Question

Which blood group can be safely transfused in emergency, when there is no time to analyse the blood group of recipient?

• A. $OandR{h}^{-}$
• B. $OandR{h}^{+}$
• C. $BandR{h}^{-}$
• D. $ABandR{h}^{+}$

Answer 1

The correct option is A $OandR{h}^{-}$

Antigens are foreign substances that induce the immune system to produce antibodies. The "I${}^A$" and "I${}^B$" alleles are responsible for the production of the A and B antigens that are present on the surface of the erythrocytes. The antibodies are present in human blood without prior exposure to the antigen which means that people with a particular ABO antigen carry the antibody against the other antigen in their serum. A person with “B” blood group carries B antigen on their RBCs and anti-A antibodies in their serum; thus, if found foreign, it can induce antibody production in recipient responsible for agglutination of blood type injected. This makes option C wrong. Similarly “AB” blood group has both “A” and “B” antigen on their RBC that can cause agglutination of blood if found foreign by the immune system of the recipient; option D is incorrect. Since, type O persons do not have either antigen on their RBCs, hence they carry both antibodies in their serum. Rh+ blood group carries Rh antigen that can induce agglutination if transfused to Rh- donor; option C is incorrect. Similarly, Rh- group does not carry the Rh antigen; hence O and Rh- blood group can be used for transfusion without testing the blood group of the recipient. The correct option is "A".