Singapore adult cohort
This study was carried using fresh blood samples from volunteer donors as well as frozen samples of PBMCs and blood plasma collected from the Singapore Systems Immunology Cohort (SSIC). [10, 11] Blood was also collected in Tempus™️ Blood RNA tubes (Life Technologies, Carlsbad, Calif) for RNA isolation. The cross-sectional cohort database was generated based on the recruitment of Singaporeans Chinese (n=216) from National University of Singapore as previously reported. [10, 11] Volunteers were classified as individuals with and without allergic rhinitis using demographics and medical history information collected from a survey questionnaire based on the Allergic Rhinitis Impact on Asthma (ARIA) [14, 15] and International Study of Asthma and Allergies in Childhood (ISAAC) guidelines. [16] Atopy status of donors were determined using a skin prick test (SPT) as previously described. [10]  A positive SPT response is determined by wheal diameter of 3 mm or greater, when compared to positive (histamine) and negative (saline) controls.