Rhesus Incompatibility: Causes, Symptoms, And Treatments

Rhesus Incompatibility: Causes, Symptoms, And Treatments

Question 1. Write briefly on the Rhesus (Rh) blood group.

Answer. The Rhesus blood group was discovered by Landsteiner and Weiner in 1940.

• Rh antigen system has three closely linked gene loci, coding for D antigen (there is no d antigen), C and/or c antigen, and E and/or e antigen. Thus, the antigens produced are C. D, E. c and e.
• An individual may have similar or different sets of these three Rh antigens on each chromosome; for example, CDE/cde, cde/cde, or CdE/cdE (each person inherits one trio gene from each parent).
• Individuals who are positive for D antigen are considered Rh—positive (85% of the population) and those who lack it are Rh—negative.
• Individuals with a weak variant of D antigen called the Du variant, are also considered Rh—positive.

“Rh Incompatibility Symptoms in Newborns”

• Alloimmunization, i.e. formation of an antibody against an antigen occurs if a person is exposed to an Rh antigen that is not on the patient’s RBCs.
• The majority of clinically important antibodies that produce a transfusion reaction are warm-reacting (IgG) antibodies (eg, anti-D, anti-Kell) rather than cold-reacting (IgM) antibodies.
  Rh incompatibility or erythroblastosis fetalis or hemolytic disease of newborn: When a mother is Rh negative and the fetus is Rh positive the fist child does not undergo Rh incompatibility.

“Rh Incompatibility and Fetal Hemolytic Disease”

This is because Rh antigen cannot pass from fetal blood into the mother’s blood due to the placental barrier but during the delivery of a child Rh antigen from fetal blood may leak into the mother’s blood due to placental detachment and the mother develops Rh antibody in her blood.

When the mother conceives for the second time and if the fetus is Rh positive the Rh antibody crosses the mother’s placental barrier and enters fetal blood and causes fetal agglutination of fetal RBCs which leads to hemolysis.

Due to excessive hemolysis children suffer from severe anemia, hydrops fetalis, and kernicterus.

“Rh Incompatibility Prevention Strategies”

Rhesus (Rh) blood group Treatment

Exchange blood transfusion should be done soon after birth,i.e. small quantities of infant’s blood successively from intra venous catheter and replacing an equal volume of compatible Rh-negative blood. So the infants ‘ positive RBCs prone to destruction are removed from circulation.

Rhesus (Rh) blood group Prevention

Destruction of Rh-positive fetal cells in maternal blood is brought about by administering a single dosage of anti-Rh antibody in the form of Rh immunoglobulin soon after the birth of a child.
This prevents active antibody formation by the mother.

“Rh Immune Globulin Treatment”

Question 2. Describe the differentiating features of primary and reactionary hemorrhage.

Answer.

The differentiating features of primary and reactionary hemorrhage.