H System<br /><ul><li>On group ‘O’red cells there is no Ao rBantigen&the membrane expresses ‘H’antigen H is a precursor ofA&B antigens.A&Bpersons have less H substance thanO group </li></li></ul><li>BOMBAY PHENOTYPE<br /><ul><li>Seen in persons with red cells which lackH,A&B antigens&whose plasma contains antiH,antiA&antiB
12 in West bengal</li></li></ul><li><ul><li>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</li></li></ul><li>GENOTYPE<br />Arises from inheritance of ‘hh’at H locus<br />This genotype do not produce ‘H’carbohydrate which is the precursor for A&B antigens<br />Both parents must carry recessive allele to transmit this blood type to children <br />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<br />
How to detect this blood group?<br />Can be detected by serum grouping or reverse grouping<br />This can detect Hantibody&test is conducted with reagent called H lacten<br />
What if you have this blood group?<br /><ul><li>Allof 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</li></li></ul><li>CASE 1: Kolkata Jan 14th 2011<br /><ul><li> Hardanpal 68yr 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.</li></li></ul><li>CASE 2: In PIMS<br />In PIMS a patient named Mallamma of age 46yrs was admitted in Gynecology department with uterine prolapse.<br />She was planned to undergo surgery for which preliminary investigations were done and her Hb. was found to be 8.4gr/100ml.<br />When blood transfusion was planned, her blood was not matching with other O+ve’s and was found to be having bombay blood group.<br />As this is a rare group and due to unavailability of donors, she was treated with parentralhaematinics.<br />
What do we do if we need bombay group blood?<br />Get all family members and relatives of the patient tested for this group. it is likely that one or the relative has this group.<br />Put up request for the requirement in leading news papers.<br />Be open to get blood from other cities.<br />Most effective way is visiting all blood banks in the city and neighbouring cities.<br />Finally one thing which all of us can do is spread more and more awareness about this group in common people.<br />