Monocyte Function in Rheumatoid Arthritis

Abstract

Monocytes derived from peripheral blood of patients with rehumatoid arthritis (RA) had a marked defect in their bactericidal activity against Staphylococcus al-bus and Listeria monocytogenes; whereas the phagocytic capacity of monocytes from RA patients for both Staph. albus and Shigella flexneri was similar to that of monocytes from healthy subjects. There were no significant differences between the patient and control groups with regard to antibody dependent cellular cytotoxicity (ADCC) of monocyte against antibody-coated EL₄ leukemia tumor cells. No correlation was observed between the rheumatoid factor (RF) liter in the serum of RA patients and the ADCC capacity of their monocytes. The ADCC of normal monocytes was reduced markedly following their incubation with serum from RA patients. It suggested that the defect in bactericidal activity in monocytes from RA patients may explain, at least in part, the susceptibility of RA patients to infections.