Blood Bank Questions with Correct Answers
Weak -D phenotype Correct Answer-Du. Will react with some D-
antigens, but not others (during IS or 37C). Red cells have the D-
antigens, but have fewer D-antigens than normal Rh-positive cell.
Rh Genotype vs. Rh Haplotype Correct Answer-Two haplotype in one
genotype
Rh Null Correct Answer-Extremely rare. Lack all Rh antigens. The lack
of antigen causes the red cell membrane to appear abnormal leading to:
stomatocytosis, spherocytosis.
Transmembrane non-glycosylated polypeptide Correct Answer-Proteins
without any carbohydrates attached. It is a protein that is intrinsic to the
red cell membrane.
HDN Correct Answer-Caused by the destruction of the RBCs of a fetus
by antibodies produced by the mother. These antibodies are directed
against those antigens on the fetal RBCs that were inherited from the
father.
HTR Correct Answer-A reaction from RBC destruction caused by
patient's antibodies directed to donor RBC antigens.
Agammaglobulinemia Correct Answer-The complete absence of
immunoglobulin in the blood.
,Cold unexpected anitbody Correct Answer-Present if either the antibody
screen or the DAT is positive.
They can sometimes mask more clinically significant antibodies (IgG).
Anti-A1 Correct Answer-Dolichos biflorus, Occurs in the serum of some
A2 and A2B individuals (along with some other weak A subgroups);
Usually IgM and reacts best at 20-25C or below; Only clinically
significant if reactivity is observed at 37C
Acquired B antigen Correct Answer-Weak reaction in Anti-B fwd
grouping. Could be E.coli deacetylation of the group A antigen making
them look like B antigens: the bacteria produces an enzyme that goes out
and finds group A RBCs and selectively clips off some of the group A
N-Acetyl groups, but not all of them. The remaining D-galactosamine
are similar enough to Group B D-galactose that when we add sugar, it
agglutinate. It appears as though the patients have additional anti-B
antigens.
Ex. Bowel obstruction or carcinoma of the bowel.
Multiple Myeloma Correct Answer-Increased serum proteins... non
specific red cell aggregation. Rouleaux.
Anti-f Correct Answer-Present any time a person carries the RHCE gene
that encodes for both "c" and "e" . You have to have at least one copy of
the RHce allege of the RHCE gene.
,Anti-Cw Correct Answer-Low frequency IgG against red cell antigen.
Clinically significant and may cause HDN. unusual antibody found in
individuals never transfused or pregnant
Stomatocytosis Correct Answer-The Rh null is produced by at least two
different genetic mechanisms. The 'amorph' type is the result of
molecular change in RHCE gene with a deleted RHD gene, whereas the
more common 'regalator' type is associated with the defect in RHAG
gene. Both genotype result in the same clinical syndrome characterized
by hemolytic of varying severity.
Rh Genes -- Rh positive, Chromosome 1 has to Locus. What are they?
Correct Answer-Locus 1: RHD
Locus 2: RHCE
Locus 1 on Chromosome 1 Correct Answer-Presence of RHD codes for
the presence of D or no D.
Locus 2 on Chromosome 2 Correct Answer-Presence of RHCE codes
for Ce, CE, cE, ce.
Rh (D) Negative in European ancestry Correct Answer-Deletion of RHD
(No D antigens in Locus 1, ce antigens present in Locus 2)
Rh (D) Negative in African Americans Correct Answer-Inactivating
mutations of RHD ( No D-antigens due to mutation in Locus 1, C/c and
E/e antigens in Locus 2)
, Rh (D) in negative African backgrounds Correct Answer-Hybrid RHD-
CE-D (RHCE inserted into RHD, so no D-antigens and weak C in Locus
1, C/c and E/e in locus 2).
Du+ blood to a D- person causes production of? Correct Answer-Anti-D
not anti-Du
Weak D reactivity with Anti-D Correct Answer-*Agglutinated with
some anti-D on direct agglutination (IS)
*Negative on direct agglutination (IS) -- D antigen detected by IAT
only.
What weak expression of D do not make anti-D? Correct Answer-*C in
trans with RHD (r' haplotype)
*Weak D "Types": single amino acid changes
*Weak D Type 2 (very weak pos when in trans with r')
Weak D Type 1 Correct Answer-R1r (D+C+E-c+e+)
Weak D Type 2 Correct Answer-R2r (D+C+E+c+e+)
Clinical significance of Rh Correct Answer-The D antibody can cause
transfusion reactions and HDN
Weak -D phenotype Correct Answer-Du. Will react with some D-
antigens, but not others (during IS or 37C). Red cells have the D-
antigens, but have fewer D-antigens than normal Rh-positive cell.
Rh Genotype vs. Rh Haplotype Correct Answer-Two haplotype in one
genotype
Rh Null Correct Answer-Extremely rare. Lack all Rh antigens. The lack
of antigen causes the red cell membrane to appear abnormal leading to:
stomatocytosis, spherocytosis.
Transmembrane non-glycosylated polypeptide Correct Answer-Proteins
without any carbohydrates attached. It is a protein that is intrinsic to the
red cell membrane.
HDN Correct Answer-Caused by the destruction of the RBCs of a fetus
by antibodies produced by the mother. These antibodies are directed
against those antigens on the fetal RBCs that were inherited from the
father.
HTR Correct Answer-A reaction from RBC destruction caused by
patient's antibodies directed to donor RBC antigens.
Agammaglobulinemia Correct Answer-The complete absence of
immunoglobulin in the blood.
,Cold unexpected anitbody Correct Answer-Present if either the antibody
screen or the DAT is positive.
They can sometimes mask more clinically significant antibodies (IgG).
Anti-A1 Correct Answer-Dolichos biflorus, Occurs in the serum of some
A2 and A2B individuals (along with some other weak A subgroups);
Usually IgM and reacts best at 20-25C or below; Only clinically
significant if reactivity is observed at 37C
Acquired B antigen Correct Answer-Weak reaction in Anti-B fwd
grouping. Could be E.coli deacetylation of the group A antigen making
them look like B antigens: the bacteria produces an enzyme that goes out
and finds group A RBCs and selectively clips off some of the group A
N-Acetyl groups, but not all of them. The remaining D-galactosamine
are similar enough to Group B D-galactose that when we add sugar, it
agglutinate. It appears as though the patients have additional anti-B
antigens.
Ex. Bowel obstruction or carcinoma of the bowel.
Multiple Myeloma Correct Answer-Increased serum proteins... non
specific red cell aggregation. Rouleaux.
Anti-f Correct Answer-Present any time a person carries the RHCE gene
that encodes for both "c" and "e" . You have to have at least one copy of
the RHce allege of the RHCE gene.
,Anti-Cw Correct Answer-Low frequency IgG against red cell antigen.
Clinically significant and may cause HDN. unusual antibody found in
individuals never transfused or pregnant
Stomatocytosis Correct Answer-The Rh null is produced by at least two
different genetic mechanisms. The 'amorph' type is the result of
molecular change in RHCE gene with a deleted RHD gene, whereas the
more common 'regalator' type is associated with the defect in RHAG
gene. Both genotype result in the same clinical syndrome characterized
by hemolytic of varying severity.
Rh Genes -- Rh positive, Chromosome 1 has to Locus. What are they?
Correct Answer-Locus 1: RHD
Locus 2: RHCE
Locus 1 on Chromosome 1 Correct Answer-Presence of RHD codes for
the presence of D or no D.
Locus 2 on Chromosome 2 Correct Answer-Presence of RHCE codes
for Ce, CE, cE, ce.
Rh (D) Negative in European ancestry Correct Answer-Deletion of RHD
(No D antigens in Locus 1, ce antigens present in Locus 2)
Rh (D) Negative in African Americans Correct Answer-Inactivating
mutations of RHD ( No D-antigens due to mutation in Locus 1, C/c and
E/e antigens in Locus 2)
, Rh (D) in negative African backgrounds Correct Answer-Hybrid RHD-
CE-D (RHCE inserted into RHD, so no D-antigens and weak C in Locus
1, C/c and E/e in locus 2).
Du+ blood to a D- person causes production of? Correct Answer-Anti-D
not anti-Du
Weak D reactivity with Anti-D Correct Answer-*Agglutinated with
some anti-D on direct agglutination (IS)
*Negative on direct agglutination (IS) -- D antigen detected by IAT
only.
What weak expression of D do not make anti-D? Correct Answer-*C in
trans with RHD (r' haplotype)
*Weak D "Types": single amino acid changes
*Weak D Type 2 (very weak pos when in trans with r')
Weak D Type 1 Correct Answer-R1r (D+C+E-c+e+)
Weak D Type 2 Correct Answer-R2r (D+C+E+c+e+)
Clinical significance of Rh Correct Answer-The D antibody can cause
transfusion reactions and HDN
