Lipopolysaccharides

Lipopolysaccharides (LPS) also known as lipoglycans and endotoxins are large molecules found on the outer membrane of gram negative bacteria. They provoke a strong innate immune response. LPS is an exogenous pyrogen.

One study found higher levels of serum IgA and IgM against LPS in chronic fatigue syndrome patients, indicating bacterial translocation from the intestine into the bloodstream. . Serum IgA was significantly correlated to the severity of illness.

Some LPS molecules have been implicated in autoimmune disease including multiple sclerosis and Guillain-Barré syndrome.