Fast Five Quiz: How Much Do You Know About Chronic Fatigue Syndrome?

Michael Stuart Bronze, MD


December 04, 2015

Some have suggested that the infectious agent responsible for CFS is Chlamydia pneumoniae, which may become activated after contact with another infectious agent. In hospitals or commercial laboratories, immunoglobulin M (IgM) tests and immunoglobulin G (IgG) enzyme-linked immunosorbent assay are used to test for antibodies against C pneumoniae. As with elevated Epstein-Barr virus IgG viral capsid antigen titers, many individuals in the healthy population have elevated IgG titers to C pneumoniae, making the epidemiologic link to CFS more difficult.

Some patients with CFS are found to have elevated IgM C pneumoniae titers, indicating a recent C pneumoniae infection, and these patients are the most likely to respond to antichlamydial therapy. However, definitive proof supporting causality is lacking.

For more on the etiology of CFS, read here.