SERUM-SOLUBLE CD23 LEVELS IN GIANT-CELL ARTERITIS

Lymphocytes and monocytes express various levels of membrane-bound CD2 3, the low affinity receptor for IgE (Fc epsilon RII), and in some cas es release it as a soluble form. Soluble CD23 (sCD23) has been implica ted in the regulation of many immunological functions of T and B lymph ocytes, macrophages and myeloid cells in humans. To study serum sCD23 levels in inflammatory conditions, we selected a systemic disease sens itive to corticotherapy, the giant cell arteritis, which is characteri zed by an inflammation of the temporal artery. Serum sCD23 levels, as measured by a radioimmunoassay, were increased in these patients, and returned to normal values within the 24 h following initiation of cort icotherapy. The data suggest that the increase in sCD23 levels in gian t cell arteritis results from an overproduction.