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This post hoc analysis of the randomized, double-blind, placebo-controlled trial ACTT-2 (Adaptive COVID-19 Treatment Trial-2) sought to determine whether any patient characteristics are associated with treatment benefit from the immunomodulator baricitinib among hospitalized patients with COVID-19 who fall into the "high-risk" quartile. Visual Abstract. A Risk Profile Using Simple Hematologic Parameters to Assess Benefits From Baricitinib in Patients Hospitalized With COVID-19: A Post Hoc Analysis of the Adaptive COVID-19 Treatment Trial-2 This post hoc analysis of the randomized, double-blind, placebo-controlled trial ACTT-2 (Adaptive COVID-19 Treatment Trial-2) sought to determine whether any patient characteristics are associated with treatment benefit from the immunomodulator baricitinib among hospitalized patients with COVID-19 who fall into the "high-risk" quartile. Background: The ACTT risk profile, which was developed from ACTT-1 (Adaptive COVID-19 Treatment Trial-1), demonstrated that hospitalized patients with COVID-19 in the high-risk quartile (characterized by low absolute lymphocyte count [ALC], high absolute neutrophil count [ANC], and low platelet count at baseline) benefited most from treatment with the antiviral remdesivir. It is unknown which patient characteristics are associated with benefit from treatment with the immunomodulator baricitinib. Objective: To apply the ACTT risk profile to the ACTT-2 cohort to investigate potential baricitinib-related treatment effects by risk quartile. Design: Post hoc analysis of ACTT-2, a randomized, double-blind, placebo-controlled trial. (ClinicalTrials.gov: NCT04401579) Setting: Sixty-seven trial sites in 8 countries. Participants: Adults hospitalized with COVID-19 (n = 999; 85% U.S. participants). Intervention: Baricitinib+remdesivir versus placebo+remdesivir. Measurements: Mortality, progression to invasive mechanical ventilation (IMV) or death, and recovery, all within 28 days; ALC, ANC, and platelet count trajectories. Results: In the high-risk quartile, baricitinib+remdesivir was associated with reduced risk for death (hazard ratio [HR], 0.38 [95% CI, 0.16 to 0.86]; P = 0.020), decreased progression to IMV or death (HR, 0.57 [CI, 0.35 to 0.93]; P = 0.024), and improved recovery rate (HR, 1.53 [CI, 1.16 to 2.02]; P = 0.002) compared with placebo+remdesivir. After 5 days, participants receiving baricitinib+remdesivir had significantly larger increases in ALC and significantly larger decreases in ANC compared with control participants, with the largest effects observed in the high-risk quartile. Limitation: Secondary analysis of data collected before circulation of current SARS-CoV-2 variants. Conclusion: The ACTT risk profile identifies a subgroup of hospitalized patients who benefit most from baricitinib treatment and captures a patient phenotype of treatment response to an immunomodulator and an antiviral. Changes in ALC and ANC trajectory suggest a mechanism whereby an immunomodulator limits severe COVID-19. Primary Funding Source: National Institute of Allergy and Infectious Diseases. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 standard of care (SOC) evolved rapidly during 2020 and 2021, but its cumulative effect over time is unclear.Objective: To evaluate whether recovery and mortality improved as SOC evolved, using data from ACTT (Adaptive COVID-19 Treatment Trial).Design: ACTT is a series of phase 3, randomized, double-blind, placebo-controlled trials that evaluated COVID-19 therapeutics from February 2020 through May 2021. ACTT-1 compared remdesivir plus SOC to placebo plus SOC, and in ACTT-2 and ACTT-3, remdesivir plus SOC was the control group. This post hoc analysis compared recovery and mortality between these comparable sequential cohorts of patients who received remdesivir plus SOC, adjusting for baseline characteristics with propensity score weighting. The analysis was repeated for participants in ACTT-3 and ACTT-4 who received remdesivir plus dexamethasone plus SOC. Trends in SOC that could explain outcome improvements were analyzed. (ClinicalTrials.gov: NCT04280705 [ACTT-1], NCT04401579 [ACTT-2], NCT04492475 [ACTT-3], and NCT04640168 [ACTT-4]).Setting: 94 hospitals in 10 countries (86% U.S. participants).Participants: Adults hospitalized with COVID-19.Intervention: SOC.Measurements: 28-day mortality and recovery.Results: Although outcomes were better in ACTT-2 than in ACTT-1, adjusted hazard ratios (HRs) were close to 1 (HR for recovery, 1.04 [95% CI, 0.92 to 1.17]; HR for mortality, 0.90 [CI, 0.56 to 1.40]). Comparable patients were less likely to be intubated in ACTT-2 than in ACTT-1 (odds ratio, 0.75 [CI, 0.53 to 0.97]), and hydroxychloroquine use decreased. Outcomes improved from ACTT-2 to ACTT-3 (HR for recovery, 1.43 [CI, 1.24 to 1.64]; HR for mortality, 0.45 [CI, 0.21 to 0.97]). Potential explanatory factors (SOC trends, case surges, and variant trends) were similar between ACTT-2 and ACTT-3, except for increased dexamethasone use (11% to 77%). Outcomes were similar in ACTT-3 and ACTT-4. Antibiotic use decreased gradually across all stages.Limitation: Unmeasured confounding.Conclusion: Changes in patient composition explained improved outcomes from ACTT-1 to ACTT-2 but not from ACTT-2 to ACTT-3, suggesting improved SOC. These results support excluding nonconcurrent controls from analysis of platform trials in rapidly changing therapeutic areas.Primary Funding Source: National Institute of Allergy and Infectious Diseases. [ABSTRACT FROM AUTHOR]

Byline: Scott R. Penzak, PharmD (Warren G. Magnuson Clinical Center, Pharmacy Department, National Institutes of Health, spenzak@mail.cc.nih.gov); Kristin H. Busse, PharmD (Warren G. Magnuson Clinical Center, Pharmacy Department, National Institutes [...]

Combining interleukin 2 (IL-2) with other AIDS drugs appears to be more effective than the AIDS drugs alone. This was the conclusion of researchers who randomly assigned 78 HIV patients to take AIDS drugs only or AIDS drugs plus IL-2. Those who took AIDS drugs plus IL-2 had greater immune recovery and greater viral suppression compared to those who only took AIDS drugs. However, IL-2 caused many side effects and further research is needed to determine whether it will improve survival rates.

The article presents a study which shows that marked shifts in immune and antiviral responses that preceded changes in medical condition indicates clearance of replicating Ebola virus from peripheral blood leukocytes which is significant for systemic viral clearance. The measureement of host gene expression by microarray in daily peripheral blood samples collected from a patient with severe Ebola virus disease is mentioned.

BACKGROUND Data from studies in nonhuman primates suggest that the triple monoclonal antibody cocktail ZMapp is a promising immune-based treatment for Ebola virus disease (EVD). METHODS Beginning in March 2015, we conducted a randomized, controlled trial of ZMapp plus the current standard of care as compared with the current standard of care alone in patients with EVD that was diagnosed in West Africa by polymerasechain- reaction (PCR) assay. Eligible patients of any age were randomly assigned in a 1:1 ratio to receive either the current standard of care or the current standard of care plus three intravenous infusions of ZMapp (50 mg per kilogram of body weight, administered every third day). Patients were stratified according to baseline PCR cycle-threshold value for the virus (<22 vs. >22) and country of enrollment. Oral favipiravir was part of the current standard of care in Guinea. The primary end point was mortality at 28 days. RESULTS A total of 72 patients were enrolled at sites in Liberia, Sierra Leone, Guinea, and the United States. Of the 71 patients who could be evaluated, 21 died, representing an overall case fatality rate of 30%. Death occurred in 13 of 35 patients (37%) who received the current standard of care alone and in 8 of 36 patients (22%) who received the current standard of care plus ZMapp. The observed posterior probability that ZMapp plus the current standard of care was superior to the current standard of care alone was 91.2%, falling short of the prespecified threshold of 97.5%. Frequentist analyses yielded similar results (absolute difference in mortality with ZMapp, -15 percentage points; 95% confidence interval, -36 to 7). Baseline viral load was strongly predictive of both mortality and duration of hospitalization in all age groups. CONCLUSIONS In this randomized, controlled trial of a putative therapeutic agent for EVD, although the estimated effect of ZMapp appeared to be beneficial, the result did not meet the prespecified statistical threshold for efficacy. (Funded by the National Institute of Allergy and Infectious Diseases and others; PREVAIL II ClinicalTrials .gov number, NCT02363322.) [ABSTRACT FROM AUTHOR]

From September 2014 to April 2015, 6 persons who had occupational exposures to Zaire ebolavirus in West Africa received investigational agent rVSV-ZEBOV or TKM-100802 for postexposure prophylaxis and were monitored in the United States. All patients experienced self-limited symptoms after postexposure prophylaxis; none developed Ebola virus disease. [ABSTRACT FROM AUTHOR]

Background: Unique challenges posed by emerging infectious diseases often expose inadequacies in the conventional phased investigational therapeutic development paradigm. The recent Ebola outbreak in West Africa presents a critical case-study highlighting barriers to faster development. During the outbreak, clinical trials were implemented with unprecedented speed. Yet, in most cases, this fast-tracked approach proved too slow for the rapidly evolving epidemic. Controversy abounded as to the most appropriate study designs to yield safety and efficacy data, potentially causing delays in pivotal studies. Preparation for research during future outbreaks may require acceptance of a paradigm that circumvents, accelerates, or reorders traditional phases, without losing sight of the traditional benchmarks by which drug candidates must be assessed for activity, safety and efficacy.Methods: We present the design of an adaptive, parent protocol, ongoing in West Africa until January 2016. The exigent circumstances of the outbreak and limited prior clinical experience with experimental treatments, led to more direct bridging from preclinical studies to human trials than the conventional paradigm would typically have sanctioned, and required considerable design flexibility.Results: Preliminary evaluation of the "barely Bayesian" design was provided through computer simulation studies. The understanding and public discussion of the study design will help its future implementation. [ABSTRACT FROM AUTHOR]

Background: Influenza virus (IFV) infection is associated with increased morbidity and mortality in people with underlying lung disease. Treatment options for IFV are currently limited and antiviral resistance is a growing concern. DAS181, an inhaled antiviral with a unique mechanism of action, has shown promise in early clinical trials involving generally healthy human subjects. This study was undertaken to assess the safety and tolerability of DAS181 in individuals with underlying reactive airway disease.Methods: This was a randomized, double-blind, placebo-controlled, crossover phase 1 study of DAS181-F02. Dry particle inhaler administration of 10 mg was done on 3 consecutive days in ten adult volunteers with well-controlled asthma. The primary outcome was the frequency of adverse events (AEs), grade 1 or higher that occurred during each study period.Results: There were 280 AEs among ten evaluable subjects (56.8 % active; 43.2 % placebo); 90.7 % were grade 1. No grade 3 or higher AEs occurred. A statistically significant association between exposure to DAS181 and experiencing any AE, a grade 1 AE, or a grade 2 AE was not detected. Overall, the majority of AEs were classified as possibly related (35.7 %), unlikely related (38.9 %), or unrelated (15.4 %) to study drug administration. However, there was a statistically significant association between exposure to DAS181 and experiencing a definitely or probably related AE. Respiratory effects, including dyspnea, dry cough, and chest discomfort related to respirations, accounted for all of the definitely related AEs and one of the most common probably related AEs.Conclusions: DAS181 was safe in this small study of otherwise healthy subjects with well-controlled asthma. However, the generalizability of these results is limited by the small sample size and generally mild nature of the subjects' asthma at baseline. The increased association of respiratory events classified as probably or definitely related to DAS181 administration suggests caution may need to be employed when administering DAS181 to individuals with less stable reactive airway disease. Further investigation in a controlled setting of the safety and efficacy of DAS181 in a larger population of asthmatic subjects with varying disease activity is warranted.Trial Registration: ClinicalTrials.gov NCT01113034 Trial Registration Date: April 27, 2010. [ABSTRACT FROM AUTHOR]

Background: More than 26 000 cases of Ebola virus disease (EVD) have been reported in western Africa, with high mortality. Several patients have been medically evacuated to hospitals in the United States and Europe. Detailed clinical data are limited on the clinical course and management of patients with EVD outside western Africa. Objective: To describe the clinical characteristics and management of a cluster of patients with EVD, including the first cases of Ebola virus (EBOV) infection acquired in the United States. Design: Retrospective clinical case series. Setting: Three U.S. hospitals in September and October 2014. Patients: First imported EVD case identified in the United States and 2 secondary EVD cases acquired in the United States in critical care nurses who cared for the index case patient. Measurements: Clinical recovery, EBOV RNA level, resolution of Ebola viremia, survival with discharge from hospital, or death. Results: The index patient had high EBOV RNA levels, developed respiratory and renal failure requiring critical care support, and died. Both patients with secondary EBOV infection had nonspecific signs and symptoms and developed moderate illness; EBOV RNA levels were moderate, and both patients recovered. Limitation: Both surviving patients received uncontrolled treatment with multiple investigational agents, including convalescent plasma, which limits generalizability of the results. Conclusion: Early diagnosis, prompt initiation of supportive medical care, and moderate clinical illness likely contributed to successful outcomes in both survivors. The inability to determine the potential benefit of investigational therapies and the effect of patient-specific factors that may have contributed to less severe illness highlight the need for controlled clinical studies of these interventions, especially in the setting of a high level of supportive medical care. [ABSTRACT FROM AUTHOR]

The article presents a historical perspective on risk of infection facing health-care workers (HCW) during the provision of cardiopulmonary resuscitation (CPR) to patients with Ebola virus disease. Topics covered include the duty of physicians to treat in the face of perceived or actual HCW risk, the value of personnel safety and simulation-based training, and protocols implemented at the U.S. National Institutes of Health aimed to reduce HCW risk.

Pneumocystis jirovecii can colonize patients with chronic obstructive pulmonary disease. To determine if colonization occurs in asthma patients, sputum samples from 10 patients with mild asthma, who were not receiving oral corticosteroids, were evaluated by a sensitive real-time PCR assay that targets a multicopy gene of P. jirovecii. 2 patients (20%) had Pneumocystis DNA detected; 1 patient had 3 positive samples over an 11-day period. Thus, Pneumocystis colonization occurs in asthma patients, and further studies are warranted to evaluate its role in airways disease.Trial Registration Number: NCT01113034. [ABSTRACT FROM AUTHOR]

Background: Prospective studies establishing the temporal relationship between the degree of inflammation and human influenza disease progression are scarce. To assess predictors of disease progression among patients with influenza A(H1N1)pdm09 infection, 25 inflammatory biomarkers measured at enrollment were analyzed in two international observational cohort studies. Methods: Among patients with RT-PCR-confirmed influenza A(H1N1)pdm09 virus infection, odds ratios (ORs) estimated by logistic regression were used to summarize the associations of biomarkers measured at enrollment with worsened disease outcome or death after 14 days of follow-up for those seeking outpatient care (FLU 002) or after 60 days for those hospitalized with influenza complications (FLU 003). Biomarkers that were significantly associated with progression in both studies (p<0.05) or only in one (p<0.002 after Bonferroni correction) were identified. Results: In FLU 002 28/528 (5.3%) outpatients had influenza A(H1N1)pdm09 virus infection that progressed to a study endpoint of complications, hospitalization or death, whereas in FLU 003 28/170 (16.5%) inpatients enrolled from the general ward and 21/39 (53.8%) inpatients enrolled directly from the ICU experienced disease progression. Higher levels of 12 of the 25 markers were significantly associated with subsequent disease progression. Of these, 7 markers (IL-6, CD163, IL-10, LBP, IL-2, MCP-1, and IP-10), all with ORs for the 3rd versus 1st tertile of 2.5 or greater, were significant (p<0.05) in both outpatients and inpatients. In contrast, five markers (sICAM-1, IL-8, TNF-α, D-dimer, and sVCAM-1), all with ORs for the 3rd versus 1st tertile greater than 3.2, were significantly (p≤.002) associated with disease progression among hospitalized patients only. Conclusions: In patients presenting with varying severities of influenza A(H1N1)pdm09 virus infection, a baseline elevation in several biomarkers associated with inflammation, coagulation, or immune function strongly predicted a higher risk of disease progression. It is conceivable that interventions designed to abrogate these baseline elevations might affect disease outcome. [ABSTRACT FROM AUTHOR]

Background: Short cycle treatment interruption could reduce toxicity and drug costs and contribute to further expansion of antiretroviral therapy (ART) programs. Methods: A 72 week, non-inferiority trial enrolled one hundred forty six HIV positive persons receiving ART (CD4+ cell count ≥125 cells/mm3 and HIV RNA plasma levels <50 copies/ml) in one of three arms: continuous, 7 days on/7 days off and 5 days on/2 days off treatment. Primary endpoint was ART treatment failure determined by plasma HIV RNA level, CD4+ cell count decrease, death attributed to study participation, or opportunistic infection. Results: Following enrollment of 32 participants, the 7 days on/7 days off arm was closed because of a failure rate of 31%. Six of 52 (11.5%) participants in the 5 days on/2 days off arm failed. Five had virologic failure and one participant had immunologic failure. Eleven of 51 (21.6%) participants in the continuous treatment arm failed. Nine had virologic failure with 1 death (lactic acidosis) and 1 clinical failure (extra-pulmonary TB). The upper 97.5% confidence boundary for the difference between the percent of non-failures in the 5 days on/2 days off arm (88.5% non-failure) compared to continuous treatment (78.4% non failure) was 4.8% which is well within the preset non-inferiority margin of 15%. No significant difference was found in time to failure in the 2 study arms (p = 0.39). Conclusions: Short cycle 5 days on/2 days off intermittent ART was at least as effective as continuous therapy. [ABSTRACT FROM AUTHOR]

Background: Osteonecrosis has been reported to occur occasionally among HIV-infected patients. The diagnosis of symptomatic osteonecrosis of the hip in two of the authors' patients, together with reports from community physicians, raised a concern that the prevalence of osteonecrosis is increasing.Objective: To determine the prevalence of osteonecrosis of the hip in asymptomatic HIV-infected patients and to identify potential risk factors associated with osteonecrosis.Design: Survey and comparison study.Setting: The Clinical Center of the U.S. National Institutes of Health.Participants: 339 asymptomatic HIV-infected adults (of 364 asked to participate) and 118 age- and sex-matched HIV-negative volunteers enrolled between 1 June and 15 December 1999.Measurements: Osteonecrosis of the hip, as documented by magnetic resonance imaging. Data from clinic records and a patient questionnaire administered before magnetic resonance imaging were used in an analysis of risk factors. A subset of patients was evaluated for hypercoagulable state.Results: Fifteen (4.4% [95% CI, 2.5% to 7.2%]) of 339 HIV-infected participants had osteonecrosis lesions on magnetic resonance imaging, and no HIV-negative participants had similar lesions. Among HIV-infected participants, osteonecrosis occurred more frequently in those who used systemic corticosteroids, lipid-lowering agents, or testosterone; those who exercised routinely by bodybuilding; and those who had detectable levels of anticardiolipin antibodies.Conclusions: Patients infected with HIV have an unexpectedly high occurrence of osteonecrosis of the hip. Although screening asymptomatic patients is not warranted, HIV-infected patients with persistent groin or hip pain should be evaluated for this debilitating complication. [ABSTRACT FROM AUTHOR]

Presents a study on the immunologic and virologic consequences of discontinuing antiretroviral therapy in HIV-infected patients. Characteristics of the participants; Laboratory tests done on participants; Data analysis; Results.

Evaluates the toxicity and clinical efficiency of interferon-α2b (IFN-α) in patients with asymptomatic HIV infection. Description and function of zidovudine; Obstacles inherent in studying anti-HIV therapies in asymptomatic infected persons; Comparison of the IFN-α and placebo groups after randomization.

Background: Although several experimental therapeutics for Ebola virus disease (EVD) have been developed, the safety and efficacy of the most promising therapies need to be assessed in the context of a randomized, controlled trial.Methods: We conducted a trial of four investigational therapies for EVD in the Democratic Republic of Congo, where an outbreak began in August 2018. Patients of any age who had a positive result for Ebola virus RNA on reverse-transcriptase-polymerase-chain-reaction assay were enrolled. All patients received standard care and were randomly assigned in a 1:1:1:1 ratio to intravenous administration of the triple monoclonal antibody ZMapp (the control group), the antiviral agent remdesivir, the single monoclonal antibody MAb114, or the triple monoclonal antibody REGN-EB3. The REGN-EB3 group was added in a later version of the protocol, so data from these patients were compared with those of patients in the ZMapp group who were enrolled at or after the time the REGN-EB3 group was added (the ZMapp subgroup). The primary end point was death at 28 days.Results: A total of 681 patients were enrolled from November 20, 2018, to August 9, 2019, at which time the data and safety monitoring board recommended that patients be assigned only to the MAb114 and REGN-EB3 groups for the remainder of the trial; the recommendation was based on the results of an interim analysis that showed superiority of these groups to ZMapp and remdesivir with respect to mortality. At 28 days, death had occurred in 61 of 174 patients (35.1%) in the MAb114 group, as compared with 84 of 169 (49.7%) in the ZMapp group (P = 0.007), and in 52 of 155 (33.5%) in the REGN-EB3 group, as compared with 79 of 154 (51.3%) in the ZMapp subgroup (P = 0.002). A shorter duration of symptoms before admission and lower baseline values for viral load and for serum creatinine and aminotransferase levels each correlated with improved survival. Four serious adverse events were judged to be potentially related to the trial drugs.Conclusions: Both MAb114 and REGN-EB3 were superior to ZMapp in reducing mortality from EVD. Scientifically and ethically sound clinical research can be conducted during disease outbreaks and can help inform the outbreak response. (Funded by the National Institute of Allergy and Infectious Diseases and others; PALM ClinicalTrials.gov number, NCT03719586.). [ABSTRACT FROM AUTHOR]

Reports on the persistence of a dormant pool of HIV virus established during primary infection and can resist antiretroviral therapy. Appearance of HIV in the plasma of patients; Speed in which latent HIV reservoir emerge in the CD4+ T-cell compartment.

Presents cases of patients who developed Pneumocystis carinii pneumonia following aerosolized pentamidine prophylaxis for HIV/AIDS treatment. Medical background of the patients; Treatment administered to the patients; Benefits from aerosolized pentamidine.

Reports that high-level HIV-1 viremia suppresses viral antigen-specific CD4+ T cell proliferation. Discussion about the antiretroviral therapy; Suppression of proliferation of HIV-specific CD4 T cells in the context of high levels of antigen; Development of effective virus-specific immune responses.

Background: Available data on the characteristics of patients with Ebola virus disease (EVD) and clinical management of EVD in settings outside West Africa, as well as the complications observed in those patients, are limited.Methods: We reviewed available clinical, laboratory, and virologic data from all patients with laboratory-confirmed Ebola virus infection who received care in U.S. and European hospitals from August 2014 through December 2015.Results: A total of 27 patients (median age, 36 years [range, 25 to 75]) with EVD received care; 19 patients (70%) were male, 9 of 26 patients (35%) had coexisting conditions, and 22 (81%) were health care personnel. Of the 27 patients, 24 (89%) were medically evacuated from West Africa or were exposed to and infected with Ebola virus in West Africa and had onset of illness and laboratory confirmation of Ebola virus infection in Europe or the United States, and 3 (11%) acquired EVD in the United States or Europe. At the onset of illness, the most common signs and symptoms were fatigue (20 patients [80%]) and fever or feverishness (17 patients [68%]). During the clinical course, the predominant findings included diarrhea, hypoalbuminemia, hyponatremia, hypokalemia, hypocalcemia, and hypomagnesemia; 14 patients (52%) had hypoxemia, and 9 (33%) had oliguria, of whom 5 had anuria. Aminotransferase levels peaked at a median of 9 days after the onset of illness. Nearly all the patients received intravenous fluids and electrolyte supplementation; 9 (33%) received noninvasive or invasive mechanical ventilation; 5 (19%) received continuous renal-replacement therapy; 22 (81%) received empirical antibiotics; and 23 (85%) received investigational therapies (19 [70%] received at least two experimental interventions). Ebola viral RNA levels in blood peaked at a median of 7 days after the onset of illness, and the median time from the onset of symptoms to clearance of viremia was 17.5 days. A total of 5 patients died, including 3 who had respiratory and renal failure, for a mortality of 18.5%.Conclusions: Among the patients with EVD who were cared for in the United States or Europe, close monitoring and aggressive supportive care that included intravenous fluid hydration, correction of electrolyte abnormalities, nutritional support, and critical care management for respiratory and renal failure were needed; 81.5% of these patients who received this care survived. [ABSTRACT FROM AUTHOR]

To better understand the components of an effective immune response to human immunodeficiency virus (HIV), the CD8+ T-cell responses to HIV, hepatitis C virus (HCV), and cytomegalovirus (CMV) were compared with regard to frequency, immunodominance, phenotype, and interleukin-2 (IL-2) responsiveness. Responses were examined in rare patients exhibiting durable immune-mediated control over HIV, termed long-term nonprogressors (LTNP) or elite controllers, and patients with progressive HIV infection (progressors). The magnitude of the virus-specific CD8+ T-cell response targeting HIV, CMV, and HCV was not significantly different between LTNP and progressors, even though their capacity to proliferate to HIV antigens was preserved only in LTNP. In contrast to HIV-specific CD8+ T-cell responses of LTNP, HLA B5701-restricted responses within CMV pp65 were rare and did not dominate the total CMV-specific response. Virus-specific CD8+ T cells were predominantly CD27+45RO+ for HIV and CD27-45RA+ for CMV; however, these phenotypes were highly variable and heavily influenced by the degree of viremia. Although IL-2 induced significant expansions of CMV-specific CD8+ T cells in LTNP and progressors by increasing both the numbers of cells entering the proliferating pool and the number of divisions, the proliferative capacity of a significant proportion of HIV-specific CD8+ T cells was not restored with exogenous IL-2. These results suggest that immunodominance by HLA B5701-restricted cells is specific to HIV infection in LTNP and is not a feature of responses to other chronic viral infections. They also suggest that poor responsiveness to IL-2 is a property of HIV-specific CD8+ T cells of progressors that is not shared with responses to other viruses over which immunologic control is maintained. [ABSTRACT FROM AUTHOR]

Objective: The objective of the trial was to evaluate in a pilot setting the safety and efficacy of interleukin-2 (IL-2) therapy when used without concomitant antiretroviral therapy as a treatment for HIV infection. Design and Setting: This was a multicentre randomised three-arm trial conducted between September 1998 and March 2001 at three clinical centres in the United Kingdom. Participants: Participants were 36 antiretroviral treatment naïve HIV-1-infected patients with baseline CD4 T lymphocyte counts of at least 350 cells/mm³. Interventions: Participants were randomly assigned to receive IL-2 at 15 million international units (MIU) per day (12 participants) or 9 MIU/day (12 participants) or no treatment (12 participants). IL-2 was administered by twice-daily subcutaneous injections for five consecutive days every 8 wk. Outcome Measures: Primary outcome was the change from baseline CD4 T lymphocyte count at 24 wk. Safety and plasma HIV RNA levels were also monitored every 4 wk through 24 wk. The two IL-2 dose groups were combined for the primary analysis. Results: Area under curve (AUC) for change in the mean CD4 T lymphocyte count through 24 wk was 129 cells/mm³ for those assigned IL-2 (both dose groups combined) and 13 cells/mm³ for control participants (95% CI for difference, 51.3-181.2 cells/mm³; p = 0.0009). Compared to the control group, significant increases in CD4 cell count were observed for both IL-2 dose groups: 104.2/mm³ (p = 0.008) and 128.4 cells/mm³ (p = 0.002) for the 4.5 and 7.5 MIU dose groups, respectively. There were no significant differences between the IL-2 (0.13 log10 copies/ ml) and control (0.09 log10 copies/ml) groups for AUC of change in plasma HIV RNA over the 24-wk period of follow-up (95% CI for difference, -0.17 to 0.26; p = 0.70). Grade 4 and dose-limiting side effects were in keeping with those previously reported for IL-2 therapy. Conclusions: In participants with HIV infection and baseline CD4 T lymphocyte counts of at least 350 cells/mm³, intermittent subcutaneous IL-2 without concomitant antiretroviral therapy was well tolerated and produced significant increases in CD4 T lymphocyte counts and did not adversely affect plasma HIV RNA levels. [ABSTRACT FROM AUTHOR]

Discusses the role of virus-specific T-cell function in induction and maintenance of T-cell responses in experimental animals. Observation of T cells in infected patients; Role of diminished responses in the loss of control of replication; Evaluation of the effects of viremia.

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. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus type 1 (HIV-1) infection has been associated with perturbations of plasmacytoid dendritic cells (PDC), including diminished frequencies in the peripheral blood and reduced production of type I interferons (IFNs) in response to in vitro stimulation. However, recent data suggest a paradoxical increase in production of type 1 interferons in vivo in HIV-infected patients compared to uninfected controls. Using a flow cytometric assay to detect IFN-α-producing cells within unseparated peripheral blood mononuclear cells, we observed that short-term interruptions of antiretroviral therapy are sufficient to result in significantly reduced IFN-α production by PDC in vitro in response to CpG A ligands or inactivated HIV particles. The primary cause of diminished IFN- production was reduced responsiveness of PDC to de novo stimulation, not diminished per cell IFN-α production or migration of cells to lymphoid organs. Real-time PCR analysis of purified PDC from patients prior to and during treatment interruptions revealed that active HIV-1 replication is associated with upregulation of type I IFN-stimulated gene expression. Treatment of hepatitis C virus-infected patients with IFN-α2b and ribavirin for hepatitis C virus infection resulted in a profound suppression of de novo IFN-α production in response to CpG A or inactivated HIV particles, similar to the response observed in HIV-infected patients. Together, these results suggest that diminished production of type I interferons in vitro by PDC from HIV-1-infected patients may not represent diminished interferon production in vivo. Rather, diminished function in vitro is likely a consequence of prior activation via type I interferons or HIV virions in vivo. [ABSTRACT FROM AUTHOR]

Virus-specific CD4+ T-cell responses are thought to be required for the induction and maintenance of many effective CD8+ T-cell and B-cell immune responses in experimental animals and humans. Although the presence of human immunodeficiency virus (HIV)-specific CD4+ T cells has been documented in patients at all stages of HIV infection, many fundamental questions regarding their frequency and function remain. A 10-color, 12-parameter flow cytometric panel was utilized to examine the frequency, memory phenotype (CD27, CCR7, and CD45RA), and cytokine production (interleukin-2 [IL-2], gamma interferon, and tumor necrosis factor alpha) of CD4+ T cells specific for HIV antigens as well as for adenovirus, Epstein-Barr virus (EBV), influenza H1N1 virus, influenza H3N2 virus, cytomegalovirus, varicella-zoster virus (VZV), and tetanus toxoid in normal controls, long-term nonprogressors (LTNP), and HIV-infected patients with progressive disease on or off therapy. The HIV-specific CD4+ T-cell responses in LTNP and patients on therapy were similar in frequency, phenotype, and cytokine production to responses directed against adenovirus, EBV, influenza virus, and VZV. HIV-specific CD4+ T cells from patients off antiretroviral therapy demonstrated a shift towards a CCR7- CD45RA- phenotype and a reduced percentage of IL-2-producing cells. The alterations in cytokine production during HIV viremia were found to be intrinsic to the HIV-specific CD4+ T cells and caused a requirement for IL-2 supplied exogenously for proliferation to occur. These observations suggest that many previously described changes in HIV-specific CD4+ T-cell function and phenotype are a consequence of high levels of antigen in viremic patients. In addition, defects in function and phenotype of HIV-specific CD4+ T cells are not readily discernible in the context of antiretroviral therapy but rather are similar to responses to other viruses. [ABSTRACT FROM AUTHOR]