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author:("agar, Brian K")
1.  Reply to Tsai et al 
PMCID: PMC3762385  PMID: 23840048
2.  Hepatitis B Vaccine Responsiveness and Clinical Outcomes in HIV Controllers 
PLoS ONE  2014;9(8):e105591.
Hepatitis B virus (HBV) vaccine responsiveness is associated with reduced risk of AIDS or death in HIV-infected individuals. Although HIV controllers (HIC) typically have favorable immunologic and clinical characteristics compared to non-controllers, vaccine responsiveness has not been studied.
Methods and Findings
In the U.S. Military HIV Natural History Study, HBV vaccine response was defined as antibody to hepatitis B surface antigen (anti-HBs) ≥10 IU/L after last vaccination. For determination of vaccine responsiveness, HIC (n = 44) and treatment-naïve non-controllers (n = 476) were not on highly active antiretroviral therapy (HAART) when vaccinated while treated non-controllers (n = 284) received all HBV vaccine doses during viral load (VL)-suppressive HAART. Progression to AIDS or death was also compared for all HIC (n = 143) and non-controllers (n = 1566) with documented anti-HBs regardless of the timing of HBV vaccination. Positive vaccine responses were more common in HIC (65.9%) compared to HAART-naïve non-controllers (36.6%; P<0.001), but similar to non-controllers on HAART (59.9%; P = 0.549). Factors associated with vaccine response for HIC compared to HAART-naïve non-controllers include HIC status (OR 2.65, 95% CI 1.23–5.89; P = 0.014), CD4 count at last vaccination (OR 1.28, 1.15–1.45 for every 100 cells/uL; P<0.001), and number of vaccine doses administered (OR 0.56, 0.35–0.88; P = 0.011). When HIC were compared to non-controllers on HAART, only CD4 count at last vaccination was significant (OR 1.23, 1.1–1.38 for every 100 cells/uL; P<0.001). The rate of AIDS or death per 100 person/years for HIC compared to non-controllers was 0.14 (95% CI 0–0.76) versus 0.98 (95% CI 0.74–1.28) for vaccine responders and 0 (95% CI 0–2.22) versus 4.11 (95% CI 3.38–4.96) for non-responders, respectively.
HIC have improved HBV vaccine responsiveness compared to treatment-naïve non-controllers, but similar to those on VL-suppressive HAART. Progression to AIDS or death can be predicted by HBV vaccine responder status for non-controllers, however these events are rarely observed in HIC.
PMCID: PMC4140789  PMID: 25144773
3.  Delayed-type hypersensitivity (DTH) test anergy does not impact CD4 reconstitution or normalization of DTH responses during antiretroviral therapy 
Delayed-type hypersensitivity (DTH) testing is an in vivo assessment of cell-mediated immunity. Although highly active antiretroviral therapy (HAART) improves immunologic parameters, the relationship between DTH responsiveness and CD4 gains on HAART is not completely understood. We investigated CD4 reconstitution and the change in DTH responses from treatment baseline through 24 months of viral load (VL)-suppressive HAART in the U.S. Military HIV Natural History Study.
Treatment-naïve subjects with VL <400 copies/mL after ≥24 months on HAART were included (n=302). DTH testing consisted of ≥3 recall antigens, and responses were classified by the number of positive skin tests: anergic (0–1) or non-anergic (≥2). Pre-HAART DTH results were compared for the outcome of CD4 reconstitution at 24 months of HAART. Improvement in DTH responses was also analyzed for those anergic before HAART initiation.
Non-anergic responses were observed in 216 (72%) participants, while 86 (28%) individuals were anergic prior to HAART initiation. Demographically there were similar distributions of age at HIV diagnosis and HAART initiation, as well as gender and race or ethnicity. There were no significant differences between non-anergic and anergic participants in pre-HAART CD4 count (409 cells/μL, interquartile range (IQR) 315–517 vs. 373 cells/μL, IQR 228–487; p=0.104) and VL (4.3 log10 copies/mL, IQR 3.4–4.9 vs. 4.4 log10 copies/mL, IQR 3.6–5.0; p=0.292). Median CD4 gains 24 months after HAART initiation were similar between the non-anergic (220 cells/μL, IQR 115–358) and anergic groups (246 cells/μL, IQR 136–358; p=0.498). For individuals anergic before HAART initiation, DTH normalization occurred at 24 months post-HAART in the majority of participants (51 of 86, 59%). Normalization of DTH responses was not associated with CD4 count at HAART initiation (OR 0.73, 95% CI 0.47, 1.09 per 100 cells; p=0.129) nor with AIDS diagnoses prior to HAART (OR 0.34, 95% CI 0.04, 2.51; p=0.283).
DTH responsiveness has been shown to predict HIV disease progression independent of CD4 count in untreated individuals. In the setting of HAART, pre-HAART anergy does not appear to impact CD4 gains or the ability to normalize DTH responses after 24 months of VL-suppressive HAART.
PMCID: PMC3916671  PMID: 24499779
HIV; HAART; antiretroviral therapy; delayed-type hypersensitivity; DTH; CD4 cell count; anergy; anergic
4.  Combining Epidemiologic and Biostatistical Tools to Enhance Variable Selection in HIV Cohort Analyses 
PLoS ONE  2014;9(1):e87352.
Variable selection is an important step in building a multivariate regression model for which several methods and statistical packages are available. A comprehensive approach for variable selection in complex multivariate regression analyses within HIV cohorts is explored by utilizing both epidemiological and biostatistical procedures.
Three different methods for variable selection were illustrated in a study comparing survival time between subjects in the Department of Defense’s National History Study and the Atlanta Veterans Affairs Medical Center’s HIV Atlanta VA Cohort Study. The first two methods were stepwise selection procedures, based either on significance tests (Score test), or on information theory (Akaike Information Criterion), while the third method employed a Bayesian argument (Bayesian Model Averaging).
All three methods resulted in a similar parsimonious survival model. Three of the covariates previously used in the multivariate model were not included in the final model suggested by the three approaches. When comparing the parsimonious model to the previously published model, there was evidence of less variance in the main survival estimates.
The variable selection approaches considered in this study allowed building a model based on significance tests, on an information criterion, and on averaging models using their posterior probabilities. A parsimonious model that balanced these three approaches was found to provide a better fit than the previously reported model.
PMCID: PMC3906149  PMID: 24489902
5.  Race/ethnicity and HAART initiation in a military HIV infected cohort 
Prior studies have suggested that HAART initiation may vary by race/ethnicity. Utilizing the U.S. military healthcare system, which minimizes confounding from healthcare access, we analyzed whether timing of HAART initiation and the appropriate initiation of primary prophylaxis among those at high risk for pneumocystis pneumonia (PCP) varies by race/ethnicity.
Participants in the U.S. Military HIV Natural History Study from 1998-2009 who had not initiated HAART before 1998 and who, based on DHHS guidelines, had a definite indication for HAART (CD4 <200, AIDS event or severe symptoms; Group A), an indication to consider HAART (including CD4 <350; Group B) or electively started HAART (CD4 >350; Group C) were analyzed for factors associated with HAART initiation. In a secondary analysis, participants were also evaluated for factors associated with starting primary PCP prophylaxis within four months of a CD4 count <200 cells/mm3. Multiple logistic regression was used to compare those who started vs. delayed therapy; comparisons were expressed as odds ratios (OR).
1262 participants were evaluated in the analysis of HAART initiation (A = 208, B = 637, C = 479 [62 participants were evaluated in both Groups A and B]; 94% male, 46% African American, 40% Caucasian). Race/ethnicity was not associated with HAART initiation in Groups A or B. In Group C, African American race/ethnicity was associated with lower odds of initiating HAART (OR 0.49, p = 0.04). Race and ethnicity were also not associated with the initiation of primary PCP prophylaxis among the 408 participants who were at risk.
No disparities in the initiation of HAART or primary PCP prophylaxis according to race/ethnicity were seen among those with an indication for therapy. Among those electively initiating HAART at the highest CD4 cell counts, African American race/ethnicity was associated with decreased odds of starting. This suggests that free healthcare can potentially overcome some of the observed disparities in HIV care, but that unmeasured factors may contribute to differences in elective care decisions.
PMCID: PMC3922739  PMID: 24460764
HIV; HAART; Race; Ethnicity; Indications for HIV treatment; Disparities in care; African Americans
6.  Results of a 25 Year Longitudinal Analysis of the Serologic Incidence of Syphilis in a Cohort of HIV Infected Patients with Unrestricted Access to Care 
Sexually transmitted diseases  2012;39(6):10.1097/OLQ.0b013e318249d90f.
The well described biological and epidemiologic associations of syphilis and HIV are particularly relevant to the military, as service members are young and at risk for sexually transmitted infections. We therefore used the results of serial serologic testing to determine the prevalence, incidence, and risk factors for incident syphilis in a cohort of HIV-infected Department of Defense beneficiaries.
Participants with a positive non-treponemal test at HIV diagnosis that was confirmed on treponemal testing were categorized as prevalent cases, whereas participants with an initial negative non-treponemal test who subsequently developed a confirmed positive non-treponemal test as incident cases.
At HIV diagnosis the prevalence of syphilis was 5.8% (n=202). 4239 participants contributed 27,192 person years (PY) to the incidence analysis and 347 (8%) developed syphilis (rate 1.3/100 PY; [1.1, 1.4]). Syphilis incidence was highest during the calendar years 2006 - 2009 (2.5/100 PY; [2.0, 2.9]). In multivariate analyses, younger age (per 10 year increase HR 0.8;[0.8-0.9]); male gender (HR 5.6; [2.3-13.7]); non European-American ethnicity (African-American (HR 3.2; [2.5-4.2]; Hispanic HR 1.9; [1.2-3.0]); history of hepatitis B (HR 1.5; [1.2-1.9]) or gonorrhea (HR 1.4; [1.1 −1.8]) were associated with syphilis.
The significant burden of disease both at and after HIV diagnosis, observed in this cohort, suggests that the cost-effectiveness of extending syphilis screening to at risk military members should be assessed. In addition, HIV infected persons continue to acquire syphilis, emphasizing the continued importance of prevention for positive programs.
PMCID: PMC3846570  PMID: 22592829
Seroincidence; Seroprevalence; Risk Factors; Syphilis; HIV infected persons
7.  Early Postseroconversion CD4 Cell Counts Independently Predict CD4 Cell Count Recovery in HIV-1–Postive Subjects Receiving Antiretroviral Therapy 
The relationship between CD4+ T-cell counts determined soon after seroconversion with HIV-1 (baseline CD4), nadir CD4, and CD4 levels attained during highly active antiretroviral therapy (HAART) is unknown.
Longitudinal, including baseline (at or soon after HIV diagnosis), intermediate (nadir), and distal (post-HAART) CD4+ T-cell counts were assessed in 1085 seroconverting subjects who achieved viral load suppression from a large well-characterized cohort. The association of baseline with post-HAART CD4+ T-cell count was determined after adjustment for other relevant covariates.
A higher baseline CD4+ T-cell count predicted a greater post- HAART CD4+ T-cell count, independent of the nadir and other explanatory variables. Together, baseline and nadir strongly predicted the post-HAART CD4+ count such that a high baseline and lower nadir were associated with a maximal immune recovery after HAART. Likelihood of recovery of the baseline count after HAART was significantly higher when the nadir/baseline count ratio was consistently ≥0.6.
Among viral load suppressing seroconverters, the absolute CD4+ T-cell count attained post-HAART is highly dependent on both baseline and nadir CD4+ T-cell counts. These associations further support the early diagnosis and initiation of HAART among HIV-infected persons.
PMCID: PMC3786783  PMID: 21546844
CD4 count; highly active antiretroviral therapy; outcomes; predictors; treatment response
8.  Responsiveness of T Cells to Interleukin-7 Is Associated with Higher CD4+ T Cell Counts in HIV1-Positive Individuals with Highly Active Antiretroviral Therapy-Induced Viral Load Suppression 
The Journal of infectious diseases  2009;199(12):1872-1882.
Despite suppression of the human immunodeficiency virus type 1(HIV-1) load by highly active antiretroviral therapy (HAART), recovery of CD4+ T cell counts can be impaired. We investigated whether this impairment may be associated with hyporesponsiveness of T cells to γ-chain (γc) cytokines known to influence T cell homeostasis.
The responsiveness of T cells to interleukin (IL)-2, IL-7, and IL-15 was determined by assessing cytokine-induced phosphorylation of the signal transducer and activator of transcription 5 (STAT5) in peripheral T cells obtained from 118 HIV-positive subjects and 13 HIV-negative subjects.
The responsiveness of T cells to interleukin (IL)-7 but not to IL-2 or IL-15 was lower among HIV-positive subjects than among HIV-negative subjects. Among subjects with viral load suppression, the degree of IL-7 responsiveness (1) correlated with naive CD4+ T cell counts and was a better immune correlate of the prevailing CD4+ T cell count than were levels of human leukocyte antigen-DR1 or programmed death-1, which are predictors of T cell homeostasis during HIV infection; and (2) was greater in subjects with complete (i.e., attainment of ≥500 CD4+ T cells/mm3 ≥5 years after initiation of HAART) versus incomplete immunologic responses. The correlation between plasma levels of IL-7 and CD4+ T cell counts during HAART was maximal in subjects with increased IL-7 responsiveness.
Responsiveness of T cells to IL-7 is associated with higher CD4+ T cell counts during HAART and thus may be a determinant of the extent of immune reconstitution.
PMCID: PMC3777824  PMID: 19432535
9.  Independent Effects of Genetic Variations in Mannose-Binding Lectin Influence the Course of HIV Disease: The Advantage of Heterozygosity for Coding Mutations 
The in vivo impact of mannose-binding lectin (MBL), a molecule involved in innate immunity, on the pathogenesis of human immunodeficiency virus (HIV)–1 infection and AIDS is unknown.
A total of 1102 HIV-positive and 2213 HIV-negative adult subjects were screened for polymorphisms in the coding and promoter regions of MBL2, the gene that encodes MBL.
Variations in MBL2 did not influence the risk of acquiring HIV-1. Heterozygosity for coding mutations (O allele) and homozygosity for the −221 promoter polymorphism (X allele) in MBL2 were associated with a delay in and an accelerated rate of disease progression, respectively. MBL2 variations influenced the rate of progression to AIDS-defining illnesses. In a multivariate model, the effects of MBL2 variations were independent of several parameters known to influence disease progression, including steady-state viral load, baseline CD4+ T cell counts, and delayed-type hypersensitivity skin test responses, an in vivo marker of cell-mediated immunity. The effects of MBL2 variations were most evident in those who possessed protective genotypes of CCR5 and a high copy number of CCL3L1, the most potent HIV-suppressive CCR5 ligand.
MBL2 genotypes are independent determinants of HIV disease progression and heterozygosity for MBL2 coding mutations confer disease-retarding effects. MBL-dependent immune responses may play a role in the pathogenesis of HIV infection.
PMCID: PMC3777826  PMID: 18498240
10.  Prevalence and Factors Associated With Sleep Disturbances Among Early-Treated HIV-Infected Persons 
Persons infected with human immunodeficiency virus (HIV) have a high prevalence of insomnia (46%) and daytime drowsiness (30%). Factors associated with insomnia among patients with HIV infection include depression and increased waist size. Screening for sleep disturbances should be considered among HIV-infected persons.
Background. Sleep disturbances are reportedly common among persons infected with human immunodeficiency virus (HIV), but recent data, including comparisons with HIV-uninfected persons, are limited.
Methods. We performed a cross-sectional study among early-treated HIV-infected military beneficiaries (n = 193) to determine the prevalence and factors associated with insomnia (Pittsburgh Sleep Quality Index [PSQI]) and daytime sleepiness (Epworth Sleepiness Scale [ESS]). Data were compared with HIV-uninfected persons (n = 50) matched by age, sex, race or ethnicity, and military rank.
Results. Forty-six percent of HIV-infected persons had insomnia (PSQI >5), and 30% reported daytime drowsiness (ESS ≥10). The prevalence of insomnia and daytime sleepiness was not significantly higher compared with the HIV-uninfected group (38% [P = .30] and 20% [P = .18], respectively). In the multivariate model, factors associated with insomnia among HIV infected patients included depression (odds ratio [OR], 16.8; 95% confidence interval [CI], 2.0–142.1; P = .01), increased waist size (OR, 2.7; 95% CI, 1.4–5.1; P = .002), and fewer years of education (OR, 0.8; 95% CI, .7–.95; P = .006). Neurocognitive impairment (diagnosed in 19% of HIV-infected participants) was not associated with insomnia; however, HIV-infected persons with insomnia were 3.1-fold more likely to have a decline in activities of daily living than those without insomnia (23% vs 9%; P = .01). Only 18% of HIV-infected persons reported using a sleep medication at least weekly.
Conclusions. HIV-infected persons have a high prevalence of insomnia, but among an early-treated cohort this rate was not significantly higher compared with HIV-uninfected persons. Factors associated with insomnia among HIV-infected patients include depression and increased waist size. Prompt diagnosis and treatment of sleep disturbances are advocated and may improve quality of life.
PMCID: PMC3334363  PMID: 22431801
11.  Hepatitis B Virus Coinfection Negatively Impacts HIV Outcomes in HIV Seroconverters 
The Journal of Infectious Diseases  2011;205(2):185-193.
(See the editorial commentary by Peters and Marston, on pages 166–8.)
Background. Understanding the impact of hepatitis B virus (HBV) in human immunodeficiency virus (HIV) coinfection has been limited by heterogeneity of HIV disease. We evaluated HBV coinfection and HIV-related disease progression in a cohort of HIV seroconverters.
Methods. Participants with HIV diagnosis seroconversion window of ≤3 years and serologically confirmed HBV infection (HB) status were classified at baseline into 4 HB groups. The risk of clinical AIDS/death in HIV seroconverters was calculated by HB status.
Results. Of 2352 HIV seroconverters, 474 (20%) had resolved HB, 82 (3%) had isolated total antibody to hepatitis B core antigen (HBcAb), and 64 (3%) had chronic HB. Unadjusted rates (95% confidence intervals [CIs]) of clinical AIDS/death for the HB-negative, resolved HB, isolated HBcAb, and chronic HB groups were 2.43 (2.15–2.71); 3.27 (2.71–3.84); 3.75 (2.25–5.25); and 5.41 (3.41–7.42), respectively. The multivariable risk of clinical AIDS/death was significantly higher in the chronic HB group compared to the HB-negative group (hazard ratio [HR], 1.80; 95% CI, 1.20–2.69); while the HRs were increased but nonsignificant for those with resolved HB (HR, 1.17; 95% CI, .94–1.46) and isolated HBcAb (HR, 1.14; 95% CI, .75–1.75).
Conclusions. HBV coinfection has a significant impact on HIV outcomes. The hazard for an AIDS or death event is almost double for those with chronic HB compared, with HIV-monoinfected persons.
PMCID: PMC3244364  PMID: 22147794
12.  Identification of an Abbreviated Test Battery for Detection of HIV-Associated Neurocognitive Impairment in an Early-Managed HIV-Infected Cohort 
PLoS ONE  2012;7(11):e47310.
HIV-associated neurocognitive disorders (HAND) remain prevalent despite improved antiretroviral treatment (ART), and it is essential to have a sensitive and specific HAND screening tool.
Participants were 200 HIV-infected US military beneficiaries, managed early in the course of HIV infection, had few comorbidities, and had open access to ART. Participants completed a comprehensive, seven-domain (16-test), neuropsychological battery (∼120 min); neurocognitive impairment (NCI) was determined using a standardized score derived from demographically adjusted T-scores (global deficit score ≥0.5). Restricting the estimated administration time of the screening battery to < = 20 minutes, we examined the sensitivity and specificity of detecting NCI for all possible combinations of 2-, 3-, and 4- tests from the comprehensive battery.
Participants were relatively healthy (median CD4 count: 546 cells/mm3) with 64% receiving ART. Prevalence of NCI was low (19%). The best 2-test screener included the Stroop Color Test and the Hopkins Verbal Learning Test-Revised (11 min; sensitivity = 73%; specificity = 83%); the best 3-test screener included the above measures plus the Paced Auditory Serial Addition Test (PASAT; 16 min; sensitivity = 86%; specificity = 75%). The addition of Action Fluency to the above three tests improved specificity (18 min; sensitivity = 86%; specificity = 87%).
Combinations of widely accepted neuropsychological tests with brief implementation time demonstrated good sensitivity and specificity compared to a time intensive neuropsychological test battery. Tests of verbal learning, attention/working memory, and processing speed are particularly useful in detecting NCI. Utilizing validated, easy to administer, traditional neuropsychological tests with established normative data may represent an excellent approach to screening for NCI in HIV.
PMCID: PMC3493574  PMID: 23144815
13.  Elevated CD8 Counts During HAART are Associated with HIV Virologic Treatment Failure 
To evaluate whether elevated CD8 counts are associated with increased risk of virologic treatment failure in HIV-infected individuals.
Retrospective cohort study.
U.S. Military HIV Natural History Study participants who initiated HAART in 1996-2008, had 6- and 12-month post-HAART HIV RNA <400 c/ml, ≥2 subsequent HIV viral loads and a baseline CD8 count were eligible (n=817). Baseline was 12 months after HAART start, virologic failure was defined as confirmed HIV RNA ≥400 c/ml, and CD8 counts ≥1200 cells/mm3 were considered elevated. Cox models were used to examine the effect of baseline and time-updated CD8 counts on virologic failure.
There were 216 failures for a rate of 5.6 per 100 person-years (95% confidence interval [CI] 4.9-6.4). Among those initiating HAART in 2000-2008, participants with elevated baseline CD8 counts had significantly greater risk of virologic failure compared to those with baseline CD8 counts ≤600 cells/mm3 (hazard ratio [HR] = 2.68, 95% CI 1.13 – 6.35). Participants with elevated CD8 counts at >20% of prior 6-month follow-up visits had greater risk of failure at the current visit than those who did not (HR = 1.53, 95% CI 1.14 - 2.06). Those with CD8 counts that increased after HAART start had greater risk of failure than those with CD8 counts that decreased or remained the same (HR = 1.59, 95% CI 1.19 – 2.13).
Initial or serial elevated CD8 counts while on HAART or an increase in CD8 counts from HAART initiation may be early warnings for future treatment failure.
PMCID: PMC3173352  PMID: 21602694
Human immunodeficiency virus; CD8 count; antiretroviral therapy; HIV viral load suppression; HIV virologic failure
14.  Long-term Durability of Immune Responses After Hepatitis A Vaccination Among HIV-Infected Adults 
The Journal of Infectious Diseases  2011;203(12):1815-1823.
Background.  Vaccination provides long-term immunity to hepatitis A virus (HAV) among the general population, but there are no such data regarding vaccine durability among human immunodeficiency virus (HIV)–infected adults.
Methods.  We retrospectively studied HIV-infected adults who had received 2 doses of HAV vaccine. We analyzed blood specimens taken at 1 year, 3 years, and, when available, 6–10 years postvaccination. HAV immunoglobulin G (IgG) values of ≥10 mIU/mL were considered seropositive.
Results.  We evaluated specimens from 130 HIV-infected adults with a median age of 35 years and a median CD4 cell count of 461 cells/mm3 at or before time of vaccination. Of these, 49% had an HIV RNA load <1000 copies/mL. Initial vaccine responses were achieved in 89% of HIV-infected adults (95% confidence interval [CI], 83%–94%), compared with 100% (95% CI, 99%–100%) of historical HIV-uninfected adults. Among initial HIV-infected responders with available specimens, 90% (104 of 116; 95% CI, 83%–95%) remained seropositive at 3 years and 85% (63 of 74; 95% CI, 75%–92%) at 6–10 years. Geometric mean concentrations (GMCs) among HIV-infected adults were 154, 111, and 64 mIU/mL at 1, 3, and 6–10 years, respectively, compared with 1734, 687, and 684 mIU/mL among HIV-uninfected persons. Higher GMCs over time among HIV-infected adults were associated with lower log10 HIV RNA levels (β = −.12, P = .04).
Conclusions.  Most adults with well-controlled HIV infections had durable seropositive responses up to 6–10 years after HAV vaccination. Suppressed HIV RNA levels are associated with durable HAV responses.
PMCID: PMC3100512  PMID: 21606540
15.  Hepatitis B Vaccine Antibody Response and the Risk of Clinical AIDS or Death 
PLoS ONE  2012;7(3):e33488.
Whether seroresponse to a vaccine such as hepatitis B virus (HBV) vaccine can provide a measure of the functional immune status of HIV-infected persons is unknown.This study evaluated the relationship between HBV vaccine seroresponses and progression to clinical AIDS or death.
Methods and Findings
From a large HIV cohort, we evaluated those who received HBV vaccine only after HIV diagnosis and had anti-HBs determination 1–12 months after the last vaccine dose. Non-response and positive response were defined as anti-HBs <10 and ≥10 IU/L, respectively. Participants were followed from date of last vaccination to clinical AIDS, death, or last visit. Univariate and multivariable risk of progression to clinical AIDS or death were evaluated with Cox regression models. A total of 795 participants vaccinated from 1986–2010 were included, of which 41% were responders. During 3,872 person-years of observation, 122 AIDS or death events occurred (53% after 1995). Twenty-two percent of non-responders experienced clinical AIDS or death compared with 5% of responders (p<0.001). Non-response to HBV vaccine was associated with a greater than 2-fold increased risk of clinical AIDS or death (HR 2.47; 95% CI, 1.38–4.43) compared with a positive response, after adjusting for CD4 count, HIV viral load, HAART use, and delayed type hypersensitivity skin test responses (an in vivo marker of cell-mediated immunity). This association remained evident among those with CD4 count ≥500 cells/mm3 (HR 3.40; 95% CI, 1.39–8.32).
HBV vaccine responses may have utility in assessing functional immune status and risk stratificating HIV-infected individuals, including those with CD4 count ≥500 cells/mm3.
PMCID: PMC3310879  PMID: 22457767
16.  Hepatitis E Virus Infection in HIV-infected Persons 
Emerging Infectious Diseases  2012;18(3):502-506.
To determine whether hepatitis E virus (HEV) is a cause of hepatitis among HIV-infected persons, we evaluated 1985–2009 data for US military beneficiaries. Evidence of acute or prior HEV infection was detected for 7 (4%) and 5 (3%) of 194 HIV-infected persons, respectively. HEV might be a cause of acute hepatitis among HIV-infected persons.
PMCID: PMC3309581  PMID: 22377220
Hepatitis E virus; HIV; epidemiology; hepatitis; military; viruses
17.  Clinical, demographic and laboratory parameters at HAART initiation associated with decreased post-HAART survival in a U.S. military prospective HIV cohort 
Although highly active antiretroviral therapy (HAART) has improved HIV survival, some patients receiving therapy are still dying. This analysis was conducted to identify factors associated with increased risk of post-HAART mortality.
We evaluated baseline (prior to HAART initiation) clinical, demographic and laboratory factors (including CD4+ count and HIV RNA level) for associations with subsequent mortality in 1,600 patients who began HAART in a prospective observational cohort of HIV-infected U.S. military personnel.
Cumulative mortality was 5%, 10% and 18% at 4, 8 and 12 years post-HAART. Mortality was highest (6.23 deaths/100 person-years [PY]) in those with ≤ 50 CD4+ cells/mm3 before HAART initiation, and became progressively lower as CD4+ counts increased (0.70/100 PY with ≥ 500 CD4+ cells/mm3). In multivariate analysis, factors significantly (p < 0.05) associated with post-HAART mortality included: increasing age among those ≥ 40 years (Hazard ratio [HR] = 1.32 per 5 year increase), clinical AIDS events before HAART (HR = 1.93), ≤ 50 CD4+ cells/mm3 (vs. CD4+ ≥ 500, HR = 2.97), greater HIV RNA level (HR = 1.36 per one log10 increase), hepatitis C antibody or chronic hepatitis B (HR = 1.96), and HIV diagnosis before 1996 (HR = 2.44). Baseline CD4+ = 51-200 cells (HR = 1.74, p = 0.06), and hemoglobin < 12 gm/dL for women or < 13.5 for men (HR = 1.36, p = 0.07) were borderline significant.
Although treatment has improved HIV survival, defining those at greatest risk for death after HAART initiation, including demographic, clinical and laboratory correlates of poorer prognoses, can help identify a subset of patients for whom more intensive monitoring, counseling, and care interventions may improve clinical outcomes and post-HAART survival.
PMCID: PMC3320559  PMID: 22339893
Highly active antiretroviral therapy; mortality; CD4+ lymphocyte count
18.  The Timing of Hepatitis B Virus (HBV) Immunization Relative to Human Immunodeficiency Virus (HIV) Diagnosis and the Risk of HBV Infection Following HIV Diagnosis 
American Journal of Epidemiology  2010;173(1):84-93.
To assess associations between the timing of hepatitis B virus (HBV) immunization relative to human immunodeficiency virus (HIV) diagnosis and vaccine effectiveness, US Military HIV Natural History Study cohort participants without HBV infection at the time of HIV diagnosis were grouped by vaccination status, retrospectively followed from HIV diagnosis for incident HBV infection, and compared using Cox proportional hazards models. A positive vaccine response was defined as hepatitis B surface antibody level ≥10 IU/L. Of 1,877 participants enrolled between 1989 and 2008, 441 (23%) were vaccinated prior to HIV diagnosis. Eighty percent of those who received vaccine doses only before HIV diagnosis had a positive vaccine response, compared with 66% of those who received doses both before and after HIV and 41% of those who received doses only after HIV (P < 0.01 for both compared with persons vaccinated before HIV only). Compared with the unvaccinated, persons vaccinated only before HIV had reduced risk of HBV infection after HIV diagnosis (hazard ratio = 0.38, 95% confidence interval: 0.20, 0.75). No reduction in HBV infection risk was observed for other vaccination groups. These data suggest that completion of the vaccine series prior to HIV infection may be the optimal strategy for preventing this significant comorbid infection in HIV-infected persons.
PMCID: PMC3025642  PMID: 21051446
hepatitis B vaccines; hepatitis B virus; HIV; immunization; vaccination
19.  Clinical Evaluation of the Potential Utility of Computational Modeling as an HIV Treatment Selection Tool by Physicians with Considerable HIV Experience 
AIDS Patient Care and STDs  2011;25(1):29-36.
The HIV Resistance Response Database Initiative (RDI), which comprises a small research team in the United Kingdom and collaborating clinical centers in more than 15 countries, has used antiretroviral treatment and response data from thousands of patients around the world to develop computational models that are highly predictive of virologic response. The potential utility of such models as a tool for assisting treatment selection was assessed in two clinical pilot studies: a prospective study in Canada and Italy, which was terminated early because of the availability of new drugs not covered by the system, and a retrospective study in the United States. For these studies, a Web-based user interface was constructed to provide access to the models. Participating physicians entered baseline data for cases of treatment failure and then registered their treatment intention. They then received a report listing the five alternative regimens that the models predicted would be most effective plus their own selection, ranked in order of predicted virologic response. The physicians then entered their final treatment decision. Twenty-three physicians entered 114 cases (75 unique cases with 39 entered twice by different physicians). Overall, 33% of treatment decisions were changed following review of the report. The final treatment decisions and the best of the RDI alternatives were predicted to produce greater virologic responses and involve fewer drugs than the original selections. Most physicians found the system easy to use and understand. All but one indicated they would use the system if it were available, particularly for highly treatment-experienced cases with challenging resistance profiles. Despite limitations, the first clinical evaluation of this approach by physicians with substantial HIV-experience suggests that it has the potential to deliver clinical and economic benefits.
PMCID: PMC3030912  PMID: 21214377
20.  Risk Factors Influencing Antibody Responses to Kaposi’s Sarcoma-Associated Herpesvirus Latent and Lytic Antigens in Patients Under Antiretroviral Therapy in South Texas 
Kaposi’s sarcoma-associated herpesvirus (KSHV) seropositivity and lytic antibody titer are predictors for Kaposi’s sarcoma (KS).
We examined demographic, viral and immunological factors that influence KSHV latent and lytic antibodies in HIV-infected patients.
Detection rate of KSHV latent but not lytic antibodies was lower in patients with CD4 cells/mm3 ≤200 than >200 (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.11–0.61) and CD8 cells/mm3 ≤400 than >400 (OR, 0.26; 95% CI, 0.07–0.67). Overall seropositivity rate was higher in patients with CD4 cells/mm3 ≤200 than >200 (OR, 2.34; 95% CI, 1.37–4.02) and HIV copies/mL >400 than ≤400 (OR, 1.70; 95% CI, 1.09–2.65). Lytic antibody level was inversely correlated with CD4 count (P<0.001). Lytic seropositivity (OR, 2.47; 95% CI, 1.35–4.50) and antibody level (adjusted difference mean optical density [admOD], 0.324; 95% CI, 0.16–0.46) were higher in patients with HIV infection >15 than ≤15 years. Hispanics had higher lytic seropositivity rate (OR, 1.71; 95% CI, 1.07–2.73) and antibody level (admOD, 0.111; 95% CI, 0.03–0.18) than non-Hispanics.
Lower CD4 and CD8 counts impair antibody response to KSHV latent antigens. Immune deterioration, long-term HIV infection and Hispanic status are risk factors for KS predictors.
PMCID: PMC3051282  PMID: 21084997
KSHV; Kaposi’s sarcoma; Latent and lytic antibodies; Risk factors; HIV/AIDS
21.  Impact of Weight on Immune Cell Counts among HIV-Infected Persons▿ 
Prior studies have shown that weight may impact immune cell counts. However, few data exist about the relationship of weight and immune cell counts among HIV-infected patients. We examined documented HIV seroconverters (mean window, 15.7 months) in a prospective U.S. Military HIV Natural History Study (1 January 1986 to 20 January 2010). We estimated the association of the time-updated body mass index (BMI) category with changes in immune cell counts from HIV diagnosis across time (mean follow-up of 5.1 years) using multiply adjusted longitudinal linear mixed-effects models. Of 1,097 HIV seroconverters, 448 (41%) were overweight and 93 (8%) were obese at HIV diagnosis. Immune cell counts at HIV diagnosis did not significantly differ by BMI category. In the longitudinal models for those diagnosed before the advent of the highly active antiretroviral therapy (HAART) era, mean postdiagnosis decreases in the white cell count, total lymphocyte count, CD4 count, CD4 percentage, and CD4/CD8 ratio were less as the BMI category increased (all with P values of <0.05). Among HIV seroconverters diagnosed in the HAART era, obese compared to normal-weight patients had significantly smaller increases in CD4 counts, CD4 percentages, and the CD4/CD8 ratio (all with P values of <0.05). Similar findings were also noted among underweight versus normal-weight patients. In conclusion, although BMI was not associated with immune cell levels at the time of HIV diagnosis, weight appears to affect immune cells counts over the course of infection. In the HAART era, being either underweight or obese was associated with smaller increases in several important immune cell levels, including the CD4/CD8 ratio.
PMCID: PMC3122603  PMID: 21525303
22.  Is Kaposi’s Sarcoma Occurring at Higher CD4 Counts Over the Course of the HIV Epidemic? 
AIDS (London, England)  2010;24(18):2881-2883.
We evaluated longitudinal rates of Kaposi sarcoma (KS) and trends in CD4 counts at the time of KS diagnosis during the HIV epidemic (1985–2008). Although rates of KS have decreased, cases are now occurring at higher CD4 counts over time, with more than a third of cases diagnosed in 2002–2008 occurring at CD4 counts ≥350 cells/mm3. These data support future studies evaluating the impact of HAART initiation at higher CD4 counts to further reduce KS.
PMCID: PMC2978255  PMID: 20827160
23.  A Randomized Clinical Trial Comparing Revaccination with Pneumococcal Conjugate Vaccine (PCV) to Polysaccharide Vaccine (PPV) among HIV-Infected Adults 
The Journal of infectious diseases  2010;202(7):1114-1125.
The risk of pneumococcal disease persists and antibody responses to revaccination with the 23-valent polysaccharide vaccine (PPV) are low among HIV-infected adults. We determined whether revaccination with the 7-valent pneumococcal conjugate vaccine (PCV) would enhance these responses.
In a randomized clinical trial, we compared the immunogenicity of revaccination with PCV (n=131) or PPV (n=73) among HIV-infected adults (median CD4 count 533 cells/mm3) vaccinated with PPV 3–8 years earlier. HIV-uninfected adults (n=25) without prior pneumococcal vaccination received one dose of PCV. A positive response was defined as a ≥2-fold rise (baseline to day 60) in capsule-specific IgG with a post-vaccination level value ≥1000 ng/ml for at least 2 of the 4 serotypes.
HIV-infected persons demonstrated a higher frequency of positive antibody responses to PCV vs. PPV (57% vs. 36%, p=0.004) and greater IgG concentration mean changes from baseline to day 60 for serotypes 4, 9V, and 19F (all p<0.05), but not for serotype 14. However by day 180 both outcomes were similar. Responses to PCV were greater in frequency and magnitude for all serotypes in HIV-uninfected compared with those in HIV-infected adults.
Among persons with HIV infection, revaccination with PCV was only transiently more immunogenic than PPV, and responses were inferior to those in HIV-uninfected subjects with primary vaccination. Pneumococcal vaccines with more robust and sustained immunogenicity are needed for HIV-infected adults.
PMCID: PMC2932785  PMID: 20795819
24.  Are HIV-Positive Persons Progressing Faster After Diagnosis Over the Epidemic? 
PMCID: PMC2901894  PMID: 20611033
HIV; epidemiology; progression; CD4 counts
25.  Anal Cancers among HIV-Infected Persons: HAART Is Not Slowing Rising Incidence 
AIDS (London, England)  2010;24(4):535-543.
To evaluate the incidence rates of anal cancer over the HIV epidemic and assess the impact of HAART use on anal cancer events.
We evaluated the incidence of and factors associated with anal cancer using longitudinal data from the prospective U.S. Natural History Study (1985-2008). Poisson regression and Cox proportional hazard models were utilized.
Among 4,506 HIV-infected males with 37,806 person-years (PY) of follow-up, anal cancer rates (per 100,000 PY) increased 5-fold, from 11 in the pre-HAART to 55 in the HAART era, p=0.02. Rates continued to increase, reaching 128 in 2006-2008. Persons with HIV infection for >15 years had a 12-fold higher rate than those with <5 years (348 vs. 28, p<0.01). At cancer diagnosis (n=19), median age was 42 years, median CD4 count was 432 cells/mm3, 74% had a CD4 nadir <200 cells/mm3, 42% had a prior AIDS event, and 74% had received HAART. From separate models, prior AIDS event (HR 3.88, p=0.01) and lower CD4 nadir (HR 0.85 per 50 cell, p=0.03) were associated with anal cancer, with a trend for a history of gonorrhea (HR 2.43, p=0.07). Duration of HAART use was not associated with a reduced risk of anal cancer (HR 0.94, p=0.42).
Incidence rates of anal cancer have progressively increased during the HIV epidemic. Persons with a longer duration of HIV infection have a substantially higher rate of anal cancer. Since HIV-infected persons are experiencing longer life expectancies and HAART does not appear protective of anal cancer, studies on preventive strategies are needed.
PMCID: PMC3132114  PMID: 19926961
HIV; anal cancer; incidence rates; antiretroviral therapy; HAART; epidemiology

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