Publications by authors named "Brian Agan"

Introduction: Viral blips have been associated with larger reservoir size and slower decay. Earlier antiretroviral therapy (ART) initiation may decrease the risk of blips.

Methods: We analyzed participants from the U.

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  • PTSD negatively impacts the adherence and effectiveness of antiretroviral therapy (ART) in veterans with HIV, leading to increased nonadherence and modifications in treatment.
  • This study analyzed over 22,000 person-years of data from veterans who deployed to Iraq and Afghanistan, finding a 6% increase in nonadherence and a 38% increase in ART modifications linked to PTSD.
  • Veterans with multiple deployments saw an even greater likelihood of nonadherence; the impact of PTSD on treatment changes was most pronounced in the first decade after diagnosis, highlighting the need for regular PTSD screening in this population.
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Lethal COVID-19 outcomes are attributed to classic cytokine storm. We revisit this using RNA sequencing of nasopharyngeal and 40 autopsy samples from patients dying of SARS-CoV-2. Subsets of the 100 top-upregulated genes in nasal swabs are upregulated in the heart, lung, kidney, and liver, but not mediastinal lymph nodes.

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People with human immunodeficiency virus (HIV) are at risk for chronic kidney disease (CKD) due to HIV and antiretroviral therapy (ART) nephrotoxicity. Immediate ART initiation reduces mortality and is now the standard of care, but the long-term impact of prolonged ART exposure on CKD is unknown. To evaluate this, the Strategic Timing of Antiretroviral Treatment (START) trial randomized 4,684 ART-naïve adults with CD4 cell count > 500 cells/mm to immediate versus deferred ART.

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  • A study investigated the relationship between COVID-19 vaccination and the risk of developing venous thrombosis or embolism (VTE) after infection, particularly examining the impact of booster shots.
  • The research analyzed data from Military Health System beneficiaries who tested positive for COVID-19 between 2020 and 2022, finding that vaccinated individuals had significantly lower odds of developing VTE compared to those unvaccinated.
  • Results indicated that the risk of post-COVID-19 VTE was particularly low during the Omicron variant era, and those receiving booster shots had an even greater reduction in VTE risk.
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Unlabelled: Antigen-based rapid diagnostic tests (Ag-RDTs) provide timely results, are simple to use, and are less expensive than molecular assays. Recent studies suggest that antigen-based testing aligns with virus culture-based results (a proxy of contagiousness at the peak viral phase of illness); however, the performance of Ag-RDTs for newer SARS-CoV-2 variants is unclear. In this study, we (i) assessed the performance of Ag-RDTs and diagnostic antibodies to detect a range of SARS-CoV-2 variants and (ii) determined whether Ag-RDT results correlated with culture positivity.

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Use of HIV pre-exposure prophylaxis (PrEP) among U.S. military service members at high risk for HIV infection remains suboptimal, resulting in preventable new HIV infections and decreased medical readiness among service members.

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  • The study examined 595 SARS-CoV-2 sequences from Military Health System beneficiaries to assess how vaccination affected viral diversity from December 2020 to April 2022.
  • Results indicated that vaccination had limited influence on the diversity of the SARS-CoV-2 spike protein and showed little evidence of a significant sieve effect among major variants.
  • The findings suggest that during periods of rapid variant replacement, other factors overshadowed the influence of vaccination on viral diversity, and caution is needed when using sieve analysis methods in non-clinical trial settings.
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  • * The study found that neutralization responses from human and hamster sera before the Omicron variant were highly correlated, suggesting that hamster sera can effectively substitute for human sera in understanding variant differences.
  • * Although the XBB.1.5 booster led to broad neutralization against XBB sub-lineage variants, a significant decrease in effectiveness was noted against the newer JN.1 variant, indicating the potential need for vaccine updates to improve antibody coverage.
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Background: Post-COVID conditions (PCC) are difficult to characterize, diagnose, predict, and treat due to overlapping symptoms and poorly understood pathology. Identifying inflammatory profiles may improve clinical prognostication and trial endpoints.

Methods: 1,988 SARS-CoV-2 positive U.

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Antigenic assessments of SARS-CoV-2 variants inform decisions to update COVID-19 vaccines. Primary infection sera are often used for assessments, but such sera are rare due to population immunity from SARS-CoV-2 infections and COVID-19 vaccinations. Here, we show that neutralization titers and breadth of matched human and hamster pre-Omicron variant primary infection sera correlate well and generate similar antigenic maps.

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People with human immunodeficiency virus (HIV) are at risk for chronic kidney disease (CKD) due to HIV and antiretroviral therapy (ART) nephrotoxicity. Immediate ART initiation reduces mortality and is now the standard of care, but the long-term impact of prolonged ART exposure on CKD is unknown. To evaluate this, the Strategic Timing of Antiretroviral Treatment (START) trial randomized 4,684 ART-naïve adults with CD4 cell count under 500 cells/mm to immediate versus deferred ART.

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Background: The consequences of low-level viremia in people with HIV are unclear. We used data from the US Military HIV Natural History Study to examine the association of low-level viremia (LLV) and serious non-AIDS events (SNAEs).

Methods: Included participants initiated antiretroviral therapy after 1996 and had ≥3 viral loads (VLs) measured, using an assay with a lower limit of detection of <50 copies/mL, ≥6 months after antiretroviral therapy initiation.

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Background: Chronic neuropsychological sequelae following SARS-CoV-2 infection, including depression, anxiety, fatigue, and general cognitive difficulties, are a major public health concern. Given the potential impact of long-term neuropsychological impairment, it is important to characterize the frequency and predictors of this post-infection phenotype.

Methods: The Epidemiology, Immunology, and Clinical Characteristics of Emerging Infectious Diseases with Pandemic Potential (EPICC) study is a longitudinal study assessing the impact of SARS-CoV-2 infection in U.

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Objective: To investigate the relationship between neurocognitive deficits and structural changes on brain magnetic resonance imaging in people living with HIV (PLWH) with good virological control on combination antiretroviral therapy, compared with socioeconomically matched control participants recruited from the same communities.

Methods: Brain magnetic resonance imaging scans, and clinical and neuropsychological data were obtained from virologically controlled PLWH (viral load of <50 c/mL and at least 1 year of combination antiretroviral therapy) and socioeconomically matched control participants. Magnetic resonance imaging was carried out on 3 T scanner with 8-channel head coils and segmented using Classification using Derivative-based Features.

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Background: The long-term effects of coronavirus disease 2019 (COVID-19) on physical fitness are unclear, and the impact of vaccination on that relationship is uncertain.

Methods: We compared survey responses in a 1-year study of US military service members with (n = 1923) and without (n = 1591) a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We fit Poisson regression models to estimate the association between history of SARS-CoV-2 infection and fitness impairment, adjusting for time since infection, demographics, and baseline health.

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Subtype B HIV-1 has been the primary driver of the HIV-1 epidemic in the United States (U.S.) for over forty years and is also a prominent subtype in the Americas, Europe, Australia, the Middle East and North Africa.

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In an effort to improve military readiness, in 2014 the US Air Force reduced the frequency of mandated HIV medical evaluation visits from every 6 months to every 12 months. We employ this natural experiment using data for 2676 active-duty Military Health System beneficiaries living with HIV with a difference-in-differences empirical strategy using the Army, Navy, and Marines as a control group to estimate the causal effect of reducing the frequency of mandated evaluation visits on the quality and cost of medical care for active-duty military members living with HIV. We find that reducing the frequency of mandated HIV medical evaluation visits reduced the likelihood of regular HIV visits by 23 percentage points but did not affect the likelihood of receiving other preventive care, adhering to HIV therapy, or maintaining viral testing and suppression.

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Some people remain healthier throughout life than others but the underlying reasons are poorly understood. Here we hypothesize this advantage is attributable in part to optimal immune resilience (IR), defined as the capacity to preserve and/or rapidly restore immune functions that promote disease resistance (immunocompetence) and control inflammation in infectious diseases as well as other causes of inflammatory stress. We gauge IR levels with two distinct peripheral blood metrics that quantify the balance between (i) CD8 and CD4 T-cell levels and (ii) gene expression signatures tracking longevity-associated immunocompetence and mortality-associated inflammation.

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Background And Objectives: Neurologic outcomes in people with HIV (PWH) on long-duration antiretroviral therapy (ART) are not fully understood, and the underlying pathophysiology is unclear. To address this, we established a cohort of such individuals and compared them with HIV-negative controls using a novel matching technique. Both groups underwent extensive cognitive testing, evaluation for psychiatric measures, and MRI and CSF analyses.

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Article Synopsis
  • Researchers analyzed symptom data from 1,273 COVID-19 patients to identify clusters that correspond with varying disease severity and long-term outcomes.
  • Three distinct symptom clusters were identified: the "Nasal cluster" (runny/stuffy nose), the "Sensory cluster" (loss of smell/taste), and the "Respiratory/Systemic cluster" (respiratory and systemic symptoms).
  • The Respiratory/Systemic cluster showed higher hospitalization rates and long-term symptoms, with increased inflammatory markers, suggesting it could help predict COVID-19 prognosis and risks for long COVID.
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Importance: Understanding the factors associated with post-COVID conditions is important for prevention.

Objective: To identify characteristics associated with persistent post-COVID-19 symptoms and to describe post-COVID-19 medical encounters.

Design, Setting, And Participants: This cohort study used data from the Epidemiology, Immunology, and Clinical Characteristics of Emerging Infectious Diseases With Pandemic Potential (EPICC) study implemented in the US military health system (MHS); MHS beneficiaries aged 18 years or older who tested positive for SARS-CoV-2 from February 28, 2020, through December 31, 2021, were analyzed, with 1-year follow-up.

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The associations between clinical phenotypes of coronavirus disease 2019 (COVID-19) and the host inflammatory response during the transition from peak illness to convalescence are not yet well understood. Blood plasma samples were collected from 129 adult SARS-CoV-2 positive inpatient and outpatient participants between April 2020 and January 2021, in a multi-center prospective cohort study at 8 military hospitals across the United States. Plasma inflammatory protein biomarkers were measured in samples from 15 to 28 days post symptom onset.

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The rapid emergence of SARS-CoV-2 variants challenges vaccination strategies. Here, we collected 201 serum samples from persons with a single infection or multiple vaccine exposures, or both. We measured their neutralization titers against 15 natural variants and 7 variants with engineered spike mutations and analyzed antigenic diversity.

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