Effect of immunotherapy on sCD23 levels in patients allergic to Hymenoptera venom

Background: sCD23 is the designation given to the low affinity IgE receptor. The soluble fragment of this receptor (sCD23) participates in the regulation of IgE synthesis. Objective: The purpose of this study is to examine the effect of a venom immunotherapy regimen on sCD23 levels. Methods: We measured sCD23 levels by ELISA in Hymenoptera venom-allergic patients (positive skin tests and a history of systemic reactions to Hymenoptera sting) in serial sera collected over a course of venom immunotherapy with a mean duration of 54 months. Mean pre-sCD23 and post-sCD23 levels were compared using a Student's two-tailed t test. Results: sCD23 levels were found to be unchanged over the course of venom immunotherapy. Conclusions: This is the first longitudinal study that has been done. It suggests that while both immunotherapy and sCD23 are known to be involved in the regulations of IgE synthesis in the atopic patient, the immunomodulation seen in venom immunotherapy is not mediated through sCD23 in any simple regulatory manner.