Evaluation of beta 1,4-galactosyltransferase in rheumatoid arthritis and its role in the glycosylation network associated with this disease.

Evidence indicating an important link between glycosylation changes and autoimmune rheumatic disease is presented. Attention is especially focused on the interrelationship between reduced galactosylation of the oligosaccharides of IgG, auto-sensitization which is thought to be of central importance in the pathogenesis of rheumatoid arthritis (RA), and the enzyme beta 1,4-galactosyltransferase (GTase) that catalyses the addition of galactose to the oligosaccharide chains on this molecule. Data are presented to indicate that GTase undergoes a variety of normal and disease associated changes. These variations are believed to contribute to the pathological processes in rheumatoid disease, and a hypothesis is suggested, whereby disease is associated with the dysregulation of an integrated glycosylation network, comprising IgG galactosylation, lymphocytic GTase and anti-GTase antibodies, that is a component of the normal immune system.