EVIDENCE OF IMPAIRED POLYMORPHONUCLEAR LEUKOCYTE PHAGOCYTIC FUNCTIONSAND CHEMILUMINESCENCE RESPONSE IN RHEUMATOID-ARTHRITIS

In this study, the phagocytic uptake of H-3-thymidine-labelled Staphyl ococcus aureus and bacterial killing (Bk) by polymorphonuclear leucocy tes (PMN) from patients with rheumatoid arthritis (RA) were investigat ed and compared to the luminol-enhanced chemiluminescence response (LC L) to phorbolmyristic acetate (PMA), a receptor and second message-ind ependent activator of respiratory burst activity in definite or classi cal rheumatoid arthritis (RA), with regard to the inflammatory activit y of the disease process, and compared to patients with osteoarthritis (OA) and healthy controls. PMN of RA patients showed a significant re duction in uptake (57.8+/-4.4%) and less Bk capacity (27.3+/-4.2%) com pared to OA patients (uptake 71.4+/-4.3%, Bk 20.6+/-2.9%; P<0.001) and controls (uptake 73.2+/-5.2%, Bk 19.3+/-4.2%; P<0.001). In contrast, PMN LCL response was markedly enhanced in RA patients compared to OA p atients (P<0.001) and controls (P<0.001). There was no significant inf luence of inflammatory activity on various PMN functions in RA and no difference was found between OA and control subjects. These data clear ly demonstrated impaired PMN phagocytic functions (uptake, Bk) and enh anced LCL in RA, suggesting ''priming'' and/or activated peripheral bl ood PMN, which might be of clinical importance concerning altered host defence in these patients.