Clinical and immunologic evaluation of Cedrus deodara pollen: a new allergen from India

Background: Allergy to pollen from gymnosperms is well documented in the We st. However, many allergenic species are native to the Himalayan region of India, and Cedrus deodara (Pinaceae) was selected for allergologic investig ation. The objective was to define the allergologic and immunochemical aspe cts of C. deodara pollen. Methods: Pollen antigen from C. deodara (CD) was prepared and characterized by biochemical and biologic assays. Specific IgE binding was determined by means of ELISA and immunoblotting. Results: CD pollen antigen caused marked skin sensitivity in 7.5% of an ato pic population. A significantly elevated level of CD-specific IgE antibodie s was observed in 65.8% of the skin-positive patients. Immunoblotting showe d protein fractions of 37, 44, 58, and 78 kDa with 100% binding with the pa tients' sera suspected to be due to carbohydrate moieties. Conclusions: Patients from the Himalayan region, where CD occurs naturally, were sensitized more than patients from distant places. The immunochemical characterization revealed multiple protein fractions from low to very high molecular mass (14-126 kDa) mostly in the acidic pi range. CD pollen has b een recognized as a new allergen from India for the first time.