MIF production of lymphocytes from patients with rheumatoid arthritis with antigen-antibody complexes

Immune complexes, human erythrocytes coated with human IgG antibody, inhibit the migration of lymphocytes from rheumatoid arthritis (RA) patients. No correlation could be observed between migration inhibition and Waaler-Rose titre (sheep cell agglutination titre) in inidvidual patients. Production of migration inhibitory factor (MIF) could be detected in 16 of 20 cultures of RA lymphocytes incubated with antigen-antibody complexes, when the supernates were tested with guinea pig macrophages. Only two supernates of healthy persons showed migration inhibition activity under these conditions. The results suggest that migration inhibition by antigen antibody complexes in RA represents a true reaction of delayed hypersensitivity.