Increased expression of ABO blood group antigens secretion phenotype with O blood group and age advances.

Objectives: To ascertain the prevalence of ABH antigen secretors and non-secretors among Yemenis. In addition to explore the factors that may affect the expression of the secretion phenotype.

Methods: This cross-sectional study was carried out between May and September 2022 on 215 healthy Yemeni individuals at the International Malaysian University, Ibb, Yemen.