposure in HIV-exposed uninfected infants.

Background: Combination antiretroviral (cARV) regimens are recommended for pregnant women with HIV to prevent perinatal HIV transmission. Safety is a concern for infants who were HIV-exposed but uninfected, particularly for neurodevelopmental problems, such as language delays. Methods: We studied late language emergence (LLE) in HIV-exposed but uninfected children enrolled in a US-based prospective cohort study. LLE was defined as a caregiver-reported score ⩽10th percentile in any of 4 domains of the MacArthur-Bates Communicative Development Inventory for 1-year olds and as ≥1 standard deviation below age-specific norms for the Ages and Stages Questionnaire for 2-year olds. Logistic regression models were used to evaluate associations of in utero cARV exposure with LLE, adjusting for infant, maternal and environmental characteristics. Results: 1129 language assessments were conducted among 792 1- and 2-year-old children (50% male, 62% black and 37% Hispanic). Overall, 86% had in utero exposure to cARV and 83% to protease inhibitors. LLE was identified in 26% of 1-year olds and 23% of 2-year olds, with higher rates among boys. In adjusted models, LLE was not associated with maternal cARV or ARV drug classes in either age group. Among cARV-exposed 1-year olds, increased odds of LLE was observed for those exposed to atazanavir (adjusted odds ratio = 1.83, 95% confidence interval: 1.10–3.04), particularly after the first trimester (adjusted odds ratio = 3.56, P = 0.001), compared with atazanavir-unexposed infants. No associations of individual ARV drugs with LLE were observed among 2-year olds. Conclusions: In utero cARV exposure showed little association with LLE, except for a higher risk of language delay observed in 1-year-old infants with atazanavir exposure.

Influence of single nucleotide polymorphisms in factor VIII and von Willebrand factor genes on plasma factor VIII activity: the ARIC Study

Factor VIII (FVIII) functions as a cofactor for factor IXa in the contact coagulation pathway and circulates in a protective complex with von Willebrand factor (VWF). Plasma FVIII activity is strongly influenced by environmental and genetic factors through VWF-dependent and -independent mechanisms. Single nucleotide polymorphisms (SNPs) of the coding and promoter sequence in the FVIII gene have been extensively studied for effects on FVIII synthesis, secretion, and activity, but impacts of non-disease-causing intronic SNPs remain largely unknown. We analyzed FVIII SNPs and FVIII activity in 10,434 healthy Americans of European (EA) or African (AA) descent in the Atherosclerosis Risk in Communities (ARIC) study. Among covariates, age, race, diabetes, and ABO contributed 2.2%, 3.5%, 4%, and 10.7% to FVIII intersubject variation, respectively. Four intronic FVIII SNPs associated with FVIII activity and 8 with FVIII-VWF ratio in a sex- and race-dependent manner. The FVIII haplotypes AT and GCTTTT also associated with FVIII activity. Seven VWF SNPs were associated with FVIII activity in EA subjects, but no FVIII SNPs were associated with VWF Ag. These data demonstrate that intronic SNPs could directly or indirectly influence intersubject variation of FVIII activity. Further investigation may reveal novel mechanisms of regulating FVIII expression and activity.

Hearing Loss in Perinatally HIV-infected and HIV-exposed but Uninfected Children and Adolescents

Background: Little is known about hearing loss in children with HIV infection (HIV+). We examined the prevalence of hearing loss in perinatally HIV+ and HIV-exposed but uninfected (HEU) children, compared these with the percentage with hearing loss in the general population and evaluated possible risk factors for hearing loss in HIV+ and HEU children. Methods: Audiometric examinations were completed in children who met any prespecified criteria for possible hearing loss. The hearing examination consisted of a tympanogram in each ear and pure-tone air-conduction threshold testing from 500 through 4000 Hz. Hearing loss was defined as the pure-tone average over these frequencies ≥20 dB hearing level. The associations of demographic variables, parent/caregiver, HIV disease and HIV treatment with hearing loss were evaluated with univariate and multivariable logistic regression models. Results: Hearing testing was completed in 231 children (145 HIV+ and 86 HEU). Hearing loss occurred in 20.0% of HIV+ children and 10.5% of HEU children. After adjusting for caregiver education level, HIV infection was associated with increased odds of hearing loss (adjusted odds ratio = 2.13, 95% confidence interval: 0.95–4.76, P = 0.07). Among HIV+ children, those with a Centers for Disease Control and Prevention class C diagnosis had over twice the odds of hearing loss (adjusted odds ratio = 2.47, 95% confidence interval: 1.04–5.87, P = 0.04). The prevalence of hearing loss was higher in both HIV+ and HEU children compared with National Health and Nutrition Examination Survey III children. Conclusions: Hearing loss was more common in both HIV+ and HEU children than in children from a US population sample. More advanced HIV illness increased the risk of hearing loss in HIV+ children.

Generalizing Study Results: A Potential Outcomes Perspective

Great care is taken in epidemiologic studies to ensure the internal validity of causal effect estimates; however, external validity has received considerably less attention. When the study sample is not a random sample of the target population, the sample average treatment effect, even if internally valid, cannot usually be expected to equal the average treatment effect in the target population. The utility of an effect estimate for planning purposes and decision making will depend on the degree of departure from the true causal effect in the target population due to problems with both internal and external validity. Herein, we review concepts from recent literature on generalizability, one facet of external validity, using the potential outcomes framework. Identification conditions sufficient for external validity closely parallel identification conditions for internal validity, namely conditional exchangeability; positivity; the same distributions of the versions of treatment; no interference; and no measurement error. We also require correct model specification. Under these conditions, we discuss how a version of direct standardization (the g-formula, adjustment formula, or transport formula) or inverse probability weighting can be used to generalize a causal effect from a study sample to a well-defined target population, and demonstrate their application in an illustrative example.

Docetaxel and irinotecan in recurrent or metastatic head and neck cancer: A phase 2 trial of the eastern cooperative oncology group

Docetaxel and irinotecan have single‐agent antitumor activity in squamous cell carcinoma of the head and neck (SCCHN). The authors sought to evaluate their combination in the treatment of patients with recurrent or metastatic SCCHN.

Possible Race and Gender Divergence in Association of Genetic Variations with Plasma von Willebrand Factor: A Study of ARIC and 1000 Genome Cohorts

The synthesis, secretion and clearance of von Willebrand factor (VWF) are regulated by genetic variations in coding and promoter regions of the VWF gene. We have previously identified 19 single nucleotide polymorphisms (SNPs), primarily in introns that are associated with VWF antigen levels in subjects of European descent. In this study, we conducted race by gender analyses to compare the association of VWF SNPs with VWF antigen among 10,434 healthy Americans of European (EA) or African (AA) descent from the Atherosclerosis Risk in Communities (ARIC) study. Among 75 SNPs analyzed, 13 and 10 SNPs were associated with VWF antigen levels in EA male and EA female subjects, respectively. However, only one SNP (RS1063857) was significantly associated with VWF antigen in AA females and none was in AA males. Haplotype analysis of the ARIC samples and studying racial diversities in the VWF gene from the 1000 genomes database suggest a greater degree of variations in the VWF gene in AA subjects as compared to EA subjects. Together, these data suggest potential race and gender divergence in regulating VWF expression by genetic variations.