Critically-Elevated Interleukin-6 (IL-6): A Prognostic Biomarker for Post-Acute Sequelae of COVID-19 (PASC)? (P2-7.001)

Abstract

<h3>Objective:</h3> To investigate whether IL-6 is a prognostic factor in SARS-CoV-2 related encephalopathy in development of PASC. <h3>Background:</h3> It is currently unclear whether elevated IL-6 can be a prognostic factor in development of PASC. <h3>Design/Methods:</h3> A retrospective chart review was performed on hospitalized SARS-CoV-2 infection encephalopathy patients during March-May of 2020 at an urban tertiary care center. Patients were divided into two subgroups according to critically elevated (CE-IL6) vs non-critically elevated (NCE-IL6) initial serum IL-6 levels (as defined as &gt;86.95 pg/mL as per previous literature). Charts were analyzed for patients who had follow-up between 4 weeks and 1 year from initial visit to analyze subsequent development of new or persisting respiratory, cardiac, renal, or neurological symptoms to determine incidence of PASC. <h3>Results:</h3> Of 57 encephalopathy SARS-CoV-2 infection patients reviewed, 29 and 28 patients were found to be in the CE-IL6 and NCE-IL6 groups, respectively (average serum IL-6 level of 543.73 pg/mL vs 47.85 pg/mL, p = 0.0039). Among the CE-IL6 group, 68.97% patients had follow-up at least 4 weeks post admission vs 64.29% in NCE-IL6 group (p &gt; 0.05), with an average total follow up time of 529.89 days post initial admission in CE-IL6 and 520.31 days for NCE-IL6 (p &gt; 0.05). In the follow-up CE-IL6 group, 90% reported any one of the PASC symptoms whereas in the follow-up NCE-IL6 group, 22.22% reported any PASC symptoms (RR = 4.05, 95% CI [1.69–9.73], p = 0.0018). 12 patients received Tocilizumab (IL-6 inhibitor) in the CE-IL6 group and only 58.33% of them developed PASC. <h3>Conclusions:</h3> Encephalopathic patients who had critically elevated IL-6 serum levels on initial hospital admission for SARS-CoV-2 infection may be at increased risk of developing of PASC which could be attenuated by IL-6 inhibitor. Work in progress to confirm these findings by expanding sample size, increasing follow up time and stratifying for confounding factors. <b>Disclosure:</b> Mr. Trivedi has nothing to disclose. Mr. Jaffry has nothing to disclose. Ms. Faiz has nothing to disclose. Mr. Ors has nothing to disclose. Mr. Mandava has nothing to disclose. Mr. Jaffry has nothing to disclose. Miss Shaikh has nothing to disclose. Dr. Surathi has nothing to disclose. Dr. Tofade has nothing to disclose. Mr. Huff has nothing to disclose. Dr. Redko has nothing to disclose. Dr. Souayah has received publishing royalties from a publication relating to health care.