Title:Warm Reactive Anti-A1 Agglutinin in an A2B individual: A Rare Case with Review of Literature
Volume: 16
Issue: 1
Author(s): Manish Raturi*Anuradha Kusum
Affiliation:
- Department of Immunohematology and Blood Transfusion, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Swami Ram Nagar, Jolly Grant Dehradun – 248016 Uttarakhand,India
Keywords:
A2, A2B type, subgroups, anti-A1 lectin, agglutinin, G1PO.
Abstract: The prevalence of the major subgroup of A as A1 in almost 80% of the A group population
is a known fact. A2 and the remaining subgroups such as Aend, Am, Ax etc comprise the remaining
population, based on erythrocyte agglutinability and various serological reactions. These A subgroups
can often result in an ABO typing discrepancy. Anti-A1 antibody often appears as an irregular
cold agglutinin in the sera of A2 or A2B individuals who lack the corresponding antigen. Rather
notably, the literature suggests that 1% to 8% of A2 and 22% to 35% of A2B individuals possess an
allo-anti-A1 in their sera, which reacts at a temperature below 25°C. Although routinely, it does not
pose any problem either during or post blood transfusion, however, the literature reports of hemolysis
happening in procedures that are performed at lower temperatures, particularly in hypothermic
situations. We report herein, a case of a massively bleeding A2B Indian lady after the expulsion of
her dead fetus and an underlying uterine fibroid having a warm reactive allo-anti-A1 agglutinin that
warranted an urgent blood transfusion management.
