Quick Review Cards for Medical Laboratory Science

ABO Discrepancies Immunohematology Review 444

ANTI-A ANTI-B A 1 CELLS B CELLS POSSIBLE CAUSE* RESOLUTION

0

4+

4+

4+

3+

4+

*Other explanations may be possible.

Incubate reverse grouping at RT for 30 min. If still neg,

incubate at 4°C for 15–30 min. Include controls: pt RBCs

in 4% albumin, pt serum with O cells.

Type RBCs with anti-A 1 (Dolichos biflorus lectin). Test serum

with several additional A1,A2, & O cells.

Use washed RBCs suspended in saline for forward grouping.

Perform saline replacement technique in reverse grouping.

Perform ab panel at RT. If cold alloantibody identified,

repeat reverse grouping with A 1 & B cells that lack

corresponding ag.

Type cells with anti-A 1 (Dolichos biflorus lectin). Test serum

with several additional A1,A 2 , & O cells.

Check medical history for infection by GI bacteria (some have

enzymes that convert A ag to B-like ag.) Retype RBCs with

different monoclonal anti-B or acidified human anti-B

(pH 6.0; doesn’t react with acquired B ag).

0

1+

2+

2+

1+

0

0

4+

2+

2+

0

4+

Missing isoagglu-

tinins in group O

A 2 with anti-A 1

Rouleaux

AB with cold

alloantibody

A 2 B with anti-A 1

Acquired B antigen

0

0

4+

4+

4+

2+