ABSTRACT
Allergic rhinitis [AR] is a common disease in children. Eosinophils play an important role in the pathogenesis of allergic rhinitis by releasing toxic granule proteins which are directly involved in the late phase of allergic inflammation. For underst and ing the role of eosinophils in the pathogenesis of allergic rhinitis, the serum level of eosinophil cationic protein [ECP] was measured in children with AR. Blood eosinophilia and serum total IgE level were also evaluated in these patients. The study involved 50 children with AR and 22 normal children as control group. AR was diagnosed by history, skin tests and RAST. Blood sample was taken from each subject, absolute eosinophil count was done and serum used for measuring total IgE and ECP levels by monoclonal antibody based fluorometric assay. Allergen specific IgE antibody was measured by quantitative radioallergosorbent test [RAST] Serum ECP levels in the patient groups were significantly higher than those in the control group [P < 0.01]. All the patient groups studied showed significant high levels of serum total IgE [P<0.001] and total eosinophil count [P<0.01] compared with control group. The increased. level of ECP in patients with AR reflects eosinophil activation and this indicates the role of eosinophil degradation in the pathogenesis of allergic rhinitis. This result may help in developing pharmacological agents that can inhibit migration and /or degradation of eosinophils and hence control of the disease