Cluster Of Differentiation 23 (CD23)

CD23 is the "low affinity" receptor for IgE, an antibody isotype involved in allergy and resistance to parasites and is important in regulation of IgE levels. Unlike many of the antibody receptors, CD23 is a C-type lectin. It is found on mature B cells, activated macrophages, eosinophils, follicular dendritic cells and platelets.

There are two forms of CD23: CD23a and CD23b. CD23a is present on follicular B cells, while CD23b requires IL-4 to be expressed on T-cells, monocytes, Langerhans cells, eosinophils and macrophages.The allergen responsible in dust mite allergy, Der-p-1, is known to cleave CD23 from a cells surface. As CD23 is soluble it can move freely and interact with cells in plasma.