CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

346

Neutrophil Activation and Their Derived Nets Contribute to Thrombotic Risk in Pulmonary PASC Natalie Subia, Dominic Chow, Cecilia Shikuma, Juwon Park University of Hawaii at Manoa, Honolulu, HI, USA Background: Over one-third of all individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experience persistent residual symptoms. Previously, we found that COVID convalescents with pulmonary symptoms had elevated low-density granulocyte (LDG) levels and enhanced ability to form neutrophil extracellular traps (NETs) and aggregation with platelets. Although evidence supports that immunothrombosis plays a crucial role in COVID-19 pathogenesis, its involvement in pulmonary post-acute sequelae of SARS-CoV-2 infection (PPASC) is poorly known. Methods: To analyze markers linked to thrombosis and inflammation in COVID-19 convalescents, plasma samples collected from participants naïve to SARS-CoV-2 (NP; n=11), infected with SARS-CoV-2 with no residual symptoms (NRS; n=10), and with pulmonary symptoms (PPASC; n=12) were used. We assessed ten analytes (coagulation: vWF-a2, Protein C, ADAMTS13, Tissue Factor (TF); inflammation: IFN-gamma (IFN-γ), MMP-9, MPO; complement pathway: Complement component C2, C5, and C9 in the plasma samples by Luminex assay. To identify factors involved in neutrophil activation in COVID-19 convalescents, we further assessed associations between LDG parameters (number, activation, NET formation) and soluble factors. Results: The median age of participants was 57, 55, and 54.5 years for the NP, NRS, and PPASC groups respectively. Months post-infection did not differ between NRS (5 [IQR;1.5-9.5]) and PPASC (6 [IQR:4-14]). Compared with NP, TF and ADAMTS13 levels were statistically decreased in PPASC, and PPASC individuals tended to have higher MPO and vWF-a2 levels. C2a levels were statistically higher in both PPASC and NRS than in the NP, while C5a and C9 expressions were comparable between groups. Further correlation analysis of LDG parameters with soluble factors in PPASC showed that the percentages of LDGs and NET-forming counts were positively correlated with MMP9, MPO, IFN-γ, and vWF-a2 expression, but negatively correlated with ADAMTS13 expression (Table 1). Interestingly, C9 levels were positively associated with the percentages of NET-forming LDGs, vWF-a2, and C5a in PPASC, but these associations were not shown in NRS. Conclusion: The associations between LDG parameters and markers for coagulation and neutrophil activation in PPASC suggest that neutrophils and their derived NETs contribute to thrombotic risk in PPASC. Further studies are necessary to understand the role of sC5b-C9 complex in PPASC. Persistence of SARS-CoV-2 in Platelets and Megakaryocytes in Long COVID Feifan He 1 , Boxin Huang 1 , Andrea Cottignies-Calamarte 1 , Wiem Bouchneb 2 , Agathe Goubard 3 , Faroudy Boufassa 4 , Jacques Csllebert 2 , Dominique Salmon 3 , Morgane Bomsel 1 1 Université de Paris Cité, Paris, France, 2 Assistance Publique–Hôpitaux de Paris, Paris, France, 3 Institut Alfred Fournier, Paris, France, 4 Centre for Epidemiology and Population Health, Paris, France Background: We have shown that acute COVID-19 pathophysiology is profoundly altered by infection of lung megakaryocytes (MKs) and platelets by SARS‐CoV‐2 (Zhu et al, 2022). A significant proportion of COVID-19 patients have symptoms persisting for > 3 months after initial infection with SARS CoV-2, referred to as Long COVID or Post-acute Sequelae of SARS-CoV-2 (PASC) patients. Persistent or re-emerging symptoms are varied, with a predominance of asthenia, neuro-cognitive impairment and cardio-vascular symptoms. The pathophysiology underlying long-onset COVID remains poorly understood. Methods: Blood was collected from patients with Long COVID with symptoms duration > 3 months (LC) (n=30), previously infected by SARS-CoV-2 but without persistent symptoms (resolved COVID-19 (CR), n=10), or healthy donor (n=20). MK frequency in blood was quantified by flow cytometry. Platelets and blood MKs were analysed for microclots, the presence of Spike protein and

RNA was isolated, cDNA was synthesized and complete genome amplification using ARTIC network V3 multiplex primers was done and sequenced in a MiSeq platform. Reads were assembled and consensus sequences extracted using Geneious R11. Maximum likelihood phylogenetic analysis was performed using PhyMLv.3.0 with representative sequences from different lineages and the ten best matched SARS-CoV-2 genomes for each timepoint consensus. Infection cases were defined according to the phylogenetic reconstruction and comparisons between the SARS-CoV-2 consensus sequences infecting the different timepoints of each patient in the longitudinal analysis. Results: A total of 55 samples derived from 26 different cancer patients were analyzed. Assembled genomes belong to B.1.1.33 (n=37) and B.1.1.28 (n=7) lineages. The 11 remaining were not classified due to low genome coverage. Most of the patients (n=16) showed the same identical viral sequence in the different timepoints analyzed, and were classified as sustained viremia. For 4 cases, the genomes analyzed were distributed in different clades of the maximum likelihood reconstruction and were considered reinfections. Finally, six cases showed overtime virus evolution, and the timespan of the samples ranged from 7 to 78 days. Conclusion: In this study, evaluating the SARS-CoV-2 complete genome from 26 cases, we report different longitudinal profiles of SARS-CoV-2 infection in cancer patients. SARS-CoV-2 Mild Infection as Risk Factor for Herpes Human Viruses Reactivation Serena Vita 1 , Elisa Petruccioli 1 , Eleonora Cimini 1 , Maria Beatrice Valli 1 , Patrizia De Marco 1 , Settimia Sbarra 1 , Stefania Notari 1 , Cecilia Lindestam Arlehamn 2 , Alessandro Sette 2 , Andrea Antinori 1 , Carla Fontana 1 , Fabrizio Maggi 1 , Delia Goletti 1 , Emanuele Nicastri 1 , for the VIROMA-INMI Group 1 Lazzaro Spallanzani National Institute for Infectious Diseases, Rome, Italy, 2 La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA Background: Reactivation of Herpes Human Viruses (HHV) has been described mostly in severe SARS-CoV-2 patients (pts) [1]. We aim to study HHV reactivation, HHV-mediated T-cell response and inflammatory milieu during SARS-CoV-2-mild infection. Methods: We enrolled pts with SARS-COV-2 infection at baseline (T0), days 7 (T7) and 30 (T30) and healthy donors (HD). We evaluated HHV-serology, HHV DNA-plasma level and the IFN-γ production after whole blood stimulation with SARS-CoV-2-spike peptides, HHV peptides designed to elicit CD4/CD8 response for Varicella Zoster Virus (VZV), Cytomegalovirus (CMV), HHV1/2, Epstein-Barr virus (EBV), and IL-2, IL-6, IL-8, TNF- α, IFN-γ, CXCL-10 plasma levels. Results: We enrolled 19 HD and 53 COVID pts with WHO median score 2 (IQR 2-4). No differences in terms of age, sex, and SARS-CoV-2 vaccinations in the 2 groups were observed. All HD referred a previous SARS- CoV-2 infection. There were no clinical HHV reactivations. At T0, no difference in lymphocytes count (while CD3 and CD4 T cells differed both with a p<0.01), in HHV seroprevalences, HHV-antibodies level and HHV reactivation were reported between groups. Blood EBV-DNA was more commonly detected at T0-T7-T30, with no difference between groups. A higher CMV-T-cell response compared to that induced by the other HHV was constantly found in both pts (p<0.0001) and HD (p=0.003). However, the CMV-CD8 response of pts was significantly higher compared to HD at T30 (p=0.032), whereas the EBV-induced CD4 and CD8 response was lower compared to HD at T0 and T7 (T0 p=0.005; p=0.003; T7 p=0.008 p=0.003). As expected, at T7 the SARS- CoV-2 response of pts was higher compared to HD (p=0.026). In pts an increased EBV-CD8 response (T0/T7 p=0.005; T0/T30 p=0.0004) was reported. Pts showed the highest SARS-CoV 2-specific response at T7 compared to T0 (p=0.044). No difference in HD over time was found. Plasma IL-2, IL-6, IFN-γ and CXCL-10 were significantly higher at T0, T7 in pts compared to HD (for all p<0.007), while no difference at T30 was observed. Conclusion: Inflammatory milieu, HHV T-cells response are present during SARS-CoV-2 mild infection, despite not significant plasma HHV detection. In COVID pts we observed a consistently high CMV and a decreased EBV T-cell response, probably reflecting EBV viremia. Indeed, among HHV, the CMV response appears to be the driving force with a higher CD8-mediated proportion. The identification of subclinical HHV- reactivation during SARS-CoV 2 mild infection is worthy of further investigations. The figure, table, or graphic for this abstract has been removed.

345

Poster Abstracts

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CROI 2024