IgG3 regulates tissue-like memory B cells in HIV-infected individuals.

Immunoglobulin G3 (IgG3) has an uncertain role in the response to infection with and vaccination against human immunodeficiency virus (HIV). Here we describe a regulatory role for IgG3 in dampening the immune system-activating effects of chronic HIV viremia on B cells. Secreted IgG3 was bound to IgM-expressing B cells in vivo in HIV-infected chronically viremic individuals but not in early-viremic or aviremic individuals. Tissue-like memory (TLM) B cells, a population expanded by persistent HIV viremia, bound large amounts of IgG3. IgG3 induced clustering of B cell antigen receptors (BCRs) on the IgM+ B cells, which was mediated by direct interactions between soluble IgG3 and membrane IgM of the BCR (IgM-BCR). The inhibitory IgG receptor CD32b (FcγRIIb), complement component C1q and inflammatory biomarker CRP contributed to the binding of secreted IgG3 onto IgM-expressing B cells of HIV-infected individuals. Notably, IgG3-bound TLM B cells were refractory to IgM-BCR stimulation, thus demonstrating that IgG3 can regulate B cells during chronic activation of the immune system.

A Longitudinal Study of COVID-19 Sequelae and Immunity: Baseline Findings.

BACKGROUND: A substantial proportion of persons who develop COVID-19 report persistent symptoms after acute illness. Various pathophysiologic mechanisms have been implicated in the pathogenesis of postacute sequelae of SARS-CoV-2 infection (PASC). OBJECTIVE: To characterize medical sequelae and persistent symptoms after recovery from COVID-19 in a cohort of disease survivors and controls. DESIGN: Cohort study. (ClinicalTrials.gov: NCT04411147). SETTING: National Institutes of Health Clinical Center, Bethesda, Maryland. PARTICIPANTS: Self-referred adults with laboratory-documented SARS-CoV-2 infection who were at least 6 weeks from symptom onset were enrolled regardless of presence of PASC. A control group comprised persons with no history of COVID-19 or serologic evidence of SARS-CoV-2 infection, recruited regardless of their current health status. Both groups were enrolled over the same period and from the same geographic area. MEASUREMENTS: All participants had the same evaluations regardless of presence of symptoms, including physical examination, laboratory tests and questionnaires, cognitive function testing, and cardiopulmonary evaluation. A subset also underwent exploratory immunologic and virologic evaluations. RESULTS: 189 persons with laboratory-documented COVID-19 (12% of whom were hospitalized during acute illness) and 120 antibody-negative control participants were enrolled. At enrollment, symptoms consistent with PASC were reported by 55% of the COVID-19 cohort and 13% of control participants. Increased risk for PASC was noted in women and those with a history of anxiety disorder. Participants with findings meeting the definition of PASC reported lower quality of life on standardized testing. Abnormal findings on physical examination and diagnostic testing were uncommon. Neutralizing antibody levels to spike protein were negative in 27% of the unvaccinated COVID-19 cohort and none of the vaccinated COVID-19 cohort. Exploratory studies found no evidence of persistent viral infection, autoimmunity, or abnormal immune activation in participants with PASC. LIMITATIONS: Most participants with COVID-19 had mild to moderate acute illness that did not require hospitalization. The prevalence of reported PASC was likely overestimated in this cohort because persons with PASC may have been more motivated to enroll. The study did not capture PASC that resolved before enrollment. CONCLUSION: A high burden of persistent symptoms was observed in persons after COVID-19. Extensive diagnostic evaluation revealed no specific cause of reported symptoms in most cases. Antibody levels were highly variable after COVID-19. PRIMARY FUNDING SOURCE: Division of Intramural Research, National Institute of Allergy and Infectious Diseases.

Effect of HIV Antibody VRC01 on Viral Rebound after Treatment Interruption.

BACKGROUND: The discovery of potent and broadly neutralizing antibodies (bNAbs) against human immunodeficiency virus (HIV) has made passive immunization a potential strategy for the prevention and treatment of HIV infection. We sought to determine whether passive administration of VRC01, a bNAb targeting the HIV CD4-binding site, can safely prevent or delay plasma viral rebound after the discontinuation of antiretroviral therapy (ART). METHODS: We conducted two open-label trials (AIDS Clinical Trials Group [ACTG] A5340 and National Institutes of Health [NIH] 15-I-0140) of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of VRC01 in persons with HIV infection who were undergoing interruption of ART. RESULTS: A total of 24 participants were enrolled, and one serious alcohol-related adverse event occurred. Viral rebound occurred despite plasma VRC01 concentrations greater than 50 µg per milliliter. The median time to rebound was 4 weeks in the A5340 trial and 5.6 weeks in the NIH trial. Study participants were more likely than historical controls to have viral suppression at week 4 (38% vs. 13%, P=0.04 by a two-sided Fisher's exact test in the A5340 trial; and 80% vs. 13%, P<0.001 by a two-sided Fisher's exact test in the NIH trial) but the difference was not significant at week 8. Analyses of virus populations before ART as well as before and after ART interruption showed that VRC01 exerted pressure on rebounding virus, resulting in restriction of recrudescent viruses and selection for preexisting and emerging antibody neutralization-resistant virus. CONCLUSIONS: VRC01 slightly delayed plasma viral rebound in the trial participants, as compared with historical controls, but it did not maintain viral suppression by week 8. In the small number of participants enrolled in these trials, no safety concerns were identified with passive immunization with a single bNAb (VRC01). (Funded by the National Institute of Allergy and Infectious Diseases and others; ACTG A5340 and NIH 15-I-0140 ClinicalTrials.gov numbers, NCT02463227 and NCT02471326 .).

Clonally expanded CD4+ T cells can produce infectious HIV-1 in vivo.

Reservoirs of infectious HIV-1 persist despite years of combination antiretroviral therapy and make curing HIV-1 infections a major challenge. Most of the proviral DNA resides in CD4(+)T cells. Some of these CD4(+)T cells are clonally expanded; most of the proviruses are defective. It is not known if any of the clonally expanded cells carry replication-competent proviruses. We report that a highly expanded CD4(+) T-cell clone contains an intact provirus. The highly expanded clone produced infectious virus that was detected as persistent plasma viremia during cART in an HIV-1-infected patient who had squamous cell cancer. Cells containing the intact provirus were widely distributed and significantly enriched in cancer metastases. These results show that clonally expanded CD4(+)T cells can be a reservoir of infectious HIV-1.

Lytic granule loading of CD8+ T cells is required for HIV-infected cell elimination associated with immune control.

Virus-specific CD8+ T cells probably mediate control over HIV replication in rare individuals, termed long-term nonprogressors (LTNPs) or elite controllers. Despite extensive investigation, the mechanisms responsible for this control remain incompletely understood. We observed that HIV-specific CD8+ T cells of LTNPs persisted at higher frequencies than those of treated progressors with equally low amounts of HIV. Measured on a per-cell basis, HIV-specific CD8+ T cells of LTNPs efficiently eliminated primary autologous HIV-infected CD4+ T cells. This function required lytic granule loading of effectors and delivery of granzyme B to target cells. Defective cytotoxicity of progressor effectors could be restored after treatment with phorbol ester and calcium ionophore. These results establish an effector function and mechanism that clearly segregate with immunologic control of HIV. They also demonstrate that lytic granule contents of memory cells are a critical determinant of cytotoxicity that must be induced for maximal per-cell killing capacity.

Association between high cumulative dose of benzodiazepine in Chinese patients and risk of dementia: a preliminary retrospective case-control study.

BACKGROUND: Evidence describing the association between high-dose benzodiazepine use and dementia has been conflicting. Most previous studies involved Caucasian populations, with only limited data on Chinese subjects. Possible differences exist between Chinese and Caucasian populations with regard to metabolism and prescription practice. This study aimed to assess the association between high-dose benzodiazepine use and dementia in a Chinese population. METHOD: A retrospective case-control study was carried out in all public hospitals under the Hong Kong Hospital Authority Hong Kong West Cluster between 2000 and 2015. The study recruited 273 Chinese adults (91 cases, 182 controls) aged 75 and over, with at least 6 years of follow-up data. Each dementia case was matched with two controls according to sex, age group, and duration of follow-up. The number of patients with benzodiazepine ever-use and the exposure density based on the prescribed daily doses were assessed. Prescribed daily doses were categorized as either <1096 or ≥1096. Odds ratios and 95% confidence intervals were computed by multivariate analysis. RESULTS: The difference in exposure density between the dementia and control groups was statistically significant between prescribed daily doses <1096 and ≥1096 (P = 0.02). There were two multivariate analyses models; one factored in depression (model 1), and the other (model 2) did not. Model 2 showed a statistically significant association (odds ratio = 1.71, 95% confidence intervals = 1.02-2.89, P = 0.04) between benzodiazepine exposure density and dementia. CONCLUSION: High-dose benzodiazepine use may be associated with dementia in the Chinese population. Prospective studies are required.

Virological response after 6 week triple-drug regimens for hepatitis C: a proof-of-concept phase 2A cohort study.

BACKGROUND: Direct-acting antiviral drugs have a high cure rate and favourable tolerability for patients with hepatitis C virus (HCV). Shorter courses could improve affordability and adherence. Sofosbuvir and ledipasvir with ribavirin have high efficacy when taken for 8 weeks but not for 6 weeks. We assessed whether the addition of a third direct-acting antiviral drug to sofosbuvir and ledipasvir would allow a shorter treatment duration. METHODS: In this single-centre, open-label, phase 2A trial, we sequentially enrolled treatment-naive patients with HCV genotype 1 infection into three treatment groups: 12 weeks of sofosbuvir and ledipasvir; 6 weeks of sofosbuvir, ledipasvir, and GS-9669; or 6 weeks of sofosbuvir, ledipasvir, and GS-9451. Patients and investigators were not masked to treatment assignment. The primary endpoint was the propotion of patients with sustained viral response at 12 weeks after treatment completion (SVR12), assessed by serum HCV RNA concentrations lower than 43 IU/mL (the lower limit of quantification). We did an intention-to-treat analysis for the primary endpoint and adverse events. This study is registered with ClinicalTrials.gov, number NCT01805882. FINDINGS: Between Jan 11, 2013, and Dec 17, 2013, we enrolled 60 patients, and sequentially assigned them into three groups of 20. We noted an SVR12 in all 20 patients (100%, 95% CI 83-100) allocated to sofosbuvir and ledipasvir for 12 weeks; in 19 (95%, 75-100) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (one patient relapsed 2 weeks after completion of treatment); and in 19 (95%, 75-100%) of the 20 patients allocated to sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (one patient was lost to follow-up after reaching sustained viral response at 4 weeks). Most adverse events were mild and no patients discontinued treatment. Two serious adverse events occurred (pain after a post-treatment liver biopsy and vertigo), both unrelated to study drugs. INTERPRETATION: In this small proof-of-concept study, two different three-drug regimens that were given for 6 weeks resulted in high cure rates for HCV infection with excellent tolerability. Addition of a third potent direct-acting antiviral drug can reduce the duration of treatment required to achieve sustained viral response in patients with chronic HCV genotype 1 infection without cirrhosis. FUNDING: National Institute of Allergy and Infectious Diseases (NIAID), National Cancer Institute and Clinical Center Intramural Program, German Research Foundation, National Institutes of Health, Gilead Sciences.

Sofosbuvir and ribavirin for hepatitis C genotype 1 in patients with unfavorable treatment characteristics: a randomized clinical trial.

IMPORTANCE: The efficacy of directly acting antiviral agents in interferon-free regimens for the treatment of chronic hepatitis C infections needs to be evaluated in different populations. OBJECTIVE: To determine the efficacy and safety of sofosbuvir with weight-based or low-dose ribavirin among a population with unfavorable treatment characteristics. DESIGN, SETTING, AND PATIENTS: Single-center, randomized, 2-part, open-label phase 2 study involving 60 treatment-naive patients with hepatitis C virus (HCV) genotype 1 enrolled at the National Institutes of Health (October 2011-April 2012). INTERVENTIONS: In the study's first part, 10 participants with early to moderate liver fibrosis were treated with 400 mg/d of sofosbuvir and weight-based ribavirin for 24 weeks. In the second part, 50 participants with all stages of liver fibrosis were randomized 1:1 to receive 400 mg of sofosbuvir with either weight-based or low-dose 600 mg/d of ribavirin for 24 weeks. MAIN OUTCOMES AND MEASURES: The primary study end point was the proportion of participants with undetectable HCV viral load 24 weeks after treatment completion (sustained virologic response of 24 weeks [SVR24]). RESULTS: In the first part of the study, 9 participants (90%; 95% CI, 55%-100%) achieved SVR24. In the second part, 7 participants (28%) in the weight-based group and 10 (40%) in the low-dose group relapsed after treatment completion leading to SVR24 rates of 68% (95% CI, 46%-85%) in the weight-based group and 48% (95% CI, 28%-69%; P = .20) in the low-dose group. Twenty individuals participated in a pharmacokinetic-viral kinetic substudy, which demonstrated a slower loss rate of infectious virus in relapsers than in participants who achieved SVR (clearance, 3.57/d vs 5.60/d; P = .009). The most frequent adverse events were headache, anemia, fatigue, and nausea. There were 7 grade 3 events including anemia, neutropenia, nausea, hypophosphatemia, and cholelithiasis or pancreatitis. No one discontinued treatment due to adverse events. CONCLUSION AND RELEVANCE: In a population of patients with a high prevalence of unfavorable traditional predictors of treatment response, a 24-week regimen of sofosbuvir and weight-based or low-dose ribavirin resulted in SVR24 rates of 68% and 48%, respectively. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01441180.

d-Dimer and CRP levels are elevated prior to antiretroviral treatment in patients who develop IRIS.

Biomarkers could be useful in evaluating immune reconstitution inflammatory syndrome (IRIS). A cohort of 45 HIV-1-infected, antiretroviral treatment (ART)-naive patients with baseline CD4 T cell counts

Defective human immunodeficiency virus-specific CD8+ T-cell polyfunctionality, proliferation, and cytotoxicity are not restored by antiretroviral therapy.

Identifying the functions of human immunodeficiency virus (HIV)-specific CD8+ T cells that are not merely modulated by the level of virus but clearly distinguish patients with immune control from those without such control is of paramount importance. Features of the HIV-specific CD8+ T-cell response in antiretroviral-treated patients (designated Rx <50) and untreated patients (long-term nonprogressors [LTNP]) matched for very low HIV RNA levels were comprehensively examined. The proliferative capacity of HIV-specific CD8+ T cells was not restored in Rx <50 to the level observed in LTNP, even though HIV-specific CD4+ T-cell proliferation in the two patient groups was comparable. This diminished HIV-specific CD8+ T-cell proliferation in Rx <50 was primarily due to a smaller fraction of antigen-specific cells recruited to divide and not to the numbers of divisions that proliferating cells had undergone. Exogenous interleukin-2 (IL-2) induced proliferating cells to divide further but did not rescue the majority of antigen-specific cells with defective proliferation. In addition, differences in HIV-specific CD8+ T-cell proliferation could not be attributed to differences in cellular subsets bearing a memory phenotype, IL-2 production, or PD-1 expression. Although polyfunctionality of HIV-specific CD8+ T cells in Rx <50 was not restored to the levels observed in LTNP despite prolonged suppression of HIV RNA levels, per-cell cytotoxic capacity was the functional feature that most clearly distinguished the cells of LTNP from those of Rx <50. Taken together, these data suggest that there are selective qualitative abnormalities within the HIV-specific CD8+ T-cell compartment that persist under conditions of low levels of antigen.

Overexpression of T-bet in HIV infection is associated with accumulation of B cells outside germinal centers and poor affinity maturation.

Nearly all chronic human infections are associated with alterations in the memory B cell (MBC) compartment, including a large expansion of CD19hiT-bethi MBC in the peripheral blood of HIV-infected individuals with chronic viremia. Despite their prevalence, it is unclear how these B cells arise and whether they contribute to the inefficiency of antibody-mediated immunity in chronic infectious diseases. We addressed these questions by characterizing T-bet-expressing B cells in lymph nodes (LN) and identifying a strong T-bet signature among HIV-specific MBC associated with poor immunologic outcome. Confocal microscopy and quantitative imaging revealed that T-bethi B cells in LN of HIV-infected chronically viremic individuals distinctly accumulated outside germinal centers (GC), which are critical for optimal antibody responses. In single-cell analyses, LN T-bethi B cells of HIV-infected individuals were almost exclusively found among CD19hi MBC and expressed reduced GC-homing receptors. Furthermore, HIV-specific B cells of infected individuals were enriched among LN CD19hiT-bethi MBC and displayed a distinct transcriptome, with features similar to CD19hiT-bethi MBC in blood and LN GC B cells (GCBC). LN CD19hiT-bethi MBC were also related to GCBC by B cell receptor (BCR)-based phylogenetic linkage but had lower BCR mutation frequencies and reduced HIV-neutralizing capacity, consistent with diminished participation in GC-mediated affinity selection. Thus, in the setting of chronic immune activation associated with HIV viremia, failure of HIV-specific B cells to enter or remain in GC may help explain the rarity of high-affinity protective antibodies.

Iatrogenic Cushing syndrome after epidural triamcinolone injections in an HIV type 1-infected patient receiving therapy with ritonavir-lopinavir.

We report the first case of a human immunodeficiency virus type 1 (HIV-1)-infected individual receiving combination antiretroviral therapy, which included ritonavir, who developed Cushing syndrome with profound complications after epidural triamcinolone injections. This case highlights the potential of ritonavir interactions even with local injections of a corticosteroid.

A randomized controlled safety/efficacy trial of therapeutic vaccination in HIV-infected individuals who initiated antiretroviral therapy early in infection.

Despite substantial clinical benefits, complete eradication of HIV has not been possible using antiretroviral therapy (ART) alone. Strategies that can either eliminate persistent viral reservoirs or boost host immunity to prevent rebound of virus from these reservoirs after discontinuation of ART are needed; one possibility is therapeutic vaccination. We report the results of a randomized, placebo-controlled trial of a therapeutic vaccine regimen in patients in whom ART was initiated during the early stage of HIV infection and whose immune system was anticipated to be relatively intact. The objectives of our study were to determine whether the vaccine was safe and could induce an immune response that would maintain suppression of plasma viremia after discontinuation of ART. Vaccinations were well tolerated with no serious adverse events but produced only modest augmentation of existing HIV-specific CD4+ T cell responses, with little augmentation of CD8+ T cell responses. Compared with placebo, the vaccination regimen had no significant effect on the kinetics or magnitude of viral rebound after interruption of ART and no impact on the size of the HIV reservoir in the CD4+ T cell compartment. Notably, 26% of subjects in the placebo arm exhibited sustained suppression of viremia (<400 copies/ml) after treatment interruption, a rate of spontaneous suppression higher than previously reported. Our findings regarding the degree and kinetics of plasma viral rebound after ART interruption have potentially important implications for the design of future trials testing interventions aimed at achieving ART-free control of HIV infection.

Short communication: Interferon/ribavirin treatment for HCV is associated with the development of hypophosphatemia in HIV/hepatitis C virus-coinfected patients.

One-third of all HIV-infected individuals in the United States are estimated to be coinfected with the hepatitis C virus (HCV). Treatment of chronic hepatitis C in patients coinfected with HIV is a complex problem associated with toxicities and drug interactions between HIV antiretrovirals and interferon and ribavirin. In recent HCV treatment studies, we observed a previously unreported development of hypophosphatemia in HIV/HCV-coinfected patients treated with interferon/ribavirin (IFN/RBV). To further investigate this observation, we retrospectively reviewed 61 HIV/HCV-coinfected patients on antiretrovirals (ARVs) during treatment with IFN/RBV as well as 154 HIV-infected patients treated with ARVs alone. We found that HIV/HCV-coinfected patients on IFN/RBV therapy were more likely to develop frequent (57% vs. 13%, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)=0.001) and higher-grade hypophosphatemia (67.0% Grade 2, 33.3% Grade 3 vs. 94.7% Grade 2, 5.3% Grade 3, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)<0.001) than untreated patients. In addition, we found that the new onset of hypophosphatemia after IFN/RBV treatment initiation was followed by a diminished frequency of this toxicity upon cessation of IFN/RBV, supporting the idea that a drug-drug interaction may increase the risk of this toxicity. To understand the risks of developing this toxicity, we evaluated the association between individual ARV use and hypophosphatemia incidence. Our data suggest that concomitant tenofovir (TDF) use may be a risk factor for the development of hypophosphatemia in HIV/HCV-coinfected patients treated with IFN/RBV. Although the etiology of this abnormality is likely multifactorial, clinicians should be aware of hypophosphatemia as a potential marker of renal toxicity in HIV/HCV-coinfected patients being treated with IFN/RBV regimens.

Two overrepresented B cell populations in HIV-infected individuals undergo apoptosis by different mechanisms.

Perturbations of B cells in HIV-infected individuals are associated with the overrepresentation of distinct B cell populations. Here we describe high extrinsic CD95 ligand (CD95L)-mediated apoptosis in CD10-/CD21lo mature/activated B cells that likely arise from HIV-induced immune activation. In addition, high intrinsic apoptosis was observed in CD10+ immature/transitional B cells that likely arise as a result of HIV-induced lymphopenia. CD10+ B cells expressed low levels of Bcl-2 and Bcl-xL, consistent with their high susceptibility to intrinsic apoptosis. Higher levels of activated Bax and Bak were induced in CD10+ B cells compared with CD95L-treated CD10- B cells, consistent with the greater involvement of mitochondria in intrinsic vs. extrinsic apoptosis. Of interest, both extrinsic apoptosis in CD95L-treated CD10- B cells and intrinsic apoptosis in CD10+ B cells were associated with caspase-8 activation. Our data suggest that two distinct mechanisms of apoptosis are associated with B cells of HIV-infected individuals, and both may contribute to the depletion and dysfunction of B cells in these individuals.