 Abstract long COVID or post acute sequelae of SARS-CoV-2, PASC, is a clinical syndrome featuring diverse symptoms that can persist for months following acute SARS-CoV-2 infection. The etiologies may include persistent inflammation, unresolved tissue damage or delayed clearance of viral protein or INA, but the biological differences they represent are not fully understood. Here we evaluate the serum proton in samples, longitudinally collected from 55 PASC individuals with symptoms lasting greater than or equal to 60 days after onset of acute infection, in comparison to samples from symptomatically recovered SARS-CoV-2 infected and uninfected individuals. Our analysis indicates heterogeneity in PASC and identified subsets with distinct signatures of persistent inflammation. Type 2 interferon signaling and canonical NFB signaling, particularly associated with TNF, appear to be the most differentially enriched signaling pathways, distinguishing a group of patients characterized also by a persistent neutrophil activation signature. These findings help to clarify biological diversity within PASC, identify. This article was authored by Arthitalla, Suhosviva Sika, Gregory Lee Zetto and others. We are article.tv, links in the description below.