Morphological changes of basophils in immunological reactions--effect of sodium cromoglycate

Basophil immunoglobulin receptors in asthmatics under immunoscanning electron microscopy

Immunolatex particles were used as markers for IgE receptors on basophils using electron-microscope scanning. These particles appeared to bind specifically to basophils. Basophils from atopic asthma patients showed greater binding to latex particles than those from intractable asthma patients or healthy subjects. Cap and patch formations on IgE receptors were frequently found in basophils of atopic asthmatics, and cap formation was observed only on basophils that were pear-shaped. The redistribution of IgE receptors, such as that by cap formation, may be a significant triggering mechanism for basophil activation. The latex density on basophils pre-treated with anti-human IgG was much greater in intractable asthmatics than in atopic asthmatics or healthy subjects, and almost all basophils with increased immunolatex particles were pear-shaped, suggesting the presence of some IgG receptors on the surface, and such receptors may play an important role in intractable asthma.

Decrease in reactivity of basophils by immunotherapy with housedust extract

Changes of basophil reactivity to housedust extract and anti-IgE during immunotherapy was examined in thirteen patients with bronchial asthma sensitive to housedust. (i) A significant decrease in the morphological reactivity of basophils to housedust extract was observed 6 months after the beginning of immunotherapy with the antigen, and a significant decrease after 12 and 18 months' therapy, accompanied with the decrease of histamine release from the cells. The percent reactive basophils to the antigen decreased from 59.2 +/- 2.9% before the therapy to 40.0 +/- 1.8% after 18 months' immunotherapy. (ii) A decrease in the morphological reactivity of basophils to anti-IgE was also shown during immunotherapy. The basophil reactivity to anti-IgE decreased significantly at the late stage (18 months) of immunotherapy. (iii) A significant reduction of specific IgE antibody to housedust was observed 12 and 18 months after the beginning of immunotherapy. It was suggested from these results that immunotherapy causes some changes on the surface of basophils and decreased reactivity of the cells, and that a decrease of reactive basophils to anti-IgE in the process of immunotherapy might be due to a decrease in number of IgE receptors essentially or functionally.

New in vitro method for detecting asthma allergen. Counting reactive basophils after addition of allergen

Changes in the morphology and number of basophils were examined after the addition in vitro of house dust extract in cells from seventy-seven patients with bronchial asthma. Morphological changes (reactive basophils) showed a close relation to the end-point titrations of antigen in skin tests, RAST score and bronchial provocation tests, but changes in number of basophils did not. With a RAST score of 2 or greater the change in reactive basophils varied from 40 to 80% (mean 58.1%), which was much greater than seen in persons with no RAST, score 0. Patients with positive bronchial inhalation tests, showed 40 to 80% (mean 57.8%) reactive basophils, whereas persons with a negative bronchial challenge test showed a range of reactive basophils from 0 to 50% (mean 28.9%). The difference in percentage of reactive basophils between the positive and negative groups of persons tested by bronchial inhalation was statistically significant.

Supravital observation of in vitro basophils in immunological reactions

The migration velocity and morphology of basophils in vitro were examined after the addition of anti-immunoglobulin (anti-IgE or anti-IgG). In atopic asthma patients with high serum IgE levels (more than 1000 i.u./ml) basophils showed increased migration velocity and showed pear-shaped and palmate processes after the addition of anti-IgE, but on the addition of anti-IgG, these basophils did not show increased migration velocity or morphological changes. In intractable asthma patients with low serum IgE levels, these changes occurred with anti-IgG but not with anti-IgE. These in vitro findings suggest a basophil reactivity to anti-IgE and anti-IgG in individual patients and support our previous differentiation of asthma patients according to basophil reaction.

Differences in response to anti-IgE and to anti-IgG in basophils from patients with bronchial asthma

Peripheral blood basophils of thirty-eight patients with bronchial asthma were examined for their reactivity to anti-IgE and anti-IgG antisera. Basophils of patients with serum IgE levels of more than 1001 i.u./ml reacted strongly to anti-IgE. Basophils of patients with serum IgE levels of less than 100 i.u./ml had a tendency to react more strongly to anti-IgG. An index (basophil ratio) was devised to compare the patient basophil reactivity to anti-IgE and anti-IgG. This basophil ratio was lower (IgE dominant) in the atopic cases which usually exhibited a high serum IgE level. Most cases with low serum IgE exhibited a high basophil ratio (IgG dominant). The basophils of seven intractable patients reacted more strongly to anti-IgG than to anti-IgE regardless of the serum IgE level.