Hyposensitization of Patients With Allergic Rhinitis by Intranasal Administration of Chemically Modified Grass Pollen Allergen

Abstract

Immunotherapy has been used for more than 60 years in patients with allergic rhinitis (21). The mechanism underlying the clinical improvement that is often achieved by such treatment is still unclear. One factor that might contribute to this effect in parenteral hyposensitization is the occurrence of high levels of so-called blocking antibodies (3). These are considered to belong mainly to the immunoglobulin class G (16, 17).A good allergen extract for hyposensitization should stimulate a high production of blocking antibodies without giving any local or general side effects. With a view to obtaining such allergen solutions, depot preparations with delayed absorption of the allergen (5, 8, 15) have been developed. Further efforts have been made, by modifying an allergen with different chemical substances (15,18,20,26), to reduce its allergenicity, i.e. its symptom-evoking properties, while at the same time retaining its immunogenicity, i.e. its ability to initiate an immune response. The term allergoid has been applied to such preparations (18).Treatment of timothy grass pollen extract with glutaraldehyde has been found to give an allergoid with ability to stim-

Use of Glutaraldehyde-Modified Timothy Grass Pollen Extract in Nasal Hyposensitisation Treatment of Hay Fever

“…In a preliminary study [3], encourag ing results were obtained in allergic rhinitis due to grass pollen using glutaraldehyde-treated, tyrosine-adsorbed mixed grass pollen allergen.…”

“…In a preliminary study [3], 5 adult pa tients with rhinitis due to allergy to timothy pollen underwent local intranasal hyposen sitization with a chemically modified mixed grass pollen allergen preparation [14]. 4 of these patients experienced diminished hay fever symptoms during the pollen season.…”

Controlled Studies of Intranasal Immunotherapy for Ragweed Pollenosis

“…Since the former types of immunoglobulins may act as protective 'blocking antibodies', immunotherapy logically could be directed towards generating the highest titers of these blocking antibodies at the nasal mucosa. Several investigators have reported success ful intranasal immunotherapy particularly for grass pollinosis [1,2,11,20,21], and the practical advantages of such treatment are obvious. During the spring of 1978 and 1979 vol unteers were screened by questionnaire, ex amination of the nose and chest, and prick testing with a battery of common allergens.…”

“…Figure 1 shows serum IgG and IgE anti-RW levels in RW-and placebo-treated subjects. IgG antibodies were measured in 1978 by the binding of 125I-AgE to protein A conjugated sepharose 4B particles which had previously been incubated with pa tients' sera [2,4]; in 1979 IgG antibodies were relatively quantitated by the binding of 125I-protein A to RW conjugated sephar ose particles which had been incubated with patients' sera [5]. IgE antibodies were mea sured by RAST both years.…”

Local immunotherapy is not documented for clinical use

“…One way is to modify the allergen preparations chemically in order to reduce their allergenicity, while retaining immunogenicity. Clinical trials of local IT have been performed with modified extracts (6,12,13). The results are promising and indicate that the principle is correct.…”