Which Trial Do We Need? Optimal Antibiotic Duration for Patients with Sepsis

Given the potential benefits of shortened antibiotic courses, prior studies comparing shorter versus longer antibiotic courses have typically adopted a non-inferiority design [3,11]. However, in a study of critically ill patients in whom suboptimal treatment could result in death, a non-inferiority trial would pose a serious ethical dilemma - how to select an acceptable increased risk of mortality to use as a non-inferiority margin? For these reasons, we have designed a trial that requires shorter antibiotic therapy demonstrate superior clinical outcomes over longer antibiotic therapy, allowing partial/full credit to be awarded based on patient and clinicians\u27 perceptions of outcome importance and severity. Should clinical outcomes be comparable among the study arms, the DOOR/RADAR framework acknowledges potential unmeasured benefits of shorter courses (e.g., reduced costs, unmeasured toxicity, and antibiotic pressures selecting for individual and global microbial resistance) and accordingly assigns superiority to shorter antibiotic courses. The duration of antibiotic therapy reflected in this adjustment would be the actual (rather than assigned) duration, allowing for a pragmatic analysis of the interventions as applied in practice while mitigating differences between intention-to-treat and per-protocol analyses resulting from poor protocol adherence

Improved assays to measure and characterize the inducible HIV reservoirResearch in context

Background: Improved assays are critical to better characterize the HIV reservoir and to reliably evaluate candidate intervention strategies. Here we describe different methods to quantify the HIV reservoir. Methods: We developed an optimized quantitative viral outgrowth assay (QVOA) to quantify the frequency of cells harboring replication-competent HIV, which is simpler and more sensitive than classical QVOAs. We also developed new inducible RNA assays that concomitantly measure the frequency of cell-associated [ca-] (gag and tat-rev) and cell-free [cf-] HIV RNA after three days of anti-CD3/CD28 stimulation. Findings: The median frequency of the infected cells measured after induction was 94 IQR[60–132], 16 IQR [9–29] and 2.9 IQR[1.9–6.8] cells/106 CD4+ T-cells for ca-RNA gag and tat-rev, and cf-RNA, respectively. There are a large proportion of transcription-competent proviruses (ca-RNA) that seemed unable to form complete virions (cf-RNA), suggesting post-transcriptional blocks or defective proviruses. Importantly, the median frequency of infected CD4+ T-cells as estimated by 3-day inducible cf-RNA assay was not statistically different from the frequency measured by the QVOA (median of 3.3 [1.9–6.2] IUPM). The latently infected cells detected by the inducible cf-RNA assay correlated highly with the QVOA ( r= 0.67, p < .001), and both assays were equivalent in 60% of the samples tested, suggesting that most cells induced to produce virions are generating replication-competent virus. Interpretation: These inducible RNA assays provide more sensitivity and a greater dynamic range for the monitoring of reduction of the reservoir by eradication strategies. Such assays may serve as robust and useful tools for clinical investigations of the HIV reservoir. Keywords: HIV reservoir, VOA, Inducible HIV RNA, Latency, Eradicatio

Improved assays to measure and characterize the inducible HIV reservoir.

BackgroundImproved assays are critical to better characterize the HIV reservoir and to reliably evaluate candidate intervention strategies. Here we describe different methods to quantify the HIV reservoir.MethodsWe developed an optimized quantitative viral outgrowth assay (QVOA) to quantify the frequency of cells harboring replication-competent HIV, which is simpler and more sensitive than classical QVOAs. We also developed new inducible RNA assays that concomitantly measure the frequency of cell-associated [ca-] (gag and tat-rev) and cell-free [cf-] HIV RNA after three days of anti-CD3/CD28 stimulation.FindingsThe median frequency of the infected cells measured after induction was 94 IQR[60-132], 16 IQR [9-29] and 2.9 IQR[1.9-6.8] cells/106 CD4+ T-cells for ca-RNA gag and tat-rev, and cf-RNA, respectively. There are a large proportion of transcription-competent proviruses (ca-RNA) that seemed unable to form complete virions (cf-RNA), suggesting post-transcriptional blocks or defective proviruses. Importantly, the median frequency of infected CD4+ T-cells as estimated by 3-day inducible cf-RNA assay was not statistically different from the frequency measured by the QVOA (median of 3.3 [1.9-6.2] IUPM). The latently infected cells detected by the inducible cf-RNA assay correlated highly with the QVOA ( r= 0.67, p &lt; .001), and both assays were equivalent in 60% of the samples tested, suggesting that most cells induced to produce virions are generating replication-competent virus.InterpretationThese inducible RNA assays provide more sensitivity and a greater dynamic range for the monitoring of reduction of the reservoir by eradication strategies. Such assays may serve as robust and useful tools for clinical investigations of the HIV reservoir

Standard vaccines increase HIV-1 transcription during antiretroviral therapy.

ObjectivesCurative strategies using agents to perturb the HIV reservoir have demonstrated only modest activity, whereas increases in viremia after standard vaccination have been described. We investigated whether vaccination against non-HIV pathogens can induce HIV transcription and thereby play a role in future eradication strategies.DesignA randomized controlled trial (NCT00329251) was performed to compare the effects of clinical vaccines with placebo on HIV transcription and immune activation.MethodsTwenty-six HIV-infected individuals on suppressive antiretroviral therapy were randomized to receive a vaccination schedule (n = 13) or placebo (n = 13). Cell-associated RNA and DNA were extracted from peripheral blood mononuclear cells, and HIV was quantified by droplet digital PCR using primers for gag and 2-LTR (for HIV DNA), unspliced gag RNA (gag usRNA), multispliced tat-rev RNA (tat-rev msRNA) and polyA mRNA.ResultsSignificant increases in gag usRNA after influenza/hepatitis B vaccination (P = 0.02) and in gag usRNA (P = 0.04) and polyA mRNA (P = 0.04) after pneumococcus/hepatitis B vaccination were seen in vaccinees but not controls. HIV DNA and plasma HIV RNA did not change in either group. Increases in CD4 and CD8 T-cell activation markers (P = 0.08 and P &lt; 0.001, respectively) and HIV-specific CD8 responses (P = 0.04 for p24 gag, P = 0.01 for p17 gag and P = 0.04 for total gag) were seen in vaccinees but not controls.ConclusionIn this study, vaccination was associated with increases in HIV cell-associated RNA and HIV-specific responses during antiretroviral therapy. Using standard vaccines to stimulate HIV transcription may therefore be a useful component of future eradication strategies