In vitro release of soluble CD23 by human lymphocytes in ragweed-sensitive versus nonatopic patients following stimulation with ragweed antigen E.

Background: Soluble CD23 is the proteolytic cleavage product of the low affinity receptor (FcERII). Functions of CD23 and its soluble products may include upregulation of IgE production and stimulation of B lymphocyte growth.

Methods: Soluble CD23 was quantitated in supernatants of lymphocytes from nine ragweed-sensitive and eight nonatopic subjects stimulated in vitro by antigen E (amb Al), crude ragweed extract, and pokeweed mitogen (PWM).

Results: Although PWM stimulation produced no significant difference between groups, sCD23 release was significantly elevated in the cells of nonatopic patients stimulated with antigen E and crude ragweed extract (P less than .05).

Conclusions: This finding supports the concept of separate pathways of activation by antigen and mitogen for sCD23 release and suggests ragweed-sensitive and nonatopic patients have fundamental differences in the response of sCD23 release to ragweed antigen stimulation.