M. pneumoniae IgG details

This antibody indicates past exposure to Mycoplasma pneumoniae, a common bacterium responsible for a type of mild-to-moderate respiratory infection sometimes called 'walking pneumonia,' since people often remain active despite having pneumonia. Because IgG antibodies persist long after infection clears, a positive result mainly reflects past exposure at some point rather than a current, active infection — for identifying a recent or ongoing infection, IgM antibodies or direct detection methods are more useful.