401. Risk of Post-COVID Conditions Correlates with IL-6 Plasma Levels and Is Reduced by Early Antibody Therapy

BACKGROUND: Post-COVID conditions (PCC) are common, and risk factors include older age and female sex. While high interleukin (IL)-6 and C-reactive protein are associated with more severe disease, it is unclear whether other cytokines are associated with PCC. This study was performed to identify factors associated with PCC development. METHODS: The Convalescent Plasma to Limit SARS-CoV-2 Associated Complications (CSSC-004) trial was a double-blind, multi-center, randomized, controlled trial comparing the use of COVID-19 convalescent plasma (CCP) to control plasma for the prevention of hospitalization among COVID-19 outpatients. Among 882 individuals participating in the trial with available biospecimens and symptom data, the association between early COVID-19 treatment, cytokine levels and PCC was evaluated. Cytokine and chemokine levels were assessed at baseline, day 14 and day 90 using a multiplexed sandwich immuosassay. Presence of any PCC symptom was assessed at day 90. Associations between COVID-19 treatment, cytokine levels and PCC were examined using multivariate logistic regression models. RESULTS: Baseline characteristics were similar by trial treatment group (Figure 1). At day 90, 292 (33.1%) participants had PCC. The most common symptoms were fatigue (14.5%), anosmia (14.5%), and ageusia (10.0%). Levels of most cytokines decreased over time (Figure 2). Six pro-inflammatory cytokines especially IL-6 were elevated at baseline among those with PCC (Figure 3). In multivariable analysis, female sex (adjusted odds ratio [AOR]=2.70[1.93-3.81]), age 50 or greater (AOR=1.32[1.17-1.50]), and elevated baseline IL-6 (AOR=1.59[1.02-2.47]) were associated with development of PCC, whereas race, obesity, vaccine status and diabetes were not. Those who received early CCP treatment (<5 days after symptom onset) compared to late CCP treatment had statistically significant lower odds of PCC (AOR=0.60 [0.38-0.95]). [Figure: see text] [Figure: see text] [Figure: see text] CONCLUSION: This study showed high prevalence of PCC symptoms at day 90, particularly among those with higher baseline levels of IL-6 or who did not receive early CCP treatment. The potential utility of IL-6 modulation as a therapeutic intervention among individuals as higher risk for PCC should be studied. DISCLOSURES: Kelly Gebo, MD, MPH, Pfizer: Advisor/Consultant|Spark HealthCare: Advisor/Consultant Sonya L. Heath, MD, Pfizer: Data Monitoring Committee/DSMB Shmuel Shoham, MD, adagio: Advisor/Consultant|Adamis: Advisor/Consultant|ansun: Grant/Research Support|Avir Pharma: Honoraria|cidara: Grant/Research Support|F2G: Grant/Research Support|Immunome: Advisor/Consultant|Karius: Honoraria|Scynexis: Advisor/Consultant|zeteo: Grant/Research Support Judith S. Currier, M.D., MSc, Merck and Company: Advisor/Consultant|Merck and Company: Honoraria Moises A. Huaman, MD, MSc, AN2 Therapeutics Inc: Grant/Research Support|Gilead Sciences Inc: Grant/Research Support|Insmed Inc: Grant/Research Support Jay S. Raval, MD, Sanofi Genzyme: Advisor/Consultant Arturo Casadevall, MD, PhD, Ortho Diagnostics: Speakers Bureau|Sabtherapeutics: Advisor/Consultant