House dust mite asthma. Correlation between allergen sensitivity in various organs.

Fifty asthmatics, candidates for hyposensitization with the house dust mite Dermatophagoides pteronyssinus (Dp), went through a series of allergy tests to evaluate the sensitivity of different organs to Dp. All patients were exposed to bronchial challenge with histamine and bronchial, nasal and conjunctival challenge with Dp, skin prick test (SPT) with Dp, analyses for Dp-specific histamine release from blood cells (HR) and for anti-Dp-IgE in serum (RAST). Results from 40 patients reacting positively in all tests were further analysed. Sensitivity to Dp in the various organs did not parallel, but a fair correlation was demonstrated between pulmonary allergen sensitivity and HR (r = 0.65, P less than 0.001), and between pulmonary sensitivity to allergen and to histamine (r = 0.47, P less than 0.001). Combined variations in HR and in (unspecific) bronchial sensitivity to histamine explained 53% of the variation in bronchial sensitivity to the allergen. This parameter showed less correlation to RAST and SPT (r = 0.31 and r = 0.35, P greater than 0.05). The results indicate that bronchial allergen challenge cannot be replaced by similar challenge of other organs, since the sensitivity of the mucosa in different organs of the same patient seems unrelated. Diagnosis should therefore be based on challenge of the organ with dominating clinical importance. In our selected group of patients, however, it was indicated that a substitution of the result of bronchial allergen challenge by measurement of unspecific bronchial reactivity, together with information on the general allergen sensitivity on a cellular level, might be possible. The unpleasant symptoms of the immediate and late bronchial reactions to allergen challenge could thereby be avoided.