CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

defined as reporting at least one symptom and not having returned to pre COVID health status. Additionally, we prospectively enrolled 44 adults with moderate-to-severe LC and 48 adults matched on age, sex, BMI, years of education, and months since acute COVID-19 who recovered fully from COVID-19 within 6 weeks (controls). In this third cohort, we excluded those with recent use of any type of corticosteroids including oral, inhaled, topical, or injectable. The cortisol awakening response was assessed in saliva (Salimetrics) at 5, 30, and 60 minutes after morning awakening in all, and diurnal cortisol was assessed after awakening, before lunch, before dinner, and before bedtime in half. The high dose adrenocorticotropic hormone (ACTH) stimulation test with blood sampling before, 30-, and 60-minutes post-injection was used to assess adrenal function in 16 LC and 16 controls. Mann Whitney U test was used to test differences between groups. Results: No significant differences in serum cortisol were observed between LC and never-LC participants among 381 participants with untimed blood draws, even if segregated by 2-hour time window of blood draw (example in Figure). The morning cortisol awakening response and diurnal pattern of cortisol secretion were preserved and not significantly different between LC and controls at all time points. Peak morning salivary cortisol trended lower in LC than controls (p=0.11). Neither LC nor controls had abnormal ACTH stimulation test results, and no differences were observed in post-stimulation cortisol levels. There was a trend towards higher pre-stimulation endogenous ACTH in LC (p=0.06). Conclusions: In people with LC not taking exogenous corticosteroids, we observed no abnormalities in serum total cortisol or salivary cortisol levels, with or without exogenous adrenal stimulation, suggesting that adrenal function is preserved in people with long COVID. The figure, table, or graphic for this abstract has been removed. Lack of Association of SARS-CoV-2 N- and S-Antigenemia With Long COVID Annukka Antar 1 , Perrine Lallemand 2 , Zoe O. Demko 1 , Armaan Jamal 1 , Nuria Gallego Marquez 1 , Tamilore Adeagbo 1 , Selin Akbas 1 , Elizabeth Pasetes 1 , Paul Blair 1 , Katy Shaw-Saliba 3 , Andrea Cox 1 , Michael Peluso 4 , Robin Dewar 5 , Alan Landay 6 , Yukari Manabe 1 1 The Johns Hopkins University School of Medicine, Baltimore, MD, USA, 2 Frederick National Laboratory for Cancer Research, Frederick, MD, USA, 3 National Institute of Allergy and Infectious Diseases, Baltimore, MD, USA, 4 University of California San Francisco, San Francisco, CA, USA, 5 National Institutes of Health, Bethesda, MD, USA, 6 University of Texas Medical Branch, Galveston, TX, USA Background: The pathobiology of long COVID (LC) remains unknown, and many hypothesize that persistent viral antigen sustains long COVID. While there have been reports documenting viral protein and RNA many months after SARS CoV-2 infection, it is not yet clear whether persistent viral antigen is associated with long COVID. Methods: SARS-CoV-2 nucleocapsid (N) antigen levels were quantified from a cohort of 214 individuals (cohort 1) aged 15 and older with first SARS-CoV-2 infection confirmed by RT-PCR between April 2020 and April 2022. A total of 466 plasma samples from 1 month (n=149 individuals), 3 months (n=44), 6 months (n=76), 12 months (n=80), 18 months (n=59), and 24 months (n=58) post infection were assessed. Plasma SARS-CoV-2 N antigen levels were determined using the quantitative Simoa SARS-CoV-2 N Protein Advantage kit and HD-X instrument (Quanterix). 90 µL of plasma were run in duplicate. In a nonoverlapping cohort of 214 different individuals (cohort 2, n=147 with first SARS-CoV-2 infection between June 2021 and August 2022, n=67 with no prior COVID-19), SARS-CoV-2 spike (S) and N antigen were assessed using antigen-capture immunogenicity assay (Meso Scale Discovery, MSD). Plasma from 1- and 4-months post-infection was assessed for those with recent infection. In both cohorts, LC was defined as reporting any symptom and also reporting not returning to usual pre-COVID health at 3+ months. Mann Whitney U test was used to assess group differences. Results: Over 97% of participants in each cohort did not require hospitalization for acute COVID-19. All 466 plasma samples assessed for N antigen by Quanterix assay were negative (<3 pg/mL), except at 1-month post-infection in one individual with severe immunosuppression, despite half of participants with surveys completed 3+ months post-infection having LC. Levels of S and N antigen assessed by MSD in the second cohort did not differ at 1- or 4-months post-infection in people who ever vs never had LC (medians, S

antigen: M1 LC 0.089 pg/mL vs M1 quick recovery [QR] 0.081; M4 LC 0.082 vs M4 QR 0.099; N antigen: M1 LC 0.027 vs M1 QR 0.034; M4 LC 0.024 vs M4 QR 0.026), nor did levels of S and N antigen differ at 1-month post-infection between people who never had COVID-19 vs LC (never COVID S antigen: 0.086, N antigen: 0.024). Conclusions: Using two assay methodologies and longitudinal samples from two cohorts of people with mild to moderate acute SARS-CoV-2, we did not identify a relationship between persistent plasma antigenemia and LC. Exploring the Molecular Pathways of Long COVID With Post-Exertional Fatigue: A Multiomic Approach Silvia Chafino-Aixa 1 , Maria Nevot 2 , Cora Loste 3 , Francisco Muñoz-López 4 , Gemma Lladós 3 , Cristina Lopez Rodriguez 5 , José Ramón Santos 3 , Bonaventura Clotet 2 , Roger Paredes 2 , Francesc Vidal 1 , Joaquim Peraire 1 , Lourdes Mateu 3 , Anna Rull 1 , Marta Massanella 2 , for the KING Cohort Study Group 1 Hospital Universitario de Tarragona Joan XXIII, Tarragona, Spain, 2 IrsiCaixa, Badalona, Spain, 3 University Hospital Germans Trias i Pujol, Badalona, Spain, 4 IrsiCaixa Institute for AIDS Research, Badalona, Spain, 5 Hospital Germans Trias i Pujol, Barcelona, Spain Background: Post-exertional malaise (PEM) is a disabling condition characterized by worsened symptoms after mental or physical exertion, commonly seen in Long-COVID (LC). While its underlying pathophysiology is unclear, potential mechanisms include oxidative stress, and metabolic derangements. We conducted a multiomic analysis to identify changes in energy metabolism, immune function and cellular stress responses in patients with LC affected by PEM (LC-PEM). Methods: We included 25 LC-PEM and 25 COVID-19 survivors without persistent symptoms (Recovered) matched by sex, age and COVID-19 severity. We detected the levels in plasma of 6 short-chain fatty acids (SCFA) by GC-MS/MS, 95 metabolites by GC-qTOF and 795 proteins in the proteomic analysis by nanoLC MS/MS. Statistical analyses included t-tests, partial-least square discriminant analysis (PLS-DA), Random Forest, Joint-Pathway analyses (KEGG database) and ROC Curve. Results: Acetic acid was the only SCFA with lower levels in the LC-PEM group (p=0.001). Metabolomics revealed 29 differentially expressed metabolites (23 increased, 6 decreased in LC-PEM, all p<0.04), while proteomics showed 51 differentially expressed proteins between groups (39 increased and 11 decreased, p<0.01 in all cases). In a multiomic analysis, the PLS-DA of the identified 81 significant compounds demonstrated clear separation between groups (Fig1A). The enrichment pathway analysis identified 25 affected pathways, including complement and coagulation cascades, glucagon signalling pathway, TCA cycle, pyruvate metabolism, fatty acid biosynthesis, different amino acid metabolisms, glycolysis/gluconeogenesis, HIF-1 signalling pathway, butanoate metabolism and glyoxylate and dicarboxylate metabolism. Random Forest highlighted glyceraldehyde-3-phosphate dehydrogenase, Protein S100-A9, Fumaric acid and Galectin-3-binding protein as most associated with LC-PEM. The ROC curve analysis of the combination of 4 compounds yielded an AUC of 0.978 (95% CI: 0.942–1.013, p<0.001, Fig1B), indicating an excellent discriminatory ability between the LC-PEM and recovered groups. Conclusions: Coagulation and inflammatory problems linked to metabolic changes, such as upregulated glycolysis and fatty acid synthesis, are associated with LC-PEM. These findings highlight the need for a multifaceted approach addressing both metabolic and immunological factors. Future research should validate these biomarkers in larger cohorts and explore targeted treatments to address these imbalances. Distinct Proinflammatory/Proangiogenetic Signatures Distinguish Children With Long COVID Danilo Buonsenso 1 , Nicola Cotugno 2 , Paolo Palma 2 1 Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy, 2 Bambino Gesu Children's Hospital, Rome, Italy Background: Recent proteomic studies have documented that Long Covid in adults is characterized by a pro-inflammatory signature with thromboinflammation. However, if similar events happen also in children with Long Covid has never been investigated. Methods: We performed proteomics analyses of blood plasma from pediatric patients younger than 19 years of age Long Covid and sex- and age-matched control groups of children with acute COVID-19, MIS-C, and healthy controls. Children were classified as Long Covid if symptoms persisted for at least 8 The figure, table, or graphic for this abstract has been removed.

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