What is the Du test?
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 does du mean in blood type?
weak D
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.
Why is there a need to test for DU when there is weak or no reaction in Rh typing?
According to the American Association of Blood Banks (AABB) Standards for Blood Banks and Transfusion Services, it is required to test donors for weak D, because transfusion of blood from weak D individuals carries the risk of alloimmunization in Rh-negative transfusion recipients.
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.
When should a weak D test be performed?
1.2 Testing for weak D shall be performed in the case of an Rh negative neonate (less than 4 months of age) of an Rh negative mother with no evidence of Rh alloimmunization. 1.3 Weak D shall be performed if there is a discrepancy in previous and current results obtained with the Rh anti-sera.
What is DU test procedure?
To test for Du, red cells are incubated at 37oC with an IgG anti-D and an antiglobulin test is performed. If serum suspended cells are used, some blood samples at the upper end of the Du spectrum will be agglutinated weakly by most anti-D reagents prior to the antiglobulin test, either at room temperature or at 37oC.
Why Du test is done?
The reason for performing the Du test early in pregnancy is to avoid mis-interpreting the cause of a positive fetal cell screening test at the time of delivery. In addition to prenatal patients, newborn babies are also tested for Du if they type as D negative.
What is a weak D test?
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.
Why is DU test done?
What is du positive blood type?
A pregnant woman with blood type Rh, Du (+), who delivered an Rh D (+) baby and was not given Rh immune globulin is presented. The Du antigen is manifested by weak expression of the D gene on the RBC envelope, and therefore Rh Du (+) is considered Rh (D) positive.
Is a pregnant woman with blood type RH du negative?
A pregnant woman with blood type Rh, Du (+), who delivered an Rh D (+) baby and was not given Rh immune globulin is presented. Th … The Rh, Du blood phenotype occurs rarely in the white population (0.23-0.60%). Its clinical significance is whether it should be considered it as Rh positive or negative.
Why is the testing of blood group necessary?
The testing of blood group is necessary for safe blood transfusions. A patient should always receive a blood type that is compatible with his own blood type.
What does a weak D positive blood test result mean?
A true weak D should give at least a 2+ positive result. Weaker results may be due to mixed field agglutination in an Rh negative individual who received Rh positive blood, or vice-versa. Obtain a recent transfusion history on patients who give inconclusive weak D results.
