ABO Discrepancies

Question 1

serum grouping problems: weak or missing expected antibodies

Answer 1

newborns, pediatric samples, elderly, hypo or agammaglobulinemia, disease

Question 2

serum grouping problems: unexpected antibody

Answer 2

rouleaux, autoantibodies (cold), alloantibodies (IgM), anti-A (subgroups of A)

Question 3

rouleax

Answer 3

excessive protein in plasma

Question 4

cell grouping problems: weak or missing expected antigens

Answer 4

recent transfusion of compatible but different ABO type RBC, subgroups

Question 5

cell grouping problems: unexpected antigens

Answer 5

contamination, rouleaux, acquired antigens, Ab to dyes in anti-A and anti-B reagents

Question 6

A subgroup with mixed field reaction

Answer 6

A3

Question 7

deacetylation of A antigen by bacteria enzymes resulting in modified A antigen that resembles B antigen

Answer 7

acquired B antigen

Question 8

resolution of acquired B antigen discrepancy

Answer 8

monoclonal anti-B reagent
acidified anti-B reagent
human derived anti-B reagent
secretor studies

Question 9

B gene produces B sugar and mutation occurs that produces an “A-like” sugar

Answer 9

B(A) phenotype