Pathogen Discovery Through Longitudinal Serological Surveillance in ME/CFS

SUMMARY Many people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) report that the illness begins with an “infectious-like” prodrome—typically, respiratory and gastrointestinal symptoms, fever, lymphadenopathy, and myalgias. Evidence of immune dysregulation consistent with infection has been reported in blood and cerebrospinal fluid (CSF) by several research groups. Proteomic studies of plasma and CSF revealed evidence of antigen-driven clonal B cell expansion. Up to 40% of patients are reported to respond to intravenous infusions of the Toll-like receptor 3 agonist, Ampligen, a double-stranded RNA analogue stabilized with uridine that is proposed to inhibit viral replication. Others report responses to antiviral drugs specific for herpesviruses, pre- and probiotics, or fecal transplantation. The observation that SARS-CoV-2 infection can lead to chronic disability with clinical features consistent with ME/CFS underscores the importance of exploring the role of infection in the pathogenesis of ME/CFS. Our hypothesis is that some individuals with ME/CFS may experience the onset or worsening of the disease due to an infectious trigger and that previous attempts to implicate infection may have been hindered by suboptimal sampling methods, with respect to the type of samples collected, the timing of collection, and/or limitations in the performance of the assays used. To address this hypothesis, we will shift from efforts during the first cycle of the Center for Solutions for ME/CFS that focused on direct detection of potential microbial triggers to a search for serological evidence of exposure prior to onset of illness using the unique resource of the Department of Defense Serum Repository (DoDSR). The DoDSR comprises >62 million samples collected since 1989 from active and reserve personnel of the Army, Navy, and Air Force linked to a clinical database that can be used to retrieve sera from individuals with specific diagnoses. More than 75% of individuals are represented by multiple specimens collected at annual intervals. Samples collected from people with ME/CFS, before and after diagnosis, and from matched controls, will be interrogated using a high-density short-peptide phage display system that enables quantitation and characterization of antiviral responses indicative of ongoing and past infections, as well as reactivation. We will also test for evidence of immune dysregulation by measuring the levels of cytokines/chemokines using a CLIA- approved Luminex assay. Finally, we will use results of phage display to develop more practical and less expensive diagnostic assays that can be used to facilitate timely identification of microbial triggers that may be associated with the onset and/or exacerbation of ME/CFS.