Rho (D) antigen is one of the protein antigens of the red cell membrane. This antigen belongs to the complex Rh/ Hr Blood group system and is the most important antigen of this system. Rho (D) antigen was discovered for the first time by Levine and Stetson in 1939 and is known to be present on the red blood cell surface of 85% of the human population. The presence or absence of th is antigen determines positivity or negativity of blood Rh.
In the clinical aspect, Rh (D) can be considered the most significant of all the red cell antigens after the A and B antigens of th ABO blood group system. The clinical significance of this antigen is due to it’s high antigenecity and it’s Participation in posttransfusion reactions and hemolytic disease of the new borns. It has been shown that 50 percent of Rh negative individuals form anti- Rho (D) following a single transfusion of Rho (D) antigen of human red blood cell membranes has been isolated as a homogeneous and immunological intact component. The antigen was prepared by the following method:
Red cell membranes were prepared free of hemoglobin as white ghost.
The components of white ghost were solubilized using ethylend amine tetra acetic acid (EDTA) followed by sodium chloride. Diaflo Ultra filter membranes were used to separate solubilized membrane components into different molecular weight classes. The hemagglutination inhibition test was employed for the detection of Rho (D) antigen and results indicated that most Rho (D) activity resides in components with moleculane weights between 10000 and 30000 daltons. When the residue of PM 10 membrane was injected to guinea pigs along with an adjuvant, a high titer of anti- Rho (D) antibody was obtained, after adsorption of serum with O negative Cells.
This work has been accomplished with the aim of producing anti- D which is a product necessary for blood typing and thus eliminating dependence on. Foreign imports. Anti- Rho (D) is also a vital prophylaxis for Rh negative mothers after their pregnancy with Rh positive fetus in order to prevent hemolytic disease of newborns in their future children.