Hypogalactosylation of immunoglobulin G sugar chains and elevated serum interleukin 6 in Castleman's disease

Immunoglobulin G (IgG) molecule has two N-linked complex type oligosaccharides, consisting of a mixture of at least 12 different structures. The pattern of these oligosaccharides is fairly constant in healthy individuals. In three patients with Castleman's disease, in whom serum interleukin 6 (IL-6) levels were elevated, agalactosyl species of serum IgG oligosaccharides were markedly increased as compared to those of normal healthy controls. A close relationship between increased IL-6 and altered IgG oligosaccharide structure is suggested.