Somporn Tipsuk

HIV DNA Set Point is Rapidly Established in Acute HIV Infection and Dramatically Reduced by Early ART

HIV DNA is a marker of HIV persistence that predicts HIV progression and remission, but its kinetics in early acute HIV infection (AHI) is poorly understood. We longitudinally measured the frequency of peripheral blood mononuclear cells harboring total and integrated HIV DNA in 19 untreated and 71 treated AHI participants, for whom 50 were in the earliest Fiebig I/II (HIV IgM −) stage, that is ≤ 2 weeks from infection. Without antiretroviral therapy (ART), HIV DNA peaked at 2 weeks after enrollment, reaching a set-point 2 weeks later with little change thereafter. There was a marked divergence of HIV DNA values between the untreated and treated groups that occurred within the first 2 weeks of ART and increased with time. ART reduced total HIV DNA levels by 20-fold after 2 weeks and 316-fold after 3 years. Therefore, very early ART offers the opportunity to significantly reduce the frequency of cells harboring HIV DNA.

HIV DNA Reservoir Increases Risk for Cognitive Disorders in cART-Naïve Patients

Objectives Cognitive impairment remains frequent in HIV, despite combination antiretroviral therapy (cART). Leading theories implicate peripheral monocyte HIV DNA reservoirs as a mechanism for spread of the virus to the brain. These reservoirs remain present despite cART. The objective of this study was to determine if the level of HIV DNA in CD14+ enriched monocytes predicted cognitive impairment and brain injury. Methods We enrolled 61 cART-naïve HIV-infected Thais in a prospective study and measured HIV DNA in CD14+ enriched monocyte samples in a blinded fashion. We determined HAND diagnoses by consensus panel and all participants underwent magnetic resonance spectroscopy (MRS) to measure markers of brain injury. Immune activation was measured via cytokines in cerebrospinal fluid (CSF). Results The mean (SD) age was 35 (6.9) years, CD4 T-lymphocyte count was 236 (139) and log10 plasma HIV RNA was 4.8 (0.73). Twenty-eight of 61 met HAND criteria. The log10 CD14+ HIV DNA was associated with HAND in unadjusted and adjusted models (p = 0.001). There was a 14.5 increased odds ratio for HAND per 1 log-value of HIV DNA (10-fold increase in copy number). Plasma CD14+ HIV DNA was associated with plasma and CSF neopterin (p = 0.023) and with MRS markers of neuronal injury (lower N-acetyl aspartate) and glial dysfunction (higher myoinositol) in multiple brain regions. Interpretation Reservoir burden of HIV DNA in monocyte-enriched (CD14+) peripheral blood cells increases risk for HAND in treatment-naïve HIV+ subjects and is directly associated with CSF immune activation and both brain injury and glial dysfunction by MRS.

Neuropsychological Impairment in Acute HIV and the Effect of Immediate Antiretroviral Therapy.

Objective:To investigate neuropsychological performance (NP) during acute HIV infection (AHI) before and after combination antiretroviral therapy (cART). Design:Prospective study of Thai AHI participants examined at 3 and 6 months after initiation of cART. Methods:Thirty-six AHI participants were evaluated pre-cART at median 19 days since HIV exposure and 3 and 6 months after cART with the Grooved Pegboard test, Color Trails 1 & 2 (CT1, CT2), and Trail Making Test A. Raw scores were standardized to 251 age- and education-matched HIV-uninfected Thais. To account for learning effects, change in NP performance was compared with that of controls at 6 months. Analyses included multivariable regression, nonparametric repeated measures analysis of variance, and Mann–Whitney U test. Results:Baseline NP scores for the AHI group were within normal range (z-scores range: −0.26 to −0.13). NP performance improved on CT1, CT2, and Trail Making Test A in the initial 3 months (P < 0.01) with no significant change during the last 3 months. Only improvement in CT1 was greater than that seen in controls at 6 months (P = 0.018). Participants who performed >1 SD below normative means on ≥2 tests (n = 8) exhibited higher baseline cerebrospinal fluid HIV RNA (P = 0.047) and had no improvement after cART. Conclusions:Most AHI individuals had normal NP performance, and early cART slightly improved their psychomotor function. However, approximately 25% had impaired NP performance, which correlated with higher cerebrospinal fluid HIV RNA, and these abnormalities were not reversed by early cART possibly indicating limited reversibility of cognitive impairment in a subset of AHI individuals.

Neuronal-Glia Markers by Magnetic Resonance Spectroscopy in HIV Before and After Combination Antiretroviral Therapy.

Objective:Combination antiretroviral therapy (cART) can suppress plasma HIV RNA to undetectable levels; yet reports indicate persistent HIV-associated neurocognitive disorders (HAND) among treated individuals. We sought to investigate imaging correlates of incomplete cognitive recovery among individuals with chronic HIV. Methods:We used single voxel proton magnetic resonance spectroscopy in 4 regions of the brain to measure changes in neuronal and glia biomarkers in cART-naive subjects before (n = 59, 27 with HAND) and after 12 months of cART. Results:At baseline, we observed elevated total choline (CHO) in the basal ganglia (BG, P = 0.002) and in the posterior cingulate gyrus (PCG, P = 0.022) associated with HIV infection. Myo-inositol (MI) was elevated in the frontal white matter (FWM, P = 0.040). N-acetylaspartate was elevated in the BG (P = 0.047). Using a mixed model approach among all HIV-infected individuals, at 6 months, we observed decreased n- acetylaspartate in FWM (P = 0.031), decreased creatine in PCG (P = 0.026) and increased MI in frontal gray matter (FGM, P = 0.023). At 12 months, we observed an increase in BG MI (P = 0.038) and in FGM (P = 0.021). Compared to those with normal cognition, HAND cases had higher FGM MI (P = 0.014) at baseline. At 12 months, individuals that remained cognitively impaired compared with those without HAND exhibited elevated CHO in the PCG (P = 0.018) and decreased glutamate in both FWM (P = 0.027) and BG (P = 0.013). Conclusions:cART started during chronic HIV is associated with reduced neuronal-glia and inflammatory markers. Alterations in CHO are noted among individuals who remain impaired after 12 months of cART.

Sex differences in soluble markers vary before and after the initiation of antiretroviral therapy in chronically HIV-infected individuals

Objective: To evaluate differences in soluble inflammatory markers between chronically HIV-infected men and women, with or without cognitive impairment, and in response to treatment. Design: Soluble biomarkers were measured in cryopreserved plasma and cerebrospinal fluid (CSF) of 60 treatment-naïve individuals (25 men and 35 women) with chronic HIV infection and 18 HIV-uninfected controls (9 men and 9 women) from Thailand. Following enrollment, participants began combination antiretroviral therapy and were evaluated for expression of these markers after 48 weeks. Methods: Plasma and CSF levels of 19 soluble biomarkers (IFN-&ggr;, TNF&agr;, TNF-RII, IL-1&agr;, IL-1&bgr;, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-15, MCP-1, t-Tau, IP-10, neopterin, IFN&agr;, I-FABP, and sCD14) were measured using either a multiparameter or standard ELISA assay. Results: Prior to combination antiretroviral therapy, women with impaired cognition had elevated levels of neopterin and TNF-RII compared with women with normal cognition in both the plasma and CSF; however, levels did not differ between cognitively impaired or normal men. In a secondary outcome-hypothesis generating analysis, sex differences were also pronounced in plasma levels of MCP-1, IL-10, I-FABP, and sCD14 in response to treatment. Neopterin, IP-10, TNF&agr;, TNF-RII, IFN&agr;, MCP-1, IL-8, I-FABP, and sCD14 plasma levels remained elevated following 48 weeks of therapy in both sexes compared with uninfected controls. Conclusion: We provide evidence of sustained immune activation after 48 weeks of treatment and identify possible sex differences in biomarkers previously linked to cognitive impairment, chronic inflammation, and gut integrity that may contribute to immunological differences between sexes in relationship to disease progression and response to therapy.

High Number of Activated CD8+ T Cells Targeting HIV Antigens Are Present in Cerebrospinal Fluid in Acute HIV Infection

Background: Central nervous system (CNS) infiltration by CD8+ T cells is associated with neuroinflammation in many neurodegenerative diseases, including HIV-associated dementia. However, the role of CD8+ T cells in the CNS during acute HIV infection (AHI) is unknown. Methods: We analyzed the phenotype, gene expression, T cell receptor (TCR) repertoire, and HIV specificity of CD8+ T cells in cerebrospinal fluid (CSF) of a unique cohort captured during the earliest stages of AHI (n = 26), chronic (n = 23), and uninfected (n = 8). Results: CSF CD8+ T cells were elevated in AHI compared with uninfected controls. The frequency of activated CSF CD8+ T cells positively correlated to CSF HIV RNA and to markers of CNS inflammation. In contrast, activated CSF CD8+ T cells during chronic HIV infection were associated with markers of neurological injury and microglial activation. CSF CD8+ T cells in AHI exhibited increased functional gene expression profiles associated with CD8+ T cells effector function, proliferation, and TCR signaling, a unique restricted TCR Vbeta repertoire and contained HIV-specific CD8+ T cells directed to unique HIV epitopes compared with the periphery. Conclusions: These results suggest that CSF CD8+ T cells in AHI expanding in the CNS are functional and directed against HIV antigens. These cells could thus play a beneficial role protective of injury seen in chronic HIV infection if combination antiretroviral therapy is initiated early.

Association between brain volumes and HAND in cART naïve HIV+ individuals from Thailand

This study aimed to determine the effects of human immunodeficiency virus (HIV) on brain structure in HIV-infected individuals with and without HIV-associated neurocognitive disorders (HAND). Twenty-nine HIV-uninfected controls, 37 HIV+, treatment-naïve, individuals with HAND (HIV+HAND+; 16 asymptomatic neurocognitive impairment (ANI), 12 mild neurocognitive disorder (MND), and 9 HIV-associated dementia HAD), and 37 HIV+, treatment-naïve, individuals with normal cognitive function (HIV+HAND−) underwent magnetic resonance imaging (MRI) and neuropsychological assessment. The HIV-infected participants had a mean (SD) age of 35 (7) years, mean (interquartile range (IQR)) CD4 count of 221 (83–324), and mean (IQR) log10 plasma viral load of 4.81 (4.39–5.48). Six regions of interest were selected for analyses including total and subcortical gray matter, total white matter, caudate, corpus callosum, and thalamus. The HIV+/HAND+ group exhibited significantly smaller brain volumes compared to the HIV-uninfected group in subcortical gray and total gray matter; however, there were no statistically significant differences in brain volumes between the HIV+HAND+ and HIV+HAND− groups or between HIV+/HAND− and controls. CD4 count at time of combination antiretroviral therapy (cART) initiation was associated with total and subcortical gray matter volumes but not with cognitive measures. Plasma viral load correlated with neuropsychological performance but not brain volumes. The lack of significant differences in brain volumes between HIV+HAND+ and HIV+HAND− suggests that brain atrophy is not a sensitive measure of HAND in subjects without advanced immunosuppression. Alternatively, current HAND diagnostic criteria may not sufficiently distinguish patients based on MRI measures of brain volumes.

HIV DNA in CD14+ reservoirs is associated with regional brain atrophy in patients naive to combination antiretroviral therapy.

Objective:To examine associations between regional brain volumes and HIV DNA in peripheral CD14+ cells (monocytes) among HIV-infected individuals naive to combination antiretroviral therapy (cART). Design:A prospective study of HIV-infected Thai individuals who met Thai national criteria for cART initiation. Enrolment was stratified by HIV DNA in a blinded fashion. Methods:CD14+ cells were isolated from peripheral mononuclear cells to high purity (median 91.4% monocytes by flow cytometry), and HIV DNA was quantified by multiplex real-time PCR. Baseline regional brain volumes obtained by T1-weighted 1.5-Tesla MRI were compared between HIV DNA groups using analysis of covariance (ANCOVA). Results:We studied 60 individuals with mean (SD) age of 34.7 (7.0) years, CD4+ T-lymphocyte count of 232 (137) cells/&mgr;l and log10 plasma HIV RNA of 4.8 (0.73). Median (interquartile range, IQR) HIV DNA copy number per 106 CD14+ cells was 54 (102). Using our previously determined optimal cut-point of 45 copies/106 cells for this cohort, a threshold value above which CD14+ HIV DNA identified HIV-associated neurocognitive disorders (HANDs), we found that CD14+ HIV DNA ≥ 45 copies/106 cells was associated with reduced volumes of the nucleus accumbens (P = 0.021), brainstem (P = 0.033) and total gray matter (P = 0.045) independently of age, CD4+ cell count and intracranial volume. Conclusion:HIV DNA burden in CD14+ monocytes is directly linked to brain volumetric loss. Our findings implicate peripheral viral reservoirs in HIV-associated brain atrophy and support their involvement in the neuropathogenesis of HAND, underscoring the need for therapies that target these cells.

Brief Report: CD14+ Enriched Peripheral Cells Secrete Cytokines Unique to HIV-Associated Neurocognitive Disorders

Abstract: Monocytes play a vital role in HIV-associated neurocognitive disorder (HAND), postulated to transport HIV into the brain and secrete pro-inflammatory cytokines. We analyzed cytokines released by cultured peripheral blood mononuclear cells enriched with the CD14+ marker isolated from HIV-infected individuals with HAND and normal cognition (NC) in combination antiretroviral therapy naive and after 1 year on treatment. Interleukin-8 and monocyte chemoattractant protein-1 levels were higher in HAND compared with NC at baseline (P = 0.002 and P < 0.0001). These cytokines remained higher in HAND patients 1 year after combination antiretroviral therapy and were significant when NC patients who were initially HAND were excluded (P = 0.012 and P = 0.002). Both correlated with baseline CD14+ peripheral blood mononuclear cell HIV DNA levels supporting the role of HIV DNA reservoir size and monocyte cytokines in HAND persistence.

Virologic failure is uncommon after treatment initiation during acute HIV infection.

Objective:In chronic HIV infection, initiation of antiretroviral therapy (ART) typically induces swift HIV RNA declines and virologic suppression within 24 weeks. The objective of this study was to investigate viral dynamics and common criteria for treatment success after ART initiation during acute HIV infection (AHI). Methods:Participants were prospectively enrolled and offered ART during AHI from May 2009–June 2015 in Bangkok, Thailand. Regimens included tenofovir, lamivudine or emtricitabine, and efavirenz with or without raltegravir and maraviroc. Participants were monitored for several HIV RNA end points: one-log reduction at week 2; two-log reduction at week 4; less than 1000 copies/ml at week 24; and less than 200 copies/ml at week 24. Factors associated with each end point, time to suppression, and virologic blips were explored. Results:Two hundred and sixty-four Thai participants initiated ART during AHI. Their median age was 27 years and 96% were men. At 2 weeks, 6.5% had not achieved a one-log reduction in HIV RNA. At 4 weeks, 11.0% had not achieved a two-log reduction. At 24 weeks, 1.1% had not achieved HIV RNA less than 1000 copies/ml and 1.5% had not achieved HIV RNA less than 200 copies/ml. Participants who initiated ART during Fiebig I demonstrated a shorter median time to virologic suppression than did all other stages combined, [4 (interquartile range 2–8) vs. 8 (interquartile range 4–12) weeks, P < 0.001] and 7.3% had subsequent blips (16.1% in other stages, P = 0.23). Conclusion:Virologic failure is uncommon in individuals who initiate ART during AHI. ART initiation during AHI is efficacious and clinicians can monitor for virologic failure after 24 weeks of therapy.