BB lecture - Details

Levels:

1) Chapter 1 View

Questions:

206 questions

🇬🇧		🇬🇧

The ISBT terminology for RBC surface antigens provides a standardized numeric system for naming authenticated antigens that is suitable for electronic data processing equipment True or False

True

In the ISBT classification, RBC antigens are assigned a

Six-digit identification number:

Antigens are not synthesized by the RBCs. These antigens are adsorbed from plasma onto the RBC membrane

Lewis

The Le gene codes for

L-fucosyltransferase,

The Le gene is needed for the expression of Lea substance, and Le and Se genes are needed to form

Leb substance.

More common among blacks than among whites and results in the Le(a–b–) phenotype.

Lele genotype

Antigens are poorly expressed at birth

Lewis

Lewis antibodies are generally (Blank) and made by (blank)

IgM (naturally occurring) made by Le(a–b–) individuals.

Frequently encountered in pregnant women.

Lewis antibodies

Not considered significant for transfusion medicine.

Lewis antibodies

Consists of the biochemically related antigens P, P1, Pk and LKE.

P blood group

Expression is variable, and poorly expressed at birth

P1 antigen

Is a common naturally occurring IgM antibody in the sera of P1– individuals; it is usually a weak, cold-reactive saline agglutinin and can be neutralized with soluble P1 substance found in hydatid cyst fluid.

Anti-P1

Is produced by the rare p individuals early in life without RBC sensitization and reacts with all

Anti-PP1Pk

RBCs except those of other p individuals. Antibodies may be a mixture of

IgG and IgM

Is associated with spontaneous abortions.

Anti-PP1Pk

Is found as a naturally occurring alloantibody in the sera of Pk individuals and is clinically significant.

Alloanti-P

Is most often the specificity associated with the cold-reactive IgG autoantibody in patients with paroxysmal cold hemoglobinuria (PCH)

Auto-anti P

The autoanti-P of PCH usually does not react by routine tests but is demonstrable as

Biphasic hemolysin only in the Donath-Landsteiner test.

Relationship of I and i antigens

Antithetical, reciprocal relationship

Most adult RBCs are rich in I and have only trace amounts of i antigen. True or False

True

At birth, infant RBCs are rich in i; I is almost undetectable; over the next

18 months , the infant’s RBCs will convert from i to I antigen.

Is typically a benign, weak, naturally occurring, saline-reactive IgM autoagglutinin, usually detectable only at 4°C

Anti-I

Typically a strong cold autoagglutinin that demonstrates high-titer reactivity at 4°C and reacts over a wide thermal range (up to 30°–32°C).

Pathogenic anti-I

May develop strong cold agglutinins with autoanti-I specificity

M. pneumoniae

Rare IgM agglutinin that reacts optimally at 4°C; potent examples may be associated with infectious mononucleosis.

Anti-i

Are cold-reactive saline agglutinins that do not bind complement or react with enzyme treated cells;may demonstrate dosage effect

Anti-M and Anti-N

Are IgG antibodies, reactive at 37°C and the antiglobulin phase. They may bind complement and have been associated with HDFN and HTRs.

Anti-S and anti-s

In MNS blood system, it is usually an IgG antibody and has been associated with HTRs and HDFN.

Anti-U

Well developed at birth and are not destroyed by enzymes.

KELL

Are destroyed by DTT, ZZAP, and glycine-acid EDTA.

KELL

Excluding ABO, the K antigen is rated second only to

D antigen in immunogenicity.

Antigen is high prevalence.

Is usually an IgG antibody reactive in the antiglobulin phase and is made in response to pregnancy or transfusion of RBCs; it has been implicated in severe HTRs and HDFN.

Anti-K

Affecting only males, is described as a rare phenotype with decreased Kell system antigen expression.

Mcleod phenotype

The clinical manifestations of abnormal RBC morphology, compensated hemolytic anemia, and neurological and muscular abnormalities. Some males with the

Mcleod Syndrome

Also have the X-linked chronic granulomatous disease.

McLeod phenotype

Antigens are destroyed by enzymes and ZZAP; they are well developed at birth.

Fya and Fyb

BCs resist infection by the malaria organism P. vivax.

Fy(a–b–)

Are usually IgG antibodies and react optimally at the antiglobulin phase of testing; both antibodies have been implicated in delayed HTRs and HDFN.

Anti-Fya and anti-Fyb

May demonstrate dosage, are often weak, and found in combination with other antibodies; both are typically IgG and reactive in the antiglobulin test.

Anti-Jka and anti-Jkb

May bind complement and are made in response to foreign RBC exposure during pregnancy or transfusion.

Kidd antibodies

Antibodies are a common cause of delayed HTRs.

Kidd system antibodies

Antibody reactivity is enhanced with enzymes, LISS, and PEG.

Kidd

Are antigens produced by codominant alleles; they are poorly developed at birth.

Lua and Lub

May be a naturally occurring saline agglutinin that reacts optimally at room temperature.

Anti-Lua

Is usually an IgG antibody reactive at the antiglobulin phase; it is usually produced in response to foreign RBC exposure during pregnancy or transfusion.

Anti-Lub

Phenotype is rare and may result from three different genetic backgrounds; only individuals with the recessive type Lu(a–b–) can make anti-Lu3.

The Lu(a–b–) phenotype

Are located on a major RBC protein, band 3, also known as the RBC anion exchanger (AE1).

The Diego system antigens

Are generally considered to be clinically significant; all have caused severe HTRs and HDFN

Anti-Dia, anti-Dib, and anti-Wra

Xpression requires the presence of a normal GPA (MNS system);

Wrb

Is a fairly common antibody to a highprevalence antigen that is sometimes clinically significant and sometimes insignificant

Anti-Yta

Antigen is found on the short arm of the X chromosome and is of higher prevalence in females (89%) than in males (66%).

Xga

Are rare and little is known about their clinical significance, has been observed in the Marshall Islands and New Guinea.

Scianna system antigens

The antigens are carried on aquaporin 1, a red cell water channel

Colton system

Has a phenotypic relationship with the D antigen

Reacts strongly with D+ RBCs and can look like anti-D.

Anti-LW

Are located on the complement fragments C4B and C4A, respectively, that are adsorbed onto RBCs from plasma.

Chido/Rodgers system

React weakly, often to moderate or high-titer endpoints in the antiglobulin test and may be tentatively identified by plasma inhibition methods.

Anti-Ch and anti-Rg

Are very rare outside of Papua, New Guinea.

Gerbich-negative phenotypes

Are carried on the decay accelerating factor and are distributed in body fluids and on RBCs, WBCs, platelets, and placental tissue.

Cromer antigens

Are located on complement receptor 1 (CR1) have weak and “nebulous” reactivity at the antiglobulin phase; they are not inhibited by plasma.

Knops antigens

More prevalent in Arab and Iranian populations,

Ina antigen

Found more commonly in Japanese, but clinical significance is not well established, since it is a rare antibody; it has caused HTRs and a fatal case of HDFN

Anti-Jra

Has characteristic shiny and refractile agglutinates under the microscope and is inhibited with urine from Sd(a+) individuals.

Anti-Sda

1. The following phenotypes are written incorrectly except for: a. Jka+ b. Jka+ c. Jka(+) d. Jk(a+)

2. Which of the following characteristics best describes Lewis antibodies? a. IgM, naturally occurring, cause HDFN b. IgM, naturally occurring, do not cause HDFN c. IgG, in vitro hemolysis, cause hemolytic transfusion reactions d. IgG, in vitro hemolysis, do not cause hemolytic transfusion reactions

3. The Le gene codes for a specific glycosyltransferase that transfers a fucose to the N-acetylglucosamine on: a. Type 1 precursor chain. b. Type 2 precursor chain. c. Types 1 and 2 precursor chain. d. Either type 1 or type 2 in any one individual but not both.

4. What substances would be found in the saliva of a group B secretor who also has Lele genes? a. H, Lea b. H, B, Lea c. H, B, Lea, Leb d. H, B, Leb

5. Transformation to Leb phenotype after birth may be as follows: a. Le(a–b–) to Le(a+b–) to Le(a+b+) to Le(a–b+) b. Le(a+b–) to Le(a–b–) to Le(a–b+) to Le(a+b+) c. Le(a–b+) to Le(a+b–) to Le(a+b+) to Le(a–b–) d. Le(a+b+) to Le(a+b–) to Le(a–b–) to Le(a–b+)

6. In what way do the Lewis antigens change during pregnancy? a. Lea antigen increases only b. Leb antigen increases only c. Lea and Leb both increase d. Lea and Leb both decrease

A type 1 chain has: a. The terminal galactose in a 1-3 linkage to subterminal N-acetylglucosamine. b. The terminal galactose in a 1-4 linkage to subterminal N-acetylglucosamine. c. The terminal galactose in a 1-3 linkage to subterminal N-acetylgalactosamine. d. The terminal galactose in a 1-4 linkage to subterminal N-acetylgalactosamine.

8. Which of the following best describes Lewis antigens? a. The antigens are integral membrane glycolipids b. Lea and Leb are antithetical antigens c. The Le(a+b–) phenotype is found in secretors d. None of the above

9. Which of the following genotypes would explain RBCs typed as group A Le(a+b–)? a. A/O Lele HH Sese b. A/A Lele HH sese c. A/O LeLe hh SeSe d. A/A LeLe hh sese

10. Anti-LebH will not react or will react more weakly with which of the following RBCs? a. Group O Le(b+) b. Group A2 Le(b+) c. Group A1 Le(b+) d. None of the above

11. Which of the following best describes MN antigens and antibodies? a. Well developed at birth, susceptible to enzymes, generally saline reactive b. Not well developed at birth, susceptible to enzymes, generally saline reactive c. Well developed at birth, not susceptible to enzymes, generally saline reactive d. Well developed at birth, susceptible to enzymes, generally antiglobulin reactive

12. Which autoantibody specificity is found in patients with paroxysmal cold hemoglobinuria? a. Anti-I b. Anti-i c. Anti-P d. Anti-P1

13. Which of the following is the most common antibody seen in the blood bank after ABO and Rh antibodies? a. Anti-Fya b. Anti-k c. Anti-Jsa d. Anti-K

14. Which blood group system is associated with resistance to P. vivax malaria? a. P b. Kell c. Duffy d. Kidd

15. The null Ko RBC can be artificially prepared by which of the following treatments? a. Ficin and DTT b. Ficin and glycine-acid EDTA c. DTT and glycine-acid EDTA d. Glycine-acid EDTA and sialidase

16. Which antibody does not fit with the others with respect to optimum phase of reactivity? a. Anti-S b. Anti-P1 c. Anti-Fya d. Anti-Jkb

17. Which of the following Duffy phenotypes is prevalent in blacks but virtually nonexistent in whites? a. Fy(a+b+) b. Fy(a–b+) c. Fy(a–b–) d. Fy(a+b–)

18. Antibody detection cells will not routinely detect which antibody specificity? a. Anti-M b. Anti-Kpa c. Anti-Fya d. Anti-Lub

19. Antibodies to antigens in which of the following blood groups are known for showing dosage? a. I b. P c. Kidd d. Lutheran

20. Which antibody is most commonly associated with delayed hemolytic transfusion reactions? a. Anti-s b. Anti-k c. Anti-Lua d. Anti-Jka

21. Anti-U will not react with which of the following RBCs? a. M+N+S+s– b. M+N–S–s– c. M–N+S–s+ d. M+N–S+s+

22. A patient with an M. pneumoniae infection will most likely develop a cold autoantibody with specificity to which antigen? a. I b. i c. P d. P1

23. Which antigen is destroyed by enzymes? a. P1 b. Jsa c. Fya d. Jka

24. The antibody to this high-prevalence antigen demonstratesmixed-field agglutination that appears shiny andrefractile under the microscope:a. Velb. JMHc. Jrad. Sda

25. Which of the following has been associated with causing severe immediate HTRs? a. Anti-JMH b. Anti-Lub c. Anti-Vel d. Anti-Sda

26. Which of the following antibodies would more likely be found in a black patient? a. Anti-Cra b. Anti-Ata c. Anti-Hy d. All of the above

27. Which of the following antigens is not in a blood group system? a. Doa b. Vel c. JMH d. Kx

28. A weakly reactive antibody with a titer of 128 is neutralized by plasma. Which of the following could be the specificity? a. Anti-JMH b. Anti-Ch c. Anti-Kna d. Anti-Kpa

29. An antibody reacted with untreated RBCs and DTTtreated RBCs but not with ficin-treated RBCs. Which of the following antibodies could explain this pattern of reactivity? a. Anti-JMH b. Anti-Yta c. Anti-Kpb d. Anti-Ch

30. The following antibodies are generally considered clinically insignificant because they have not been associated with causing increased destruction of RBCs, HDFN, or HTRs. a. Anti-Doa and anti-Coa b. Anti-Ge3 and anti-Wra c. Anti-Ch and anti-Kna d. Anti-Dib and anti-Yt

Lewis antibodies are increased in

Pregnancy

It can be mostly seen in patients with renal disease who undegoes dialysis on equiptment sterilized by formaldehyde

Anti-N

Strong-Cord RBCS Weak- Normal Adult RBC Most weak- i

I (t)

Associated with Human Leukocyte Antigen and can be destroyed by enzyme

Bennet Goodspeed

Characteristics of Anti-i except:

IgM in nature

BB lecture

Practice Known Questions

Exams

Learn New Questions

BB lecture - Leaderboard

BB lecture - Details

Levels:

Questions: