What is the Du antigen?

What is the Du antigen?

Du is the phenotypic term used to denote a weakened expression of the D antigen. Du originally defined as those red cells reacting with anti-D only when a more sensitive indirect antiglobulin test was used. The frequency of Du antigen is relatively low less than 1%.

What does it mean to have a weak D antigen?

An individual with weak D has a decreased amount of D antigens expressed on the red cell. With current serologic testing, most individuals with weak D are typed as Rh-positive via direct agglutination testing using anti-D. Relative to partial D individuals, weak D individuals are less likely to form anti-D antibodies.

Why is it called D antigen?

The name has derived from a similar antigen recognized by the serum of rabbits immunized with rhesus monkey red cells. The human Rh(D) antigen is encoded by a dominant gene which is present in approximately 80% of the population. There are therefore Rh+ and Rh− individuals.

What is DU in blood banking?

Your Rh factor — “Du,” also called “weak D” — is a weakly positive Rh D factor. Less than 1 percent of people have this. Blood banks have not always been consistent in how this is reported. You also are likely to be safe getting Rh-positive blood.

How do you test for weak D antigen?

The way to detect weak D cells reliably is to do a test for weak D (usually called a Du test). The Du test is an indirect antiglobulin test using the patient’s red cells and an IgG anti-D. An IgG anti-D must be used because antiglobulin serum contains anti-IgG.

Why is the D antigen so important?

The D antigen is the most immunogenic, meaning it provokes an immune response that makes it most likely to cause a transfusion reaction in the recipient.

What is the function of D antigen?

D antigen is a protein with many parts, found on the surface of red blood cells. The D antigen is also known as the “Rh factor,” and it tells your blood type. People are either D (Rh) negative or D (Rh) positive. If your blood type is D negative, your red blood cells do not have the D antigen.

How common is weak D?

Approximately 0.2% to 1% of routine RhD blood typings result in a “serological weak D phenotype.” For more than 50 years, serological weak D phenotypes have been managed by policies to protect RhD-negative women of child-bearing potential from exposure to weak D antigens.

What is D antigen made of?

What is weak D positive?

Uncommonly, D-positive people have significantly decreased quantities of the D antigen, so they do NOT test as D-positive with routine immediate spin testing (instead, positive reaction is only seen at the “AHG phase“). Such persons are defined as “weak D” (formerly “Du“).

The name has derived from a similar antigen recognized by the serum of rabbits immunized with rhesus monkey red cells. The human Rh(D) antigen is encoded by a dominant gene which is present in approximately 80% of the population.

Weak D (Du) testing – Testing that is done to detect a weak Rh type. Forward typing- A blood typing procedure whereby patient red blood cells are mixed with Anti-A and Anti-B reagents.

What is weak D blood type?

The weak D phenotype is a weakened form of D antigen that in routine D antigen testing will react with some anti-D but not with others (when 37 C incubation or an immediate spin is given). Weak D RBC has D antigen but fewer in number as compared to normal Rh D-positive red cells.

What is the D antigen in the blood?

The D antigen is also known as the “Rh factor,” and it tells your blood type. People are either D (Rh) negative or D (Rh) positive. If your blood type is D negative, your red blood cells do not have the D antigen.

How many red cells have the weak D antigen?

Weak D red cells have the D antigen, but have fewer D antigens per cell than normal Rh positive cells. The current preferred term for Duis “weak D.” The frequency of the weak D phenotype in Caucasians is approximately 0.3 percent (3 in 1000).

What is the meaning of the weak D phenotype?

Definition: The weak D phenotype (D u) is a weakened form of the D antigen that in routine D typing will react with some anti-D but not with others (when an immediate spin or 37° incubation is done). Weak D red cells have the D antigen, but have fewer D antigens per cell than normal Rh positive cells.

What does it mean to have weak D in blood?

Historically, weak D red blood cells were defined as having decreased D antigen levels that required the indirect antiglobulin test for detection. Weak D phenotype most commonly results from a single point mutation in the transmembrane domain of the RHD gene. More than fifty different weak D types have been reported so far.

What is a weak D blood type?

Definition: The weak D phenotype (D u) is a weakened form of the D antigen that in routine D typing will react with some anti-D but not with others (when an immediate spin or 37° incubation is done). Weak D red cells have the D antigen, but have fewer D antigens per cell than normal Rh positive cells. The current preferred term for D u is “weak D.”.

What is a weak D test?

Weak D phenotype is a weakened form of the D antigen which is weakly expressed (70 to 4000 sites). Weak D phenotype is characterized by negative reaction with standard anti-D reagent, that’s why it’s necessary to perform a specific test in order to detect weak D. Generally, this test is done on pregnant women, newborns and on Rh negative donors…

What is a weak D positive?

Weak D Phenotype. Most D-positive (“Rh-positive”) people express the antigen quite well, and the person is obviously D-positive when anti-D is mixed with their red cells. In test tubes, the reaction occurs immediately after centrifugation (in other words, at the ” immediate spin ” phase). Uncommonly, D-positive people have significantly decreased…

What is Rh weak D?

Weak D Phenotype. The main Rh antigen (the one that determines whether a person is “Rh-positive” or “Rh-negative”) is known to blood bankers as the “D” antigen. Most D-positive (“Rh-positive”) people express the antigen quite well, and the person is obviously D-positive when anti-D is mixed with their red cells.