Serum Reagins and Leucocyte Response in Patients with House-dust Mite Allergy

Abstract

Patients with atopic disease since infancy and who had had infantile eczema were found to react readily to all the challenge tests; nevertheless, even in these highly allergic subjects the titres of the positive reactions were no higher than those of other patients.The possibility that sensitization of some of the patients might have been promoted by the repeated skin, nasal, and bronchial challenge tests has to be considered. The blood samples were therefore taken before the serial in-vivo challenge tests in a random 10 patients. Some of the strongest positive serum and leuoocyte reactions were found in these 10 patients, and in only one were the blood tests weak or negative. These findings indicate that sensitization was unlikely to have been promoted by the testing procedures in the rest of the patients.The negative tests for precipitins suggest that the late bronchial reactions seen in six patients were not mediated by precipitins (as such reactions are in allergic alveolitis) and are not manifestations of Arthus-like type III immune responses in the lung. The mechanism of these late reactions in asthmatic patients has not been established, though such reactions have been described in detail previously and have been estimated to occur in about 30%,' of patients with house dust asthma (Herxheimer, 1952; McAllen, 1Q61). It seems possible that they may be due to cell-mediated immune responses (delayed hypersensitivity).Perhaps the most significant finding in our experiments is that the actual amount of antigen required to produce a tissue reaction both in vitro and in vivo is so extremely small. This is of the order of 0 05 to 1 jig. in the bronchi and 0-5 to 20 ug. in the nose; it would thus be possible under natural conditions for an allergic reaction. to be caused by the inhalation of mite material such as faecal pellets or parts -of dead mites in an amount weighing less than one whole live mite.It is concluded that the negative findings in the control tests and the high titres of sensitivity in the challenge tests on the allergic subjects establish that the mite D. pteronyssinus contains a very potent antigen. This antigen can cause high levels of reaginic antibody and can stimulate histamine release from leucocytes of sensitized patients when brought into direct contact with them in very weak dilution. It is also able to react with sensitized tissues in the skin, the nasal mucosa, and the bronchi in allergic subjects, and can cause symptoms from inhalation of very small quantities. It would therefore appear likely that the mite D. pteronyssinus is an important factor in the causation of perennial allergic asthma in this country.We Positive results were obtained in over 90% of patients, whereas the tests were either negative or very weakly positive in the control subjects. A significant degree of correlation was found between the. two tests used, but pronounced differences were observed in a few instances.Confirmation of the role of IgE in tissue sensitization was obtained from tests with anti-IgE serum on ...

Relationship between Specific Circulating IgE, Basophil Cell-Bound IgE and Histamine Release Induced by Purified Allergens of <i>Dermatophagoides Farinae</i>

“…Most of the previous studies on the cellular response from IgE-sensitized basophils or mastocytes were performed in the presence of anti-IgE [4,5], or crude allergen extracts [6]. The latter situation is not far from natural conditions of allergen exposure but the histamine-release patterns are difficult to interpret since they result from simultaneous triggerings of the IgE of different specificities by their corresponding allergens.…”

“…The ratios (Specific IgE for Dfll): (Specific IgE for Df 6) as determined in the serum or in the cell eluate by the RAST technique are presented on table I la. They are similar for the free IgE in the serum or for the cell-bound IgE in the same patient but differ from l patient to another.…”

“…The quantity of cell-bound IgE per basophil was calculat ed from the number of basophils treated, the quantity of IgE eluted and the molecular weight of IgE ( 1.9 x KPdaltons). 6 and DF 11 in sera and cell eluates from the 3 mite-sensitive patients was investigated by CRIE technique. Control experiments were carried out to determine the exposure time giv ing a specific radiostaining.…”

Antagonism by β‐adrenoceptor blocking agents of the antianaphylactic effect of isoprenaline

“…In this test a modification of the method described by Lichtenstein & Osler (1964) was used (Assem & McAllen, 1970). Leucocytes were challenged with suboptimal concentrations of mite extract ranging from 0-16 to 4 0 ug/ml.…”

Quantitation of IgE on the Basophil Surface in Atopic Patient

“…Assem and McAllen [1] measured his tamine release from atopic (house dust mite) and normal leukocytes challenged in vitro with antigen or sheep anti-IgE serum. They found greater release with lower concentra tions of anti-IgE in atopic subjects as com pared with controls.…”