An it from alleles. The absence of
An individual’sblood group never changes including reference to specific illnesses andtransplantationAn entire blood group system thatconsists of one or more erythrocyte antigens describes the term ‘blood group’, aseries of genes control the specificity, and this can be allelic or linkedclose on a single chromosome making it difficult to distinguish it fromalleles.
The absence of specific antigenscan be the bases of blood separation, consideration of a blood group could beby any detected variation or polymorphism detected in the blood. However, theterm blood group is usually restricted to blood cells, surface antigens, andgenerally to red cell surface antigens. Although detection of polymorphism inred cell surface proteins is attainable by other methods, for instance DNA sequences analysis,unless defined by an antibody such variants cannot be titled blood groups. (Daniels,2014). The ABO group system has fourmain group types that blood groups are divided into: A, B, AB, and O. The genesinherited from your parents determine this as blood type is inherited byparents. One of two ABO genes are donated by each biological parent.
The A andB genes are dominant and the O gene is recessive. Antigens and antibodies foundin the blood identify an individual’s blood group. Antibodies are a protein foundwithin the plasma, they are part of the body’s natural defence mechanismagainst invading substances such as germs. When foreign material enters thebody antibodies alert the immune system to destroy it. Whereas antigens areprotein molecules found on the surface of red blood cells. Red cells in theblood that have type A antigens on the cell surface contain antibodies against typeB red cells in its serum. If type B blood is given to an individual with type Ablood, antibodies in the recipient’s blood will destroy the red cells of theinjected blood. Similarly, type A red cells will be destroyed by anti-A antibodiesin blood type B.
Rhesus (Rh)blood grouping system splits blood groups in accordance to whether the Rhantigen (Rh factor) is present or absent on the red blood cells cell membranes.The most common Rhantigen is termed RhD, this causes the most severe immune reaction and is theprimary determinant of the Rh trait. In clinical importance Rh is secondto the ABO blood groups (Flegel, 2007). An individual that lacks the Rhantigen could be in danger if Rh positive blood is given in transfusion. Thefirst time Rh incompatible blood is given there may not be effects, however theresponse of the immune system is to produce anti Rh antibodies. After the antibodies form, if Rh positive bloodis given it can cause agglutination as they will attack the foreign red bloodcells. Resulting inhaemolysis, this causes serious illness or can be fatal.
Different antigens and antibodiesare present in each group within the ABO systems, group O red blood cells haveno antigens therefore, can be used safely for any group types. Red blood cellscan have an additional antigen present, this is known as the RhD antigen, andeach blood group can be RhD positive or RhD negative. This is determined by thepresence of the antigen, if the antigen is present, it is positive and if it isabsent, it is negative.
Stem cell transplantation of thebone marrow is a procedure that affects the patient that is receiving thetransplant. In the process the recipient’s marrow is destroyed, if differentred cells are produced by the donor’s marrow, the recipient will producedifferent red cells matching the donor’s, as the blood comes from the donorsstem cells. Peripheral blood stem cell transplant isanother method, here stem cells are taken from the donor’s blood, resulting inproduction of new blood cells. Matching human leukocyte antigens (HLA) isessential for stem cell transplants, they make up an individual’s tissue type, andthis is different from blood type. This plays a significant role in the successof the transplant, there are six major HLA antigens, and a match of all sixwill result in lower chances of complications such as graft rejection. A study reveals conversionof RBC phenotype to donor ABO phenotype, resulting in their host derived anti-donor ABO antibodies to be lost in all major mismatch patients (Esther,2014). Thalassemia is an increase in redblood cell (RBC) demand, this occurs when one of the genes involved inhaemoglobin production has a mutation, this genetic defect is inherited fromparents.
This could weaken the expression of ABO blood group antigens (Dean,2015). Haemoglobin is a protein molecule that carries oxygen in RBCs, excessivedestruction of RBCs is the result of the condition. Leukaemia affects the white bloodcells which play an important part in infection fighting in the immune system. Leukaemiaresults in abnormal production of immature white blood cells which clog up thebone marrow stopping production of other blood cells that are required forhealthy blood. Acute leukaemia is a disease that can affect an individual’sblood group (Anifowoshe et al 2017).
Patients with acute myeloid leukaemia who werereported to have ABO antigen alterations during the phase, upon remission theyre-expressed their original ABO antigen (Rakul et al 2017). It has been saidthat in some leukemic patients’ changes of the promoter of ABO genes in RBCs byleukemic cells leads to its suppression and consequent alternation in the bloodgroup, this can be identified before diagnoses or to herald leukaemia relapse (Radhakrishnan,et al 2016). Changes of RBC antigens have been described in association withhaematological malignancies, after resubmission is attained the modificationsof blood group antigens usually revert to normal (Rakul et al 2017). Liver transplant is required whenan individuals liver is diseased and needs replacing, the donor liver can comefrom a living donor or a deceased donor. This is a major surgical process, thebody will always try to destroy the transplanted liver as it is seen as foreignto the body, resulting in individuals with liver transplants having to takemedication for the rest of their lives.
A2 is a sub group for individuals withblood group A, this group is formed with patients that’s A antigen on theirRBCs has a lower expression, therefore immune mediated haemolysis is lesslikely when in contact with serum that contains anti-A antibodies (Mettu, 2013).There are three possible stages for a liver transplant, stage one (preanhepatic)the diseased organ is removed, transection of collaterals causes blood lossdeveloped from portal hypertension. Stage two (anhepatic) starting with implantationof the donor liver ending with graft reperfusion, this aspect in the procedureis dangerous as abnormalities can arise such as hemodynamic abnormalities. Stagethree (postreperfusion) starting with reperfusion of the grafted liver, thiscreates hepatic arterial anastomosis. For the new liver a form of biliarydrainage is prepared, good surgical hemostasis and closing is obtained. Inmatching organs for transplantation, the Rh factor is not usually a significantconsideration, this applies for most centres of matching organs. (Mettu, 2013).
The Rh factor (+ or -) can change as the patient can begin to develop the donorsblood type (Allanki, 2009). REVERSABLE Non matched transfusion Transfusion rejection can occur,to avoid this prior to a blood transfusion two test are required, these aretermed type and cross match. Both donor and recipient must lack the same ABOand Rh D antigens.
The process begins with determining the ABO and Rh D position,once the type is recognised this allows a blood compatible transfusion to go forward.However, as the donor’s blood can contain other antigens that are incompatibleto the recipient’s blood another test must be carried out, this is called across match. This ensures that the serum of the recipient and the RBCs of thedonor match (Dean, 2015). The tests include small amounts of the recipient’sserum and the donors RBCs, examination of the mixture is done under amicroscope. Incompatibility is shown by the donors RBCs agglutinating by antibodiesin the recipient’s serum.