136 Erythrocyte Antigens and Antibodies Flashcards

1
Q

Most of the protein blood group antigens are carried on

A

Integral transmembrane proteins (either single-pass type I or type II, or multipass)

A few are carried on glycosylphosphatidylinositol (GPI)-linked proteins or adsorbed from plasma

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2
Q

Chromosome Location of ABO Blood Group

A

9q34.2

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3
Q

Blood Group System: Decreased Plasmodium falciparum invasion, may be receptor for Escherichia coli

A

MNS

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4
Q

Blood Group System: Possibly transports CO2 or NH3 (CD240)

A

Rh

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5
Q

Blood Group System: Increased expression possibly involved in vasoocclusion in sickle cell disease

A

Lutheran

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6
Q

Blood Group System: Cleaves big endothelin-3 to ET-3, a potent vasoconstrictor (CD238)

A

Kell

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7
Q

Blood Group System: Increased expression in fucosidosis, antibodies may be important in graft rejection

A

Lewis

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8
Q

Blood Group System: Resistance to P vivax invasion

A

Duffy

P. falciparum: MNS

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9
Q

Blood Group System: Urea transporter; Impaired urea transport, urine-concentrating defect

A

Kidd

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10
Q

Blood Group System: Anion exchanger
(CD233), Band 3 cytoskeletal protein; Southeast Asian ovalocytosis, hereditary spherocytosis, renal tubular acidosis

A

Diego

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11
Q

Blood Group System: Absent from PNH III RBCs

A

Yt
Dombrock

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12
Q

Blood Group System:Monosomy 7, inability to
maximally concentrate urine, congenital dyserythropoietic anemia

A

Colton

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13
Q

Blood Group System: Renal disease, associated with pretibial epidermolysis bullosa and sensorineural deafness

A

Raph

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14
Q

Blood Group System: Acanthocytosis, muscular dystrophy, hemolytic anemia; McLeod syndrome sometimes associated with CGD, peripheral neuropathy, cardiomyopathy seizures, a late-onset dementia, and behavioral changes

A

Kx

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15
Q

Blood Group System: Hereditary elliptocytosis, hemolytic anemia, decreased 4.1R and p55

A

Gerbich

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16
Q

Blood Group System: Absent from PNH III RBCs, Dra is the receptor for uropathogenic E coli

A

Cromer

***John Milton Hagen, CD59 (also absent from PNH III RBCs)

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17
Q

Blood Group System: Congenital cataracts in Asians

A

I

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18
Q

Blood Group System: Receptor E coli and parvovirus B19

A

GLOB

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19
Q

Blood Group System: Hemolytic anemia, hereditary stomatocytosis

A

Rh-associated glycoprotein

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20
Q

Blood Group System: Multiple small calcifications around the joints in the hand and ectopic calcification or mineralization in hips, feet, pubic symphysis, and lumbar discs

A

Augustine

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21
Q

Blood Group System: Expressed on Tamm-Horsfall glycoprotein in urine that prevents adherence of pathogenic bacteria to urothelial cells

A

Sid

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22
Q

Blood Group System: Deafness, choline deficiency disease

A

CTL2

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23
Q

As of this writing, ____ blood group systems and _____ antigen collections are defined

A

39 blood group systems
5 antigen collections

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24
Q

Most significant antigens in transfusion and
transplantation

A

ABO

Because A and B antigens also are expressed on most tissue cells, ABO compatibility is a significant consideration in solid-organ transplantation.

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25
Q

Most significant antigen after A and B

A

D

The antigens C, c, E, and e are less immunogenic

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26
Q

Important cause of DHTR

A

Kidd

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27
Q

TRUE OR FALSE

Group A or B erythrocytes appear to have less H antigen than group O cells

A

TRUE

Group A or B erythrocytes appear to have less H antigen than group O cells

The sugars defining A and B antigens are added to carbohydrate chains carrying the H antigen (fucose), which is “hidden” by the A (GalNAc) or B (Gal) sugar.

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28
Q

TRUE OR FALSE

Because A and B antigens also are exclusively expressed on RBCs, ABO compatibility has no role in solid-organ transplantation.

A

FALSE

Because A and B antigens also are expressed on most tissue cells, ABO compatibility is a significant consideration in solid-organ transplantation.

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29
Q

ABO incompatibility only rarely causes severe HDFN because antibodies directed against A and B antigens are predominantly immunoglobulin (Ig) ______, which do not cross the placenta

A

Immunoglobulin (Ig) M

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30
Q

The second most important blood group system in transfusion medicine because antigen-positive RBCs frequently immunize antigen-negative individuals through transfusion and pregnancy.

A

Rh system

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31
Q

Inheritance of Rh antigens is determined by a complex of two closely linked genes:

A
  • Protein-carrying D antigen (RhD)
  • Protein carrying C or c and E or e antigens (RhCE)
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32
Q

In the Rh system, _______ common antigen combinations or haplotypes are possible

A

Eight

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33
Q

Approximately_____% of the white population is Rh-positive, and _____% is Rh-negative.

A

85% Rh-positive
15% Rh-negative

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34
Q

A substance that can evoke an immune response when introduced into an immunocompetent host and react with the antibody produced from that immune response.

A

Antigen

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35
Q

The ability of an antigen to stimulate an immune response is called

A

Immunogenicity

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36
Q

Ability to react with an antibody

A

Antigenicity

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37
Q

TRUE OR FALSE

Immunogenicity does not always correlate with the hemolytic potential of an antibody specificity

A

TRUE

Immunogenicity does not always correlate with the hemolytic potential of an antibody specificity

For example, K is more immunogenic than Jk a but anti-Jk a is more likely to cause hemolysis.

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38
Q

Order of immunogenicity

A

A and B, D, K

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39
Q

A, B, and H antigens can be detected at ______ weeks of gestation

A

5 to 6 weeks of gestation

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40
Q

Full expression of A, B, H, I, and Lewis antigens usually is present by age____ years, whereas full expression of P1 and Lutheran antigens may not occur until age ______years.

A

3 years

7 years

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41
Q

Examples of Carbohydrate Antigens:

A
  • ABO
  • H
  • I
  • LE
  • P1PK
  • GLO
  • Sd
42
Q

Protein structures that carry blood group antigens can be grouped into three categories:

A

(1) those that make a single pass through the erythrocyte membrane,
(2) those that make multiple passes through the membrane, and
(3) those that are attached to the membrane through a covalent linkage to lipid (GPI-linked).

43
Q

Defective synthesis of the ________ is responsible for paroxysmal nocturnal hemoglobinuria (PNH)

A

GPI anchor

44
Q

TRUE OR FALSE

Protein antigens are direct gene products
Carbohydrate antigens, made by transferase action, are indirect gene products.

A

TRUE

Protein antigens are direct gene products
Carbohydrate antigens, made by transferase action, are indirect gene products.

45
Q

Most blood group genes are located on autosomes; only two, _____________, are located on the X chromosome

A

Xg and XK

46
Q

Blood group systems are present only on RBCs

A

Antigens in the RH and JK blood group

RJK exclusive in RBC

47
Q

ABH antigens have broad tissue distribution.

In embryos, A, B, and H antigens are detectable on all endothelial cells and all epithelial cells except those of the _______.

A

CNS

48
Q

Antigens that are present in plasma and on platelets and lymphocytes

A

ABO, P1PK, LE, H, and I systems

ABHI will take the PLE and will ace topics on plasma, platelets and lymp

ABH on platelets and lymphocytes may be acquired at least in part by adsorption from plasma.

Secretions (saliva, milk, sweat, semen, and urine, but not cerebrospinal fluid) contain soluble A, B, H, I, and Le a and Le b antigens but no P1PK or GLOB system antigens.

49
Q

Granulocytes carry _____ antigen but no ABH

A

I antigen

GI strong without ABO

50
Q

Sd a antigen is found in most body secretions, with the greatest concentration in____________.

A

Urine

51
Q

Blood group more common in persons with cancer of the salivary glands, stomach, colon, or ovary, and with thrombosis (because of higher levels of coagulation factors VIII, V, and IX)

A

Blood group A

52
Q

Blood group more common in patients with duodenal and gastric ulcers, rheumatoid arthritis, and von Willebrand disease.

A

Blood group O

53
Q

Blood group more common in patients with Escherichia coli urinary tract infection, gonorrhea

A

Group B

54
Q

Blood group more common in patients with Sjögren syndrome

A

Le(a–b–)

55
Q

Blood group more common in patients with Helicobacter pylori

A

Group O, Le(a–b+)

56
Q

Blood group more common in patients with Parvovirus

A

Globoside

57
Q

Blood group with resistance to Pyelonephritogenic infections of E. coli, parvovirus B

A

p (PP1Pk–)

58
Q

Blood group with resistance to Plasmodium vivax, Plasmodium knowlesi

A

Fy(a–b–)

59
Q

Blood group with resistance to Plasmodium falciparum

A

Tn–, Cad–, En(a–), U–, Ge–

60
Q

Blood group associated with antibody production in Cold agglutinin disease

A

Anti-I, -IH, -i, -H, -Pr

61
Q

Blood group associated with antibody production in Warm autoimmune hemolytic anemia

A

Anti-“Rh,” –“Kell,” -U, -Wr

62
Q

Blood group associated with antibody production in Mycoplasma pneumoniae, chronic lymphocytic leukemia, Hodgkin lymphoma and non-Hodgkin
lymphomas

A

Anti-I

63
Q

Blood group associated with antibody production in Infectious mononucleosis, reticuloendothelial diseases

A

Anti-i

64
Q

Blood group associated with antibody production in Early spontaneous abortions

A

Anti-PP1P

65
Q

Blood group associated with antibody production in Paroxysmal cold hemoglobinuria, early spontaneous abortions, lymphoma

A

Anti-P

66
Q

Blood group associated with antibody production in Renal dialysis (formaldehyde exposure)

A

Anti-NF

67
Q

Blood group associated with antibody production in Virally induced hemolysis

A

Anti-Rx

68
Q

The critical receptor for P. vivax attachment

A

Fy6 antigen

Erythrocytes lacking Fy a and Fy b antigens are not infected by the malarial parasite Plasmodium vivax or by the simian malarial parasite Plasmodium knowlesi

69
Q

Phenotype is associated with hereditary stomatocytosis, hemolytic anemia (usually mild and well compensated)

A

Rh null Syndrome

Most Rh null red cells are stomatocytes, or occasionally spherocytes, and demonstrate increased osmotic fragility, increased potassium permeability, and higher potassium pump activity.

70
Q

Individuals have acanthocytosis, decreased RBC survival, very weak expression of Kell blood group antigens, lack of Kx antigen on RBCs, and a well-compensated hemolytic anemia.

A

McLeod Phenotype

RBCs with the McLeod phenotype show a defect in water transport, increased mobility of phosphatidylcholine across the membrane, and increased phosphorylation of protein band 3 and β-spectrin.

71
Q

Rare people lack A, B, and H antigens and have naturally occurring anti-A, anti-B, and anti-H in their plasma.

Without Fuc, neutrophils lack sialyl Le X and thus cannot roll and ingest bacteria.
Has condition that is called leukocyte adhesion deficiency II or congenital disorder of glycosylation II

A

Bombay (O h ) Phenotype

All cells lack Fuc

These patients have a high white blood cell count and severe recurrent infections.

72
Q

Alloantibodies:
Autoantibodies:

A

Alloantibodies: only react with antigens present on the RBCs of other people

Autoantibodies: react with self-antigens present on the patient’s own RBC

Alloantibodies also can be classified according to their mode of sensitization as naturally occurring (no apparent sensitization) or immune (after sensitization).

73
Q

The predominant antibody made in an immune response and constitutes approximately 80% of total serum Ig

A

IgG

Most IgG antibodies sensitize RBCs at 37 °C and are detected with an antiglobulin reagent

IgG blood group antibodies also are capable of fixing complement, although some subclasses do so less efficiently than others: IgG 3 > IgG 1 > IgG 2 > IgG 4

74
Q

A pentamer of five basic units (having μ heavy chains plus a short J, or joining, chain) and makes up only approximately 4% of total serum Ig

First class of Ig produced by the fetus and is the predominant antibody in a primary immune response, but it does not cross the placenta

Because of their pentameric structure, even low-affinity IgM blood group antibodies can agglutinate RBCs and activate complement.

A

IgM

IgM antibodies of low affinity may agglutinate RBCs only at temperatures below 37 °C.

Because such IgM antibodies dissociate from RBCs at higher temperatures, their reactivity may be detected in routine antiglobulin tests (using polyspecific antiglobulin) by virtue of the complement components that remain bound to the red cell membrane.

75
Q

The primary Ig in body secretions, where it exists predominantly as a dimer with a secretory component

A

IgA

Does not cross the placenta or fix complement, but aggregated IgA can activate the alternative pathway of complement, and IgA can trigger cell-mediated events

76
Q

IgG levels rise significantly between _________ weeks of gestation as a selective transport system matures and maternal IgG is actively transported across the placenta.

A

20 and 33 weeks of gestation

77
Q

Anti-A and anti-B usually are readily detected by age_________ months.

A

2 to 6 months

78
Q

Blood bank standards testing on neonates younger than 4 months

A

The mother’s serum is used (and preferred) for identifying antibodies in a newborn and for crossmatching RBC components

79
Q

Naturally occurring alloantibodies are commonly associated with the carbohydrate antigens of the _______________blood group systems.

A

ABO, H, LE, and P1PK blood group systems

80
Q

Most naturally occurring antibodies are _______

A

IgM

81
Q

TRUE OR FALSE

Except for anti-A and anti-B, most common naturally occurring antibodies do not react at body temperature and are considered clinically insignificant.

A

TRUE

Except for anti-A and anti-B, most common naturally occurring antibodies do not react at body temperature and are considered clinically insignificant.

82
Q

Immune antibodies are produced after exposure to foreign RBC antigens through:

A

Pregnancy or transfusion

Immune antibodies are found more commonly in individuals who have been multiply transfused than in multiparous women

This situation occurs because in pregnancy the immunizing dose of red cells often is too small to elicit a primary response and the foreign antigens are limited to those of the father.

83
Q

Immune antibodies most often are

A

IgG

But may be IgM and sometimes are IgA

84
Q

Antibodies that disappear after several months and are more commonly associated with delayed hemolytic transfusion reactions

A

Kidd

85
Q

The most common alloantibodies

A

Anti-C, anti-E, and anti-K

86
Q

The most potent cause of immediate hemolytic reactions

A

ABO incompatibility

Because A and B antigens are strongly expressed on RBCs and the antibodies so efficiently bind complement.

The severity of the reaction varies with antigen density and antibody characteristics.

87
Q

Antibodies commonly associated with intravascular hemolysis:

A

Anti-A, anti-B, anti-Jka, and anti-Jkb

88
Q

Antibodies commonly associated with extravascular hemolysis:

A

Rh, Kidd, Kell, Duffy, or Ss antigens

Occurs with IgG1 and IgG3 antibodies that react at body temperature

89
Q

Most commonly seen HDFN

A

ABO HDFN

Clinically mild, presumably because the antigens are not fully expressed at birth

90
Q

Cause severe HDFN, and fetal health should be carefully monitored when anti-D titers are greater than 16

A

D antigen

91
Q

AHA Antibodies

Warm autoantibodies:
Cold-reactive autoantibodies:
Paroxysmal cold hemoglobinuria (“Donath-Landsteiner” antibody:

A

Warm autoantibodies: Rh protein, Wrb, Kell, Kidd, and U
Cold-reactive autoantibodies: anti-I , i, H, Pr, P
Paroxysmal cold hemoglobinuria (“Donath-Landsteiner” antibody: antigen P (GLOB)

92
Q

The single most important test performed in the transfusion service because it is the fundamental basis for determining blood compatibility

A

ABO

The D type is the next most important test performed for blood compatibility.

93
Q

Testing RBCs with licensed antisera to identify the A or B antigens they carry

A

Forward, or cell, grouping

94
Q

Testing the corresponding serum or plasma with known A and B cells to identify the antibodies

A

Reverse, or serum, grouping

95
Q

If the ABO group of a patient cannot be determined, group ______ blood can be used for transfusion

A

Group O blood

96
Q

TRUE OR FALSE

Donors with weak D antigen are considered Rh-positive.

A

TRUE

Donors with weak D antigen are considered Rh-positive.

97
Q

Detects “atypical” or “unexpected” antibodies in the serum (ie, other than anti-A and anti-B) using group O reagent red cells that are known to carry various combinations of antigens

A

Antibody screen, or indirect antiglobulin test

The antibody screen will not detect all atypical antibodies in serum, such as antibodies to low-prevalence antigens not present on screening cells and antibodies that are not apparent at 37 °C and in the antiglobulin phase.

98
Q

A test detects antibody or complement bound to RBCs in vivo

A

Direct antiglobulin test (often referred to as the direct Coombs test

Positive direct antiglobulin test results are associated with the following:
* (a) transfusion reactions, in which recipient alloantibody coats transfused donor RBCs or transfused donor antibody coats recipient RBCs;
* (b) HDFN, in which maternal antibody crosses the placenta and coats fetal RBCs;
* (c) autoimmune hemolytic anemias, in which autoantibody coats the patient’s own RBCs;
* (d) drug or drug–antibody complex interactions with RBCs that sometimes lead to hemolysis;
* (e) passenger lymphocyte syndrome, in which transient antibody produced by passenger lymphocytes from a transplanted organ coats recipient RBCs; and
* (f) hypergammaglobulinemia, in which Ig nonspecifically adsorb onto circulating RBCs.

A positive direct antiglobulin test result does not always indicate decreased red cell survival.

99
Q

Refers to a set of donor and recipient tests that are performed before red cell transfusion

A

Compatibility testing

Routine recipient testing includes an ABO, D, and antibody screening on a blood sample collected within three days of the intended transfusion.

Repeat donor testing and crossmatching are not performed for plasma and platelet components, but the recipient’s ABO and Rh phenotypes must be known for appropriate selection of components.

100
Q

TRUE OR FALSE

The chance of finding compatible units usually reflects the antigen prevalence in the population.

A

TRUE

The chance of finding compatible units usually reflects the antigen prevalence in the population.

101
Q

A panel of 8 to 16 different group O red cells that have been typed for antigens corresponding to clinically significant antibodies

A

Antibody identification

Absence of reactivity with autologous cells implies the antibody is an alloantibody, whereas a positive result suggests autoantibody or a positive direct antiglobulin test result