Rh Blood Group System (ASCPi)

Rh genes are located where?

Chromosome 1 (Short arm)

HDFN

The Rh blood group system is the primary cause of:

Extravascular hemolysis

What type of hemolysis does the Rh blood group cause?

Fisher-Race (DCE)

The antigens were produced by 3 closely linked set of alleles, each gene was responsible for producing a product or antigen on the red cell surface

Wiener (Rh-Hr)

The gene responsible for defining Rh actually produced an agglutinogen that contained a series of blood factor, in which each factor is an antigen recognized by an antibody

Rosenfield (Alpha-numeric)

It has no genetic basis; number is assigned to each antigen of the Rh system in order of discovery

The system

Using the nomenclature of ISBT, the first three numbers represent:

Antigenic specificity

Using the nomenclature of ISBT, the last three numbers represent:

22% BSA

Rh typing uses ______ as control.

In Black people

Weak D (Du) occurs more commonly:

Indirect Antiglobulin Test

Weak D typing follows the principle of:

Washing

It is the most important step in the AHG phase

Check cells

O-positive red cells coated with anti-D then are added to a negative anti-D test

C trans to RHD

• Also known as the “Positioning Effect”

• Dce/Ce; D allele is in trans (opposite side) to the allele carrying C

Del (D--)

No genes needed to synthesize Cc or Ee

Rh null

No Rh antigens on its RBC

• Mild compensated hemolytic anemia

• Stomatocytosis

• Hyperbilirubinemia

• Low haptoglobin

• Increased hbF

• Low Hb and Hct

Rh mod

• Partially suppressed Rh gene expression

  • Similar to Rh null but milder

D mosaic

• Missing or altered epitope of D

• Produces anti-D (directed to missing epitope)

LW antigen

Demonstrated as antigen present on Rhesus monkey and on majority of human RBC; originally thought to be the same antigen as Rh