Superoxide anion production by circulating polymorphonuclear leucocytes in rheumatoid arthritis.

In twelve rheumatoid arthritis (RA) patients, receiving only nonsteroid anti-inflammatory therapy, superoxide anion (02-) generation by polymorphonuclear leucocytes (PMNs) was assessed by Cytochrome C reduction. The 02- production by non-activated PMNs in RA patients was significantly higher than in healthy controls. The 02- production by PMNs activated by zymosan and phorbol myristate acetate was significantly lower than in controls. PMNs from controls preincubated with rheumatoid sera generated higher 02- levels than the same PMNs incubated in normal sera.