Term
| What are other names for the Direct Antiglobulin test? |
|
Definition
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|
Term
| What does the DAT detect? |
|
Definition
| Red cells that have been coated with IgG antibodies or complement in vivo |
|
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Term
| What could IgG sensitization on RBCs be due to? |
|
Definition
| HDN, autoantibodies, drugs, autoimmune hemolytic anemia, or transfusion reactions |
|
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Term
| When does the DAT demonstrate mixed field agglutination? |
|
Definition
| HDN (ABO incompatibility) and transfusion reaction investigations |
|
|
Term
| What is mixed field agglutination? |
|
Definition
| cloud of smoke due to presence of two different cell populations |
|
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Term
| When can mixed field agglutination be observed? |
|
Definition
| ABO antibodies readily lyse red cells, less to test, or transfusion reactions in which the donor red cell will be coated with antibodies or complement which are few in comparison to patient's own red cells |
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Term
| When will a DAT be strongly positive? |
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Definition
| HDN due to Rh incompatibility, or autoimmune hemolytic anemia |
|
|
Term
| What is the antibody screen? |
|
Definition
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|
Term
|
Definition
| presence of red cells that have been coated with IgG antibodies or complement from patients serum in vitro. |
|
|
Term
| What are the patients red cells tested with in IAT? |
|
Definition
| O screening cells with known antigenic composition |
|
|
Term
| What do the antigens in the IAT represent? |
|
Definition
| blood group systems most often encountered in crossmatch problems and cases of HDN |
|
|
Term
| What are the phases that the IAT are read at? |
|
Definition
| Immediate spin, 37 C and AHG |
|
|
Term
| What are immediate spin reactions due to? |
|
Definition
|
|
Term
| What are 37 C reactions due to? |
|
Definition
|
|
Term
| What are AHG reactions due to? |
|
Definition
|
|
Term
| Name the thee enhancement media |
|
Definition
| PEG, LISS, or 15%/22% bovine albumin |
|
|
Term
| Why is enhancement media used? |
|
Definition
| utilized to increase the reactivity of any antibody present by decreasing the zeta potential |
|
|
Term
| Why do you add check cells to all negative tubes? |
|
Definition
| to assure that AHG is not neutralized |
|
|
Term
| What should check cells produce? |
|
Definition
|
|
Term
| What does agglutination or hemolysis indicate? |
|
Definition
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|
Term
|
Definition
| HDN, immediate or delayed transfusion reactions, antoimmune diseases, drugs |
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|
Term
| What can a delay in the washing technique priot to the AHG phase cause |
|
Definition
| false negatives because the antibody may elute off the screening cells |
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