A Comparison of FcepsilonRI-mediated RANTES Release from Human Platelets Between Allergic Patients and Healthy Individuals

Background: Recently some studies have suggested that human platelets may play an important role in allergic inflammation through the high affinity IgE receptor (FcepsilonRI), the low affinity IgE receptor (FcepsilonRII/CD23) and the low affinity IgG receptor (FcgammaRIIA/CD32) expressed on the cell surface. We reported that human platelets via the FcepsilonRI induced the release of the chemical mediator serotonin and the chemokine RANTES (regulated upon activation, normal T expressed and presumably secreted), but the biological implication of human platelets in type I allergy has not yet been understood clearly.

Methods: We compared the levels of RANTES release from platelets obtained from allergic patients and healthy individuals, stimulated with monoclonal antibody (Ab) to human FcepsilonRI alpha-chain, or human myeloma IgE and anti-human IgE Ab.

Results: We confirmed that the level of RANTES release from platelets of allergic patients stimulated with human IgE and anti-human IgE was significantly higher than that of healthy individuals.

Conclusions: We demonstrated that the surface expression levels of FcepsilonRI on the platelets from allergic patients and healthy individuals were not significantly different, but that the platelets of allergic patients were more activated by the IgE-FcepsilonRI pathway than those of healthy individuals. Taken together, these results suggest a novel and important role for human platelets in perpetuating allergic inflammation through the IgE and FcepsilonRI.