Antibody Response following Prolonged Hyposensitization with <i>Dermatophagoides pteronyssinus</i> Extract

Abstract

An antigen-binding radioimmunoassay was used to measure IgG, IgA and IgE antibody (ab) to Dermatophagoides pteronyssinus in sera from patients who had been hyposensitized with either aqueous D. pteronyssinus extract or placebo. An allergen, F₄P₁, was obtained from D. pteronyssinus culture and ¹²⁵I-labelled for use in the assay. The radio-allergosorbent test was also used to measure IgE ab to D. pteronyssinus and IgE ab to Dermatophagoides farinae. The radioimmunoassay results showed a selective rise in IgG ab in sera from D. pteronyssinus-treated (DP) patients. An increase of greater than twofold in IgG ab in post-treatment sera was found in 27 of 29 DP patients compared to 1 of 29 placebo-treated (‘placebo’) patients (p < < 0.001). The mean rise in IgG ab in DP patients was sixfold, and the maximum rise was 50-fold. There was little change in the levels of IgA ab or IgE ab in either DP or ‘placebo’ patients during treatment. The DP patients showed significant clinical improvement compared with the ‘placebo’ patients (p < 0.01). However, no correlation was found between post-treatment IgG ab and post-treatment symptom scores, or between the changes in IgG ab and the changes in symptom scores during treatment. The time course of the antigen-binding assay was investigated using very low concentrations of F₄P₁ The results showed that antigen-binding was slow, even in the presence of an excess of IgG ab. The role of IgG ab in hyposensitization is discussed.

The Immune Response to Bee Venom

“…Thus, the anti body response to PLA: is distinct from that to inhalant allergens in three respects: (i) there was IgG antibody to PLAi in most of the non-allergic bee keepers; (ii) IgG antibody to PLA2 was often much higher than the IgE antibody and there was no correlation between the two classes, and (iii) the IgG antibodies to PLA; did not appear to be produced locally in the nose. The IgG/IgE antibody ratios were often low in subjects who had rhinitis and did not appear to be related to the severity of symptoms [26], By contrast, IgG/IgE ratios of anti-PLA: were often very high in patients who had severe generalized reactions to bee stings. This emphasizes that at present simple measurements of IgE antibodies and blocking antibodies cannot predict the nature of allergic symptoms.…”

Failure hyposensitisation in treatment of children with grass-pollen asthma.

“…We studied 13 boys and seven girls aged 9 to 14 years (median 11 years). They were selected as follows.…”

Immune Response to Bee Venom

“…(mean 722:1) than for Rye 1 (mean 6.3:1) [10] or antigen-Pl (7.6:1) [11]. This study was undertaken to determine if these differences were a function of the route of administration or of the dose of antigen received by comparing the response to bee venom PLA2 with that to HYAL (bee venom con tains approximately 10 times more PLA2 than HYAL).…”