Premium
A comparative study of the tryptase release test and the cellular allergen stimulation test (CAST) in mite sensitive patients
Author(s) -
Rossi Re,
Giorgio Monasterolo,
D. Operti
Publication year - 1998
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1046/j.1365-2222.1998.00310.x
Subject(s) - tryptase , allergen , immunoglobulin e , immunology , medicine , stimulation , basophil activation , allergy , house dust mite , leukotriene c4 , mite , radioimmunoassay , pyroglyphidae , antibody , leukotriene , asthma , mast cell , basophil , biology , botany
Background The stimulation of blood basophils to release mediators in vitro is widely used for diagnosis of allergic diseases. Tryptase release and sulphidopeptideleukotriene production are both triggered by cross‐bridging of adjacent IgE molecules on the surface of IgE‐bearing basophils. Objective We have compared the sensitivity of tryptase release test (TRT) and cellular allergen stimulation test (CAST) which, respectively, measure tryptase and sulphidopeptideleukotrienes that are produced upon cell stimulation by mite extracts. Methods Blood was taken from 247 patients with allergy to mites and 137 non‐allergic control subjects. We measured tryptase release from basophils after allergen challenge in vitro by sandwich radioimmunoassay. The sulphidopeptideleukotrienes production was quantified by an ELISA test based on a monoclonal antibody which recognized leukotriene T4 (LTC4) and its metabolites LTD4 and LTE4. Results Our data show that both methods are equally effective to distinguish allergic patients from normal controls ( P > 0.0001). There was a significant correlation between mite‐specific serum IgE and CAST results ( r = 0.69 for Dermatophagoides pteronyssinus ; r = 0.73 for Dermatophagoides farinae ). Correlations between IgE against mites and tryptase values appeared rather poor ( r = 0.47 for Dermatophagoides pteronyssinus ; 0.49 for Dermatophagoides farinae ). Moreover, the data were used for the calculation of sensitivity, specificity, prevalence, and overall efficiency (Roc/Galen & Gambino analysis). The results were as follows: 71%, 87%, 64%, 76% (CAST results for Dermatophagoides farinae ); 64%, 78%, 53%, 70% (TRT results for Dermatophagoides farinae ). Conclusion The partial discrepancies observed could be interpreted as a consequence of conditions that were technically not optimal. False‐positive results may be due to the action of some non‐specific cytotoxic agent, false‐negative results may be due to hyporesponsive basophils or the low number of cells participating in the reaction and finally, in the case of TRT, to G4 monoclonal antibody to tryptase employed.