Predictors for Developing Severe ME/CFS Following Mononucleosis

Abstract

Background : Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating illness affecting over a million people in the US. About 9-12% of individuals develop this syndrome six months following Infectious Mononucleosis (IM); those who meet > 1 set of criteria for ME/CFS are termed severe ME/CFS. We sought to determine why some individuals develop ME/CFS following IM while most recover. Methods: Our study was a prospective cohort study conducted at Northwestern University. We recruited a cohort of college students before, during, and after being infected with IM. Those who developed IM were followed-up with at six months to determine whether they recovered or met criteria for ME/CFS. We explored baseline levels and severity at follow-up of IM variables for those who recovered from IM and those who developed severe ME/CFS 6 months following IM. Findings: Pre-illness variables that differentiated these groups included baseline gastrointestinal symptoms and certain cytokines. At onset of IM, gastrointestinal symptoms differentiated the two groups. Interpretation: The differences that emerged predicted the onset of severe ME/CFS following IM. Our research has thus uncovered risk factors predisposing to non-recovery following IM so that preventative and treatment strategies for ME/CFS may now be devised and studied. Funding: This work was supported by the National Institute of Allergy and Infectious Diseases [grant number AI 105781]. Declaration of Interest: The authors declare no competing interests. Ethical Approval: Institutional Review Board approval was obtained.