Fehaid M A Alanazi, Abdelhamid M Alanazi, Salem I Alanazi, Sarah M W Alrwaeli, Renad H S Alsharari, Fai H S Alsharari, Raghad F K Alruwaili, Shatha H I Alhusaynawi, Musaad M M Alanazi, Osama J O Alkhamali, Raghad A R Alruwaili
These serologically defined frequencies exceed those reported in the included regional comparator studies and may support routine anti-A1 lectin subgrouping, although molecular confirmation is warranted.
OBJECTIVE: The A2 and A2B subgroups are of clinical importance because some A2 and, more often, A2B individuals may produce anti-A1 antibodies that can cause hemolytic transfusion reactions, and their frequency varies across populations. As no data were available for Al-Qurayyat, northern Saudi Arabia, this study determined the prevalence of the A2 and A2B subgroups among local blood donors and their distribution by RhD status.
METHODS: A cohort of 247 samples previously typed as blood group A (n=202) or AB (n=45) at a local blood bank (5 September to 14 November 2024) was subtyped with anti-A1 lectin (Dolichos biflorus) by the standard tube technique, and proportions were expressed with 95% Wilson confidence intervals.
RESULTS: Within group A, 153 samples (75.74%) were A1 and 49 (24.26%) were A2, whereas within group AB, 26 (57.78%) were A1B and 19 (42.22%) were A2B; relative to all A-antigen-positive donors, the A2 and A2B frequencies were 19.84% and 7.69%, and 226 donors (91.5%) were RhD positive. The proportion of A2-type phenotypes was significantly higher in group AB than in group A (χ2=5.09; p=0.024).
CONCLUSION: These serologically defined frequencies exceed those reported in the included regional comparator studies and may support routine anti-A1 lectin subgrouping, although molecular confirmation is warranted.