Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Taking sides : clashing views on controversial issues in human sexuality

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Clashing views on controversial issues in human sexuality.

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Properties of a disease-specific prion probe

In a recently published article, Paramithiotis et al. describe antibodies specific for the prion Tyr-Tyr-Arg (YYR) repeat motif. These antibodies interact with the pathological isoform of the prion protein (PrPSC), but not with the normal cellular isoform (PrpC). Because of this restricted specificity, they suggest that YYR-specific antibodies could be useful for the diagnosis and treatment of prion diseases (Fig. O. The monoclonal antibodies, all of the IgM isotype, were produced by immunizing mice with a synthetic peptide (CYYRRYYRYY). When coupled to magnetic beads, these YYR-specific antibodies immunoprecipitate Prpsc much more efficiently than PrpC. Notably, the Paramithiotis study did not rely on antibodies to YYR for specific detection of PrP. Their immunoblots were not ultimately probed with Prpsc-specific antibodies, but rather with \u27regular\u27 antibodies. The latter can detect PrP (but do not distinguish between Prpsc and PrpC) in a precipitate that could include any protein containing solvent-accessible tyrosine and arginine residues. This report is notably similar to that of Korth et al. 2, who described a Prpsc-specific IgM (designated 15B3) after immunizing with full-length recombinant bovine PrP. The 15B3 epitope consists of three separate, linear segments of PrP (15B3-1, 15B3-2 and 15B3-3). The YYR epitope (bold) identified by Paramithiotis et al. is included in or located near two of the 15B3 segments (underlined): GSDYEDRYYR (l5B3-1) and YYRPVDOYS (l5B3-2). Thus, these two independent studies relying on the same method of immunoprecipitation have identified similar IgM antibodies interacting with the same region on PrP, and possibly with the same YYR motifs

A prion protein epitope selective for the pathologically misfolded conformation

Conformational conversion of proteins in disease is likely to be accompanied by molecular surface exposure of previously sequestered amino-acid side chains. We found that induction of β-sheet structures in recombinant prion proteins is associated with increased solvent accessibility of tyrosine. Antibodies directed against the prion protein repeat motif, tyrosine-tyrosinearginine, recognize the pathological isoform of the prion protein but not the normal cellular isoform, as assessed by immunoprecipitation, plate capture immunoassay and flow cytometry. Antibody binding to the pathological epitope is saturable and specific, and can be created in vitro by partial denaturation of normal brain prion protein. Conformation-selective exposure of Tyr-Tyr-Arg provides a probe for the distribution and structure of pathologically misfolded prion protein, and may lead to new diagnostics and therapeutics for prion diseases