Delayed neutrophil apoptosis in very early rheumatoid arthritis patients is abrogated by methotrexate therapy

Abstract

Objectives. To analyse the activation state and apoptosis of circulating neutrophils in untreated very early rheumatoid arthritis (VERA) and after exposure to low dose corticosteroids and methotrexate (MTX). Methods. Neutrophils were isolated from the peripheral blood of VERA patients at 3 different times: before any treatment was started, 2 weeks after starting a low dose of prednisone (5-10 mg) and 4 months after reaching more than 20mg/week of MTX. The expression of different activation markers (CD11b, CD64, CD86 and CD69) in freshly isolated neutrophils was analysed by flow cytometry. Apoptosis was measured by the loss of DNA content, which was analysed by flow cytometry using propidium iodide. Results. Compared to neutrophils from healthy controls, we have found a delayed neutrophil apoptosis within 6 h and 22 h of cultured polymorphonuclear leukocytes (PMN) derived from VERA patients without any treatment or treated with corticosteroids. The delay of PMN apoptosis was restored to control levels after treatment with MTX. Conclusion. The treatment of VERA patients with corticosteroids did not affect the delay of neutrophil apoptosis. However, delayed apoptosis was restored to control levels after treatment with low dose MTX, which highlights the importance of early RA treatment with MTX. © Copyright Clinical and Experimental Rheumatology 2007.