Profiles of Birch Allergen Component Sensitization and Its Association with Pollen Food Allergy Syndrome in Northern China

Abstract

Xiaoyan Wang,1,2 Lijia Chen,1 Jiaqi Ding,3 Hongtian Wang,1 Xueyan Wang1,2 1Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, People’s Republic of China; 2Beijing Laboratory of Allergic Diseases, Beijing Municipal Education Commission, Beijing, 100038, People’s Republic of China; 3Department of Otolaryngology, Qingdao Women and Children’s Hospital Affiliated to Qingdao University, Qingdao, Shandong, 0355729, People’s Republic of ChinaCorrespondence: Xueyan Wang, Hongtian Wang, Tieyi Road, No. 10th, Haidian District, Beijing, 100038, People’s Republic of China, Tel [phone], Email [email protected]; [email protected]: To investigate the major allergen components associated with birch pollen allergy in northern China and elucidate clinical relevance to pollen food allergy syndrome (PFAS).Methods: Fifty-eight patients were recruited for a cross-sectional study and categorized into two groups: PFAS group and non-PFAS group, as well as apple allergy group and non-apple allergy group. The sIgE levels of birch pollen and its components, namely Bet v 1, Bet v 2, Bet v 4, and Bet v 6, were analyzed.Results: Among 58 participants, 44 individuals (75.9%) reported PFAS. 32 out of 44 (72.7%) participants reported apple allergy. Bet v 1 exhibited the highest sensitization rate at 82.8%, followed by Bet v 2 (29.3%) and Bet v 6 (1.7%). The combined sensitization rate for Bet v 1 and/or Bet v 2 was 93.1%. A total of 77.6% of the subjects demonstrated sensitization to single component, while 19.0% exhibited sensitization to two components. The sIgE levels of birch pollen and Bet v 1 were significantly elevated in PFAS group compared to non-PFAS group (p=0.001, p< 0.001, respectively), as well as in apple-allergic and non-apple-allergic group (p< 0.001, p< 0.001, respectively). The optimal cut-off values for birch pollen and Bet v 1 sIgE were determined to be 7.09 kUA/L (with a sensitivity of 84.1% and specificity of 78.6%) and 5.11 kUA/L (with a sensitivity of 75.0% and specificity of 85.7%) when diagnosing PFAS. In terms of apple allergy, the optimal cut-off value were 9.40 kUA/L (with a sensitivity of 81.3% and specificity of 76.9%) and 6.53 kUA/L (with a sensitivity of 84.4% and specificity of 84.6%), respectively.Conclusion: The predominant sensitization pattern is mono-sensitization to Bet v 1, but when considering immunotherapy, Bet v 2 should also be taken into account. Bet v 1 serves as a valuable biomarker for diagnosing PFAS and apple allergy.Keywords: birch pollen, allergen component, Bet v 1, pollen food allergy syndrome, apple allergy

Keywords

• birch pollen
• allergen component
• bet v 1
• pollen food allergy syndrome
• apple allergy