Inflammasome activation in patients with Kaposi sarcoma herpesvirus (KSHV)-associated disorders.

Kaposi sarcoma herpesvirus (KSHV)-associated disorders include Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated multicentric Castleman disease (MCD) and KSHV-inflammatory cytokine syndrome (KICS). PEL, MCD, and KICS are associated with elevated circulating inflammatory cytokines. However, activation of the inflammasome, which generates IL-1 and IL-18 via active caspase-1/4/5, has not been evaluated in patients with KAD. Here we report that patients with HIV and one or more KAD present with higher plasma levels of IL-18 and increased caspase-1/4/5 activity in circulating monocytes as compared to HIV-negative healthy volunteers (HV) or people with HIV without KAD (PWH). Within KAD subtypes, KICS and MCD shared enhanced caspase-1/4/5 activity and IL-18 production when compared to HV and PWH, while patients with PEL showed remarkably high levels of inflammasome complex formation (known as apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD) (ASC)-speck). Moreover, caspase-1/4/5 activity and IL-18 plasma levels correlated with KSHV viral load, indicating KSHV-driven inflammasome activation in KAD. Accordingly, factors released by KSHV-latently infected cells triggered inflammasome activation and cytokine production in bystander monocytes, in vitro. Finally, both supervised and unsupervised analyses with inflammasome measurements and other inflammatory biomarkers demonstrate a unique inflammatory profile in patients with PEL, MCD, and KICS as compared to KS. Our data indicate that detrimental inflammation in patients with KAD is at least partially driven by KSHV-induced inflammasome activation in monocytes, thus offering novel approaches to diagnose and treat these complex disorders.

SARS-CoV-2 RNA and nucleocapsid antigen are blood biomarkers associated with severe disease outcomes that improve in response to remdesivir.

BACKGROUND: Although antivirals remain important for the treatment COVID-19, methods to assess treatment efficacy are lacking. Here, we investigated the impact of remdesivir on viral dynamics and their contribution to understanding antiviral efficacy in the multicenter ACTT-1 clinical trial that randomized patients to remdesivir or placebo. METHODS: Longitudinal specimens collected during hospitalization from a substudy of 642 COVID-19 patients were measured for viral RNA (upper respiratory tract and plasma), viral nucleocapsid antigen (serum), and host immunologic markers. Associations with clinical outcomes and response to therapy were assessed. RESULTS: Higher baseline plasma viral loads were associated with poorer clinical outcomes, and decreases in viral RNA and antigen in blood but not the upper respiratory tract correlated with enhanced benefit from remdesivir. The treatment effect of remdesivir was most pronounced in patients with elevated baseline nucleocapsid antigen levels: the recovery rate ratio was 1.95 (95%CI 1.40-2.71) for levels >245 pg/ml vs 1.04 (95%CI 0.76-1.42) for levels < 245 pg/ml. Remdesivir also accelerated the rate of viral RNA and antigen clearance in blood, and patients whose blood levels decreased were more likely to recover and survive. CONCLUSIONS: Reductions in SARS-CoV-2 RNA and antigen levels in blood correlated with clinical benefit from antiviral therapy.

Effect of Neutralizing Monoclonal Antibody Treatment on Early Trajectories of Virologic and Immunologic Biomarkers in Patients Hospitalized With COVID-19.

BACKGROUND: Neutralizing monoclonal antibodies (nmAbs) failed to show clear benefit for hospitalized patients with coronavirus disease 2019 (COVID-19). Dynamics of virologic and immunologic biomarkers remain poorly understood. METHODS: Participants enrolled in the Therapeutics for Inpatients with COVID-19 trials were randomized to nmAb versus placebo. Longitudinal differences between treatment and placebo groups in levels of plasma nucleocapsid antigen (N-Ag), anti-nucleocapsid antibody, C-reactive protein, interleukin-6, and D-dimer at enrollment, day 1, 3, and 5 were estimated using linear mixed models. A 7-point pulmonary ordinal scale assessed at day 5 was compared using proportional odds models. RESULTS: Analysis included 2149 participants enrolled between August 2020 and September 2021. Treatment resulted in 20% lower levels of plasma N-Ag compared with placebo (95% confidence interval, 12%-27%; P < .001), and a steeper rate of decline through the first 5 days (P < .001). The treatment difference did not vary between subgroups, and no difference was observed in trajectories of other biomarkers or the day 5 pulmonary ordinal scale. CONCLUSIONS: Our study suggests that nmAb has an antiviral effect assessed by plasma N-Ag among hospitalized patients with COVID-19, with no blunting of the endogenous anti-nucleocapsid antibody response. No effect on systemic inflammation or day 5 clinical status was observed. CLINICAL TRIALS REGISTRATION: NCT04501978.

Vaccination Ameliorates Cellular Inflammatory Responses in SARS-CoV-2 Breakthrough Infections.

BACKGROUND: Data on cellular immune responses in persons with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection following vaccination are limited. The evaluation of these patients with SARS-CoV-2 breakthrough infections may provide insight into how vaccinations limit the escalation of deleterious host inflammatory responses. METHODS: We conducted a prospective study of peripheral blood cellular immune responses to SARS-CoV-2 infection in 21 vaccinated patients, all with mild disease, and 97 unvaccinated patients stratified based on disease severity. RESULTS: We enrolled 118 persons (aged 50 years [SD 14.5 years], 52 women) with SARS-CoV-2 infection. Compared to unvaccinated patients, vaccinated patients with breakthrough infections had a higher percentage of antigen-presenting monocytes (HLA-DR+), mature monocytes (CD83+), functionally competent T cells (CD127+), and mature neutrophils (CD10+); and lower percentages of activated T cells (CD38+), activated neutrophils (CD64+), and immature B cells (CD127+CD19+). These differences widened with increased disease severity in unvaccinated patients. Longitudinal analysis showed that cellular activation decreased over time but persisted in unvaccinated patients with mild disease at 8-month follow-up. CONCLUSIONS: Patients with SARS-CoV-2 breakthrough infections exhibit cellular immune responses that limit the progression of inflammatory responses and suggest mechanisms by which vaccination limits disease severity. These data may have implications for developing more effective vaccines and therapies. Clinical Trials Registration. NCT04401449.

Severe Mycobacterial Immune Reconstitution Inflammatory Syndrome (IRIS) in Advanced Human Immunodeficiency Virus (HIV) Has Features of Hemophagocytic Lymphohistiocytosis and Requires Prolonged Immune Suppression.

BACKGROUND: People with HIV and mycobacterial infections can develop immune reconstitution inflammatory syndrome (IRIS) after starting antiretroviral therapy (ART). Severe mycobacterial IRIS has an overlapping clinical phenotype with hemophagocytic lymphohistiocytosis (HLH). We evaluated the pathophysiologic similarities between mycobacterial IRIS and HLH to identify clinical and immune predictors of mycobacterial IRIS severity. METHODS: HLH criteria were applied to a longitudinal cohort of 80 patients with HIV (CD4 <100 cells/µL) and mycobacterial infections. Participants were subdivided into IRIS meeting HLH criteria (HLH-IRIS), IRIS without HLH (IRIS), and those without IRIS (non-IRIS). Clinical outcomes were evaluated by regression analyses. Soluble biomarkers and T-cell subsets were assessed at baseline and IRIS-equivalent time points. RESULTS: HLH-IRIS patients required corticosteroids more frequently (OR: 21.5; 95%CI: 5.6-114.8) and for longer duration (21.2; 95%CI: 10.7-31.7 weeks) than those not meeting HLH criteria. Utilizing decision tree analyses, hemoglobin <9.2 g/dL was the best predictor of HLH-IRIS before ART, whereas ferritin, CXCL9 and sCD25 were most diagnostic for HLH at IRIS onset. At the IRIS timepoint, but not baseline, HLH-IRIS patients had lower regulatory and higher activated T cells along with greater production of IFNγ-IL-18 axis biomarkers compared with both IRIS and non-IRIS groups. Principal component analysis corroborated the distinct clustering of HLH-IRIS patients. CONCLUSIONS: Severe mycobacterial IRIS and HLH have an overlapping pathogenesis involving IFNγ and unopposed T-cell activation causing severe inflammatory disease clinically distinguished by hyperferritinemia (hyperferritinemic IRIS [FIRIS]). Hemoglobin, ferritin, CXCL9, and sCD25 identify high-risk patients and may improve risk stratification and therapeutic strategies for mycobacterial IRIS.

Polyfunctional Antigen Specific CD4+ T cell Responses in Patients With Human Immunodeficiency Virus/AIDS and Histoplasmosis Immune Reconstitution Inflammatory Syndrome.

In the combination antiretroviral era, there are limited data regarding the pathogenesis of histoplasmosis immune reconstitution inflammatory syndrome (IRIS) in people with human immunodeficiency virus (HIV). We immunologically characterized 10 cases of histoplasmosis, 4 of whom developed histoplasmosis IRIS. CD4+ T cells in histoplasmosis IRIS demonstrated a significant polyfunctional cytokine response to histoplasma antigen.

Clinical, Virologic, and Immunologic Evaluation of Symptomatic Coronavirus Disease 2019 Rebound Following Nirmatrelvir/Ritonavir Treatment.

BACKGROUND: Nirmatrelvir/ritonavir, the first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) protease inhibitor, reduces the risk of hospitalization and death by coronavirus disease 2019 (COVID-19) but has been associated with symptomatic rebound after therapy completion. METHODS: Six individuals with relapse of COVID-19 symptoms after treatment with nirmatrelvir/ritonavir, 2 individuals with rebound symptoms without prior antiviral therapy and 7 patients with acute Omicron infection (controls) were studied. Soluble biomarkers and serum SARS-CoV-2 nucleocapsid protein were measured. Nasal swabs positive for SARS-CoV-2 underwent viral isolation and targeted viral sequencing. SARS-CoV-2 anti-spike, anti-receptor-binding domain, and anti-nucleocapsid antibodies were measured. Surrogate viral neutralization tests against wild-type and Omicron spike protein, as well as T-cell stimulation assays, were performed. RESULTS: High levels of SARS-CoV-2 anti-spike immunoglobulin G (IgG) antibodies were found in all participants. Anti-nucleocapsid IgG and Omicron-specific neutralizing antibodies increased in patients with rebound. Robust SARS-CoV-2-specific T-cell responses were observed, higher in rebound compared with early acute COVID-19 patients. Inflammatory markers mostly decreased during rebound. Two patients sampled longitudinally demonstrated an increase in activated cytokine-producing CD4+ T cells against viral proteins. No characteristic resistance mutations were identified. SARS-CoV-2 was isolated by culture from 1 of 8 rebound patients; Polybrene addition increased this to 5 of 8. CONCLUSIONS: Nirmatrelvir/ritonavir treatment does not impede adaptive immune responses to SARS-CoV-2. Clinical rebound corresponds to development of a robust antibody and T-cell immune response, arguing against a high risk of disease progression. The presence of infectious virus supports the need for isolation and assessment of longer treatment courses. CLINICAL TRIALS REGISTRATION: NCT04401436.

Classical complement and inflammasome activation converge in CD14highCD16- monocytes in HIV associated TB-immune reconstitution inflammatory syndrome.

Inflammasome-derived cytokines, IL-1ß and IL-18, and complement cascade have been independently implicated in the pathogenesis of tuberculosis (TB)-immune reconstitution inflammatory syndrome (TB-IRIS), a complication affecting HIV+ individuals starting antiretroviral therapy (ART). Although sublytic deposition of the membrane attack complex (MAC) has been shown to promote NLRP3 inflammasome activation, it is unknown whether these pathways may cooperatively contribute to TB-IRIS. To evaluate the activation of inflammasome, peripheral blood mononuclear cells (PBMCs) from HIV-TB co-infected patients prior to ART and at the IRIS or equivalent timepoint were incubated with a probe used to assess active caspase-1/4/5 followed by screening of ASC (apoptosis-associated speck-like protein containing a CARD domain) specks as a readout of inflammasome activation by imaging flow cytometry. We found higher numbers of monocytes showing spontaneous caspase-1/4/5+ASC-speck formation in TB-IRIS compared to TB non-IRIS patients. Moreover, numbers of caspase-1/4/5+ASC-speck+ monocytes positively correlated with IL-1ß/IL-18 plasma levels. Besides increased systemic levels of C1q and C5a, TB-IRIS patients also showed elevated C1q and C3 deposition on monocyte cell surface, suggesting aberrant classical complement activation. A clustering tSNE analysis revealed TB-IRIS patients are enriched in a CD14highCD16- monocyte population that undergoes MAC deposition and caspase-1/4/5 activation compared to TB non-IRIS patients, suggesting complement-associated inflammasome activation during IRIS events. Accordingly, PBMCs from patients were more sensitive to ex-vivo complement-mediated IL-1ß secretion than healthy control cells in a NLRP3-dependent manner. Therefore, our data suggest complement-associated inflammasome activation may fuel the dysregulated TB-IRIS systemic inflammatory cascade and targeting this pathway may represent a novel therapeutic approach for IRIS or related inflammatory syndromes.

Responses to a Neutralizing Monoclonal Antibody for Hospitalized Patients With COVID-19 According to Baseline Antibody and Antigen Levels : A Randomized Controlled Trial.

BACKGROUND: In a randomized, placebo-controlled, clinical trial, bamlanivimab, a SARS-CoV-2-neutralizing monoclonal antibody, given in combination with remdesivir, did not improve outcomes among hospitalized patients with COVID-19 based on an early futility assessment. OBJECTIVE: To evaluate the a priori hypothesis that bamlanivimab has greater benefit in patients without detectable levels of endogenous neutralizing antibody (nAb) at study entry than in those with antibodies, especially if viral levels are high. DESIGN: Randomized, placebo-controlled trial. (ClinicalTrials.gov: NCT04501978). SETTING: Multicenter trial. PATIENTS: Hospitalized patients with COVID-19 without end-organ failure. INTERVENTION: Bamlanivimab (7000 mg) or placebo. MEASUREMENTS: Antibody, antigen, and viral RNA levels were centrally measured on stored specimens collected at baseline. Patients were followed for 90 days for sustained recovery (defined as discharge to home and remaining home for 14 consecutive days) and a composite safety outcome (death, serious adverse events, organ failure, or serious infections). RESULTS: Among 314 participants (163 receiving bamlanivimab and 151 placebo), the median time to sustained recovery was 19 days and did not differ between the bamlanivimab and placebo groups (subhazard ratio [sHR], 0.99 [95% CI, 0.79 to 1.22]; sHR > 1 favors bamlanivimab). At entry, 50% evidenced production of anti-spike nAbs; 50% had SARS-CoV-2 nucleocapsid plasma antigen levels of at least 1000 ng/L. Among those without and with nAbs at study entry, the sHRs were 1.24 (CI, 0.90 to 1.70) and 0.74 (CI, 0.54 to 1.00), respectively (nominal P for interaction = 0.018). The sHR (bamlanivimab vs. placebo) was also more than 1 for those with plasma antigen or nasal viral RNA levels above median level at entry and was greatest for those without antibodies and with elevated levels of antigen (sHR, 1.48 [CI, 0.99 to 2.23]) or viral RNA (sHR, 1.89 [CI, 1.23 to 2.91]). Hazard ratios for the composite safety outcome (<1 favors bamlanivimab) also differed by serostatus at entry: 0.67 (CI, 0.37 to 1.20) for those without and 1.79 (CI, 0.92 to 3.48) for those with nAbs. LIMITATION: Subgroup analysis of a trial prematurely stopped because of futility; small sample size; multiple subgroups analyzed. CONCLUSION: Efficacy and safety of bamlanivimab may differ depending on whether an endogenous nAb response has been mounted. The limited sample size of the study does not allow firm conclusions based on these findings, and further independent trials are required that assess other types of passive immune therapies in the same patient setting. PRIMARY FUNDING SOURCE: U.S. government Operation Warp Speed and National Institute of Allergy and Infectious Diseases.

An Inflammatory Composite Score Predicts Mycobacterial Immune Reconstitution Inflammatory Syndrome in People with Advanced HIV: A Prospective International Cohort Study.

BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) is a common cause of morbidity among people with human immunodeficiency virus (PWH) who initiate antiretroviral therapy (ART) with severe lymphopenia. Easily accessible tools that reliably predict emergence and elucidate pathogenesis of IRIS are needed to facilitate improved clinical management. METHODS: Plasma levels of biomarkers were measured before ART initiation in a large multinational cohort of ART-naive PWH with severe immunosuppression (CD4+ count <100 cells/mm3) in United States, Kenya, and Thailand. We performed a series of multiparametric analyses of inflammatory and clinical biomarkers and developed a composite score merging relevant biomarkers for use in a prediction model. RESULTS: We identified a distinct baseline inflammatory profile and changes in inflammatory networks among biomarkers in participants who subsequently developed mycobacterial or viral IRIS. We also developed a composite score incorporating biomarkers associated with IRIS (interleukin-6 [IL-6], IL-10, IL-27, sCD14, interferon-γ, tumor necrosis factor-α, hyaluronic acid, D-dimer, body mass index, and hemoglobin) that accurately predicted mycobacterial IRIS and death in this cohort. CONCLUSIONS: Systemic inflammatory profiles in PWH with severe immunosuppression are predictive of IRIS. Composite scores for the prediction of mycobacterial IRIS and death could be useful for risk stratification in PWH and lymphopenia initiating ART. CLINICAL TRIALS REGISTRATION: NCT00286767.

Lost in Translation: Lack of CD4 Expression due to a Novel Genetic Defect.

CD4 expression identifies a subset of mature T cells primarily assisting the germinal center reaction and contributing to CD8+ T-cell and B-cell activation, functions, and longevity. Herein, we present a family in which a novel variant disrupting the translation-initiation codon of the CD4 gene resulted in complete loss of membrane and plasma soluble CD4 in peripheral blood, lymph node, bone marrow, skin, and ileum of a homozygous proband. This inherited CD4 knockout disease illustrates the clinical and immunological features of a complete deficiency of any functional component of CD4 and its similarities and differences with other clinical models of primary or acquired loss of CD4+ T cells. The first inherited loss of any functional component of CD4, including soluble CD4, is clinically distinct from any other congenital or acquired CD4 T-cell defect and characterized by compensatory changes in T-cell subsets and functional impairment of B cells, monocytes, and natural killer cells.

Prospective International Study of Incidence and Predictors of Immune Reconstitution Inflammatory Syndrome and Death in People Living With Human Immunodeficiency Virus and Severe Lymphopenia.

BACKGROUND: Patients living with human immunodeficiency virus (PLWH) with low CD4 counts are at high risk for immune reconstitution inflammatory syndrome (IRIS) and death at antiretroviral therapy (ART) initiation. METHODS: We investigated the clinical impact of IRIS in PLWH and CD4 counts <100 cells/µL starting ART in an international, prospective study in the United States, Thailand, and Kenya. An independent review committee adjudicated IRIS events. We assessed associations between baseline biomarkers, IRIS, immune recovery at week 48, and death by week 48 with Cox models. RESULTS: We enrolled 506 participants (39.3% were women). Median age was 37 years, and CD4 count was 29 cells/µL. Within 6 months of ART, 97 (19.2%) participants developed IRIS and 31 (6.5%) died. Participants with lower hemoglobin at baseline were at higher IRIS risk (hazard ratio [HR], 1.2; P = .004). IRIS was independently associated with increased risk of death after adjustment for known risk factors (HR, 3.2; P = .031). Being female (P = .004) and having a lower body mass index (BMI; P = .003), higher white blood cell count (P = .005), and higher D-dimer levels (P = .044) were also significantly associated with increased risk of death. Decision-tree analysis identified hemoglobin <8.5 g/dL as predictive of IRIS and C-reactive protein (CRP) >106 µg/mL and BMI <15.6 kg/m2 as predictive of death. CONCLUSIONS: For PLWH with severe immunosuppression initiating ART, baseline low BMI and hemoglobin and high CRP and D-dimer levels may be clinically useful predictors of IRIS and death risk.

The Effects of Recombinant Human Lactoferrin on Immune Activation and the Intestinal Microbiome Among Persons Living with Human Immunodeficiency Virus and Receiving Antiretroviral Therapy.

Lactoferrin modulates mucosal immunity and targets mechanisms contributing to inflammation during human immunodeficiency virus disease. A randomized placebo-controlled crossover clinical trial of recombinant human (rh) lactoferrin was conducted among 54 human immunodeficiency virus-infected participants with viral suppression. Outcomes were tolerability, inflammatory, and immunologic measures, and the intestinal microbiome. The median age was 51 years, and the median CD4+ cell count was 651/µL. Adherence and adverse events did not differ between rh-lactoferrin and placebo. There was no significant effect on plasma interleukin-6 or D-dimer levels, nor on monocyte/T-cell activation, mucosal integrity, or intestinal microbiota diversity. Oral administration of rh-lactoferrin was safe but did not reduce inflammation and immune activation. Clinical Trials Registration: NCT01830595.

Increased Metabolic Activity on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Human Immunodeficiency Virus-Associated Immune Reconstitution Inflammatory Syndrome.

Background: Immune reconstitution inflammatory syndrome (IRIS) represents an unexpected inflammatory response shortly after initiation of antiretroviral therapy (ART) in some human immunodeficiency virus (HIV)-infected patients with underlying neoplasia or opportunistic infections, including tuberculosis. We hypothesized that IRIS is associated with increased glycolysis and that 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) could help identify high-risk subjects. Methods: In this prospective cohort study, 30 HIV-infected patients (CD4+ count <100 cells/µL) underwent FDG-PET/CT scans at baseline and 4-8 weeks after ART initiation. Ten patients developed IRIS (6 mycobacterial). Results: At baseline, total glycolytic activity, total lesion volume, and maximum standardized uptake values (SUVs) of pathologic FDG uptake (reflective of opportunistic disease burden) were significantly higher in IRIS vs non-IRIS (P = .010, .017, and .029, respectively) and significantly correlated with soluble inflammatory biomarkers (interferon-γ, myeloperoxidase, tumor necrosis factor, interleukin 6, soluble CD14). Baseline bone marrow (BM) and spleen FDG uptake was higher in mycobacterial IRIS specifically. After ART initiation, BM and spleen mean SUV decreased in non-IRIS (P = .004, .013) but not IRIS subjects. Our results were supported by significantly higher glucose transporter 1 (Glut-1) expression of CD4+ cells and monocytes after ART initiation in IRIS/mycobacterial IRIS compared with non-IRIS patients. Conclusions: We conclude that increased pathologic metabolic activity on FDG-PET/CT prior to ART initiation is associated with IRIS development and correlates with inflammatory biomarkers. Abnormally elevated BM and spleen metabolism is associated with mycobacterial IRIS, HIV viremia, and Glut-1 expression on CD4+ cells and monocytes. Clinical Trials Registration: NCT02147405.

Emergence of Polyfunctional Cytotoxic CD4+ T Cells in Mycobacterium avium Immune Reconstitution Inflammatory Syndrome in Human Immunodeficiency Virus-Infected Patients.

Background: Immune reconstitution inflammatory syndrome (IRIS) is an aberrant inflammatory response in individuals with advanced human immunodeficiency virus (HIV) infection, after antiretroviral therapy (ART) initiation. The pathogenesis of Mycobacterium avium complex (MAC)-associated IRIS has not been fully elucidated. Methods: We investigated monocyte and CD4+ T-cell responses in vitro, tumor necrosis factor (TNF) expression in tissues, and plasma cytokines and inflammatory markers, in 13 HIV-infected patients with MAC-IRIS and 14 HIV-uninfected patients with pulmonary MAC infection. Results: Prior to ART, HIV-infected compared with HIV-uninfected patients, had reduced TNF+ monocytes (P = .013), although similar cytokine (interferon gamma [IFN-γ], TNF, interleukin 2 [IL-2], and interleukin 17 [IL-17])-expressing CD4+ T cells. During IRIS, monocyte cytokine production was restored. IFN-γ+ (P = .027), TNF+ (P = .004), and polyfunctional CD4+ T cells (P = 0.03) also increased. These effectors were T-betlow, and some expressed markers of degranulation and cytotoxic potential. Blockade of cytotoxic T-lymphocyte associated protein 4 and lymphocyte activation gene-3 further increased CD4+ T-cell cytokine production. Tissue immunofluorescence showed higher proportions of CD4+ and CD68+ (monocyte/macrophage) cells expressed TNF during IRIS compared with HIV-uninfected patients. Plasma IFN-γ (P = .048), C-reactive protein (P = .008), and myeloperoxidase (P < .001) levels also increased, whereas interleukin 10 decreased (P = .008) during IRIS. Conclusions: Advanced HIV infection was associated with impaired MAC responses. Restoration of monocyte responses and expansion of polyfunctional MAC-specific T-betlow CD4+ T cells with cytotoxic potential after ART initiation may overwhelm existing regulatory and inhibitory mechanisms, leading to MAC-IRIS.

Cytokine-Mediated Systemic Adverse Drug Reactions in a Drug-Drug Interaction Study of Dolutegravir With Once-Weekly Isoniazid and Rifapentine.

Background: Once-weekly isoniazid and rifapentine for 3 months is a treatment option in persons with human immunodeficiency virus and latent tuberculosis infection. This study aimed to examine pharmacokinetic drug-drug interactions between this regimen and dolutegravir, a first-line antiretroviral medication. Methods: This was a single-center, open-label, fixed-sequence, drug-drug interaction study in healthy volunteers. Subjects received oral dolutegravir 50 mg once daily alone (days 1-4) and concomitantly with once-weekly isoniazid 900 mg, rifapentine 900 mg, and pyridoxine 50 mg (days 5-19). Dolutegravir concentrations were measured on days 4, 14, and 19, and rifapentine, 25-desacetyl-rifapentine, and isoniazid concentrations were measured on day 19. Cytokines and antidrug antibodies to isoniazid and rifapentine were examined at select time points. Results: The study was terminated following the development of flu-like syndrome and elevated aminotransferase levels in 2 of 4 subjects after the third isoniazid-rifapentine dose. Markedly elevated levels of interferon-γ, CXCL10, C-reactive protein, and other cytokines were temporally associated with symptoms. Antidrug antibodies were infrequently detected. Dolutegravir area under the curve (AUC) was decreased by 46% (90% confidence interval, 27-110%; P = .13) on day 14. Rifapentine and 25-desacetyl rifapentine levels on day 19 were comparable to reference data, whereas isoniazid AUCs were approximately 67%-92% higher in the subjects who developed toxicities. Conclusions: The combined use of dolutegravir with once-weekly isoniazid-rifapentine resulted in unexpected and serious toxicities that were mediated by endogenous cytokine release. Additional investigations are necessary to examine the safety and efficacy of coadministering these medications. Clinical Trials Registration: NCT02771249.

Administration of interleukin-7 increases CD4 T cells in idiopathic CD4 lymphocytopenia.

Idiopathic CD4 lymphopenia (ICL) is a rare syndrome defined by low CD4 T-cell counts (<300/µL) without evidence of HIV infection or other known cause of immunodeficiency. ICL confers an increased risk of opportunistic infections and has no established treatment. Interleukin-7 (IL-7) is fundamental for thymopoiesis, T-cell homeostasis, and survival of mature T cells, which provides a rationale for its potential use as an immunotherapeutic agent for ICL. We performed an open-label phase 1/2A dose-escalation trial of 3 subcutaneous doses of recombinant human IL-7 (rhIL-7) per week in patients with ICL who were at risk of disease progression. The primary objectives of the study were to assess safety and the immunomodulatory effects of rhIL-7 in ICL patients. Injection site reactions were the most frequently reported adverse events. One patient experienced a hypersensitivity reaction and developed non-neutralizing anti-IL-7 antibodies. Patients with autoimmune diseases that required systemic therapy at screening were excluded from the study; however, 1 participant developed systemic lupus erythematosus while on study and was excluded from further rhIL-7 dosing. Quantitatively, rhIL-7 led to an increase in the number of circulating CD4 and CD8 T cells and tissue-resident CD3 T cells in the gut mucosa and bone marrow. Functionally, these T cells were capable of producing cytokines after mitogenic stimulation. rhIL-7 was well tolerated at biologically active doses and may represent a promising therapeutic intervention in ICL. This trial was registered at www.clinicaltrials.gov as #NCT00839436.

Persistent, Albeit Reduced, Chronic Inflammation in Persons Starting Antiretroviral Therapy in Acute HIV Infection.

BACKGROUND: Serious non-AIDS events cause substantial disease and death despite human immunodeficiency virus (HIV) suppression with antiretroviral therapy (ART). Biomarkers of inflammation, coagulation cascade activation, and fibrosis predict these end-organ events. We aimed to determine whether ART initiation during acute HIV infection would attenuate changes in these biomarker levels. METHODS: Plasma samples were obtained from participants starting ART during acute or chronic HIV infection and from HIV-uninfected participants from Bangkok, Thailand. Biomarkers of inflammation (C-reactive protein [CRP], interleukin 6, soluble interleukin 6 receptor [sIL-6R], soluble gp130, tumor necrosis factor [TNF]), enterocyte turnover (intestinal fatty acid binding protein [I-FABP]), lipopolysaccharide-induced monocyte activation (soluble CD14 [sCD14]), coagulation cascade activation [D-dimer], and fibrosis (hyaluronic acid [HA]) were measured at baseline and through 96 weeks of ART. RESULTS: CRP, TNF, sIL-6R, I-FABP, sCD14, D-dimer, and HA levels were elevated in acute HIV infection. Early ART was associated with increased I-FABP levels but normalization of TNF, sIL-6R, and D-dimer levels. CRP, sCD14, and HA levels decreased during ART but remained elevated compared with HIV-uninfected participants. Higher sCD14, CRP, and D-dimer levels were associated with higher peripheral blood mononuclear cell and gut integrated HIV DNA levels. Decreases in sCD14 and CRP levels were correlated with increases in CD4 T-cell counts. CONCLUSIONS: ART initiated in early acute HIV infection was associated with normalization of the coagulation cascade and several systemic inflammatory biomarkers, but the acute-phase response, enterocyte turnover, monocyte activation, and fibrosis biomarkers remained elevated. Additional interventions to attenuate inflammation may be needed to optimize clinical outcomes in persons with HIV infection.

A Paradoxical Treatment for a Paradoxical Condition: Infliximab Use in Three Cases of Mycobacterial IRIS.

The management of corticosteroid refractory immune reconstitution inflammatory syndrome (IRIS) is currently unclear. Infliximab administration was associated with clinical improvement without significant adverse events in 3 patients with mycobacterial IRIS. Immunologic and virologic responses to antiretroviral therapy were unaffected. Tumor necrosis factor blockade may be beneficial for IRIS and warrants further study in clinical trials.

The effects of storage temperature on PBMC gene expression.

BACKGROUND: Cryopreservation of peripheral blood mononuclear cells (PBMCs) is a common and essential practice in conducting research. There are different reports in the literature as to whether cryopreserved PBMCs need to only be stored ≤ -150 °C or can be stored for a specified time at -80 °C. Therefore, we performed gene expression analysis on cryopreserved PBMCs stored at both temperatures for 14 months and PBMCs that underwent temperature cycling 104 times between these 2 storage temperatures. Real-time RT-PCR was performed to confirm the involvement of specific genes associated with identified cellular pathways. All cryopreserved/stored samples were compared to freshly isolated PBMCs and between storage conditions. RESULTS: We identified a total of 1,367 genes whose expression after 14 months of storage was affected >3 fold in PBMCs following isolation, cryopreservation and thawing as compared to freshly isolated PBMC aliquots that did not undergo cryopreservation. Sixty-six of these genes were shared among two or more major stress-related cellular pathways (stress responses, immune activation and cell death). Thirteen genes involved in these pathways were tested by real-time RT-PCR and the results agreed with the corresponding microarray data. There was no significant change on the gene expression if the PBMCs experienced brief but repetitive temperature cycling as compared to those that were constantly kept ≤ -150 °C. However, there were 18 genes identified to be different when PBMCs were stored at -80 °C but did not change when stored < -150 °C. A correlation was also found between the expressions of 2'-5'- oligoadenylate synthetase (OAS2), a known interferon stimulated gene (IFSG), and poor PBMC recovery post-thaw. PBMC recovery and viability were better when the cells were stored ≤ -150 °C as compared to -80 °C. CONCLUSIONS: Not only is the viability and recovery of PBMCs affected during cryopreservation but also their gene expression pattern, as compared to freshly isolated PBMCs. Different storage temperature of PBMCs can activate or suppress different genes, but the cycling between -80 °C and -150 °C did not produce significant alterations in gene expression when compared to PBMCs stored ≤ -150 °C. Further analysis by gene expression of various PBMC processing and cryopreservation procedures is currently underway, as is identifying possible molecular mechanisms.