Protein Expression Profile of Indigenous and Commercial Extracts
of Amaranthus Pollen in Allergy Patients
Syed M. Hasnain, Halima Al Sini, Alanoud Al-Qassim,
Abdulrahman Al Frayh*, Mohammad O. Gad-El-Rab*, Ayodele A. Alaiya
King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
*College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Background: Amaranthus viridis and Amaranthus lividus, pollen are the most prevalent in various parts of Saudi Arabia. Amaranthus species are allergenic and potential cause of respiratory allergy. However, neither are commercially available for diagnostic or therapeutic purposes.
Method: SPT was applied in this study. Five allergy patients were skin tested with locally prepared (indigenous and commercial pollen) as well as commercial extracts. Amaranthus pollen was collected from various indigenous sources. A. palmeri, A. retroflexus, A. hybridus, A. tuberculatus were acquired from Greer and A. retroflexus, A. tamariscinus were acquired from Allergon. The raw pollen from these species was extracted in buffered saline PH 8.1. Protein patterns of eight different types of Amaranthus samples as well as serum samples from patients were analyzed using two-dimensional polyacrylamide gel electrophoresis (2-DE)/SDS PAGE and computer-assisted image analysis (PDQUEST).
Results: We have generated and characterized the expression of multiple proteins in human serum samples of patients exposed to 7 different types of Amaranthus allergens. Two patients demonstrated similar high expression changes to 2 types of Amaranthus allergens and were classified as group 1 while three samples showed low expression to Amaranthus and were referred to as group 2 of the Amaranthus allergens. Changes in the expression of 12 proteins were observed between groups 1 and group 2 samples.
Conclusion: There appear to be proteins diversity in six major Amaranthus species and similarities in the two indigenous species. While the reactive and cross-reactive proteins between the indigenous and commercial species are being investigated, the available commercial extracts appear to have different protein profile and may not be fully relevant to this region for the diagnosis of inhalant pollen allergy and subsequent specific immunotherapy. Further validation of observed protein spots is warranted in order to support their usefulness as potential Amaranthus biomarkers for the diagnosis and therapy monitoring of allergy patients.