Kasturba Hospital Rare Blood Donor Registry
Apart from ABO and Rhesus Blood Group Systems, there are now 36 other minor blood group systems including Kell, Kidd, Duffy, Lutheran and Lewis blood group system. Among these 36 minor blood group systems, there are nearly 200 blood groups with more than 600 blood group antigens.
Rare Blood Group
Rare blood group can be defined as any blood type that makes it difficult to obtain compatible blood transfusion for a patient.
Rare Blood Donor
A rare blood phenotype donor can be defined as the donor who usually lack either a single high prevalence antigen or a combination of multiple antigens together. This property makes their blood quite unique and rare. Usually, the prevalence of rare donor is 1 in 1000.
HOD: Dr. Shamee Shastry
Madhav Nagar, Manipal, Karnataka 576104
Blood group Antigen and Antibodies
Antigen – An antigen is a substance on the red cell membrane (carbohydrate/protein) which can stimulate the immune system to produce an antibody. Blood group of an individual is determined by the antigens expressed on the red cells. A high-incidence antigen is found on the red cells of most of the population. When an antigen is absent on the red cells of the majority of people it is called a low incidence antigen.
Antibody – Antibody is produced by the immune system in response to a foreign antigen when the body comes in contact with an antigen it does not recognize.
An antibody which can react at 37°C (body temperature) resulting in destruction of red cells bearing the corresponding antigen and ultimately causing hemolysis is called a clinically significant antibody.
Responder/Non-Responder – Routine transfusion practice includes only ABO and D antigen typing of the donors. So, when a patient is transfused, the differences in the red cell antigen makeup can cause immune response and the patient can produce antibodies against the antigens which they lack. Responders are people who produce antibodies when they are transfused with blood which has the antigens that they lack. This includes about 3-5% of the general population. Non-responders do not produce an immune response even when transfused with blood which has the antigens that they lack.
Repeated exposure to foreign red cells with multiple transfusions in clinical cases including thalassemia, sickle cell anemia and pregnancy can increase the chance of an individual in producing antibodies. When a patient with multiple antibodies or a patient with naturally occurring antibodies to a high incidence antigen requires blood transfusion, it becomes difficult to provide matched blood. Since only A, B, O and D antigens are routinely typed, blood cannot be provided immediately. Screening the available donor units in the blood center for those antigens should be done and it is a labour intensive and long standing process.
Blood group antigens are distributed unevenly among different population based on the ethnicity. For example prevalence of Bombay (Oh) phenotype is 1 in 1000 in India and 1 in 1,00,000 in Europe.
Bombay phenotype, P null, -D-/-D- , In(a+b-), Co(a-b-), CdE/CdE (ryry) and I-i- are the various rare blood group phenotypes reported in India. Extended phenotyping of donor blood is pivotal in creating a donor panel and in identifying rare phenotypes present in the local population.
Kasturba Hospital, Blood Centre has screened for clinically significant blood group antigens among regular blood donors and formed a registry for rare phenotypes. The centre keeps updating the registry as applicable.
Currently the rare blood phenotypes present in the registry are listed below. This list will be updated regularly.
- Bombay phenotype,
- [R2R2, Jkb-, M-, Le(a-b-)],
- [R2R2, Jka-, Fy b-],
- [R2R2, Fy b-, P1-, N-, S-],
- [R1R1, Fy a-, Jka-, s-, P1- ],
- [R1R1, Fy a-, Jka-, P1-, N-, S-, Le(a-b-)],
- [R1R1, Fy a-, Jk(b-), s-, P1-],
- [R1R1, Fy a-, Jk b-, M-, P1-],
- [rr, Fy b-, Jka-, P1-, N-],
- [rr, Fy a-, Jkb-, P1-, S-]
- [rr, Fy a-, Jka-, s-, N-]
- [rr, M-, S-]
- [r’r, Fy a-, Jkb-, M-, S- P1- ]
- [r’r, Fy b-, Jkb-, S-]
- [R0r, Fy a-, Jkb-, N-, S- P1-]
- [R0r, Fy b-, Jkb-, M-, S- ]
- [R1r, H-, Fy a-, Jka-, N-, S- P1-]
- [R1R2, H-, Fy b-, Jka-, M-, S-]
- [R1R2, H-, Le(a-b-)]
Clinicians who require rare blood groups for a patient need to fill up the blood requisition form. The complete patient details including Name, hospital id, age/sex, full diagnosis, details of the hospital, name of the clinician in-charge of the case, , total number of blood units required, antibodies identified in the patient, full immune hematological workup done should be filled and sent to the Kasturba Hospital Blood Centre (soft copy may be sent through email). Currently the services are restricted to the regional level, patients admitted within the state of Karnataka.
- Sanmukh R.Joshi, K Vasantha, A profile of rare blood in India and its impact in transfusion service.Asian Journal of Transfusion Science,2012;6(1):42-3
- https://www.isbtweb.org/workingparties/rare-donors.Raredonors. ISBT