“Do Tryptase, ECP and specific IgE measurement by nasal incubation increase the specific nasal provocation test sensitivity?”

BACKGROUND The specific Nasal Provocation Test (sNPT) is a third level diagnostic tool. SNPT has been evaluated measuring nasal resistance and nasal symptoms, reaching a 50% sensitivity. This study focused on the evaluation of three allergic response markers, triggered by nasal challenge (nasal tryptase, specific IgE, Eosinophil Cationic Protein-ECP) at the aim of increasing sNPT sensitivity. SUBJECTS AND METHOD Twenty patients suffering from allergic rhinitis and 16 age-matched not allergic subjects were enrolled in the study. The markers were evaluated by a new method, based on in situ incubation, before and after sNPT. RESULTS Tryptase levels increased in 65% of the patients, were unchanged in 20% , and slightly decreased in 15%. The increase recorded was significant in mite-allergic patients (p=0.005), but not significant (p>0.05) in pollen-allergic patients. ECP values increased in 65% of the patients, were unchanged in 10%, and highly decreased in 25%. ECP increase was not significant (p>0.05). Specific IgE levels increased in 35% of the patients, were unchanged in 55%, and decreased in 10%. The IgE increase was significant in pollen- allergic patients (p<0.05), while it was not significant in mite-allergic patients (p>0.05). The markers were not detected in the control group. CONCLUSIONS The dosage of the markers provided an additional 35% sensitivity, which together with the basal 50% reached an over-all sensitivity of 85% of the sNPT.