Biomedical scences Essay Example | Topics and Well Written Essays - 3250 words

Biomedical scences - Essay Example D is inherited as the Mendelian dominant trait while d is inherited as the recessive trait. The RBCs which bear the D and Dd isotypes are referred to as Rh+ individuals and persons having the d isotype are referred to as Rh- individuals. Almost all of the Rh+ people have the D isotype and similarly the Rh- individuals have the d isotype. When the Rh+ blood is transfused to an Rh- person then anti-Rh factor will develop in the patient’s blood within 12 days. If there is a second transfusion of the same blood (Rh+ blood) to that person then cross reaction with Rh factor and anti-Rh factor will cause agglutination reactions leading to hemolytic diseases of adults and newborn. If the mother is rhesus negative and the fetus is rhesus positive (the RBC contains Rhesus antigen inherited from a rhesus positive father), then antibodies will be formed against the rhesus antigen (in the fetus) and will cross the placenta and enter the mother’s blood. In the first pregnancy there w ill be no issues but during the second pregnancy these antibodies will cross the placenta and cross react with the Rhesus antigens of the fetus carried during the second pregnancy and cause agglutination reactions. This will cause erythroblastosis fetalis leading to hemolytic anemia and sometimes deposition of unconjugated bilirubin (derived from the breakdown of hemoglobin from the lysis of RBC’s) in the basal ganglia leading to neural deficits (Chatterjee, 2004). 2. All the six Rh agglutinogens namely the C, c, D, d, E and e are involved in the hemolytic reactions and are of the delayed type. Although routine blood group tests has eliminated the risk of compatibility of RhD isotype but the other isotypes may lead to sensitization in cases of diseases like sickle cell anemia. This disease is prevalent in blacks who express the E antigen and hence produce the anti-E agglutinins which lead to difficulties of donor selection in them for transfusion purposes as in sickle