Antibody detection and ID

Discovered antibodies against RBCs(nonABO) are usually

Unexpected (immune alloantibodies)

Expected antibodies are those against

ABO antigens

AHG is also known as

Coombs test

Screen cells and panel cells come from

Group O donors

Screen cells are either

2 or 3 cell panels

Ideally you want as many

Homozygous cells as possible

Panel cells contain

8-20 cells with known RBC phenotypes

Momozygous expression of antigens on screening cells is desirable because

Some antibodies show dosage

Common antibodies that show dosage

Rh (not D), Kidd, Duffy, MNSs, and Lutheran

Proper detection and ID of RBC antibodies is important for

Appropriate blood products, HDN, and hemolytic anemias

Check cells are

O positive RBCs coated with anti-d

Purpose of check cells

Used to ensure AHG tests with negative results are not false negatives

If CC test is negative

Washing method was inadequate and protein is bound to the red cells causing neutralization, or reagent was left out

When AHG is negative

There should be free AHG in the test tube

When CC are added

The free AHG should agglutinate the sensitized RBCs

possible interpretations

Single alloantibody, two alloantibodies w ags on cell 2 only, probable IgGalloantibody

Possible interpretations

Single or multiple antibodies probably IgM

Possible interpretations

Multiple alloantibodies warm and cold, potent cold antibody binding complement at AHG

Cold or IgM insignificant antibodies

I, Lewis, M, N, P1, Lu a, K

Significant antibodies that react at or past 37

Rh, K, S,s, K, Kell, Duffy, Kidd, Lu b, Xg a

Auto control involves

Testing patient serum against pt cells

Positive auto control means

Positive DAT and free antibody in pt serum

Positive auto control does not

Rule out alloantibody possibility

Positive auto control is associated with

Autoimmune hemolytic anemia, drug induced hemolytic anemia, HTR, or benign conditions

Follow up positive auto control with

DAT and elution

NEAT

No enhancement added test

PEG

Ur elves water molecules away and help ag/ab to get closer to bind

Zeta potential

Reduction of the electrical charged around the cells to allow the antibody to bind

Panel cells

Cells that have more antigen phenotypes than screen cells that allow the identification of antibody

Negative auto control means

Alloantibody

Sufficient evidence to prove suspected antibody

Testing pt serum w 3 antigen positive and 3 antigen negative

Patient should be negative for

The antigen for the antibody being tested for

Antigen typing on a patient can’t happen if

They have been transfused w/in 3 months

IgG DAT positive cells can cause

False positive reactions

How are IgG DAT positive cells treated

Glycine EDTA to strip antibody then perform DAT and antibody type (not with Kell)

When a patient has a significant antibody you must

Antigen type donor units for the antigen (not for IgM)

Cross match w antigen negative units must be

Carried through AHG even if the antibody is cold