Biological characterization of glutaraldehyde-modified Parietaria judaica pollen extracts
Article first published online: 27 FEB 2004
Clinical & Experimental Allergy
Volume 34, Issue 2, pages 303–309, February 2004
How to Cite
Ibarrola, I., Sanz, M. L., Gamboa, P. M., Mir, A., Benahmed, D., Ferrer, A., Arilla, M. C., Martínez, A. and Asturias, J. A. (2004), Biological characterization of glutaraldehyde-modified Parietaria judaica pollen extracts. Clinical & Experimental Allergy, 34: 303–309. doi: 10.1111/j.1365-2222.2004.01859.x
- Issue published online: 27 FEB 2004
- Article first published online: 27 FEB 2004
- Submitted 13 May 2003; revised 18 September 2003; accepted 16 October 2003
- basophil activation;
- chemical modification;
- histamine release test;
- lymphocyte proliferation;
- Parietaria judaica;
- skin prick test
Background Allergoids are widely used in specific immunotherapy (SIT) for the treatment of IgE-mediated allergic diseases, but all techniques for standardization of conventional allergic extracts may not be appropriate for standardization of a glutaraldehyde (GA)-modified extract because of the unique characteristics of these extracts.
Objective To assess an accurate methodology for standardization of chemically modified extracts.
Methods GA-modified extracts from Parietaria judaica pollen were purified by diafiltration. Biochemical properties were investigated by determination of amino groups, chromatography, and SDS-PAGE. The IgE-binding activity was determined by skin prick test, enzyme allergosorbent test inhibition, basophil activation, and histamine release tests. Peripheral blood mononuclear cells (PBMCs) from P. judaica pollen-allergic subjects were stimulated with either native or allergoid extracts, and proliferation was measured.
Results Biochemical data indicated a high degree of allergen polymerization resulting in extract components higher than 100 kDa. IgE-binding activity, both in vivo and in vitro, was reduced by more than 99.8%. Both allergen and allergoid induced PBMC proliferation and synthesis of blocking IgG antibodies at similar rates. Moreover, no evidence of introduction of new determinants by chemical modification was found.
Conclusions The preparation of GA-modified extracts by diafiltration is faster and more reliable than previous chromatographic methods. These modified extracts have drastically reduced their allergenicity while maintaining their immunogenicity, and therefore they can be used in safer and shortened schedules of SIT.