Table 2

Potential sites of myelomonocytic activation in rheumatoid arthritis and corresponding steps of macrophage intermediate or terminal (trans) differentiation



Differentiation step

Joint or juxta-articular

Synovial membrane

• Recently immigrated monocytes

• Mφ (M1/M2? [64]; resident/inflammatory? [13])

• Dendritic cells

Cartilage-pannus junction

Subchondral bone


Vascular endothelium



Peripheral blood

Circulating monocytes

Bone marrow

• Myelomonocytic precursors

• Endothelial cells

Subendothelial space

Mφ/foam cells/pericytes

Rheumatoid nodules

Epitheloid cells and multinucleated giant cells

Lung interstitial space

Alveolar Mφ

Mφ, macrophages. Reproduced with permission from Kinne RW, Stuhlmuller B, Palombo-Kinne E, Burmester GR: The role of macrophages in rheumatoid arthritis. In Rheumatoid Arthritis. Edited by Firestein GS, Panayi GS, Wollheim FA. New York: Oxford University Press; 2006:55–75 [2].

Kinne et al. Arthritis Research & Therapy 2007 9:224   doi:10.1186/ar2333