RH BLOOD GROUP SYSTEM

A red cell antigen with clinical importance because of its role in Hemolytic Disease of the Newborn

Rh Blood Group System

Other name for Hemolytic Disease of the Newborn

Erythroblastosis fetalis

Match the ff.

1. Discovered the first human Ab directed against the D Ag

2. Reported anti-Rh in the sera of several women who had recently had babies suffering from erythroblastosis fetalis

3. Observed anti-Rh in Rh negative patients who had received ABO compatible but Rh positive blood

4. Reported on an Ab made by guinea pigs and rabbits when are transfused with rhesus monkey RBCs

A. Levine

B. Levine and Stetson

C. Wiener and Peters

D. Landsteiner and Wiener

1. B

2. A

3. C

4. D

True or False

Abs formed in women is identical with those Abs formed by rabbits and guinea pigs

False

A non-glycosylated carbon, hydrogen, oxygen, and nitrogen in the red cell membrane inherited as autosomal dominant

Rh Ag

Match the ff.

1. Antigens from the system were produced by 3 closely linked sets of alleles.

2. Assigns a number to each antigen of Rh system and no genetic basis but simply demonstrates the presence or absence of the Ags on the red cells

3. One gene responsible for defining Rh produced an agglutinogen with 3 Rh factors

4. Numeric technology

A. Rosenfield (Alpha-numeric)

B. Wiener (Rh-Hr)

C. Fisher-Race (DCE)

D. ISBT

1. C

2. A

3. B

4. D

Convert the ff. Wiener to Fisher-Race and Rosenfield. Additionally, determine whether it would be Rh+ or Rh-

1. R’r

2. R2R2

3. R⁰r

4. R⁰R⁰

5. R²r

6. R¹R²

1. R’r - Fisher-Race: DCe/dce Rosenfield: 1, 2, -3, 4, 5

2. R2R2 - Fisher-Race: DcE/DcE Rosenfield: 1, -2, 3, 4, -5

3. R⁰r - Fisher-Race: Dce/dce Rosenfield: 1, -2, -3, 4, 5

4. R⁰R^{0 -} Fisher-Race: Dce/Dce Rosenfield: 1, -2, -3, 4, 5

5. R²r - Fisher-Race: DcE/dce Rosenfield: 1, -2, 3, 4, 5

6. R¹R² - Fisher-Race: DCe/DcE Rosenfield: 1, 2, 3, 4, 5

ALL are Rh+

What chromosome number does RHAG resides?

Chromosome 6

What chromosome number does RHD and RHCE located?

Chromosome 1

Produces Rh-associated glycoprotein that is similar to the structure of Rh proteins and a coexpressor

RHAG

Match the ff.

1. D antigen is appear to be complete but few in number therefore it is weakly expressed

2. Structure of D antibody is in mosaic structure, composed of 4 fragments

3. Inheritance of Ce (r’) gene in trans to the RHD gene (2%)

4. The remaining portion of the antigen will stimulate production of alloantibody

5. Presence of D^u antigen

A. C-trans

B. Partial D

C. Genetic Weak D

1. C

2. B

3. A

4. B

5. C

Indicate if the following statement is T or F about the characteristics of antibodies

1. Majority are IgM

2. Does not react in saline medium

3. Immune antibodies

4. Binds complement

5. Rh antibodies are not capable of causing severe transfusion reaction

6. Can’t cross the placenta

1. F - IgG

2. T

3. T

4. F

5. F

6. F

Weakened expression of all Rh Ags

Rh_mod

Rh genes are inherited, but not expressed

Rh_null

What immunoglobulin is present on HDN?

IgG alloantibody

What are the 5 conditions before HDN occurs?

1. Mother must be exposed thru transfusion or pregnancy to a RC antigen she lacks

2. Antigenic exposure must result in immunization and antibody production

3. Ab must cross the placenta

4. Ab must be sufficient

5. Infant must have an antigen corresponding to maternal antibody

What are the clinical manifestations of HDN?

1. Anemia

2. Jaundice

3. Enlargement of the liver and spleen

4. Generalized edema —> hydrops fetalis

True or False

ABO-HDN is most common in type A or B babies born in Rh-positive mothers

False, it’s born to type O mothers

What is given to prevent sensitization of Rh negative mother with Rh positive child?

Rh Ig / Rhogam

Concentrated and purified anti-D gamma globulin

Rh Ig / Rhogam

What are the criteria for administration of Rhogam?

1. Rh and Du negative mother

2. Mother’s antibody screen is negative for anti-D

3. Baby is Rh+

True or False

If anti-D is positive in the mother, Rhogam should not be administered

True

This determines the volume of feto-maternal hemorrhage and vials/dosage of Rhogam to be given

Kleihauer acid elution

What is the most important procedure in assessing the severity of HDN in utero that requires ultrasound of the mother?

Amniocentesis

What procedure is indirectly infusing packed RBC through the fetal abdominal wall into the peritoneum?

Intrauterine Transfusion

This is used to correct severe anemia to prevent death in utero when the risk of early delivery is high

Intrauterine Transfusion

What are the 6 criteria for selection of blood?

1. Blood must be less than 7 days old

2. Group O, Rh-neg RBC

3. Compatible with mother’s blood

4. CMV (-)

5. Gamma irradiated

6. Does not contain Hb S