Allergic rhinitis, olfactory disorders and secretory IgA.

Abstract

The authors point out the possible relationship between the biochemical and immunological components of nasal mucus in subjects affected by allergic rhinitis and/or olfactory disorders. Fifty seven subjects (33 F, 24 M) aged between 19 and 73 years, (median age 65 SD 14.60) were studied. Twenty seven of them were normosmic affected by allergic rhinitis and taken as control group, (14 were positive to allergometric tests and/or RAST, while the other 13 were negative), 30 were dysosmic, and subdivided into parosmic (n = 6), anosmic (n = 15) and hyposmic (n = 9) (only one was negative both to allergometric tests and to RAST). In all patients we assessed: nasal mucus (it was analysed for: mucus quantity, pH, protein concentration, K+ concentration and the SIgA antibodies, tested both by radian immunodiffusion and by ELISA), allergometric tests, PRIST, RAST, anterior rhinomanometry, evoked olfactory potential. As regard to allergometric tests, we have no observed statistically significant differences between the control and the dysosmic group, although all the dysosmic patients (except one) were positive both to allergometric tests and to RAST. Total (PRIST) and specific (RAST) IgE values (except for the anosmic subjects who had IgE values moderately higher) were similar to the results obtained by allergometric tests. As regards to nasal secretion quantity, it was reduced (p: n.s.), like the pH (p: n.s.), in the parosmic subjects. On the other hand, proteins concentration of nasal secretion was lowered in hyposmic (p: n.s.) and anosmic (p = 0.05) subjects, while there were no differences between parosmic subjects and control group. The values of SIgA in controls and hyposmic subjects were not too different and similar to those observed by other authors; however they were slightly increased in controls affected by allergic rhinitis with positivity both to RAST and/or allergometric tests (p: n.s.), while they were reduced in the parosmic and significantly in the anosmic patients (p < 0.01). On the basis of that data, the authors conclude that, (though related to a limited case reports) being the secretory IgA values inversely proportional to the gravity of olfactory pathology, a their protective role (if the anatomic-functional substratum is efficient), in the pathologies examined, can be easily hypothesized. Besides, that data highlight that their concentration is slightly decreased in those patients affected by allergic rhinitis, without olfactory disorders (p: n.s.).