Question

Determine the cause of the positive DATs for the patients below:

Patient #4:

Mom is O negative with an Anti-D

Baby is A positive, DAT 2+

Name 2 antibodies that could be causing the positive DAT. _____________, __________

Answer 1

Importance of DAT ( Direct AntiGlobulin Test):

This test is performed to detect anti-D antibody or other antibodies attached to the red cell surface within the blood stream. This occurs in the following circumstances :

1. When there is a Rh-positive baby in the womb of a sensitised Rh-negative woman, the antibodies produced in mother's serum cross the placenta and after entering the baby's blood stream, these antibodies will attach to the baby's Rh-positive red blood cells.

- these sensitised cells are clumped and removed from the circulation causing

a) Heamolytic Disease of the New born: Erythroblastosis fetalis,

b) Hyper bilirubinemia.,

c) Lymphocytic Leukemia

- when the baby is born , the baby blood is collected ( cord blood) and tested by the DAT to detect Anti 'D' antibodies on red blood cells.

2) Transfusion reactions,

3) Drug induced red cell sensitisation,

4) Autoimmune haemolytic anemia

Name of the Two antibodies are :

IgG and Complement 3 (C3)

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