Lymphocytes from patients with rheumatoid arthritis produce agalactosylated IgG in vitro.

The percentage of oligosaccharide chains lacking galactose was measured in IgG obtained from pokeweed mitogen-activated cultures of blood lymphocytes from patients with rheumatoid arthritis and controls. Secreted IgG from rheumatoid arthritis lymphocytes was deficient in galactose compared with IgG from the lymphocytes of controls. This confirms that agalactosylation is a significant feature of the disease and demonstrates that it can occur at the B cell level and is not merely a post-secretory event.