Dynamics of blood neutrocytes and adhesion molecule CD11b in mouse collagen-induced arthritis: comparison with prednisolone treatment

Abstract

It has been reported that peripheral blood neutrocytes from Rheumatoid Arthritis patients expressed significant higher basal levels of CD11b than normal donors. And non-steroidal anti-inflammatory drugs diminished an adhesion molecule CD11b/CD18. We investigated the second population of blood leukocyte i.e. neutrocyte by using Flow cytometry in collagen-induced arthritis (CIA), one of the most-established models of Rheumatoid Arthritis. On CIA-day 28, when a dim sign has begun to develop in limbs, neutrocyte/lymphocyte rate and the percent of Ly6G+ cells co-expressing CD11b increased significantly without a change of white blood cell count. On day35, the neutrocyte/lymphocyte rate and the percent of CD11b+/Ly6G+ cells returned to the normal value when the remarkable increase in the score of symptoms developed clearly. The group of Prednisolone treatment 10mg/body was accompanied with significant decrease of leukocyte count but the onset of arthritis was completely suppressed and the circulating number of neutrocyte, ups and downs in the percentage of CD11b+/Ly6G+fraction were almost similar with control. We conclude that as for CIA, the peripheral blood neutrophilia and an increase of adhesion factor CD11b are present before onset of arthritis. Prednisolone inhibited the onset of arthritis completely, but did not inhibit the neutrophilia and the neutrocyte surface expression of CD11b. [Jpn J Physiol 55 Suppl:S231 (2005)]