Objectives: We investigated the use of eosinophilic cationic protein (ECP) as an indicator of clinical efficiency of specific immunotherapy (SIT) in patients with allergic rhinitis sensitive to house dust mites.
Patients and methods: Specific immunotherapy was administered to 49 patients (20 males, 29 females; mean age 34.2 years; range 16 to 66 years) with perennial allergic rhinitis. Nasal secretion and serum ECP levels were measured before, at the 6th month of, and two years after completion of, treatment. Comparisons were made within the patient group and with a control group of 16 healthy subjects (10 males, 6 females; mean age 23 years; range 17 to 26 years).
Results: Pretreatment nasal ECP levels were significantly higher than those found after the treatment (p<0.001). Nasal ECP levels measured before SIT were significantly different from those of the control group (p<0.05). However, serum ECP levels did not differ significantly between the two groups (p>0.05). Serum ECP levels in the patient group tended to decrease with treatment (p>0.05).
Conclusion: We conclude that, in addition to the symptoms and clinical findings, nasal ECP measurement may be a reliable and suitable laboratory method to monitor and evaluate the effectiveness of treatment.