Human IgG antibody responses to grass pollen antigens: effects of immunotherapy and comparison of serum and secretory profiles

Heterogeneity of a major allergen from olive (Olea europea) pollen

Studies were carried out in order to confirm and extend knowledge of the physico-chemical properties of an allergenic material found in the pollen of the olive tree (Olea europea). The sera from 88% of patients who were sensitive to olive pollen contained IgE that reacted with a 19,000 Mr component and many also reacted to a 17,000 Mr band as shown by SDS-PAGE immunoblotting. A monoclonal antibody (OL-1) produced to the 19,000 Mr component also reacted with the 17,000 Mr band, and with bands at 21,000 and 41,000 under non-reduced conditions. HPLC separation followed by SDS-PAGE and immunoblotting of the fractions indicated that the allergen fraction from which the 19,000 and 17,000 components were derived had a mol. wt between 50 and 60 kD. Isoelectricfocusing followed by immunoblotting and development with (OL-1) indicated heterogeneity of the allergen with respect to pI values. Two of the strongest components of the six identified which reacted with (OL-1) had pIs of about 5.0 and 6.0 confirming the published data. The study therefore showed that olive pollen contains a number of allergenic components, with various mol. wts and pI values, with some epitopes in common, which may in the native state be bound together or aggregated.

A long-term follow-up study of hyposensitization with immunoblotting

The formation of specific IgE, IgG1, and IgG4 antibodies was investigated by immunoblotting during hyposensitization with timothy grass-pollen extract and 6 years later, Until the end of immunotherapy, specific IgG antibody levels increased. Also simultaneously, the number of allergenic components detected by IgG increased. However, this IgG response was similar in responding and nonresponding patients; thus, it did not correlate with the clinical outcome of the therapy. More allergenic compounds were also detected by IgE on immunoblots, but again without correlation to success of therapy. Six years after immunotherapy, the therapeutic effect was still present, although by now the observed immunoglobulin-binding patterns were similar to patterns observed in the same patients' sera collected before the initiation of hyposensitization. Thus, changes of antibody-binding patterns in immunoblot do not relate to the success or failure of immunotherapy.

The role of nasal secretions in allergic disease of the nose

Findings in recent years have stressed the importance of research on the target organ in IgE-mediated allergies of the respiratory tract. In this review we have focussed on the nasal secretions (NS) as a contract medium between allergens and the respiratory mucosa. Our findings have demonstrated that NS show different allergen extraction activities in relation to different conditions. Whereas NS of allergic and inflamed noses extracted allergens very rapidly, NS of normal noses showed no extraction activity. Furthermore, it could be demonstrated that the IgE specificities in NS are comparable with those in the serum of individual patients not indicating a local IgE synthesis. The presence and function of basophilic cells and eosinophils and their mediators are discussed in the light of recent studies.

Reactivities of immunoglobulin E and immunoglobulin G subclasses identified by isoelectric focusing-immunoprint in allergic patients

Probing of IgE or IgG subclass reactivities on single allergenic components in an extract is tedious and time-consuming under native conditions. Isoelectric focusing immunoblotting combines a powerful, highly resolving native separation method with the specificity and sensitivity of immunological test methods. This method is easy and quick to perform. The potential usefulness of this method is demonstrated by eight examples of a type I or type III allergy analyzing IgE and IgG subclass reactivities and their distribution.