Bombay Blood Group

The Bombay blood group was discovered fifty years ago in Bombay as it included varied phenotypic characteristic when compared to the standard blood typing such as A, B and O. The RH factor of the blood groups were studied to understand the antigenic structures based on which the H antigenic characteristic became very important. The phenotypic characteristic of Bombay blood group was hence discovered as Oh wherein the 'h' represents its varied nature when compared to the other blood groups.

Bombay blood group contains 'h' characteristic. The RBCs are not agglutinated by the anti-A, anti-B. Bombay Blood group is not restricted only to Indians but is noticed among Caucasians, Japanese etc. Only about 0.01% of the world population has the Bombay blood group, which makes it an essential need to maintain a record of the respective blood type individuals for emergencies.

It is very easy to assume the blood group as O if the blood cells do not agglutinate with A and B antigens. However this may lead to adverse reactions such as hemolytic transfusion rejection when the respective blood group is transfused in to the patient. Confirmatory tests are essential to identify Bombay blood group - as the protein containing H antigen clearly differs from the O blood type. Therefore confirmatory tests such as anti-H lectin Ulex Europaeus are used to detect the presence of A ,B and OH types in the RBCs but does not agglutinate the Oh type.