Central Nervous System Safety During Brief Analytic Treatment Interruption of Antiretroviral Therapy Within 4 Human Immunodeficiency Virus Remission Trials: An Observational Study in Acutely Treated People Living With Human Immunodeficiency Virus.

BACKGROUND: The central nervous system (CNS) is a likely reservoir of human immunodeficiency virus (HIV), vulnerable to viral rebound, inflammation, and clinical changes upon stopping antiretroviral therapy (ART). It is critical to evaluate the CNS safety of studies using analytic treatment interruption (ATI) to assess HIV remission. METHODS: Thirty participants who started ART during acute HIV infection underwent CNS assessments across 4 ATI remission trials. ART resumption occurred with plasma viral load >1000 copies/mL. CNS measures included paired pre- vs post-ATI measures of mood, cognitive performance, and neurologic examination, with elective cerebrospinal fluid (CSF) sampling, brain diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). RESULTS: Median participant age was 30 years old and 29/30 were male. Participants' median time on ART before ATI was 3 years, and ATI lasted a median of 35 days. Post-ATI, there were no differences in median mood scores or neurologic findings and cognitive performance improved modestly. During ATI, a low level of CSF HIV-1 RNA was detectable in 6 of 20 participants with plasma viremia, with no group changes in CSF immune activation markers or brain DTI measures. Mild worsening was identified in post-ATI basal ganglia total choline MRS, suggesting an alteration in neuronal membranes. CONCLUSION: No adverse CNS effects were observed with brief, closely monitored ATI in participants with acutely treated HIV, except an MRS alteration in basal ganglia choline. Further studies are needed to assess CNS ATI safety in HIV remission trials, particularly for studies using higher thresholds to restart ART and longer ATI durations.

Viral Blips After Treatment Initiation During Acute Human Immunodeficiency Virus Infection.

Transient viral blips ≥20 copies/mL were observed in 16.9% of acutely treated adults with HIV. Blip incidence increased from 0.0 (95% CI, 0.0-2.9)/100 person-years after ART in Fiebig I to 15.9 (7.6-29.2) in Fiebig V. Increasing viral load and Fiebig stage at ART initiation were independently predictive of blips.

Plasmacytoid dendritic cells sense HIV replication before detectable viremia following treatment interruption.

Plasmacytoid dendritic cells (pDCs) are robust producers of IFNα and one of the first immune cells to respond to SIV infection. To elucidate responses to early HIV-1 replication, we studied blood pDCs in 29 HIV-infected participants who initiated antiretroviral therapy during acute infection and underwent analytic treatment interruption (ATI). We observed an increased frequency of partially activated pDCs in the blood before detection of HIV RNA. Concurrent with peak pDC frequency, we detected a transient decline in the ability of pDCs to produce IFNα in vitro, which correlated with decreased phosphorylation of IFN regulatory factory 7 (IRF7) and NF-κB. The levels of phosphorylated IRF7 and NF-κB inversely correlated with plasma IFNα2 levels, implying that pDCs were refractory to in vitro stimulation after IFNα production in vivo. After ATI, decreased expression of IFN genes in pDCs inversely correlated with the time to viral detection, suggesting that pDC IFN loss is part of an effective early immune response. These data from a limited cohort provide a critical first step in understanding the earliest immune response to HIV-1 and suggest that changes in blood pDC frequency and function can be used as an indicator of viral replication before detectable plasma viremia.

Brief Report: Safety of Frequent Blood Sampling in Research Participants in an Acute HIV Infection Cohort in Thailand.

INTRODUCTION: Anemia is a potential adverse effect of phlebotomy during participation in research. Clinical studies of acute HIV infection (AHI) require frequent phlebotomy to maximize scientific yield, but this participant population may also be at increased risk for anemia and other adverse events. OBJECTIVE: The objective of this study was to describe baseline and longitudinal hemoglobin changes among participants with AHI. METHODS: Participants with AHI (n = 202) were enrolled in a prospective cohort study in Thailand. AHI was diagnosed using pooled nucleic acid testing and sequential HIV antibody immunoassays. Antiretroviral therapy was initiated on enrollment. During 48 weeks of study participation, a total of 629 mL of blood was drawn over 14 visits. Hemoglobin levels were measured serially, and abnormalities were graded using the Division of AIDS (National Institute of Allergy and Infectious Diseases) adverse event table. RESULTS: AHI was diagnosed at a median of 18 days after infection. Mean hemoglobin at enrollment of male participants was 14.8 g/dL, and for females, it was 13.0 g/dL. Over 48 weeks, there was a mean increase of 0.2 g/dL among men (P = 0.01) and a decrease of 0.7 g/dL among women (P = 0.03). The overall prevalence of anemia was low, with 7 (3.5%) of 202 fulfilling grade 1 or 2 anemia criteria. CONCLUSIONS: Anemia was rare after frequent phlebotomy in research participants with AHI, before and after antiretroviral therapy. Given that the blood volume drawn from this study did not pose substantial clinical risk, increasing the volume of blood drawn for research purposes in acute HIV-infected research participants could be considered for future studies.

Neurologic signs and symptoms frequently manifest in acute HIV infection.

OBJECTIVE: To determine the incidence, timing, and severity of neurologic findings in acute HIV infection (pre-antibody seroconversion), as well as persistence with combination antiretroviral therapy (cART). METHODS: Participants identified with acute HIV were enrolled, underwent structured neurologic evaluations, immediately initiated cART, and were followed with neurologic evaluations at 4 and 12 weeks. Concurrent brain MRIs and both viral and inflammatory markers in plasma and CSF were obtained. RESULTS: Median estimated HIV infection duration was 19 days (range 3-56) at study entry for the 139 participants evaluated. Seventy-three participants (53%) experienced one or more neurologic findings in the 12 weeks after diagnosis, with one developing a fulminant neurologic manifestation (Guillain-Barré syndrome). A total of 245 neurologic findings were noted, reflecting cognitive symptoms (33%), motor findings (34%), and neuropathy (11%). Nearly half of the neurologic findings (n = 121, 49%) occurred at diagnosis, prior to cART initiation, and most of these (n = 110, 90%) remitted concurrent with 1 month on treatment. Only 9% of neurologic findings (n = 22) persisted at 24 weeks on cART. Nearly all neurologic findings (n = 236, 96%) were categorized as mild in severity. No structural neuroimaging abnormalities were observed. Participants with neurologic findings had a higher mean plasma log10 HIV RNA at diagnosis compared to those without neurologic findings (5.9 vs 5.4; p = 0.006). CONCLUSIONS: Acute HIV infection is commonly associated with mild neurologic findings that largely remit while on treatment, and may be mediated by direct viral factors. Severe neurologic manifestations are infrequent in treated acute HIV.

Impact of early cART in the gut during acute HIV infection.

Early after HIV infection there is substantial depletion of CD4+ T cells in the gastrointestinal (GI) tract lamina propria (LP), with associated epithelial barrier damage, leading to microbial translocation and systemic inflammation and immune activation. In this study, we analyzed these early events in the GI tract in a cohort of Thai acute HIV-infected patients and determined the effect of early combination antiretroviral treatment (cART). HIV-uninfected and chronically and acutely HIV-infected patients at different Fiebig stages (I-V) underwent colonic biopsies and then received cART. Immunohistochemistry and quantitative image analysis were performed on cross-sectional and longitudinal colon biopsy specimens (day 0 to week 96) to measure GI tract damage (infiltration of polymorphonuclear cells), inflammation (M×1, TNF-α), immune activation (Ki-67), and the CD4+ T cell population in the LP. The magnitude of GI tract damage, immune activation, and inflammation was significantly increased, with significantly depleted CD4+ T cells in the LP in all acutely infected groups prior to cART compared with HIV-uninfected control participants. While most patients treated during acute infection resolved GI tract inflammation and immune activation back to baseline levels after 24 weeks of cART, most acutely infected participants did not restore their CD4+ T cells after 96 weeks of cART.