Effect of extracorporeal granulocytapheresis (G-1) on antigen-induced arthritis in rabbits

Abstract

To investigate the role of granulocytes in arthritis, extracorporporeal granulocytapherersis (G-1) was performed using the column containing cellulose acetate beads in rabbits with immune arthritis.
After injection of ovalbumin into the knee joints of ovalbumin-sensitized animals to induce joint swelling, markedly increased number of granulocytes in peripheral blood and granulocytes accumulation into the arthritic joint were shown. Approximately 18% of granulocytes in whole blood were removed by G-1. Effect of G-1 on granulocytes was investigated by flow cytometry. G-1 treated granulocytes showed a significant decrease in active oxygen production (p<0.05) and lost of LECAM-1 expression (p <0.05) compared with pre treatment granulocytes. The joint swelling was significantly lower in the G-1 group than in the control group, as well as the decreased number of infiltrating leukocytes into the arthritic joint (p< 0.001) .
G-1 appeared to prevent a signficant damage to the tissue by actively controlling leukocytes function and distribution in the inflammatory joints. The results suggested that G-1 could be an effective treatment for inflammatory disorders which granulocytes are chronically or heavily involved.