Rh-Blood TYPES. Rh-Blood groups: Rh-Blood groups: The Rh-factor named for the rhesus monkey because it was first studied using the blood of this animal.

Rh-Blood TYPESRh-Blood TYPES

Rh-Blood groups: Rh-Blood groups: The Rh-factor named for the rhesus monkey The Rh-factor named for the rhesus monkey because it was first studied using the blood of this because it was first studied using the blood of this animal. animal. Rh-agglutinogens (antigens): there are six Rh-agglutinogens (antigens): there are six common types of Rh-antigens each of which is common types of Rh-antigens each of which is called Rh-factor. These types are C, D, E, c, d, & called Rh-factor. These types are C, D, E, c, d, & e.The type D (Rh)-antigen is more antigenic. e.The type D (Rh)-antigen is more antigenic. The major difference between ABO system and The major difference between ABO system and Rh system is that agglutinins causing transfusion Rh system is that agglutinins causing transfusion reactions in ABO developed spontaneously, reactions in ABO developed spontaneously, where in the Rh system spontaneous agglutinins where in the Rh system spontaneous agglutinins NEVERNEVER occur,unless the Rh occur,unless the Rh-- person exposed first person exposed first to Rh+ blood by transfusion.,Or if the to Rh+ blood by transfusion.,Or if the Rh-Rh-femalesfemaleshaving having (Rh+) (Rh+) child, anti-D antibodies developed child, anti-D antibodies developed in her blood slowly reaching maximum in her blood slowly reaching maximum concentration about 2-4 months later.Exposure to concentration about 2-4 months later.Exposure to another Rh+ blood, transfusion reaction occurs .another Rh+ blood, transfusion reaction occurs .

anyone who anyone who has antigen D on RBC membranehas antigen D on RBC membrane is is said to be said to be Rh-positive (Rh+) or D-positive (D+) Rh-positive (Rh+) or D-positive (D+) about about 85%85% of population are Rh+, while persons who of population are Rh+, while persons who does does not have antigen D on their RBC is said tonot have antigen D on their RBC is said to be be Rh-negative (Rh-) or D-Rh-negative (Rh-) or D- & about & about 15%15% are D are D-- (Rh (Rh-- Rh+ is dominantRh+ is dominant while Rh- is recessive. while Rh- is recessive. Rh-agglutinins: Rh-agglutinins: The Rh+ individual has no antibody The Rh+ individual has no antibody in their plasma. The Rh- person has also in their plasma. The Rh- person has also no antibody no antibody D in the plasmaD in the plasma, but Rh- individual forms the , but Rh- individual forms the antibody D when transfused with Dantibody D when transfused with D++ (Rh (Rh++) cells. ) cells. Antibodies against Rh-antigen do not develop unless Antibodies against Rh-antigen do not develop unless an Rh- person is an Rh- person is exposed to Rh+ bloodexposed to Rh+ blood. This can . This can occur through a transfusion or entrance of fetal occur through a transfusion or entrance of fetal blood into the maternal circulation across the blood into the maternal circulation across the placenta. placenta.

Table: Rh –type, agglutiongen, agglutinin, and % of each Rh -group

Rh-type Agglutinogen on RBC

Agglutinins in plasma

%

Rh+ D - 85

Rh- No D antigen - Unless exposed to Rh+ blood

15

The The ABOABO blood type & the blood type & the RhRh -blood type -blood type usually are designated together.usually are designated together.

((ABO systemABO system))(Rh system)(Rh system)

For example a person designated as For example a person designated as A A positive (A+)positive (A+) is blood is blood group A group A in the ABO- in the ABO- system and Rh+ in the Rh blood group. Thissystem and Rh+ in the Rh blood group. This person has person has antigens A & D on RBCantigens A & D on RBC & & antibody-antibody-BB& & in in no antibody-no antibody-DD the plasmathe plasma. .

Rh –Transfusion ReactionRh –Transfusion Reaction:: is the reaction is the reaction between antigen -D in Rh+ between antigen -D in Rh+ blood of donor & blood of donor & antibody D in Rh- blood of recipientantibody D in Rh- blood of recipient. When an . When an Rh- receives a first transfusion of Rh+ bloodRh- receives a first transfusion of Rh+ blood, , the recipient becomes the recipient becomes sensitized to the Rh+ sensitized to the Rh+ antigen & produces antibodies D. If the same antigen & produces antibodies D. If the same person receive a second transfusion of Rh+ person receive a second transfusion of Rh+ blood, reactions results & clumping of RBC’s blood, reactions results & clumping of RBC’s occurs.occurs.

Hemolytic disease of newborn (HDN) or Hemolytic disease of newborn (HDN) or erythroblastosis fetaliserythroblastosis fetalis::HDNHDN: is a disease of the fetus & neonate. characterized : is a disease of the fetus & neonate. characterized

by by agglutination of RBCs of the fetus due to reaction agglutination of RBCs of the fetus due to reaction between between antigen Dantigen D in the fetusin the fetus & & antibody D produce antibody D produce by the motherby the mother. Fetus may develop hemolytic anemia in . Fetus may develop hemolytic anemia in two major ways as a consequence of developing two major ways as a consequence of developing antibodies. antibodies. 1. Rh- incompatibility1. Rh- incompatibility. . 2. ABO- incompatibility2. ABO- incompatibility..

1.1.HDN due to Rh-incompatibility.HDN due to Rh-incompatibility.

Mother Rh- (Rh- Rh -Mother Rh- (Rh- Rh - ) ) X X father+ (Rh+ Rh-)father+ (Rh+ Rh-) Fetus 50% Rh+ (Rh+ RhFetus 50% Rh+ (Rh+ Rh--)) & 50% Rh& 50% Rh- - (Rh(Rh- - RhRh- - ))

A 100% chance of producing an Rh+ fetus if the A 100% chance of producing an Rh+ fetus if the father is homozygous (Rh+ Rh+).father is homozygous (Rh+ Rh+).

Mother (Rh- Rh-)Mother (Rh- Rh-) X X father (Rh+ Rh+)father (Rh+ Rh+) Fetus 100% Rh+ RhFetus 100% Rh+ Rh--

At the time of delivery small amount of fetal blood which At the time of delivery small amount of fetal blood which contain antigen D leak into the maternal circulation &contain antigen D leak into the maternal circulation & some some of them develop antibody D during postpartum periodof them develop antibody D during postpartum period.. In the In the woman’swoman’s first pregnancyfirst pregnancy there is no problemthere is no problem. . TheThe leakage of leakage of fetal blood which contain antigen D is usually the result of afetal blood which contain antigen D is usually the result of a teartear in the placentain the placenta that takes place during delivery. Thus that takes place during delivery. Thus there is no enough time for the mother to produce enough D- there is no enough time for the mother to produce enough D- antibodies to harm the fetusantibodies to harm the fetus.. In the later pregnanciesIn the later pregnancies,, a a problem can arise because the mother has been sensitized problem can arise because the mother has been sensitized (i.e. forming antibody-D) against antigen D.(i.e. forming antibody-D) against antigen D. When the mother When the mother becomes pregnant again with another Rh+ fetus,becomes pregnant again with another Rh+ fetus, and if there and if there is any leakage of fetal blood into the mother’s blood through is any leakage of fetal blood into the mother’s blood through the placenta she rapidly producethe placenta she rapidly produce large amounts of Rh-large amounts of Rh-antibodies & HDN develops in the fetusantibodies & HDN develops in the fetus. . The term The term erythroblastosis fetalis is also used to describe HDN since erythroblastosis fetalis is also used to describe HDN since blood smears from these babies show the presence of many blood smears from these babies show the presence of many immature red blood cells orimmature red blood cells or erythroblastserythroblasts..

Prevalence of disease:Prevalence of disease: About About 3% 3% of second of second Rh –positive babies exhibit some signs of Rh –positive babies exhibit some signs of HDN;HDN; 17%17% of the third babies exhibit the of the third babies exhibit the disease; and the incidence rises progressively disease; and the incidence rises progressively with subsequent pregnancieswith subsequent pregnancies. About . About 50% 50% of of Rh negative individuals are sensitized Rh negative individuals are sensitized (develop an anti-Rh titer) by transfusion of (develop an anti-Rh titer) by transfusion of RhRh++blood.blood.

Symptoms of diseaseSymptoms of disease: : 11.Hemolysis,&.Hemolysis,&severe severe jaundicejaundice 2. edema (hydrops fetalis). 2. edema (hydrops fetalis). 3.Kernicterus3.Kernicterus due to deposition of bilirubin in the basal ganglia due to deposition of bilirubin in the basal ganglia which result in which result in brain damage & mental retardationbrain damage & mental retardation.. 44. . Splenomegaly & hepatomegaly (i.e. enlargement Splenomegaly & hepatomegaly (i.e. enlargement of spleen & liver).of spleen & liver).

Laboratory findings of HDN:Laboratory findings of HDN:Presence of Presence of erythroblastserythroblasts and and reticulocytosisreticulocytosis in in the blood smear.the blood smear.Low PCV.Low PCV.Level of unconjugated Level of unconjugated bilirubibilirubin will be high (more n will be high (more than than 10 mg/dl10 mg/dl).).

Treatment of HDNTreatment of HDN1.Treatment of mother1.Treatment of mother:: The Rh- woman should be The Rh- woman should be given an injection of given an injection of single dose of anti-D antibodies single dose of anti-D antibodies within within 7272 hours during the hours during the postpartum periodpostpartum period or or during pregnancy during pregnancy oror immediately after immediately after each each abortionabortion.. The injection contains anti-D against antigen-The injection contains anti-D against antigen-D.The injected antibodies will bind to Rh – antigens of D.The injected antibodies will bind to Rh – antigens of fetus erythrocytes that may have entered the mother's fetus erythrocytes that may have entered the mother's blood and destroy the antigen D on fetal RBC before blood and destroy the antigen D on fetal RBC before the immune system of the mother is activated. the immune system of the mother is activated. In other In other words, the fetal RBCs will be destroyed before the words, the fetal RBCs will be destroyed before the mother is able to develop her own antibodies against mother is able to develop her own antibodies against these erythrocytes. Hence she will be able to conceive these erythrocytes. Hence she will be able to conceive another Rh+ child without any complication.another Rh+ child without any complication.

2.Treatment of erythroblastic neonate:2.Treatment of erythroblastic neonate: 11. . By By exchange transfusionexchange transfusion i.e. slowly removing the i.e. slowly removing the newborn’s blood & replacing it with Rh—blood to newborn’s blood & replacing it with Rh—blood to reduces the level of maternal antibody-D, which reduces the level of maternal antibody-D, which thereby decreases the level of fetal RBC hemolysisthereby decreases the level of fetal RBC hemolysis. . 2.2. Exposure of newborn to Exposure of newborn to fluorescent lightfluorescent light to to breakdown the large amount of bilirubin formed as a breakdown the large amount of bilirubin formed as a result of erythrocyte destruction. High levels of result of erythrocyte destruction. High levels of bilirubin are toxic to the nervous system and can bilirubin are toxic to the nervous system and can damage brain tissuesdamage brain tissues..3.3.In addition fetal Rh-typing In addition fetal Rh-typing with obtained material by with obtained material by amniocentesis or amniocentesis or choronic villuschoronic villus samplingsampling is now possible. is now possible.

HDN due to ABO-incompatibility:HDN due to ABO-incompatibility: when a when a mother of type Omother of type O blood becomes pregnant blood becomes pregnant & the fetus has & the fetus has type A or B antigenstype A or B antigens on on RBCRBC this may result in anemia known as this may result in anemia known as HDN. The ABO-HDN is the more common HDN. The ABO-HDN is the more common that Rh-HDN. that Rh-HDN. Approximately 23%Approximately 23% of all of all pregnancies involve incompatible ABO pregnancies involve incompatible ABO system. system.

1- Blood Typing : blood typing and blood 1- Blood Typing : blood typing and blood matching is done by mixing the blood with matching is done by mixing the blood with saline. Then it is mixed with anti-A,anti-B & saline. Then it is mixed with anti-A,anti-B & anti-D after several minutes ,look for anti-D after several minutes ,look for agglutination . agglutination .

2- Cross Matching : RBCs of the donor 2- Cross Matching : RBCs of the donor mixed with the serum of the recipient and mixed with the serum of the recipient and look for agglutination.If it is +ve the blood is look for agglutination.If it is +ve the blood is incompatible,if there is no agglutination the incompatible,if there is no agglutination the blood of the donor and recipient is blood of the donor and recipient is compatiblecompatible..

Acute kidney ShutdownAcute kidney ShutdownThere are three causes:There are three causes:1-Toxic substances from hemolyzing blood due to 1-Toxic substances from hemolyzing blood due to

antigen-antibody reaction cause renal antigen-antibody reaction cause renal vasoconstriction.vasoconstriction.

2- circulatory shock due to loss of RBCs,the blood 2- circulatory shock due to loss of RBCs,the blood pressure decreases renal blood flow and urine out pressure decreases renal blood flow and urine out put decreases.put decreases.

3-Excess hemoglobin of haptoglobin leak into kidney 3-Excess hemoglobin of haptoglobin leak into kidney tubule and precipitate into tubule and block them.tubule and precipitate into tubule and block them.

ALL OF THE ABOVE 3 CAUSES ACUTE RENAL ALL OF THE ABOVE 3 CAUSES ACUTE RENAL SHUT DOWN AND DEATH WITHIN AWEEKSHUT DOWN AND DEATH WITHIN AWEEK..