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. . 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.