CD153 in Rheumatoid Arthritis: Detection of a Soluble Form in Serum and Synovial Fluid, and Expression by Mast Cells in the Rheumatic Synovium

Objective. A CD30-CD153 mast cell axis has been described in skin inflammations and Hodgkin's lymphoma. We investigated if a Soluble form of CD153 is present in the serum and synovial fluid (SF) of patients with rheumatoid arthritis (RA), and determined whether mast cells express CD153 in the synovium of these patients. Methods. Soluble forms of CD30 and CD153 were quantified in serum and SF of patients with RA by ELISA. Consecutive sections of synovial biopsies from 12 patients were stained against tryptase (mast-cell marker), CD30, and CD 153. Results. Elevated concentrations of the soluble form of CD 153 were found in serum from 14/15 RA patients. In the SF, 11/20 patients had detectable levels of soluble CD 153. CD30 and CD 153 were expressed in all biopsies that were studied. Mast cells were present in all the synovial biopsies, and expressed CD153 in one-third of the cases. Conclusion. We observed that CD153 was expressed in the synovium of patients with RA and we were able to correlate the serum levels of soluble CD 153 with SF levels in the same patients. Because CD30 can activate mast cells to release chemokines without degranulation, Our finding that mast cells express CD153 in RA synovium raises the possibility that a CD30-CD153 axis may contribute to the activation of synovial mast cells in the absence of degranulation. (First Release Jan 15 2009: J Rheumatol 2009;36:501-7; doi: 10.3899/jrheum.080288)