CD40LG and myalgic encephalomeyelitis/chronic fatigue syndrome: Raised serum concentrations of IgA and IgM to lipopolysaccharide (LPS) of gram-negative enterobacteria, such as Pseudomonas aeruginosa, Morganella morganii, Proteus mirabilis, Pseduomonas putida, Citrobacter koseri, and Klebsiella pneumoniae have been reported in CFS patients [12].