BOMBAY BLOOD GROUP

By,Prashant D. Kulkarni. 9th A 55

H System On group ‘O’red cells there is no A

or B antigen & the membrane expresses ‘H’ antigen. H is a precursor of A & B antigens. A & B persons have less H substance than O group.

BOMBAY PHENOTYPE•Seen in persons with red cells which lack H, A & B antigens & whose plasma contains anti H, anti A & anti B . •First discovered in Bombay by Dr .Y . M. Bhende.•Present in about 4 per million of human population generally.•In Mumbai it is 1 in 10,000•More common in India •179 cases reported in India •35 to 40 in Mumbai•12 in West bengal

• When Bombay blood group was first encountered it was found not to contain AorB antigen so was thought to be ‘O’ blood group.

• But these pts could not safely receive normal ‘O’blood group,this proved to be because they lack ‘H’ antigen.

GENOTYPEArises from inheritance of ‘hh’at H locus.This genotype do not produce

‘H’carbohydrate which is the precursor for A&B antigens.

Both parents must carry recessive allele to transmit this blood type to children.

Pts with this blood group should be transfused only with this group because hemolysis occurs if transfused with other groups which may lead to death.

How to detect this blood group?

Can be detected by serum grouping or reverse grouping.

This can detect H antibody & test is conducted with reagent called H lacten.

What if you have this blood group? All of us should know our blood group. If it is ‘O’ group make sure it is not Bombay group. Persons with this group should be cautious & alert. They should register themselves with leading blood

banks or hospitals so that in case of emergencies they can be contacted.

It has been proposed to preserve few units of such group in frozen state[cryopreservation]for acute emergencies.

As this is a rare blood group, during elective surgeries ,autologous blood donation can be done.

CASE 1: Kolkata Jan 14th 2011• Hardanpal 68 yrs old renal cell carcinoma

patient has O+ve blood group but he could not be given blood from normal donors of the same group.

• He was diagnosed to have bombay blood group on reverse grouping.

• On tracing for donors of this group, in a place called Bata nagar three members of the same family were found to have this group.

CASE 2: In PIMSIn PIMS a patient named Mallamma of age 46 yrs

was admitted in Gynecology department with uterine prolapse.

She was planned to undergo surgery for which preliminary investigations were done and her Hb. was found to be 8.4gr/100ml.

When blood transfusion was planned, her blood was not matching with other O+ve’s and was found to be having bombay blood group.

As this is a rare group and due to unavailability of donors, she was treated with parental haematinics.

What do we do if we need bombay group blood?Get all family members and relatives of the

patient tested for this group. it is likely that one or the relative has this group.

Put up request for the requirement in leading news papers.

Be open to get blood from other cities.Most effective way is visiting all blood banks in

the city and neighbouring cities.Finally one thing which all of us can do is

spread more and more awareness about this group in common people.

Thank You

Prashant D. Kulkarni. 9th A 55