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1.  Tenofovir use and urinary biomarkers among HIV-infected women in the Women's Interagency HIV Study (WIHS) 
Background
Tenofovir has been associated with renal tubular injury. Biomarkers that signal early tubular dysfunction are needed because creatinine rise lags behind tenofovir-associated kidney dysfunction. We examined several urinary biomarkers to determine if rises accompanying tenofovir initiation preceded creatinine changes.
Methods
Three urinary biomarkers of tubular impairment- neutrophil gelatinase-associated lipocalin (NGAL), N-acetyl- β -D-glucosaminidase (NAG), and β-2-microglobulin (β2MG)-were measured across three time points (one pre-tenofovir visit and two post tenofovir visits) in one hundred and thirty two HIV-positive women from the Women's Interagency HIV Study (WIHS). Women initiating HAART containing tenofovir were propensity score matched to women initiating HAART without tenofovir and women not on HAART.
Results
There were no differences between groups for NGAL or NAG but β2MG was 19 times more likely to be elevated among tenofovir users at the 2nd post tenofovir visit compared to non-TDF users at the pre-tenofovir visit (p<0.01). History of proteinuria was associated with elevated NGAL (p <0.01). Factors associated with elevated NAG were GFR<60 ml/min, history of proteinuria, hepatitis C (p<0.01 for all) and diabetes mellitus (p=0.05). Factors associated with increased odds of elevated β2MG were HIV RNA>100,000 copies/ml, hepatitis C, boosted protease inhibitor (PI) use, and GFR<60 ml/min (p≤0.01 for all).
Conclusions
β2MG levels are elevated in women on tenofovir indicating probable early renal dysfunction. Biomarker elevation is additionally associated with baseline chronic kidney disease, uncontrolled viremia, and boosted PI use. Future studies are needed to explore urinary biomarker thresholds in identifying treated HIV-infected individuals at risk for renal dysfunction.
doi:10.1097/QAI.0b013e31828175c9
PMCID: PMC3692572  PMID: 23254151
Tenofovir; urinary biomarkers; HIV infected women
2.  A Single-Nucleotide Polymorphism in CYP2B6 Leads to >3-Fold Increases in Efavirenz Concentrations in Plasma and Hair Among HIV-Infected Women 
The Journal of Infectious Diseases  2012;206(9):1453-1461.
Background. Efavirenz exhibits marked interindividual variability in plasma levels and toxicities. Prior pharmacogenetic studies usually measure exposure via single plasma levels, examine limited numbers of polymorphisms, and rarely model multiple contributors. We analyzed numerous genetic and nongenetic factors impacting short-term and long-term exposure in a large heterogeneous population of human immunodeficiency virus (HIV)–infected women.
Methods. We performed 24-hour intensive pharmacokinetic studies in 111 women receiving efavirenz under actual-use conditions and calculated the area-under-the-concentration-time curve (AUC) to assess short-term exposure; the efavirenz concentration in hair was measured to estimate long-term exposure. A total of 182 single-nucleotide polymorphisms (SNPs) and 45 haplotypes in 9 genes were analyzed in relationship to exposure by use of multivariate models that included a number of nongenetic factors.
Results. Efavirenz AUCs increased 1.26-fold per doubling of the alanine aminotransferase level and 1.23-fold with orange and/or orange juice consumption. Individuals with the CYP2B6 516TT genotype displayed 3.5-fold increases in AUCs and 3.2-fold increases in hair concentrations, compared with individuals with the TG/GG genotype. Another SNP in CYP2B6 (983TT) and a p-glycoprotein haplotype affected AUCs without substantially altering long-term exposure.
Conclusions. This comprehensive pharmacogenomics study showed that individuals with the CYP2B6 516TT genotype displayed >3-fold increases in both short-term and long-term efavirenz exposure, signifying durable effects. Pharmacogenetic testing combined with monitoring of hair levels may improve efavirenz outcomes and reduce toxicities.
doi:10.1093/infdis/jis508
PMCID: PMC3466997  PMID: 22927450
3.  Atazanavir Concentration in Hair Is the Strongest Predictor of Outcomes on Antiretroviral Therapy 
In a longitudinal study of outcomes on atazanavir-based therapy in a large cohort of HIV-infected women, hair levels of atazanavir were the strongest independent predictor of virologic suppression. Hair antiretroviral concentrations may serve as a useful tool in HIV care.
Background. Adequate exposure to antiretrovirals is important to maintain durable responses, but methods to assess exposure (eg, querying adherence and single plasma drug level measurements) are limited. Hair concentrations of antiretrovirals can integrate adherence and pharmacokinetics into a single assay.
Methods. Small hair samples were collected from participants in the Women's Interagency HIV Study (WIHS), a large cohort of human immunodeficiency virus (HIV)-infected (and at-risk noninfected) women. From 2003 through 2008, we analyzed atazanavir hair concentrations longitudinally for women reporting receipt of atazanavir-based therapy. Multivariate random effects logistic regression models for repeated measures were used to estimate the association of hair drug levels with the primary outcome of virologic suppression (HIV RNA level, <80 copies/mL).
Results. 424 WIHS participants (51% African-American, 31% Hispanic) contributed 1443 person-visits to the analysis. After adjusting for age, race, treatment experience, pretreatment viral load, CD4 count and AIDS status, and self-reported adherence, hair levels were the strongest predictor of suppression. Categorized hair antiretroviral levels revealed a monotonic relationship to suppression; women with atazanavir levels in the highest quintile had odds ratios (ORs) of 59.8 (95% confidence ratio, 29.0–123.2) for virologic suppression. Hair atazanavir concentrations were even more strongly associated with resuppression of viral loads in subgroups in which there had been previous lapses in adherence (OR, 210.2 [95% CI, 46.0–961.1]), low hair levels (OR, 132.8 [95% CI, 26.5–666.0]), or detectable viremia (OR, 400.7 [95% CI, 52.3–3069.7]).
Conclusions. Antiretroviral hair levels surpassed any other predictor of virologic outcomes to HIV treatment in a large cohort. Low antiretroviral exposure in hair may trigger interventions prior to failure or herald virologic failure in settings where measurement of viral loads is unavailable. Monitoring hair antiretroviral concentrations may be useful for prolonging regimen durability.
doi:10.1093/cid/cir131
PMCID: PMC3079399  PMID: 21507924
4.  NNRTI pharmacokinetics in a large unselected cohort of HIV-infected women 
Background
Small intensive pharmacokinetic (PK) studies of medications in early-phase trials cannot identify the range of factors that influence drug exposure in heterogeneous populations. We performed PK studies in large numbers of HIV-infected women on nonnucleoside-reverse-transcriptase-inhibitors (NNRTIs) under conditions of actual use to assess patient characteristics that influence exposure and evaluated the relationship between exposure and response.
Methods
225 women on NNRTI-based antiretroviral regimens from the Women’s Interagency HIV Study (WIHS) were enrolled into 12 or 24-hour PK studies. Extensive demographic, laboratory and medication covariate data was collected before and during the visit to be used in multivariate models. Total NNRTI drug exposure was estimated by area-under-the-concentration-time curves (AUC).
Results
Hepatic inflammation and renal insufficiency were independently associated with increased nevirapine (NVP) exposure in multivariate analyses; crack cocaine, high fat diets, and amenorrhea were associated with decreased levels (n=106). Higher efavirenz (EFV) exposure was seen with increased transaminase, albumin levels, and orange juice consumption; tenofovir use, increased weight, being African-American and amenorrhea were associated with decreased exposure (n=119). With every 10-fold increase in NVP or EFV exposure, participants were 3.3 and 3.6 times as likely to exhibit virologic suppression, respectively. Patients with higher drug exposure were also more likely to report side effects on therapy.
Conclusions
Our study identifies and quantitates previously unrecognized factors modifying NNRTI exposure in the “real-world” setting. Comprehensive PK studies in representative populations are feasible and may ultimatley lead to dose optimization strategies in patients at risk for failure or adverse events.
PMCID: PMC2700138  PMID: 19408353
HIV; antiretrovirals; nevirapine; efavirenz; pharmacokinetics; drug exposure; women
5.  Protease Inhibitor Levels in Hair Samples Strongly Predict Virologic Responses to HIV Treatment 
AIDS (London, England)  2009;23(4):471-478.
Objective
Antiretroviral (ARV) therapies fail when behavioral or biologic factors lead to inadequate medication exposure. Currently available methods to assess ARV exposure are limited. Levels of ARVs in hair reflect plasma concentrations over weeks to months and may provide a novel method for predicting therapeutic responses.
Design/methods
The Women's Interagency HIV Study, a prospective cohort of HIV-infected women, provided the basis for developing and assessing methods to measure commonly-prescribed protease inhibitors (PIs) - lopinavir (LPV) and atazanavir (ATV) - in small hair samples. We examined the association between hair PI levels and initial virologic responses to therapy in multivariate logistic regression models.
Results
ARV concentrations in hair were strongly and independently associated with treatment response for 224 women starting a new PI-based regimen. For participants initiating LPV/RTV, the odds ratio (OR) for virologic suppression was 39.8 (95%CI 2.8–564) for those with LPV hair levels in the top tertile (>1.9ng/mg) compared to the bottom (≤0.41ng/mg) when controlling for self-reported adherence, age, race, starting viral load and CD4, and prior PI experience. For women starting ATV, the adjusted OR for virologic success was 7.7 (95%CI 2.0-29.7) for those with hair concentrations in the top tertile (>3.4ng/mg) compared to the lowest (≤1.2ng/mg).
Conclusions
PI levels in small hair samples were the strongest independent predictor of virologic success in a diverse group of HIV-infected adults. This noninvasive method for determining ARV exposure may have particular relevance for the epidemic in resource-poor settings due to the ease of collecting and storing hair.
doi:10.1097/QAD.0b013e328325a4a9
PMCID: PMC2654235  PMID: 19165084
Hair levels; therapeutic drug monitoring; antiretroviral exposure; virologic response; protease inhibitors; atazanavir; lopinavir; WIHS cohort
6.  Association of self-reported race with AIDS death in continuous HAART users in a cohort of HIV-infected women in the United States 
AIDS (London, England)  2013;27(15):2413-2423.
Objective:
To assess the association of race with clinical outcomes in HIV-positive women on continuous HAART.
Design:
Prospective study that enrolled women from 1994 to 1995 and 2001 to 2002.
Setting:
Women's Interagency HIV Study, a community-based cohort in five US cities.
Participants:
One thousand, four hundred and seventy-one HIV-positive continuous HAART users.
Main outcome measures:
Times to AIDS and non-AIDS death and incident AIDS-defining illness (ADI) after HAART initiation.
Results:
In adjusted analyses, black vs. white women had higher rates of AIDS death [adjusted hazard ratio (aHR) 2.14, 95% confidence interval (CI) 1.30, 3.50; P = 0.003] and incident ADI (aHR 1.58, 95% CI 1.08, 2.32; P = 0.02), but not non-AIDS death (aHR 0.91, 95% CI 0.59, 1.39; P = 0.65). Cumulative AIDS death incidence at 10 years was 17.3 and 8.3% for black and white women, respectively. Other significant independent pre-HAART predictors of AIDS death included peak viral load (aHR 1.70 per log10, 95% CI 1.34, 2.16; P < 0.001), nadir CD4+ cell count (aHR 0.65 per 100 cells/μl, 95% CI 0.56, 0.76; P < 0.001), depressive symptoms by Center for Epidemiology Studies Depression score at least 16 (aHR 2.10, 95% CI 1.51, 2.92; P < 0.001), hepatitis C virus infection (aHR 1.57, 95% CI 1.02, 2.40; P = 0.04), and HIV acquisition via transfusion (aHR 2.33, 95% CI 1.21, 4.49; P = 0.01). In models with time-updated HAART adherence, association of race with AIDS death remained statistically significant (aHR 3.09, 95% CI 1.38, 6.93; P = 0.006).
Conclusion:
In continuous HAART-using women, black women more rapidly died from AIDS or experienced incident ADI than their white counterparts after adjusting for confounders. Future studies examining behavioral and biologic factors in these women may further the understanding of HAART prognosis.
doi:10.1097/01.aids.0000432537.92958.73
PMCID: PMC3815041  PMID: 24037210
AIDS; HAART; HIV; race; survival; women

Results 1-6 (6)