BACKGROUND. Convalescent plasma is the only antibody-based therapy currently available for patients with coronavirus disease 2019 (COVID-19). It has robust historical precedence and sound biological plausibility. Although promising, convalescent plasma has not yet been shown to be safe as a treatment for COVID-19. METHODS. Thus, we analyzed key safety metrics after transfusion of ABO-compatible human COVID-19 convalescent plasma in 5000 hospitalized adults with severe or life-threatening COVID-19, with 66% in the intensive care unit, as part of the US FDA expanded access program for COVID-19 convalescent plasma. RESULTS. The incidence of all serious adverse events (SAEs), including mortality rate (0.3%), in the first 4 hours after transfusion was <1%. Of the 36 reported SAEs, there were 25 reported incidences of related SAEs, including mortality (n = 4), transfusion-associated circulatory overload (n = 7), transfusion-related acute lung injury (n = 11), and severe allergic transfusion reactions (n = 3). However, only 2 of 36 SAEs were judged as definitely related to the convalescent plasma transfusion by the treating physician. The 7-day mortality rate was 14.9%. CONCLUSION. Given the deadly nature of COVID-19 and the large population of critically ill patients included in these analyses, the mortality rate does not appear excessive. These early indicators suggest that transfusion of convalescent plasma is safe in hospitalized patients with COVID-19. TRIAL REGISTRATION. ClinicalTrials.gov NCT04338360. FUNDING. Mayo Clinic, Biomedical Advanced Research and Development Authority (75A50120C00096), National Center for Advancing Translational Sciences (UL1TR002377), National Heart, Lung, and Blood Institute (5R35HL139854 and R01 HL059842), National Institute of Diabetes and Digestive and Kidney Diseases (5T32DK07352), Natural Sciences and Engineering Research Council of Canada (PDF-532926-2019), National Institute of Allergy and Infectious Disease (R21 AI145356, R21 AI152318, and AI152078), Schwab Charitable Fund, United Health Group, National Basketball Association, Millennium Pharmaceuticals, and Octapharma USA Inc.

Importance: Passive antibody transfer is a longstanding treatment strategy for infectious diseases that involve the respiratory system. In this context, human convalescent plasma has been used to treat coronavirus disease 2019 (COVID-19), but the efficacy remains uncertain. Objective: To explore potential signals of efficacy of COVID-19 convalescent plasma. Design: Open-label, Expanded Access Program (EAP) for the treatment of COVID-19 patients with human convalescent plasma. Setting: Multicenter, including 2,807 acute care facilities in the US and territories. Participants: Adult participants enrolled and transfused under the purview of the US Convalescent Plasma EAP program between April 4 and July 4, 2020 who were hospitalized with (or at risk of) severe or life threatening acute COVID-19 respiratory syndrome. Intervention: Transfusion of at least one unit of human COVID-19 convalescent plasma using standard transfusion guidelines at any time during hospitalization. Convalescent plasma was donated by recently-recovered COVID-19 survivors, and the antibody levels in the units collected were unknown at the time of transfusion. Main Outcomes and Measures: Seven and thirty-day mortality. Results: The 35,322 transfused patients had heterogeneous demographic and clinical characteristics. This cohort included a high proportion of critically-ill patients, with 52.3% in the intensive care unit (ICU) and 27.5% receiving mechanical ventilation at the time of plasma transfusion. The seven-day mortality rate was 8.7% [95% CI 8.3%-9.2%] in patients transfused within 3 days of COVID-19 diagnosis but 11.9% [11.4%-12.2%] in patients transfused 4 or more days after diagnosis (p<0.001). Similar findings were observed in 30-day mortality (21.6% vs. 26.7%, p18.45 S/Co), seven-day mortality was 8.9% (6.8%, 11.7%); for recipients of medium IgG plasma (4.62 to 18.45 S/Co) mortality was 11.6% (10.3%, 13.1%); and for recipients of low IgG plasma (<4.62 S/Co) mortality was 13.7% (11.1%, 16.8%) (p=0.048). This unadjusted dose-response relationship with IgG was also observed in thirty-day mortality (p=0.021). The pooled relative risk of mortality among patients transfused with high antibody level plasma units was 0.65 [0.47-0.92] for 7 days and 0.77 [0.63-0.94] for 30 days compared to low antibody level plasma units. Conclusions and Relevance: The relationships between reduced mortality and both earlier time to transfusion and higher antibody levels provide signatures of efficacy for convalescent plasma in the treatment of hospitalized COVID-19 patients. This information may be informative for the treatment of COVID-19 and design of randomized clinical trials involving convalescent plasma. Trial Registration: ClinicalTrials.gov Identifier: NCT04338360 Key Points: Question: Does transfusion of human convalescent plasma reduce mortality among hospitalized COVID-19 patients? Findings: Transfusion of convalescent plasma with higher antibody levels to hospitalized COVID-19 patients significantly reduced mortality compared to transfusions with low antibody levels. Transfusions within three days of COVID-19 diagnosis yielded greater reductions in mortality. Meaning: Embedded in an Expanded Access Program providing access to COVID-19 convalescent plasma and designed to assess its safety, several signals consistent with efficacy of convalescent plasma in the treatment of hospitalized COVID-19 patients emerged.

Successful therapeutics and vaccines for coronavirus disease 2019 (COVID-19) have harnessed the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence that SARS-CoV-2 exists as locally evolving variants suggests that immunological differences may impact the effectiveness of antibody-based treatments such as convalescent plasma and vaccines. Considering that near-sourced convalescent plasma likely reflects the antigenic composition of local viral strains, we hypothesize that convalescent plasma has a higher efficacy, as defined by death within 30 days of transfusion, when the convalescent plasma donor and treated patient were in close geographic proximity. Results of a series of modeling techniques applied to approximately 28,000 patients from the Expanded Access to Convalescent Plasma program (ClinicalTrials.gov number: NCT04338360) support this hypothesis. This work has implications for the interpretation of clinical studies, the ability to develop effective COVID-19 treatments, and, potentially, for the effectiveness of COVID-19 vaccines as additional locally-evolving variants continue to emerge.

Background: The increased popularity and ubiquitous use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for the treatment of diabetes, heart failure, and obesity has led to significant concern for increased risk for perioperative aspiration, given their effects on delayed gastric emptying. This concern is highlighted by many major societies that have published varying guidance on the perioperative management of these medications, given limited data. We conducted a scoping review of the available literature regarding the aspiration risk and aspiration/regurgitant events related to GLP-1 RAs. Methods: A librarian-assisted search was performed using five electronic medical databases (PubMed, Embase, and Web of Science Platform Databases, including Web of Science Core Collection, KCI Korean Journal Database, MEDLINE, and Preprint Citation Index) from inception through March 2024 for articles that reported endoscopic, ultrasound, and nasogastric evaluation for increased residual gastric volume retained food contents, as well as incidences of regurgitation and aspiration events. Two reviewers independently screened titles, abstracts, and full text of articles to determine eligibility. Data extraction was performed using customized fields established a priori within a systematic review software system. Results: Of the 3712 citations identified, 24 studies met eligibility criteria. Studies included four prospective, six retrospective, five case series, and nine case reports. The GLP-1 RAs reported in the studies included semaglutide, liraglutide, lixisenatide, dulaglutide, tirzepatide, and exenatide. All studies, except one case report, reported patients with confounding factors for retained gastric contents and aspiration, such as a history of diabetes, cirrhosis, hypothyroidism, psychiatric disorders, gastric reflux, Barrett’s esophagus, Parkinson’s disease, dysphagia, obstructive sleep apnea, gastric polyps, prior abdominal surgeries, autoimmune diseases, pain, ASA physical status classification, procedural factors (i.e., thyroid surgery associated with risk for nausea, ketamine associated with nausea and secretions), and/or medications associated with delayed gastric emptying (opioids, anticholinergics, antidepressants, beta-blockers, calcium channel blockers, DPP-IV inhibitors, and antacids). Of the eight studies (three prospective and five retrospective) that evaluated residual contents in both GLP-1 users and non-users, seven studies (n = 7/8) reported a significant increase in residual gastric contents in GLP-1 users compared to non-users (19–56% vs. 5–20%). In the three retrospective studies that evaluated for aspiration events, there was no significant difference in aspiration events, with one study reporting aspiration rates of 4.8 cases per 10,000 in GLP-1 RA users compared to 4.6 cases per 10,000 in nonusers and the remaining two studies reporting one aspiration event in the GLP-1 RA user group and none in the non-user group. In one study that evaluated for regurgitation or reflux by esophageal manometry and pH, there was no significant difference in reflux episodes but a reduction in gastric acidity in the GLP-1 RA user group compared to the non-user group. Conclusions: There is significant variability in the findings reported in the studies, and most of these studies include confounding factors that may influence the association between GLP-1 RAs and an increased risk of aspiration and related events. While GLP-1 RAs do increase residual gastric contents in line with their mechanism of action, the currently available data do not suggest a significant increase in aspiration and regurgitation events associated with their use and the withholding of GLP-1 RAs to reduce aspiration and regurgitation events, as is currently recommended by many major societal guidelines. Large randomized controlled trials (RCTs) may be helpful in further elucidating the impact of GLP-1 RAs on perioperative aspiration risk.