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.