A comparison of Fc epsilon RI-mediated RANTES release from human plateletsbetween allergic patients and healthy individuals

Background: Recently some studies have suggested that human platelets may p lay an important role in allergic inflammation through the high affinity Ig E receptor (Fc epsilon RI), the low affinity IgE receptor (Fc epsilon RII/C D23) and the low affinity IgG receptor (Fc gamma RIIA/CD32) expressed on th e cell surface. We reported that human platelets via the Fc epsilon RI indu ced the release of the chemical mediator serotonin and the chemokine RANTES (regulated upon activation, normal T expressed and presumably secreted), b ut the biological implication of human platelets in type I allergy has not yet been understood clearly. Methods: We compared the levels of RANTES rele ase from platelets obtained from allergic patients and healthy individuals, stimulated with monoclonal antibody (Ab) to human Fc epsilon RI alpha -cha in, 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 hea lthy individuals. Conclusions: We demonstrated that the surface expression levels of Fc epsilon RI on the platelets from allergic patients and healthy individuals were not significantly different, but that the platelets of al lergic patients were more activated by the IgE-Fc epsilon RI pathway than t hose of healthy individuals. Taken together, these results suggest a novel and important role for human platelets in perpetuating allergic inflammatio n through the IgE and Fc epsilon RI. Copyright (C) 2001 S. Karger AG, Basel .