[Specific nasal provocative test in allergic rhinitis diagnosis: reliability and standardization]

Specific vasomotorial rhinopathy, or allergic rhinitis is to be seen as a systemic pathology characterized by a condition of hyperactivity, the target organ of which is the nose. Particular attention, among the diagnostic tests, should be reserved to the specific nasal provocative test (sNPT), which has been part of the clinical routine for years but has nonetheless failed to achieve a suitable level of standardization. With this intent, we have devoted the present work to the assay of several phlogosis mediators (tryptase, specific IgE and ECP) before and after performing the sNPT. We have studied 20 patients affected by allergic rhinitis, aged between 13 and 61, with single or multiple allergen sensitivities, but in any case with a predominant sensitization, who underwent sNPT between October 2000 and July 2001. In every patients we performed ECP, tryptase and specific IgE assay via direct incubation in the nasal mucosa, before and after specific nasal provocation. The results of the sNPT (rhinomanometry and symptoms score) were compared with the variations in the phlogosis mediators assayed at nasal level. On the basis of the variations in the rhinomanometric resistance and symptoms score, the sNPT was positive in 10 patients (50%). Tryptase and specific IgE increased to a statistically significant degree (respectively, p = 0.01 and p < 0.05) in all of the patients; the ECP variations, instead, were not significant (p > 0.05). Overall, the simultaneous assay of ECP, tryptase and specific IgE, increasing the sensibility of the sNPT, enabled a positive result to be ascertained in 60% of the subjects examined. The method is furthermore based on the principle of local reactivity in that it assays the phlogosis mediators not at systemic level, but directly in the target organ, showing itself to be more specific than level I and II tests.