Bombay Blood: how the rare blood type was discovered

Donating blood to the needy is a noble act of saving lives. Most of us are ready to do so. But the doctor first ensures the type of blood we carry, since our blood comes in various physiological types or groups. The general types are A, B, AB and O. Matching of the blood types of the donor and the recipient is vital, else it could lead to serious life-threatening complications.

It is in this connection that a heart-warming piece of news was reported about two weeks ago regarding a life-saving instance of blood donation. An infant, Sandesh Kumar from Gorakhpur, U.P., was found to have an inborn heart condition that needed surgery to set it right. This required blood donation. But the youngster has a very rare blood type. His blood is not O, A, B, or AB, but a special type called (hh)- a rare one first discovered in Bombay in 1952, and hence christened as Bombay Blood. People who carry this rare blood type, about 1 in 10, 000 Indians, can accept blood only from another Bombay Blood type individual, and not from anyone who is O, A, B or AB type.

Fortunately for baby Kumar, this problem was posted on the internet by an acquaintance of the family, and out volunteered as many as 10 individuals. The NGO called The Think Foundation, whom they got in touch with, asked donors to come forward and donate their blood in a donation centre in Mumbai. Three of them, Mr Prabodh Yatnalkar of Pune, and Alec Fernandez and Mehul Bhelekar from Mumbai came forward and donated their Bombay Blood. The blood was air-flown to Delhi where Kumar’s father received it and Kumar was treated.

Why is it called Bombay Blood, and how was it discovered? Dr Durgadas Kasbekar of CDFD Hyderabad has written a detailed and lucid article about it in the forthcoming issue of the journal Indian Journal of History of Science, and I give a short summary of it here. It was in 1952 that Drs. Y.M. Bhende, C.K. Deshpande and H.M. Bhatia of the Seth Gordhandas Sunderdas Medical College, Mumbai published a note in The Lancet (pp. 903-4, May 3, 1952) about two patients (X, a railway worker and Y, a stab wound victim) who needed blood transfusion. None of the blood types known until then worked for them. The moment their blood samples were mixed with any of the above types, the blood coagulated or clumped up. The doctor trio tried the blood of over 160 donors and found at last that one from Mr. Z, a resident of Bombay, suited the type of both patients X and Y. This donor blood type was then named by Dr. Bhende and others as the ‘Bombay Blood Type.’ Technically it is now termed the (hh) type of blood.

What is the biology behind this exceptional blood type? 

To understand this, let us first look at what each blood group type contains. Blood contains red blood cells (and other cells that are not relevant for us here, floating in a fluid called plasma. Red blood cells carry on their surface a set of markers with which the plasma interacts. This compatibility or cross-talk between the cell and the plasma is what makes each blood type special. The markers on the cell are determined by a master type called H, out of which are generated types A, B, AB and AO. When blood transfusion occurs, the compatibility between the donor blood cell type and the plasma of the recipient becomes vital, else the blood may coagulate or clump up, causing serious danger. Thus people with A type blood can accept blood from A type or O type and not from AB or B type donors. And they can donate, in turn, to those with A or AB types. Those with B type can receive from B or O types, and can donate to those with B or AB types. Those with AB type blood can receive from any one and donate to other AB. Finally those with O type blood can receive only from O, but can donate their blood to A, B, O or AB- universal donors. In contrast, the Bombay doctors found that the hh type (Bombay type people) can accept only from other hh type, and also can receive only from the hh types. This makes the Bombay Blood types a very special and rare category of people.

How did this happen and why are these people so rare? 

It is largely because of extensive inbreeding within the same lineage or close-community marriages, often consanguineous, such that the ‘blood type’ or the gene pool is greatly restricted. 
Such intra-community marriages have happened in small isolated communities such as the gypsies, Russian Jewish or Parsi communities. It is thus likely that the Bombay Blood types have common ancestral origins. This special feature is occasionally dramatized in plays and movies, such as in the Telugu film Okkadunadu where the villain (antagonist) finds to his dismay that the hero (protagonist) was the one who donated his Bombay Blood to save him. And in the Hindi film Kahaani the villain was exposed since he needed Bombay Blood for transfusion.

Bombay has many reel life heroes, but to me, the heroes in real life are the Yatnalkars, Fernandezes and Bhalekars, who helped save young Kumar and such needy fellow-citizens, and the Think Foundation and their officer Vinay Shetty. They with their Big Bs (Bombay Blood) deserve our applause and best wishes for the New Year.

dbala@lvpei.org
Source : Thehindu

More on Bombay Blood group:

The discovery of Bombay Blood Group was made more than 50 years ago with a patient who was admitted to KEM Hospital and required blood transfusions.  A sample of blood was sent to the Blood Bank for grouping as is the usual practice.  The red cells grouped like O group and hence O group blood was administered.  The patient developed haemolytic transfusion reaction, and therefore transfusion had to be stopped.

A detailed study of the patients blood revealed a rare genotype (blood group), which was neither ‘A’ nor ‘B’ nor ‘AB’ nor ‘O’.  Since the first case was detected in Mumbai (then Bombay), the blood group came to be called as Bombay Blood Group.  Blood from a Bombay Blood Group individual only should be transfused to a Bombay Blood Group patient.

It is now known that the precursor protein from which all blood groups are formed is termed as the ‘H’ Antigen.  The ‘H’ Antigen either translates into ‘A’ Antigen (the blood group is then called ‘A’) or it translates into ‘B’ Antigen (the blood group is then called ‘B’) or it translates into both ‘A’ and ‘B’ Antigens (the blood group is then called ‘AB’) or it remains as ‘H’ (the blood group is called ‘O’).  Earlier the detection of ‘O’ was on the basis of absence of both ‘A’ and ‘B’. In the case of Bombay Blood Group, there was an absence of the ‘H’ Antigen itself.  Therefore ‘A’, ‘B’, ‘AB’ and ‘O’ which are all different manifestations of ‘H’ are all alien for persons with Bombay Blood Group.  The Bombay Blood Group is termed as ‘OH’, which means absence of ‘H’.

Earlier, the Institute of Immuno Haematology (IIH) housed in the ICMR at K.E.M. Hospital, Mumbai, was the only referral laboratory for determining the Bombay Phenotype.  Samples from all over the country were sent to the IIH, which was the only place, which maintained a directory of persons detected with the Bombay Blood Group.  Here again, the presence or absence of  Rhesus Antigen would determine whether the person is Bombay Rh Positive or Bombay Rh Negative.  Today there are many laboratories and Blood Banks, which are able to detect and label Bombay Group.

Source : http://www.thinkfoundation.org/kc_bombay_blood_groups.htm