Immunochemical Characterization of Reference Alder (Alnus glutinosa) and Hazel (Corylus avellana) Pollen Extracts and the Partial Immunochemical Identity between the Major Allergens of Alder, Birch and Hazel Pollens

Abstract

Dialysed extracts of alder (Alnus glutinosa) and hazel (Corylus avellana) pollens were characterized by immunochemical methods. The alder pollen extract contained at least 33 distinct antigens of which one, antigen 5, was classified as a major allergen, three, antigens 4, 10, and 17, were classified as intermediate allergens and two, antigens 19 and 23, were classified as minor allergens. The molecular weight and pI of the major allergen were determined to be 19,000 D and 5.2, respectively. The hazel pollen extract contained at least 40 distinct antigens, two of which were classified as major allergens, antigens 8 and 13, three as intermediate allergens, antigens 12, 17, and 26, and seven as minor allergens, antigens 6, 11, 16, 18, 29, 39, and 40. The molecular weights and pI's of the major allergens of hazel pollen were determined to be: antigen 8; Mw = 12,000 D, pI = 5.1 and less than 3.5, antigen 13; Mw = 26,000 D, pI = 5.1. Further, crossed line immunoelectrophoresis and tandem crossed immunoelectrophoresis of alder, birch and hazel strongly indicate that there exists an immunochemical partial identity between the major allergens (antigens 5 (alder), 23 (birch), and 13 (hazel)) from these tree pollens.

Sensitivity of IgG-ELISA for Detecting Airborne Pollen Antigens of Betulaceae

“…Aln g I (antigen 5, 19 kD, PI 5.2), IgE against which has been found in the serum of 95% of allergic patients, consists of 159 amino acids (Florvaag et al 1982, Ipsen et al 1985, Florvaag et al 1986, Marsh et al 1986). Aln g I and Bet Y Z reveal an 86.8% homology.…”

“…They differ in only 30 amino acids and have their IgE-epitopes in the same position. The major allergen of A. incunu is of 22.5 kD (PI 4.78) (Florvaag et al 1982, Ipsen et al 1985. Practically all patients with a marked allergy to birch pollen also react to alder pollen, but the allergic symptoms in the latter case are usually less pronounced (Breiteneder et al 1992).…”

“…Alder allergens 4 and 10 are intermediate and 19 and 23 minor allergens. A total of 33 distinct antigens have been detected in alder pollen extract (Ipsen et al 1985). …”

“…Insufficient IgG-binding to Bet v I in allergic patients may result in failure to inhibit the allergic reaction (Jarolim et al 1989). Ipsen et al (1985) found 40 distinct antigens in hazel pollen extract. They studied two major allergens: antigen 8 (12 kD, p15.1) and 13 (26 kD, PI 5.1).…”

Pollen Allergenicity is Highly Dependent on the Plant Genetic Background: The “Variety”/“Cultivar” Issues

“…Evidence of cross-reactivity of birch allergens among different sources is very high: Crossreactivity exists between pollens from species within the Betulaceae family or belonging to closely related families (Valenta et al 1991a(Valenta et al -c, 1993Yman 1982Yman , 2001Eriksson et al 1987;Jung et al 1987;Ipsen et al 1985;Breiteneder et al 1993;Kos et al 1993;Wahl et al 1996). Moreover, the presence of numerous so-called cross reactivity syndrome have been described, including the "Birch-Mugwort-Celery syndrome" (Ballmer-Weber et al 2000) and the "Celery-Carrot-Birch-Mugwort-spice syndrome" when Carrot and Spices are included (Pauli et al 1985;Dietschi et al 1987;Helbling 1997;Wüthrich and Dietschi 1985;Stäger et al 1991).…”