IN-VITRO ANTIGEN-SPECIFIC SULPHIDOLEUKOTRIENE PRODUCTION IN PATIENTS ALLERGIC TO DERMATOPHAGOIDES-PTERONYSSINUS

Background Sulphidoleukotrienes (slt) are important mediators in aller gic diseases that are synthesized after allergen-specific stimulation. Objectives The aim of this study is to determine in vitro slt product ion after allergen-specific (Dermatophagoides pteronyssinus) stimulus of peripheral blood leucocytes and to observe whether histamine releas e in whole blood with the same allergen correlates with slt production . We also wanted to evaluate whether a correlation exists between the release of sit and histamine and other diagnostic procedures as well a s various clinical situations. Methods We studied 62 patients sensitiv e to Dermatophagoides pteronyssinus (Der p), 30 atopic controls and 12 healthy donors. We determined sh: production using the CAST-ELISA tec hnique and histamine release using two concentrations of Der p extract (20 and 2 ng/mL). We also carried out quantification of specific and total IgE levels, skin tests and pulmonary function test on each patie nt. Results We observed a significantly increased sit release after in vitro stimulation with Der p. Then was a significant difference in th e sit release between controls and sensitive patients (P < 0.001) and between atopic controls and sensitive patients (P < 0.001). The data a re similar to those obtained with histamine release. W(: noted a posit ive correlation (P < 0.001) between sit and histamine release (r = 0.7 1, at 2 ng/mL and r = 0.83 at 20 ng/ mL). We also found a positive (P< 0.001), although weak (r= 0.4 with at 2 ng/mL, and r= 0.34 with P = 0. 003 at 20 ng/mL) correlation between slt release and specific IgE leve ls as well as between sit release and skin-test reactivity (r = 0.49 a t 2 ng/mL and r = 0.45 at 20 ng/mL; P < 0,001). No significant correla tion between sit release and asthma severity was observed, although a trend toward higher sit production in severe and moderate asthma was d etected, We found a significant (P<0.001) but weak (r=-0.3) negative c orrelation between age and sit release. With respect to sex-related di fferences, we found significant differences (P < 0.05) in sit release between the sexes with a higher sit release in men than in women. Conc lusion We conclude that CAST-ELISA for quantification of sit productio n is a useful in vitro method for diagnosing sensitization to Der p. T here: also exists a close correlation between sit release and other pa rameters of allergic sensitization in vitro as well as in vivo.