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1.  D-Dimer Levels before HIV Seroconversion Remain Elevated Even after Viral Suppression and Are Associated with an Increased Risk of Non-AIDS Events 
PLoS ONE  2016;11(4):e0152588.
The mechanism underlying the excess risk of non-AIDS diseases among HIV infected people is unclear. HIV associated inflammation/hypercoagulability likely plays a role. While antiretroviral therapy (ART) may return this process to pre-HIV levels, this has not been directly demonstrated. We analyzed data/specimens on 249 HIV+ participants from the US Military HIV Natural History Study, a prospective, multicenter observational cohort of >5600 active duty military personnel and beneficiaries living with HIV. We used stored blood specimens to measure D-dimer and Interleukin-6 (IL-6) at three time points: pre-HIV seroconversion, ≥6 months post-HIV seroconversion but prior to ART initiation, and ≥6 months post-ART with documented HIV viral suppression on two successive evaluations. We evaluated the changes in biomarker levels between time points, and the association between these biomarker changes and future non-AIDS events. During a median follow-up of 3.7 years, there were 28 incident non-AIDS diseases. At ART initiation, the median CD4 count was 361cells/mm3; median duration of documented HIV infection 392 days; median time on ART was 354 days. Adjusted mean percent increase in D-dimer levels from pre-seroconversion to post-ART was 75.1% (95% confidence interval 24.6–148.0, p = 0.002). This increase in D-dimer was associated with a significant 22% increase risk of future non-AIDS events (p = 0.03). Changes in IL-6 levels across time points were small and not associated with future non-AIDS events. In conclusion, ART initiation and HIV viral suppression does not eliminate HIV associated elevation in D-dimer levels. This residual pathology is associated with an increased risk of future non-AIDS diseases.
PMCID: PMC4835105  PMID: 27088215
2.  The Association between Sexually Transmitted Infections, Length of Service and Other Demographic Factors in the U.S. Military 
PLoS ONE  2016;11(12):e0167892.
Numerous studies have found higher rates of sexually transmitted infections (STIs) among military personnel than the general population, but the cumulative risk of acquiring STIs throughout an individual’s military career has not been described.
Using ICD-9 diagnosis codes, we analyzed the medical records of 100,005 individuals from all service branches, divided in equal cohorts (n = 6,667) between 1997 and 2011. As women receive frequent STI screening compared to men, these groups were analyzed separately. Incidence rates were calculated for pathogen-specific STIs along with syndromic diagnoses. Descriptive statistics were used to characterize the individuals within each accession year cohort; repeat infections were censored.
The total sample included 29,010 females and 70,995 males. The STI incidence rates (per 100 person-years) for women and men, respectively, were as follows: chlamydia (3.5 and 0.7), gonorrhea (1.1 and 0.4), HIV (0.04 and 0.07) and syphilis (0.14 and 0.15). During the study period, 22% of women and 3.3% of men received a pathogen-specific STI diagnosis; inclusion of syndromic diagnoses increased STI prevalence to 41% and 5.5%, respectively. In multivariate analyses, factors associated with etiologic and syndromic STIs among women included African American race, younger age and fewer years of education. In the overall sample, increasing number of years of service was associated with an increased likelihood of an STI diagnosis (p<0.001 for trend).
In this survey of military personnel, we found very high rates of STI acquisition throughout military service, especially among women, demonstrating that STI-related risk is significant and ongoing throughout military service. Lower STI incidence rates among men may represent under-diagnosis and demonstrate a need for enhancing male-directed screening and diagnostic interventions.
PMCID: PMC5148014  PMID: 27936092
3.  Factors associated with 10 years of continuous viral load suppression on HAART 
BMC Infectious Diseases  2016;16:351.
The principal goal of HAART is sustained viral load (VL) suppression resulting in immune reconstitution and improved HIV outcomes. We studied the factors associated with 10 years of continuous VL suppression on HAART in the US Military HIV Natural History Study.
Participants with continuous VL suppression (CS, n = 149) were compared to those who did not have continuous viral load suppression (NCS, n = 127) for ≥10 years on HAART. Factors associated with >10 years of VL suppression were evaluated by multivariate logistic regression. Additionally, association between CS and CD4 reconstitution was analyzed with a mixed effects model.
Compared to NCS participants, a lower proportion of CS participants started HAART in the early HAART era (66 vs 90 %, for years 1996–1999; p < 0.001) and had less antiretroviral use prior to HAART (37 vs 83 %; p < 0.001). At initial HAART, the median CD4 cell count was higher and VL was lower for CS compared to NCS participants (375 cells/uL [256, 499] vs 261 cells/uL [146, 400]; p < 0.001 and 4.4 log10 copies/mL [3.5, 4.9] vs 4.5 log10 copies/mL [3.8, 5.0]; p = 0.048, respectively). New AIDS events were lower during HAART (5 vs 13 %; p = 0.032) and post-HAART CD4 trajectories were greater for the CS compared to NCS group. Factors negatively associated with ≥10 years of VL suppression included log10 VL at first HAART (OR 0.61, 95 % CI 0.4, 0.92; p = 0.020) and antiretroviral use prior to HAART (OR 0.16, 95 % CI 0.06, 0.38; p < .001).
Sustained VL suppression is a key to long-term health in HIV-infected patients, as demonstrated by the lower proportion of AIDS events observed 10 years after HAART initiation. The current use of more potent and well-tolerated regimens may mitigate the negative factors of pre-HAART VL and prior ARV use encountered by treatment initiated in the early HAART era.
PMCID: PMC4957300  PMID: 27449671
HIV; AIDS; Viral load; Suppression; HAART; CD4 cell count
4.  Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures 
For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates.
PMCID: PMC4924062  PMID: 27322305
common odds ratio; generalized pivotal quantity; fiducial quantity; log-binomial model; logistic regression
5.  MRSA Infections in HIV-Infected People Are Associated with Decreased MRSA-Specific Th1 Immunity 
PLoS Pathogens  2016;12(4):e1005580.
People with HIV infection are at increased risk for community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft tissue infections (SSTIs). Lower CD4 T-cell counts, higher peak HIV RNA levels and epidemiological factors may be associated with increased risk but no specific immune defect has been identified. We aimed to determine the immunologic perturbations that predispose HIV-infected people to MRSA SSTIs. Participants with or without HIV infection and with MRSA SSTI, MRSA colonization or negative for MRSA were enrolled. Peripheral blood and skin biopsies from study participants were collected. Flow cytometry, flow cytometry with microscopy, multiplex assays of cell culture supernatants and immunohistochemistry were used to evaluate the nature of the immune defect predisposing HIV-infected people to MRSA infections. We found deficient MRSA-specific IFNγ+ CD4 T-cell responses in HIV-infected people with MRSA SSTIs compared to MRSA-colonized participants and HIV-uninfected participants with MRSA SSTIs. These IFNγ+ CD4 T cells were less polyfunctional in HIV-infected participants with SSTIs compared to those without SSTIs. However, IFNγ responses to cytomegalovirus and Mycobacterium avium antigens and MRSA-specific IL-17 responses by CD4 T cells were intact. Upon stimulation with MRSA, peripheral blood mononuclear cells from HIV-infected participants produced less IL-12 and IL-15, key drivers of IFNγ production. There were no defects in CD8 T-cell responses, monocyte responses, opsonization, or phagocytosis of Staphylococcus aureus. Accumulation of CD3 T cells, CD4 T cells, IL-17+ cells, myeloperoxidase+ neutrophils and macrophage/myeloid cells to the skin lesions were similar between HIV-infected and HIV-uninfected participants based on immunohistochemistry. Together, these results indicate that MRSA-specific IFNγ+ CD4 T-cell responses are essential for the control of initial and recurrent MRSA infections in HIV-infected people.
Author Summary
Methicillin-resistant Staphylococcus aureus (MRSA) causes infections of the skin and associated tissue. HIV-infected people are at increased risks of these infections for unclear reasons. We recruited participants with or without HIV infection who had a MRSA skin or soft tissue infection, MRSA colonization, or neither, and obtained blood and skin biopsy samples. We found that HIV-infected people with MRSA infections mounted insufficient responses upon stimulation with MRSA. These participants had decreased proportions of cells producing the cytokine IFNγ and decreased function of IFNγ-producing cells in response to in vitro stimulation with MRSA, but their responses to other agents such as cytomegalovirus were intact. The decrease in IFNγ-producing cells may be due to decreased production of upstream drivers of IFNγ production, such as IL-12 and IL-15. Nonetheless, responses in the skin were not affected. As IFNγ facilitates T-cell proliferation and response to antigens, and macrophage and neutrophil responses, this antigen-specific defect may have widespread effects. Together, our data suggest that MRSA-specific IFNγ responses may be essential for effective prevention against future infections, including vaccine development.
PMCID: PMC4836670  PMID: 27093273
6.  Factors associated with HIV viral load “blips” and the relationship between self-reported adherence and efavirenz blood levels on blip occurrence: a case–control study 
The uncertain etiology of HIV viral load (VL) blips may lead to increased use of clinical resources. We evaluated the association of self-reported adherence (SRA) and antiretroviral (ART) drug levels on blip occurrence in US Military HIV Natural History Study (NHS) participants who initiated the single-tablet regimen efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF).
ART-naïve NHS participants started on EFV/FTC/TDF between 2006 and 2013 who achieved VL suppression (<50 copies/mL) within 12 months and had available SRA and stored plasma samples were included. Participants with viral blips were compared with those who maintained VL suppression without blips. Untimed EFV plasma levels were evaluated on consecutive blip and non-blip dates by high performance liquid chromatography, with a level ≥1 mcg/mL considered therapeutic. SRA was categorized as ≥85 or <85 %. Descriptive statistics were performed for baseline characteristics and univariate and multivariate Cox proportional hazard models were used to assess the relationship between covariates and blip occurrence.
A total of 772 individuals met inclusion criteria, including 99 (13 %) blip and 673 (87 %) control participants. African-American was the predominant ethnicity and the mean age was 29 years for both groups. SRA ≥ 85 % was associated with therapeutic EFV levels at both blip and non-blip time points (P = 0.0026); however no association was observed between blips and SRA or EFV levels among cases. On univariate analysis of cases versus controls, blips were associated with higher mean pre-treatment VL (HR 1.45, 95 % CI 1.11–1.89) and pre-treatment CD4 count <350 cells/µL (68.1 vs 49.7 %). Multivariate analysis also showed that blips were associated with a higher mean VL (HR 1.42, 95 % CI 1.08–1.88; P = 0.0123) and lower CD4 count at ART initiation, with CD4 ≥500 cells/µL having a protective effect (HR 0.45, 95 % CI 0.22–0.95; P = 0.0365). No association was observed for demographic characteristics or SRA.
Blips are commonly encountered in the clinical management of HIV-infected patients. Although blip occurrence was not associated with SRA or EFV blood levels in our study, blips were associated with HIV-related factors of pre-ART high VL and low CD4 count. Additional studies are needed to determine the etiology of blips in HIV-infected patients.
PMCID: PMC4802903  PMID: 27006682
Self-reported adherence; Human immunodeficiency virus; Blips
7.  Hospitalizations among HIV controllers and persons with medically controlled HIV in the U.S. Military HIV Natural History Study 
HIV controllers (HICs) experience relatively low-level viraemia and CD4 preservation without antiretroviral therapy (ART), but also immune activation that may predispose to adverse clinical events such as cardiovascular disease and hospitalization. The objective of this study was to characterize the rates and reasons for hospitalization among HICs and persons with medically controlled HIV.
Subjects with consistently well-controlled HIV were identified in the U.S. Military HIV Natural History Study. ART prescription and HIV-1 RNA data were used to categorize subjects as HICs or medically controlled as defined by ≥3 HIV-1 RNA measurements ≤2000 or ≤400 copies/mL, respectively, representing the majority of measurements spanning ≥12 months. Hospitalizations were tallied and assigned diagnostic categories. All-cause hospitalization rates were compared between groups using negative binomial regression.
Results and discussion
Of 3106 subjects followed from 2000 to 2013, 221 were HICs, including 33 elite (1.1%) and 188 viraemic (6.0%) controllers, who contributed 882 person-years (PY) of observation time. An additional 870 subjects with medically controlled HIV contributed 4217 PY. Mean hospitalization rates were 9.4/100 PY among HICs and 8.8/100 PY among medically controlled subjects. Non-AIDS-defining infections were the most common reason for hospitalization (2.95/100 PY and 2.70/100 PY, respectively) and rates of cardiovascular hospitalization were similar in both groups (0.45/100 PY and 0.76/100 PY). There was no difference in hospitalization rate for HICs compared with subjects with medically controlled HIV (adjusted incidence rate ratio 1.15 [95% confidence interval 0.80 to 1.65]).
All-cause and cardiovascular hospitalization rates did not differ between HICs and persons with medically controlled HIV. Non-AIDS defining infections were common in this young, healthy, predominantly male cohort of military personnel and beneficiaries.
PMCID: PMC4783305  PMID: 26955965
HIV; HIV non-progressors; patient admission; hospitalization; highly active antiretroviral therapy
8.  Influence of the Timing of Antiretroviral Therapy on the Potential for Normalization of Immune Status in Human Immunodeficiency Virus 1–Infected Individuals 
JAMA internal medicine  2015;175(1):88-99.
In individuals with human immunodeficiency virus 1 (HIV-1) infection who are receiving antiretroviral therapy (ART), factors that promote full immune recovery are not well characterized.
To investigate the influence of the timing of ART relative to HIV-1 infection on normalization of CD4+ T-cell counts, AIDS risk, and immune function.
Participants in the observational US Military HIV Natural History Study with documented estimated dates of seroconversion (EDS) who achieved virologic suppression with ART were evaluated. Markers indicative of immune activation, dysfunction, and responsiveness were determined. Responses to hepatitis B virus (HBV) vaccine, an indicator of in vivo immune function, were also assessed. The timing of ART was indexed to the EDS and/or entry into the cohort. The CD4+ counts in HIV-1–uninfected populations were surveyed.
Normalization of CD4+ counts to 900 cells/μL or higher, AIDS development, HBV vaccine response, as well as T-cell activation, dysfunction, and responsiveness.
The median CD4+ count in HIV-1–uninfected populations was approximately 900 cells/μL. Among 1119 HIV-1–infected participants, CD4+ normalization was achieved in 38.4% vs 28.3% of those initiating ART within 12 months vs after 12 months from the EDS (P = .001). Incrementally higher CD4+ recovery (<500,500–899, and ≥900 cells/μL) was associated with stepwise decreases in AIDS risk and reversion of markers of immune activation, dysfunction, and responsiveness to levels approximating those found in HIV-1–uninfected persons. Participants with CD4+ counts of 500 cells/μL or higher at study entry (adjusted odds ratio [aOR], 2.00; 95% CI, 1.51–2.64; P < .001) or ART initiation (aOR, 4.08; 95% CI, 3.14–5.30; P < .001) had significantly increased CD4+ normalization rates compared with other participants. However, even among individuals with a CD4+ count of 500 cells/μL or higher at both study entry and before ART, the odds of CD4+ normalization were 80% lower in those initiating ART after 12 months from the EDS and study entry (aOR, 0.20; 95% CI, 0.07–0.53; P = 001). Initiation of ART within 12 months of EDS vs later was associated with a significantly lower risk of AIDS (7.8% vs 15.3%; P = .002), reduced T-cell activation (percent CD4+HLA-DR+ effector memory T cells, 12.0% vs 15.6%; P = .03), and increased responsiveness to HBV vaccine (67.9% vs 50.9%; P = .07).
Deferral of ART beyond 12 months of the EDS diminishes the likelihood of restoring immunologic health in HIV-1–infected individuals.
PMCID: PMC4286496  PMID: 25419650
9.  Impact of the highly active antiretroviral therapy era on the epidemiology of primary HIV-associated thrombocytopenia 
BMC Research Notes  2015;8:595.
Primary HIV-associated thrombocytopenia (PHAT) typically improves with highly active antiretroviral therapy (HAART); however, cases continue to occur. Data comparing the epidemiology of PHAT between the pre-HAART and HAART eras are limited. We retrospectively examined the incidence of PHAT over 28 years in the US Military HIV Natural History Study (NHS) from 1986 to 2013.
Subjects had a nadir platelet count <100 × 109/l with no other identifiable cause. Time periods were categorized as pre-HAART (1986–1995), early HAART (1996–2001), and later HAART (2002–2013). Incidence, demographic data, and CD4 count were compared across the three eras. A generalized estimating equations model was used to assess any association of platelet count and HIV viral load in cases diagnosed during the HAART eras. 218 participants met the case definition. 86.2 % of cases occurred prior to 2002. The incidence of PHAT per 1000 person-years of follow-up was 16.3, 4.6, and 1.9 during pre-HAART, early HAART and later HAART eras respectively. CD4 cell counts were significantly higher in the HAART eras at the time of thrombocytopenia (p < 0.001). Of patients diagnosed after 1996, 96.4 % were viremic within six months preceding the platelet nadir and over half were antiretroviral naïve. Viral load (per log10 copies/ml) inversely correlated with platelet count throughout the HAART eras (p < 0.0001).
The incidence of PHAT has markedly decreased in the HAART era. However, viremic individuals, including those with healthy CD4 cell counts, may be at risk. Achieving viral suppression as early as possible may decrease the incidence further.
PMCID: PMC4619221  PMID: 26498280
HIV; Primary; Thrombocytopenia; Antiretroviral; HAART; Incidence; Viremia; CD4
10.  Human Papillomavirus Seroprevalence Among Men Entering Military Service and Seroincidence After Ten Years of Service 
MSMR  2013;20(2):21-24.
Vaccination against human papillomavirus (HPV) is recommended to prevent cervical cancer among women, but the benefits of HPV vaccination for males are less obvious. This study characterized HPV acquisition among male military members by evaluating both seroprevalence at entry into service and seroincidence of HPV infection after ten years of service. At entry, 29 of 200 (14.6%) male service members were positive for HPV serotypes 6, 11, 16, or 18. Of 199 initially seronegative for at least one of the four HPV serotypes, 68 (34.2%) seroconverted to one or more serotypes at ten years; more than one-third of these were seropostive for oncogenic HPV serotypes. This estimate of HPV seroprevalence among male military accessions is higher than that reported among U.S. civilian males. Vaccination to prevent genital warts and cancers resulting from HPV infection may decrease health care system burdens. Further analyses are warranted to understand the potential costs and benefits of a policy to vaccinate male service members.
PMCID: PMC4519827  PMID: 23461307
11.  HIV Infection, Antiretroviral Therapy Initiation and Longitudinal Changes in Biomarkers of Organ Function§ 
Current HIV research  2014;12(1):50-59.
HIV is associated with end-organ diseases of aging via unclear mechanisms. Longitudinally assessing how HIV infection and ART initiation affect biomarkers of end organ function/disease could clarify these mechanisms. We investigated longitudinal changes in clinical biomarkers following 1) HIV infection and 2) ART initiation with evidence of viral suppression.
Cohort: Veterans Aging Cohort Study Virtual Cohort (VACS VC). VACS VC is a longitudinal cohort of HIV infected (HIV+) and race-ethnicity, sex, age, and clinical site-matched uninfected Veterans enrolled in the same calendar year. Inclusion criteria: a negative and successively positive (>six months) HIV antibody test. We used Wilcoxon signed-rank tests to analyze 1) the effect of HIV infection on lipids, renal, hepatic and hematologic/cardiovascular biomarkers and 2)whether ART initiation with HIV-1 RNA<500 cpm reverts any changes back to pre-HIV levels
422 Veterans had at least 1 biomarker measurement available prior to HIV infection and prior to ART initiation. 297 had at least 1 biomarker measurement available prior to HIV infection and after ART initiation with evidence of viral suppression. Mean age prior to HIV infection was 43 years. HIV infection was associated with reduction in total cholesterol, HDL cholesterol, LDL cholesterol, serum albumin, ALT, platelet count, hemoglobin and elevation of FIB-4 score and triglycerides. These changes occurred without significant changes in BMI. ART initiation (with HIV-1 RNA<500cpm) did not reverse alteration in triglycerides, LDL cholesterol, hemoglobin, or FIB-4 to pre-HIV infection levels.
HIV infection is associated with longitudinal changes in serum levels of several biomarkers of end-organ function/disease and mortality. Multiple biomarkers (triglycerides, LDL cholesterol, hemoglobin, and FIB-4) remain altered from levels prior to HIV infection levels even following inititiation of ART and evidence of viral suppression. These results give insights into underlying mechanisms of increased risk for aging-related chronic diseases in the context of HIV infection.
PMCID: PMC4495647  PMID: 25034208
Clinical biomarkers; chronic diseases of aging; HIV infection; lipids
12.  HIV outcomes in Hepatitis B virus coinfected individuals on HAART 
Understanding the impact of hepatitis B virus (HBV) coinfection on HIV outcomes in the HAART era continues to be a critical priority given the high prevalence of coinfection and the potential for impaired immunologic, virologic and clinical recovery.
Participants from the U.S. Military HIV Natural History Study with an HIV diagnosis, on HAART and serologically confirmed HBV infection status at HAART initiation (HI) were classified into four HBV infection (HB) groups. HIV virologic, immunologic, and clinical outcomes were evaluated by HB status.
Of 2536 HIV positive HAART recipients, with HBV testing results available to determine HB status in the HI window, HB status at HI was classified as HB negative (n=1505; 66%), resolved HB (n=518; 23%); isolated HBcAb (n=139; 6%) or; chronic HB (n=131; 6%). HIV virologic suppression and failure at 6 months or 1 year were not significantly different by HB status. A significantly faster rate of increase in CD4 cell count during the period between 4 and 12 years was observed for chronic HB relative to HB negative.
Chronic and resolved HB were associated with an increased risk of AIDS/death compared to HB negative individuals (chronic HB; HR=1.68; 95% CI 1.05–2.68, resolved HB; HR=1.61; 95% CI 1.15–2.25).
HB status did not have a significant impact on HIV virologic outcomes, however, CD4 cell count reconstitution post HI and the risk of an AIDS event or death post HI may be associated with HB status.
PMCID: PMC4034265  PMID: 24694929
Hepatitis B virus; chronic hepatitis B; human immunodeficiency virus; highly active antiretroviral therapy
13.  Association between hepatitis B vaccine antibody response and CD4 reconstitution after initiation of combination antiretroviral therapy in HIV-infected persons 
BMC Infectious Diseases  2015;15:203.
Hepatitis B virus (HBV) vaccine antibody response has been associated with reduced risk of AIDS or death. However, it is unknown whether HBV vaccine responsiveness is associated with improved immune reconstitution during treatment with combination antiretroviral therapy (cART). We evaluated the relationship between HBV vaccine response status and CD4 reconstitution on cART in the U.S Military HIV Natural History Study.
Participants with viral load <400 copies/mL within 1 year on initial cART and documented HBV vaccination and surface antibody (anti-HBs) prior to cART were included. Participants were characterized as HBV vaccine responders (anti-HBs ≥10 IU/L) or non-responders (<10 IU/L) and further divided into 2 groups based on vaccine administration before or after HIV diagnosis. Linear mixed regression was used to model CD4 reconstitution during the first year of cART.
Of the 307 and 169 participants vaccinated before or after HIV diagnosis, HBV vaccine response occurred in 288 (94%) and 74 (44%), respectively. For those vaccinated before HIV diagnosis, CD4 counts increased by a median 190 [IQR 99–310] cells/mm3 for responders and 186 [IQR 116–366] cells/mm3 for non-responders during the first year (P = 0.684). Participants vaccinated after HIV diagnosis had median increases of 185 [IQR 76–270] and 143 [IQR 47–238] cells/mm3 for responders and non-responders, respectively (P = 0.134). In contrast to those with CD4 > 350 cells/mm3 at cART initiation, participants with CD4 < 200 and 200–350 cells/mm3 had significantly reduced CD4 gains in both groups by longitudinal mixed models, but there was no difference in CD4 recovery according to HBV vaccine seroresponse.
Although HBV vaccine responsiveness is associated with a reduction in HIV disease progression, HBV vaccine responders do not achieve greater CD4 gains during the first year of cART. Additional clinical markers are needed to predict the magnitude of post-cART immune recovery.
PMCID: PMC4422266  PMID: 25928043
HIV; AIDS; Hepatitis B vaccine; Antiretroviral therapy; CD4 cell count
14.  Specific Behaviors Predict Staphylococcus aureus Colonization and Skin and Soft Tissue Infections Among Human Immunodeficiency Virus-Infected Persons 
Open Forum Infectious Diseases  2015;2(2):ofv034.
Background. Few data exist on the incidence and risk factors of Staphylococcus aureus colonization and skin and soft tissue infections (SSTIs) among patients infected with human immunodeficiency virus (HIV).
Methods. Over a 2-year period, we prospectively evaluated adults infected with HIV for incident S aureus colonization at 5 body sites and SSTIs. Cox proportional hazard models using time-updated covariates were performed.
Results. Three hundred twenty-two participants had a median age of 42 years (interquartile range, 32–49), an HIV duration of 9.4 years (2.7–17.4), and 58% were on highly active antiretroviral therapy (HAART). Overall, 102 patients (32%) became colonized with S aureus with an incidence rate of 20.6 (95% confidence interval [CI], 16.8–25.0) per 100 person-years [PYs]. Predictors of colonization in the final multivariable model included illicit drug use (hazard ratios [HR], 4.26; 95% CI, 1.33–13.69) and public gym use (HR 1.66, 95% CI, 1.04–2.66), whereas antibacterial soap use was protective (HR, 0.50; 95% CI, 0.32–0.78). In a separate model, perigenital colonization was associated with recent syphilis infection (HR, 4.63; 95% CI, 1.01–21.42). Fifteen percent of participants developed an SSTI (incidence rate of 9.4 cases [95% CI, 6.8–12.7] per 100 PYs). Risk factors for an SSTI included incident S aureus colonization (HR 2.52; 95% CI, 1.35–4.69), public shower use (HR, 2.59; 95% CI, 1.48–4.56), and hospitalization (HR 3.54; 95% CI, 1.67–7.53). The perigenital location for S aureus colonization was predictive of SSTIs. Human immunodeficiency virus-related factors (CD4 count, HIV RNA level, and HAART) were not associated with colonization or SSTIs.
Conclusions. Specific behaviors, but not HIV-related factors, are predictors of colonization and SSTIs. Behavioral modifications may be the most important strategies in preventing S aureus colonization and SSTIs among persons infected with HIV.
PMCID: PMC4567094  PMID: 26380335
behaviors; colonization; HIV; human immunodeficiency virus; MRSA; risk factors; skin and soft tissue infections; Staphylococcus aureus
15.  Reply to Tsai et al 
PMCID: PMC3762385  PMID: 23840048
16.  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
17.  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
18.  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
19.  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
20.  Low prevalence of neurocognitive impairment in early diagnosed and managed HIV-infected persons 
Neurology  2013;80(4):371-379.
To describe the prevalence of neurocognitive impairment (NCI) among early diagnosed and managed HIV-infected persons (HIV+) compared to HIV-negative controls.
We performed a cross-sectional study among 200 HIV+ and 50 matched HIV-uninfected (HIV−) military beneficiaries. HIV+ patients were categorized as earlier (<6 years of HIV, no AIDS-defining conditions, and CD4 nadir >200 cells/mm3) or later stage patients (n = 100 in each group); both groups were diagnosed early and had access to care. NCI was diagnosed using a comprehensive battery of standardized neuropsychological tests.
HIV+ patients had a median age of 36 years, 91% were seroconverters (median window of 1.2 years), had a median duration of HIV of 5 years, had a CD4 nadir of 319, had current CD4 of 546 cells/mm3, and 64% were on highly active antiretroviral therapy (initiated 1.3 years after diagnosis at a median CD4 of 333 cells/mm3). NCI was diagnosed among 38 (19%, 95% confidence interval 14%–25%) HIV+ patients, with a similar prevalence of NCI among earlier and later stage patients (18% vs 20%, p = 0.72). The prevalence of NCI among HIV+ patients was similar to HIV− patients.
HIV+ patients diagnosed and managed early during the course of HIV infection had a low prevalence of NCI, comparable to matched HIV-uninfected persons. Early recognition and management of HIV infection may be important in limiting neurocognitive impairment.
PMCID: PMC3589242  PMID: 23303852
21.  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
22.  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
23.  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
24.  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
25.  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

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