A comparison of two in vitro methods for studying a defect in leucocyte movement in rheumatoid arthritis.

Filter and agarose plate techniques have been used to study an abnormality of polymorphonuclear leucocyte movement in patients with rheumatoid arthritis. The chemotactic response of normal cells towards activated rheumatoid plasma was significantly less than that towards activated control plasma when examined in Boyden chambers. This defect was not observed using the agarose plate method where the response of both control and rheumatoid cells towards activated rheumatoid plasma was identical. The existence of the plasma defect, which has been shown to be cell-directed, would not have been apparent had the agarose plate method been used alone. The choice of suitable in vitro methodologies for studying leucocyte movement in pathological conditions is therefore of some importance.