Sharon A Riddler

University of Pittsburgh, Pittsburgh, Pennsylvania, United States

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Publications (68)413.63 Total impact

  • Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 07/2014;
  • Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 05/2014;
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    ABSTRACT: Peripheral neuropathy (PN) is a common neurological complication of HIV infection that has debilitating effects on quality of life. While there has been a comprehensive evaluation of the prevalence of neuropathic signs/symptoms and risk factors (RFs) for PN or symptomatic PN (SPN) with initiation of combination antiretroviral therapy (cART) in ART-naïve patients, similar evaluation in ART-experienced patients is limited. This study investigated the prevalence and RFs for PN/SPN in ART-experienced patients enrolled in clinical salvage therapy studies. Between February 2000 and June 2007, 522 ART-experienced participants who experienced virologic failure with a prior regimen and started new regimens were followed longitudinally and annually screened for signs and symptoms of PN. Rates of PN/SPN at 3 years since parent study entry were 52.8 and 24.0 %, respectively. Aging, taller height, protease inhibitor use, and female sex were significant RFs for PN/SPN. The use of statin drugs was significantly associated with lower odds of SPN, and it may prevent progression from no SPN to SPN.
    Journal of NeuroVirology 12/2013; · 2.85 Impact Factor
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    ABSTRACT: Background. In the U.S., HIV-infected blacks have higher rates of virologic failure on antiretroviral therapy (ART) and of death compared to whites. The cause for these disparities is uncertain. We sought to examine differences in virologic outcomes among antiretroviral-naïve clinical trial participants starting randomized ART and to investigate factors to explain the differences. Methods. Individual-level data from participants initiating ART in 5 AIDS Clinical Trials Group (ACTG) studies were analyzed. Included studies were those conducted 1998-2006 with a primary outcome of virologic failure. The primary outcome measure was time to virologic failure, regardless of ART changes. Results. 2495 individuals (1151 black; 1344 white) were included with a median follow-up of 129 weeks. Compared to whites, blacks had an increased hazard of virologic failure (hazard ratio [95% confidence interval]: 1.7 [1.4, 1.9], P<0.001), with no evidence of heterogeneity across regimens (P=0.97); the association remained after adjustment for measured confounders (1.4 [1.2-1.6]; P<0.001). Increased hazard of virologic failure was associated with younger age, higher pre-treatment HIV-1 RNA level, lower pre-treatment CD4 cell count, hepatitis C antibody, less education, and recent non-adherence. Sensitivity analyses with different endpoint definitions demonstrated similar results. Conclusions. In this analysis, blacks had a 40% higher virologic failure risk than whites that was not explained by measured confounders. The observation was consistent over a range of regimens suggesting the difference may be driven by social factors but biological factors cannot be ruled out. Further research should identify the sources of racial disparities and develop strategies to reduce them.
    Clinical Infectious Diseases 09/2013; · 9.37 Impact Factor
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    ABSTRACT: Background. Bone mineral density (BMD) decreases 2-6% in the two years after antiretroviral therapy (ART) initiation. Pre-ART immune deficiency and early immune recovery may contribute to this loss. Methods. We pooled data from three treatment-naive ART initiation studies in which serial whole-body dual-energy X-ray absorptiometry scans were performed. We used linear regression to evaluate effects of baseline CD4+ and 16-week CD4+ change (both absolute and relative) on 96-week total BMD change from baseline. We performed multivariable linear regression to assess associations between baseline variables of age, sex, race/ethnicity, body mass index (BMI), hepatitis C status, parent study, HIV-1 RNA level, and assignment to a protease inhibitor (PI) or tenofovir-containing regimen on 96-week total BMD change. Results. The included 796 subjects had mean 96-week total BMD loss of 2.0%. In multivariable analysis, baseline CD4+ count was significantly associated with 96-week BMD loss; individuals with baseline CD4+ <50 cells/µL lost significantly more BMD compared to those with CD4+ ≥500 cells/µL. A greater relative, but not absolute, 16-week increase in CD4+ count was significantly associated with greater declines in BMD, but not after controlling for baseline CD4+ count. In multivariable analysis, older age, female sex, lower BMI, higher HIV-1 RNA levels, and PI and tenofovir assignment were also associated with greater BMD decline. Conclusions. Low pre-treatment CD4+ count, but not greater CD4+ count increase, is a strong and independent risk factor for bone loss after ART initiation. ART initiation at higher CD4+ counts may reduce the burden of osteoporosis and fragility fractures.
    Clinical Infectious Diseases 08/2013; · 9.37 Impact Factor
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    ABSTRACT: The role of the adenosine (ADO) suppression pathway, specifically CD39-expressing and CD73-expressing CD4 T cells in HIV-1 infection is unclear. We evaluated the frequency and numbers of CD4CD39 and CD4CD73 T cells, activated T cells, and plasma C reactive protein (CRP) levels in 36 HIV-1-positive individuals and 10 normal controls (NC). Low-level plasma viremia was evaluated using single copy assay. Mass spectrometry was used to measure hydrolysis of ATP by ectoenzyme-expressing CD4 T cells, whereas cyclic adenosine monophosphate (cAMP) levels were measured using enzyme immunoassay. Suppression of T-cell function by exogenous ADO and CD4CD73 T cells was tested by flow cytometry. CD39 and CD73 are expressed in different CD4 T-cell subsets. CD4CD73 T cells do not express CD25 and FOXP3, and their frequency and numbers were lower in HIV-1-positive individuals regardless of virologic suppression (P = 0.005 and P < 0.001, respectively). CD4CD73 numbers inversely correlated with CD4CD38DR (P = 0.002), CD8CD38DR T-cell frequency (P = 0.05), and plasma CRP levels (P = 0.01). Both subsets are required for hydrolysis of exogenous ATP to ADO and can increase CD4 T-cell cAMP levels when incubated with exogenous ATP. Low-level viremia did not correlate with activated T-cell frequency. In vitro, ADO suppressed T-cell activation and cytokine expression. CD4CD73 T cells suppressed T-cell proliferation only in the presence of exogenous 5'-AMP. The ADO-producing CD4CD73 subset of T cells is depleted in HIV-1-positive individuals regardless of viral suppression and may play a key role in controlling HIV-1-associated immune activation.
    AIDS (London, England) 06/2013; 27(10):1545-1555. · 4.91 Impact Factor
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    ABSTRACT: Objective: To compare the longitudinal changes in total bone mineral density (TBMD) across antiretroviral (ARV) regimens. Methods: A5142 was an open-label study comparing 3 ARV regimens for the initial treatment of HIV-1. Subjects were randomized equally to efavirenz (EFV) plus 2 nucleoside reverse transcriptase inhibitors (NRTIs), lopinavir/ritonavir (LPV/r) plus 2 NRTIs, or LPV/r plus EFV without NRTI. The NRTI regimen (lamivudine [3TC] plus zidovudine [ZDV], stavudine [d4T], or tenofovir [TDF]) was selected prior to randomization. TBMD was assessed via whole-body dual-energy X-ray absorptiometry (DXA) at baseline and 48 and 96 weeks. Analysis was modified intent-to-treat (ITT) ignoring regimen changes using all evaluations. Results: Significant mean declines in TBMD at week 48 were observed among subjects. In repeated-measures analysis of changes (including randomized regimen, NRTI used, and time), there was a significant difference in the NRTI-containing arms in mean percentage change in TBMD at week 48 according to NRTI used (P < .001). Subjects taking ZDV had similar changes to those taking d4T (P = .970), whereas those taking TDF had larger declines (P < .001). There was a nonsignificant trend toward greater mean declines among subjects taking LPV/r versus EFV (P = .080). Overall, TDF-containing regimens demonstrated the greatest losses in TBMD, while EFV regimens without TDF had lesser TBMD reductions even compared to the NRTI-sparing arm. From week 48 to 96, all treatment groups continued to lose TBMD at similar rates. Conclusions: Among NRTI-containing arms, NRTI selection, especially use of TDF, had a greater effect on TBMD change than randomized regimen. The long-term clinical significance remains to be demonstrated.
    HIV Clinical Trials 01/2013; 14(5):224-234. · 2.30 Impact Factor
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    ABSTRACT: HLA class I-associated polymorphisms identified at the population level mark viral sites under immune pressure by individual HLA alleles. As such, analysis of their distribution, frequency, location, statistical strength, sequence conservation and other properties offers a unique perspective from which to identify correlates of protective cellular immunity. We analyzed HLA-associated HIV-1 subtype B polymorphisms in 1888 treatment-naïve, chronically-infected individuals using phylogenetically-informed methods, and identified characteristics of HLA-associated immune pressures that differentiate protective and non-protective alleles. Over 2100 HLA-associated HIV-1 polymorphisms were identified, approximately one-third of which occurred inside or within 3 residues of an optimally-defined CTL epitope. Differential CTL escape patterns between closely related HLA alleles were common, and increased with greater evolutionary distance between allele group members. Among 9-mer epitopes, mutations at HLA-specific anchor residues represented the most frequently detected escape type: these occurred nearly twofold more frequently than expected by chance, and were computationally predicted to reduce peptide-HLA binding nearly tenfold on average. Characteristics associated with protective HLA alleles (defined using hazard ratios for progression to AIDS from natural history cohorts) included the potential to mount broad immune selection pressures across all HIV-1 proteins except Nef, the tendency to drive multi-site and/or anchor residue escape mutations within known CTL epitopes, and the ability to strongly select mutations in conserved regions within HIV's structural and functional proteins. Thus, the factors defining protective cellular immune responses may be more complex than simply targeting conserved viral regions. Study results provide new information to guide vaccine design and immunogenicity studies.
    Journal of Virology 10/2012; · 5.08 Impact Factor
  • 19th International AIDS Conference; 01/2012
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    ABSTRACT: To evaluate the effects of sex and initial antiretroviral regimen on decay of HIV-RNA and virologic outcome. We conducted a viral dynamics substudy of A5142, a trial comparing lopinavir (LPV)/ritonavir with efavirenz (LPV/EFV) versus LPV and two nucleoside reverse transcriptase inhibitor (NRTI) (LPV) versus EFV and two NRTI (EFV) in antiretroviral (ARV)-naive individuals. HIV-RNA was measured at days 2, 10, and 14 in the substudy and at weeks 1, 4, and 8 in A5142 participants. Two-phase viral decay was estimated in the substudy with biexponential mixed-effects modeling and compared using Wilcoxon tests. Week 1 HIV-RNA change was assessed as a predictor of virologic failure (HIV-RNA above 50 or 200  copies/ml) at weeks 24-96 using logistic regression. Sixty-eight individuals were enrolled in the substudy (median HIV-RNA 4.9 log(10)  copies/ml). Median rates of phase 1 viral decay by treatment were 0.61(EFV/LPV), 0.53(LPV), and 0.63(EFV) per day. Phase 1 decay was significantly faster for EFV than LPV (P = 0.023); other comparisons were not significant (P > 0.11). Viral decay did not differ by sex (P = 0.10). Week 1 HIV-RNA change, calculated in 571 participants of A5142, was greater for the EFV (median -1.47 log(10)  copies/ml) than either the LPV/EFV or LPV groups (-1.21 and -1.16 log(10 ) copies/ml, respectively; P < 0.001). Week 1 HIV-RNA change was associated with virologic failure above 50  copies/ ml at weeks 24 and 48 (P < 0.018), but not above 200  copies/ml at these time points or for any value at week 96. Phase 1 decay was faster for EFV than LPV or LPV/EFV. Week 1 HIV-RNA change predicted virologic outcome up to week 48, but not at week 96.
    AIDS (London, England) 09/2011; 25(18):2269-78. · 4.91 Impact Factor
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    ABSTRACT: Strong statistical associations between polymorphisms in HIV-1 population sequences and carriage of HLA class I alleles have been widely used to identify possible sites of CD8 T cell immune selection in vivo. However, there have been few attempts to prospectively and systematically test these genetic hypotheses arising from population-based studies at a cellular, functional level. We assayed CD8 T cell epitope-specific IFN-γ responses in 290 individuals from the same cohort, which gave rise to 874 HLA-HIV associations in genetic analyses, taking into account autologous viral sequences and individual HLA genotypes. We found immunological evidence for 58% of 374 associations tested as sites of primary immune selection and identified up to 50 novel HIV-1 epitopes using this reverse-genomics approach. Many HLA-adapted epitopes elicited equivalent or higher-magnitude IFN-γ responses than did the nonadapted epitopes, particularly in Nef. At a population level, inclusion of all of the immunoreactive variant CD8 T cell epitopes in Gag, Pol, Nef, and Env suggested that HIV adaptation leads to an inflation of Nef-directed immune responses relative to other proteins. We concluded that HLA-HIV associations mark viral epitopes subject to CD8 T cell selection. These results can be used to guide functional studies of specific epitopes and escape mutations, as well as to test, train, and evaluate analytical models of viral escape and fitness. The inflation of Nef and HLA-adapted variant responses may have negative effects on natural and vaccine immunity against HIV and, therefore, has implications for diversity coverage approaches in HIV vaccine design.
    The Journal of Immunology 09/2011; 187(5):2502-13. · 5.52 Impact Factor
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    ABSTRACT: The generalizability of antiretroviral therapy (ART) clinical trial efficacy findings to routine care settings is not well studied. We compared the relative effectiveness of initial ART regimens estimated in AIDS Clinical Trial Group (ACTG) randomized controlled trials with that among patients receiving ART at Antiretroviral Therapy Cohort Collaboration (ART-CC) study sites. Treatment-naive HIV-infected patients initiating identical ART regimens in ACTG trials (A5095 and A5142) and at 15 ART-CC cohort study sites were included. Virological failure (HIV-1 RNA >200 copies/mL) at 24 and 48 weeks, incident AIDS-defining events and mortality were measured according to study design (ART-CC cohort vs. ACTG trial) and stratified by third drug [abacavir (ABC), efavirenz (EFV), and lopinavir/r (LPV/r)]. We used logistic regression to estimate and compare odds ratios (OR) for virological failure between different regimens and study designs, and used Cox models to estimate and compare hazard ratios for AIDS and death. Compared with patients receiving ABC, those receiving EFV had roughly half the odds of 24-week virologic failure (>200 copies/mL) in both ACTG 5095 (OR = 0.53, 95% confidence interval: 0.36 to 0.79) and ART-CC (0.46, 0.37 to 0.57). Virologic superiority of EFV (vs. ABC) seemed comparable in ART-CC and ACTG 5095 (ratio of ORs 0.86, 95% confidence interval: 0.54 to 1.35). Odds ratios for 48-week virologic failure, comparing EFV with LPV/r, were also comparable in ACTG 5142 and ART-CC (ratio of ORs: 0.87, 0.45 to 1.69). Between ART regimen virologic efficacy of third drugs ABC, EFV, and LPV/r observed in the ACTG 5095 and 5142 trials seem generalizable to the routine care setting of ART-CC clinical cohorts.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 08/2011; 58(3):253-60. · 4.65 Impact Factor
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    ABSTRACT: It is uncertain how often mutations in the connection or RNase H domains of HIV-1 reverse transcriptase (RT) emerge with failure of first-line antiretroviral therapy. Full-length RT sequences in plasma obtained pretherapy and at virologic failure were compared in 53 patients on first-line efavirenz-containing regimens from AIDS Clinical Trials Group study A5142. HIV-1 was mostly subtype B (48 of 53). Mutations in the polymerase but not in connection or RNase H domains of RT increased in frequency between pretherapy and failure (K103N, P = 0.001; M184I/V, P = 0.016). Selection of mutations in C-terminal domains of RT is not common with early failure of efavirenz-containing regimens.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 04/2011; 56(4):344-8. · 4.65 Impact Factor
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    ABSTRACT: Mitochondrial DNA (mtDNA) influences metabolic diseases and perhaps antiretroviral therapy (ART) complications. We explored associations between European mtDNA haplogroups and metabolic changes among A5142 participants. Seven hundred and fifty-seven ART-naive patients were randomized to one of three class-sparing ART regimens including efavirenz and/or lopinavir/ritonavir with or without nucleoside reverse transcriptase inhibitors (NRTIs). Nonrandomized NRTIs included stavudine, tenofovir, or zidovudine, each with lamivudine. Fasting lipid profiles and whole-body dual-energy X-ray absorptiometry (DEXA) were performed. Nine European mtDNA haplogroups were determined for 231 self-identified non-Hispanic white individuals. Metabolic changes from baseline to 96 weeks were analyzed by haplogroup. Median age was 39 years, 9% were women, and 37, 32, and 30 were randomized to NRTI-containing regimens with either efavirenz or lopinavir/ritonavir, and an NRTI-sparing regimen, respectively. Among NRTI-containing regimens, 51% included zidovudine, 28% tenofovir, and 21% stavudine. Compared with other haplogroups, mtDNA haplogroup I (N = 10) had higher baseline non-HDL cholesterol [160 mg/dl (interquartile range 137-171) vs. 120 mg/dl (104-136); P = 0.005], a decrease in non-HDL cholesterol over 96 weeks [-14% (-20 to 6) vs. +25% (8 to 51); P < 0.001], tended to have more baseline extremity fat, and had more extremity fat loss by DEXA [-13% (-13 to 12) vs. +9% (-13 to 26); P = 0.08] and lipoatrophy (50 vs. 20%; P = 0.04). Haplogroup W (N = 5; all randomized to NRTI-sparing regimens) had the greatest increase in extremity fat [+35.5% (26.8 to 54.9); P = 0.02]. Lipids and extremity fat were associated with European mtDNA haplogroups in this HIV-infected population. These preliminary results suggest that mitochondrial genomics may influence metabolic parameters before and during ART.
    AIDS (London, England) 01/2011; 25(1):37-47. · 4.91 Impact Factor
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    ABSTRACT: This study examines the cost and consequences of initiating an ARV regimen including Lopinavir/ritonavir (LPV/r) or Efavirenz (EFV), using data from a recent clinical trial in a previously published model of HIV-disease. We populated the Markov model of HIV-disease with data from ACTG 5142 study to estimate the economic outcomes of starting ARV therapy with a PI-containing regimen as compared to an NNRTI-containing regimen, given their virologic and immunologic efficacy and effects on cholesterol and lipoatrophy. CNS toxicities and GI tolerability were not included in the model because of their transient nature or low cost remedies, and therefore lack of economic impact. CD4+ T-cell counts and the HIV-1 RNA (viral load) values from the study were used to assign a specific health state (HS) to each patient for each quarter year. The resulting frequencies used as "raw" data directly into the model obviate the reliance on statistical tests, and allow the model to reflect actual patient behavior in the clinical trial. An HS just below the last observed HS was used to replace a missing value. The modeled estimates (undiscounted) for the LPV/r-based regimen resulted in 1.41 quality-adjusted life months (QALMs) gained over a lifetime compared to the EFV-based regimen. The LPV/r-based regimen incurred $7,458 (1.8%) greater cost over a lifetime due to differences in drug costs and survival. The incremental cost effectiveness ratio using the discounted cost and QALYs was $88,829/QALY. Most of the higher costs accrue before the 7th year of treatment and were offset by subsequent savings. The estimates are highly sensitive to the effect of lipoatrophy on Health-related Quality of Life (HRQOL), but not to the effect of cholesterol levels. The cost effectiveness of ARV regimens may be strongly affected by enduring AEs, such as lipoatrophy. It is important to consider specific AE effects from all drugs in a regimen when ARVs are compared. ( number, NCT00050895http://[]).
    Cost Effectiveness and Resource Allocation 01/2011; 9:5. · 0.87 Impact Factor
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    ABSTRACT: Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.
    Science 12/2010; 330(6010):1551-7. · 31.20 Impact Factor
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    ABSTRACT: Currently, 1.1 million individuals in the United States are living with HIV-1 infection. Although this is a relatively small proportion of the global pandemic, the remarkable mix of ancestries in the United States, drawn together over the past two centuries of continuous population migrations, provides an important and unique perspective on adaptive interactions between HIV-1 and human genetic diversity. HIV-1 is a rapidly adaptable organism and mutates within or near immune epitopes that are determined by the HLA class I genotype of the infected host. We characterized HLA-associated polymorphisms across the full HIV-1 proteome in a large, ethnically diverse national United States cohort of HIV-1-infected individuals. We found a striking divergence in the immunoselection patterns associated with HLA variants that have very similar or identical peptide-binding specificities but are differentially distributed among racial/ethnic groups. Although their similarity in peptide binding functionally clusters these HLA variants into supertypes, their differences at sites within the peptide-binding groove contribute to race-specific selection effects on circulating HIV-1 viruses. This suggests that the interactions between the HLA/HIV peptide complex and the TCR vary significantly within HLA supertype groups, which, in turn, influences HIV-1 evolution.
    The Journal of Immunology 03/2010; 184(8):4368-77. · 5.52 Impact Factor
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    ABSTRACT: We tested the hypothesis that therapeutic vaccination against HIV-1 can increase the frequency and suppressive function of regulatory, CD4(+) T cells (Treg), thereby masking enhancement of HIV-1-specific CD8(+) T cell response. HIV-1-infected subjects on antiretroviral therapy (N = 17) enrolled in a phase I therapeutic vaccine trial received 2 doses of autologous dendritic cells (DC) loaded with HIV-1 peptides. The frequency of CD4(+)CD25(hi)FOXP3(+) Treg in blood was determined prior to and after vaccination in subjects and normal controls. Polyfunctional CD8(+) T cell responses were determined pre- and post-vaccine (N = 7) for 5 immune mediators after in vitro stimulation with Gag peptide, staphylococcal enterotoxin B (SEB), or medium alone. Total vaccine response (post-vaccine-pre-vaccine) was compared in the Treg(+) and Treg-depleted (Treg-) sets. After vaccination, 12/17 subjects showed a trend of increased Treg frequency (P = 0.06) from 0.74% to 1.2%. The increased frequency did not correlate with CD8(+) T cell vaccine response by enzyme linked immunosorbent assay for interferon gamma production. Although there was no significant change in CD8(+) T cell polyfunctional response after vaccination, Treg depletion increased the polyfunctionality of the total vaccine response (P = 0.029), with a >2-fold increase in the percentage of CD8(+) T cells producing multiple immune mediators. In contrast, depletion of Treg did not enhance polyfunctional T cell response to SEB, implying specificity of suppression to HIV-1 Gag. Therapeutic immunization with a DC-based vaccine against HIV-1 caused a modest increase in Treg frequency and a significant increase in HIV-1-specific, Treg suppressive function. The Treg suppressive effect masked an increase in the vaccine-induced anti-HIV-1-specific polyfunctional response. The role of Treg should be considered in immunotherapeutic trials of HIV-1 infection.
    PLoS ONE 01/2010; 5(3):e9852. · 3.73 Impact Factor
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    ABSTRACT: The metabolic effects of initial therapy for HIV-1 infection are important determinants of regimen selection. Open-label study in 753 subjects randomized equally to efavirenz or lopinavir/ritonavir(r) plus two nucleoside reverse-transcriptase inhibitor (NRTI) vs. the NRTI-sparing regimen of lopinavir/r plus efavirenz. Zidovudine, stavudine, or tenofovir with lamivudine was selected prior to randomization. Metabolic outcomes through 96 weeks were lipoatrophy, defined as at least 20% loss in extremity fat, and fasting serum lipids. Lipoatrophy by dual-energy X-ray absorptiometry at week 96 occurred in 32% [95% confidence interval (CI) 25-39%] of subjects in the efavirenz plus two NRTIs arm, 17% (95% CI 12-24) in the lopinavir/r plus two NRTIs arm, and 9% (95% CI 5-14) in the NRTI-sparing arm (P < or = 0.023 for all comparisons). Varying the definition of lipoatrophy (> or =10 to > or =40% fat loss) and correction for baseline risk factors did not affect the significant difference in lipoatrophy between the NRTI-containing regimens. Lipoatrophy was most frequent with stavudine-containing regimens and least frequent with tenofovir-containing regimens (P < 0.001), which were not significantly different from the NRTI-sparing regimen. Total cholesterol increases at week 96 were greatest in the NRTI-sparing arm (median +57 mg/dl) compared with the other two arms (+32-33 mg/dl; P < 0.001). Use of lipid-lowering agents was more common (25 vs. 11-13%) in the NRTI-sparing arm. Lipoatrophy was more frequent with efavirenz than lopinavir/r when combined with stavudine or zidovudine, and less frequent when either drug was combined with tenofovir. Lipoatrophy was least frequent with the NRTI-sparing regimen, but this benefit was offset by greater cholesterol elevations and the need for lipid-lowering agents.
    AIDS (London, England) 06/2009; 23(9):1109-18. · 4.91 Impact Factor
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    ABSTRACT: Some patients are unable to achieve and maintain an undetectable plasma HIV-1 RNA level with combination antiretroviral therapy (ART) and are therefore maintained on a partially suppressive regimen. To determine the immune consequences of continuing ART despite persistent viremia, we randomized 47 ART-treated individuals with low to moderate plasma HIV-1 RNA levels (200-9999 copies/ml) to either an immediate switch in therapy or a delayed switch (when plasma HIV-1 RNA became > or =10,000 copies/ml). After 48 weeks of follow-up, naive and memory CD4+ T cell percents were comparable in the two groups. The proportion of subjects with a lymphocyte proliferative response to Candida, Mycobacterium avium-intracellulare complex, or HIV-gag was also not significantly different at week 48. Delaying a treatment switch in patients with partial virologic suppression and stable CD4+ T cells does not have profound effects on immune parameters.
    AIDS research and human retroviruses 03/2009; 25(2):135-9. · 2.18 Impact Factor

Publication Stats

3k Citations
413.63 Total Impact Points


  • 1994–2014
    • University of Pittsburgh
      • • Department of Infectious Diseases and Microbiology
      • • School of Medicine
      • • Division of Infectious Diseases
      Pittsburgh, Pennsylvania, United States
  • 2011
    • Royal Perth Hospital
      Perth City, Western Australia, Australia
  • 2002–2011
    • University of California, San Diego
      San Diego, California, United States
  • 2009
    • Rush University Medical Center
      Chicago, Illinois, United States
  • 2008
    • Pittsburg State University
      Kansas, United States
  • 2003
    • Johns Hopkins University
      • Department of Epidemiology
      Baltimore, MD, United States