Abstract

Blood polymorphonuclear cells (PMNs) from 40 patients with rheumatoid arthritis (RA) and 40 normal subjects were incubated with confluent cultures of porcine aortic endothelium and their adherence assessed by either a microscopic or radiometric enumeration assay. There was no difference between the number of rheumatoid and control PMNs adhering. The synovial fluid PMNs from patients with RA were less adherent than their paired blood samples when autologous serum was present in the incubation medium and more adherent when serum was absent. Most of the RA sera tested inhibited the adhesion of normal PMNs, an effect that was not due to an increase in PMN aggregation. A similar inhibition was seen with sera obtained from patients with Felty's syndrome. These findings suggest that there is no intrinsic difference between the adhesiveness of rheumatoid PMNs and normal PMNs but that there are soluble factors present in RA serum which inhibit the attachment of normal PMNs to vascular endothelium.