Correlation between some parameters in active seasonal allergic rhinitis: a controlled clinico-immunological study

ABSTRACT

Allergic rhinitis is a global disease with increasing prevalence worldwide. It is characterized by inflammatory cells and mediators of which, eosinophil and IgE, are playing a central role. IgA with its two forms [serum IgA and secretory IgA] is one of the respiratory system defense mechanisms against pathogens, however, its role and its relation to other allergic inflammatory parameters is still under investigation. This study was conducted on twenty allergic rhinitis patients and ten apparently healthy persons as a control to test the correlation between different parameters in allergic rhinitis including; eosinophil count, IgE, IgA levels and symptoms score in active symptomatic seasonal allergic rhinitis. Results showed that blood eosinophil percentage and nasal eosinophil count as well as serum IgE were significantly increased in patients than controls. Secretory IgA [sIgA] in nasal secretion but not serum IgA was significantly increased in patients group indicating excess local production; which is probably a part in the allergic reaction. There was a positive correlation between serum eosinophil percentage and eosinophil count in nasal secretion and serum IgE levels, which may suggest that eosinophil count in nasal secretions; could be a reliable tool in diagnosis of allergic rhinitis. sIgA in nasal secretions increased in patient's group and is found to be positively correlated to nasal eosinophil count, which may suggest a role of sIgA in the pathogenesis of allergic rhinitis. Although there was a positive correlation between nasal obstruction score and nasal eosinophil count, however, as it is a subjective scoring, it can't be relied on until accurate objective scoring is used to measure nasal obstruction. The present study stressed on the importance of meticulous history taking [symptoms score]. The results stressed on the opinion that serum IgE and eosinophil count are good markers for allergic rhinitis, also, nasal cytology for eosinophil count could be used to assist in diagnosis; it is easy, simple and east to help in differentiation of allergic from non allergic rhinitis. The findings of IgA raise the point that it's measurement could be a good tool to be added to the battery of parameters for diagnosis or evaluation of the severity of allergic rhinitis together with follow up of patients. IgE, IgA, IgG immunoglobulin E, A, G., sIgA secretory IgA., HDM House dust mites, Fc fraction crystalline, ELISA Enzyme linked Immunosorbent Assay, ECP eosinophilic cationic protein, PO eosinophil peroxidase, EDN eosinophil- derived neurotoxin, TNF-alpha tumor necrosis factor alpha, SAR=seasonal allergic rhinitis, HPF high power field