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Biomedical subjects

Richard Haubrich

Publications and source records attributed to Richard Haubrich.

At least 19 recordsLinked to original sources
PubMed2006

Effects of testosterone supplementation on whole body and regional fat mass and distribution in human immunodeficiency virus-infected men with abdominal obesity.

BACKGROUND: Whole body and abdominal obesity are associated with increased risk of diabetes mellitus and heart disease. The effects of testosterone therapy on whole body and visceral fat mass in HIV-infected men with abdominal obesity are unknown. OBJECTIVE: The objective of this study was to determine the effects of testosterone therapy on intraabdominal fat mass and whole body fat distribution in HIV-infected men with abdominal obesity. METHODS: IN this multicenter, randomized, placebo-controlled, double-blind trial, 88 HIV-positive men with abdominal obesity (waist-to-hip ratio > 0.95 or mid-waist circumference > 100 cm) and total testosterone 125-400 ng/dl, or bioavailable testosterone less than 115 ng/dl, or free testosterone less than 50 pg/ml on stable antiretroviral regimen, and HIV RNA less than 10,000 copies per milliliter were randomized to receive 10 g testosterone gel or placebo daily for 24 wk. Fat mass and distribution were determined by abdominal computerized tomography and dual energy x-ray absorptiometry during wk 0, 12, and 24. We used an intention-to-treat approach and nonparametric statistical methods. RESULTS: Baseline characteristics were balanced between groups. In 75 subjects evaluated, median percent change from baseline to wk 24 in visceral fat did not differ significantly between groups (testosterone 0.3%, placebo 3.1%, P = 0.75). Total (testosterone -1.5%, placebo 4.3%, P = 0.04) and sc (testosterone-7.2%, placebo 8.1%, P < 0.001) abdominal fat mass decreased in testosterone-treated men, but increased in placebo group. Testosterone therapy was associated with significant decrease in whole body, trunk, and appendicular fat mass by dual energy x-ray absorptiometry (all P < 0.001), whereas whole body and trunk fat increased significantly in the placebo group. The percent of individuals reporting a decrease in abdomen (P = 0.01), neck (P = 0.08), and breast size (P = 0.01) at wk 24 was significantly greater in testosterone-treated than placebo-treated men. Testosterone-treated men had greater increase in lean body mass than placebo (testosterone 1.3%, placebo -0.3, P = 0.02). Plasma insulin, fasting glucose, and total high-density lipoprotein and low-density lipoprotein cholesterol levels did not change significantly. Testosterone therapy was well tolerated. CONCLUSIONS: Testosterone therapy in HIV-positive men with abdominal obesity and low testosterone was associated with greater decrease in whole body, total, and sc abdominal fat mass and a greater increase in lean mass compared to placebo. However, changes in visceral fat mass were not significantly different between groups. Further studies are needed to determine testosterone effects on insulin sensitivity and cardiovascular risk.

Abdominal Fat↗
PubMed2006

A practical method to calibrate self-reported adherence to antiretroviral therapy.

OBJECTIVE: Self-report of antiretroviral medications adherence is inexpensive and simple to use in clinical settings but grossly overestimates adherence. We investigated methods to calibrate patients' self-reported adherence to match objectively measured adherence more closely for the purpose of developing a practical and more accurate self-reported adherence measure. DESIGN: Longitudinal cohort design. METHODS: Using data from 2 prospective longitudinal clinical investigations conducted at 5 HIV clinics, we examined the discrepancy between self-reported adherence and objectively measured adherence. We evaluated the relation between attitudinal measures and the degree of discrepancy and used a cross-validation approach to propose candidate items to improve adherence survey methodology. RESULTS: Among 330 patients, self-reported adherence was consistently higher than objectively measured adherence. The best calibration models included the patient's self-reported adherence, duration of the antiretroviral regimen, and attitudinal measures (ability to take medication as instructed, believing medication can help one to live longer, whether or not it is too troublesome to take antiretrovirals, and feeling things are going the right way). CONCLUSION: The method efficiently identified survey items to improve self-reported adherence measurement. The calibrated measure more closely approximates objectively measured adherence and is more sensitive for detecting nonadherence. These models merit evaluation in other settings.

Adult↗
PubMed2006

Determinants of CD4+ T cell recovery during suppressive antiretroviral therapy: association of immune activation, T cell maturation markers, and cellular HIV-1 DNA.

BACKGROUND: Suboptimal CD4+ T cell recovery during antiretroviral therapy (ART) is a common clinical dilemma. METHODS: We analyzed viral and immunologic predictors of CD4+ T cell recovery in 116 human immunodeficiency virus type 1 (HIV-1)-infected subjects who had suppressed viremia (< or = 50 copies/mL) while receiving ART. Successive measurements of T cell immunophenotypes and cellular HIV-1 DNA levels were obtained before and during receipt of ART. On the basis of increases in the CD4+ T cell count, subjects were classified as immunologically concordant (demonstrating an increase of > or = 100 CD4+ T cells/mm3) or discordant (demonstrating an increase of <100 CD4+ T cells/mm3) after 48 weeks of ART. RESULTS: In adjusted analyses, CD4+ and CD8+ T cell activation at baseline was negatively associated with immunologic concordance at week 48 of ART (odds ratio [OR], 0.80 [P = .04] and 0.67 [P = .02], respectively). High memory (CDRA(-)CD62L-) CD8+ T cell counts at baseline (OR, 0.33 [P = .05]) predicted less CD4+ T cell recovery, whereas increased naive CD4+ T cell counts were associated with higher increases in CD4+ T cells (OR, 1.19 [P = .052]). Neither the cell-associated HIV-1 DNA level at baseline (P = .32) nor the cell-associated HIV-1 DNA level at week 48 of ART (P = .42) was associated with immunologic concordance during ART. CONCLUSIONS: These results support the potential clinical usefulness of the baseline determination of immune activation and maturation subsets in the prediction of CD4+ T cell recovery during viral suppression. Furthermore, identification of individuals with reduced potential for CD4+ T cell recovery during ART may provide a rationale for the initiation of early therapy for some patients.

Adult↗
PubMed2006

Failure of modified directly observed therapy combined with therapeutic drug monitoring to enhance antiretroviral adherence in a patient with major depression.

Improving medication nonadherence in HIV-infected patients with concomitant psychiatric issues remains a challenging therapeutic dilemma. One strategy may be to use a short course of modified directly observed therapy combined with therapeutic drug monitoring as an adherence intervention. Individual drug pharmacokinetics could be evaluated while the increased visit frequency is an opportunity to provide additional patient training and psychosocial support. We report our experience with a 43-year-old woman with severe depressive symptoms and persistent virologic failure despite appropriate therapy. Although the intervention was well-received by the patient, improvements in medication adherence behaviors waned over time. It should be recognized that not all patients are capable of achieving lifelong medication adherence and may benefit from continued supervised therapy.

Anti-HIV Agents↗
PubMed2006

Tipranavir: a protease inhibitor for multi-drug resistant HIV-1.

Since the mid-1990s, combination therapies to treat HIV-1 infection have greatly reduced morbidity and mortality from AIDS in developed countries with access to the medications. However, the development of viral resistance to available antiretrovirals is one of the many limitations to therapy that has emerged. Of the 24 licensed antiretroviral medications and medication combinations in the US, tipranavir is one of the few agents to specifically target highly treatment-experienced patients with multi-drug resistant HIV-1. It displays activity against the virus that is cross-resistant to other protease inhibitors. In this review, issues in treating multi-drug resistant HIV-1 and the potential clinical utility of tipranavir in the US will be discussed.

Adult↗
PubMed2005

Four measures of antiretroviral medication adherence and virologic response in AIDS clinical trials group study 359.

AIDS Clinical Trials Group (ACTG) 359 was a randomized, partially double-blinded factorial study of 6 antiretroviral regimens, all including saquinavir, among HIV-infected persons in whom prior therapy had failed (n = 258). Counts of remaining saquinavir capsules were determined between weeks 0 and 4; at weeks 4, 8, and 16, self-reported adherence was estimated from 2-day report of doses skipped, therapeutic coverage, and percent of doses taken were determined by electronic monitoring devices applied to saquinavir bottles, and the saquinavir 24-hour area under the curve (AUC) was estimated. Relationships were evaluated among these 4 adherence measures and the primary endpoint of week 16 HIV RNA change. Thirty percent of 254 subjects had HIV RNA < or =500 copies/mL at week 16. Only self-reported adherence and saquinavir AUC were significantly associated with week 16 HIV RNA change (P = 0.019 and 0.023, respectively), and these measures were higher in subjects with week 16 HIV RNA < or =500 copies/mL (P = 0.03 and 0.008, respectively). The ability to detect a correlation between electronically monitored adherence and virologic response was limited by the small sample size. Self-reported adherence and saquinavir AUC were significant predictors of virologic response, in this evaluation. These findings provide insight into methods of assessing and improving adherence to antiretroviral regimens.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Weighted phenotypic susceptibility scores are predictive of the HIV-1 RNA response in protease inhibitor-experienced HIV-1-infected subjects.

We analyzed retrospectively, by use of logistic regression, the role of the phenotypic susceptibility score (PSS) as a determinant of virologic outcome in a study of treatment-experienced human immunodeficiency virus (HIV) type 1-infected subjects. A model for PSS in which each drug was treated equally and scored as active or inactive was not predictive of HIV-1 RNA load (VL) suppression. However, weighting the potential contribution of each drug on the basis of inferred potency and by use of a continuous scale to quantify drug susceptibility revealed significant associations between PSS and outcome. Entry VL was a strong independent predictor of therapy outcome, and PSS was a strong predictor of the magnitude of the initial decrease in VL. This suggests that the prospective evaluation of PSS to identify regimens that maximize decreases in VL to reduce the probability of virologic rebound could improve antiretroviral treatment.

Anti-HIV Agents↗
PubMed2004

Sex-based differences in saquinavir pharmacology and virologic response in AIDS Clinical Trials Group Study 359.

AIDS Clinical Trials Group study 359 was a controlled study of saquinavir with either ritonavir or nelfinavir, together with delavirdine, adefovir, or both, in indinavir-experienced persons. Saquinavir was common in all study arms, and the study investigated relationships among characteristics of patients, saquinavir area under the curve (AUC) and trough concentrations (C(min)), and virologic response. Concentrations of saquinavir were higher when it was combined with ritonavir than when it was combined with nelfinavir and were lower with adefovir-containing regimens. Females had higher AUC and C(min) values than did males. Higher saquinavir AUC and C(min) values were associated with a greater likelihood of human immunodeficiency virus (HIV) RNA levels </=500 copies/mL (P=.008) and were better predictors of response than was the saquinavir inhibitory quotient. Males had a lower probability of having HIV RNA levels </=500 copies/mL at week 16 than did females (28% vs. 42%; adjusted odds ratio, 0.43). In this study, a greater proportion of females had HIV RNA levels </=500 copies/mL than did males, which can be attributed to higher concentrations of saquinavir in females than in males.

Adenine↗
PubMed2004

Clinically validated genotype analysis: guiding principles and statistical concerns.

Whereas previously the output of HIV resistance tests has been based on therapeutically arbitrary criteria, there is now an ongoing move towards correlating test interpretation with virological outcomes on treatment. This approach is undeniably superior, in principle, for tests intended to guide drug choices. However the predictive accuracy of a given stratagem that links genotype or phenotype to drug response is strongly influenced by the study design, data capture and analytical methodology used to derive it. For genotyping, the most widely used resistance tool in clinical practice, these considerations are further complicated by the range of mutational patterns present in the treated population. There is no definitively superior methodology for generating a genotype-response association for use in interpreting a resistance test, and the various approaches used to date all have their strengths and weaknesses. This review discusses the processes involved in constructing such tools, with particular emphasis on establishing validated mutation score rules, and examines the key issues and confounding factors that influence predictive accuracy outside the originating dataset. Since the size of the sample is a key influence on the statistical power to determine an effect, it is hoped that a greater understanding of the influence of study design and methodology will assist the development of standardized outcome measures and reporting formats that allow data pooling at the international level.

Anti-HIV Agents↗
PubMed2003

Comparison of four-drug regimens and pairs of sequential three-drug regimens as initial therapy for HIV-1 infection.

BACKGROUND: It is unclear whether therapy for human immunodeficiency virus type 1 (HIV-1) should be initiated with a four-drug or two sequential three-drug regimens. METHODS: In this multicenter trial we compared initial therapy involving four-drug regimens containing efavirenz and nelfinavir in combination with either didanosine and stavudine or zidovudine and lamivudine with therapy involving two consecutive three-drug regimens the first of which contained either efavirenz or nelfinavir. RESULTS: A total of 980 subjects were followed for a median of 2.3 years. There was no significant difference in the occurrence of regimen failures between the group that received the four-drug regimen containing didanosine, stavudine, nelfinavir, and efavirenz and the groups that received the three-drug regimens beginning with didanosine, stavudine, and nelfinavir (hazard ratio for regimen failure, 1.24) or didanosine, stavudine, and efavirenz (hazard ratio, 1.01). There was no significant difference between the group that received the four-drug regimen containing zidovudine, lamivudine, nelfinavir, and efavirenz and the groups that received the three-drug regimens beginning with zidovudine, lamivudine, and nelfinavir (hazard ratio, 1.06) or zidovudine, lamivudine, and efavirenz (hazard ratio, 1.45). A four-drug regimen was associated with a longer time to the first regimen failure than the three-drug regimens containing didanosine, stavudine, and nelfinavir (hazard ratio for a first regimen failure, 0.55); didanosine, stavudine, and efavirenz (hazard ratio, 0.63); or zidovudine, lamivudine, and nelfinavir (hazard ratio, 0.49), but not the three-drug regimen containing zidovudine, lamivudine, and efavirenz (hazard ratio, 1.21). CONCLUSIONS: There was no significant difference in the duration of successful HIV-1 treatment between a single four-drug regimen and two consecutive three-drug regimens. Among these treatment strategies, initiating therapy with the three-drug regimen of zidovudine, lamivudine, and efavirenz is the optimal choice.

Adult↗
PubMed2003

Safety and immunogenicity of hepatitis A vaccine in human immunodeficiency virus-infected patients: a double-blind, randomized, placebo-controlled trial.

The safety and immunogenicity of inactivated hepatitis A (HepA) vaccine was assessed in 133 hepatitis A virus-seronegative, human immunodeficiency virus (HIV)-infected adults. Patients were randomly assigned to receive, in a blinded fashion, either 2 doses of vaccine (1440 enzyme-linked immunosorbent assay units) or placebo 6 months apart. Seroconversion at month 9 was observed in 68% of those with CD4 cell counts >/=200 cells/mm(3) but in only 9% of those with lower CD4 cell counts (P=.004). HepA vaccine was well tolerated and had no effect on the course of HIV infection or plasma HIV RNA load.

CD4 Lymphocyte Count↗
PubMed2003

A controlled Phase II trial assessing three doses of enfuvirtide (T-20) in combination with abacavir, amprenavir, ritonavir and efavirenz in non-nucleoside reverse transcriptase inhibitor-naive HIV-infected adults.

Enfuvirtide is a novel antiretroviral that blocks HIV-1 cell fusion and viral entry. This Phase II, controlled, open-label, randomized, multicentre dose-ranging trial explored the safety, antiviral activity and pharmacokinetics of enfuvirtide, administered by subcutaneous (s.c.) injection, in 71 HIV-1-infected, protease inhibitor-experienced, non-nucleoside reverse transcriptase inhibitor (NNRTI)-naive adults for 48 weeks. Study participants were randomized to receive enfuvirtide at a deliverable dose of 45, 67.5 or 90 mg twice daily; the 45 mg twice daily dose required 2 injections/day, while the higher doses required 4 injections/day. A background oral antiretroviral (ARV) regimen of abacavir (300 mg twice daily), amprenavir (1200 mg twice daily), ritonavir (200 mg twice daily) and efavirenz (600 mg once daily) was provided with enfuvirtide. A control group received the background ARV regimen alone. All potential participants underwent an HIV genotype at screen to ensure a homogenous population and to exclude patients with evidence of genotypic resistance to NNRTIs. Overall, the tolerability of the combination of abacavir, amprenavir, ritonavir, efavirenz and enfuvirtide was generally comparable to control through 48 weeks. No enfuvirtide dose-dependent adverse events (AEs) were observed across treatment groups. Injection site reactions (ISRs) occurred at least once in 68.5% of the enfuvirtide-treated population, and most ISRs were mild to moderate in severity, with no apparent dose relationship. Excluding ISRs, the most common treatment-emergent AEs were nausea, diarrhoea, dizziness and fatigue; with no clinically significant differences in the incidence of AEs observed between the control and enfuvirtide groups. Each treatment group benefited from ARV therapy, with a trend of increasing antiviral and immunological activity associated with increasing enfuvirtide dose. At 48 weeks, the median HIV-1 RNA change from baseline for the ITT population was -2.24 log10 copies/ml for the combined enfuvirtide groups compared with -1.87 log10 copies/ml for the control group. In addition, 54.9% of patients in the enfuvirtide group achieved HIV-1 RNA < or = 400 copies/ml versus 36.8% of patients in the control group. These results indicate that enfuvirtide has a favourable safety profile and is a promising new antiviral agent for HIV-infected patients who have been on previously failing ARV regimens.

Adult↗
PubMed2002

Durability of response to treatment among antiretroviral-experienced subjects: 48-week results from AIDS Clinical Trials Group Protocol 359.

The 24-week extension of AIDS Clinical Trials Group Protocol 359, a study of human immunodeficiency virus (HIV)-infected, indinavir-experienced patients, was designed to study the durability of "salvage" treatment regimens. Patients received saquinavir in combination with either ritonavir or nelfinavir and, in addition, delavirdine, adefovir, or both. Patients who demonstrated a virologic response at weeks 12-16 were eligible to continue therapy in the extension through week 48. Of the 105 eligible subjects who were enrolled in the extension, 86 (82%) completed 48 weeks, and 49 (57%) of those 86 had HIV RNA levels <or=500 copies/mL at week 48. For these 86 subjects who completed 48 weeks, the median change in CD4 cell count from baseline was +72 cells/mm(3). Greater body weight, higher CD4 cell count, and greater degree of phenotypic susceptibility to indinavir and saquinavir at baseline were significantly associated with durable virologic suppression. These results show that some patients who experience treatment failure can demonstrate durable virologic and immunologic responses with salvage antiretroviral regimens.

Antiviral Agents↗
PubMed2002

Predictive value of HIV-1 viral load on risk for opportunistic infection.

OBJECTIVE: The relationship between HIV-1 viral load and the risk for opportunistic infection (OI) was examined in Adult AIDS Clinical Trial Group (AACTG) 722, a virology substudy of AACTG 323: a phase 4 randomized study designed to examine the use of chronic suppressive versus episodic fluconazole therapy. METHODS: The primary analysis used a case-control sampling scheme with two controls per "case" (subjects that developed an OI) matched by gender, age, and time on study. Forty-five cases and matched controls were identified and used in the analysis. RESULTS: Study 722 accrued 518 subjects between 5/97 and 11/99. Forty-five subjects developed serious OIs or refractory candidiasis. Median baseline CD4 count was 24 cell/mm3 for cases and 46 for controls (p =.003). Median viral load (VL) was 5.02 log10 copies/mL for cases and 4.08 for controls (p =.002). Multivariate analysis found four independent variables associated with time to OI: baseline VL and CD4 (RR = 2.2 per log increment and 6.0 per 50-cell increment, respectively), a one log increase in VL at any time (RR = 15), and history of an OI (RR = 5.2). CONCLUSIONS: VL and changes in VL were independently associated with risk of development of OIs in a prospective study and should be considered by clinicians when assessing patients for risk of OI.

AIDS-Related Opportunistic Infections↗
PubMed2002

Early adoption of HIV-1 resistance testing in the San Diego County Ryan White CARE Act Program: predictors and outcome.

This research identifies predictors and outcomes of early use of human immunodeficiency virus type 1 (HIV-1) resistance testing in the San Diego County Ryan White CARE Act program. Between January and November 2000, 98 patients receiving care in 7 clinics participated in the resistance testing program. Provider characteristics predictive of participation included number of patients and percent of practice devoted to HIV care and number of HIV-related continuing medical education hours over the preceding 12 months. Providers rarely requested expert panel review of test results, and expert review was not predictive of better viral load responses. Regimens specified before knowledge of resistance results had more active drugs than those prescribed after knowledge of test results. Phenotypic susceptibility was predictive of virologic response, as was degree of prior nucleoside analogue exposure. There was little relationship between phenotypic susceptibility and a clinician's decision to prescribe a drug. Early adopters of this technology were more experienced HIV providers than their colleagues and utilized susceptibility information using reasoning processes in which resistance was a contributory but not necessarily dominating factor.

Adult↗