Immunohematology

  1. What type of immunity:
    Is a specific response of the immune system in which antibodies specific to a particular antigen are produced
    Plasma cells produce antibodies
    Acquired immunity
  2. What type of immunity:
    Is a nonspecific reaction of the immune system that attacks all invaders
    Includes physical and biochemical barriers and cells such as leukocytes and NK cells
    Innate immunity
  3. Where are HLAs (Human leukocyte antigens) present on?
    • Leukocytes
    • Tissue cells
  4. What are the genes that encode the HLA antigens part of?
    Major histocompatibility complex (MHC)
  5. What chromosome is MHC on and what is it divided into?
    • Chromosome 6
    • Divided into Class I, II, III
  6. What does Class I of the MHC include?
    A, B, C loci
  7. What does Class II of the MHC include?
    DR, DP, and DQ
  8. What does Class III of the MHC include?
    Complement proteins
  9. What does an immune response to transfused incompatible HLA antigens cause?
    • Fever and chills
    • Non-hemolytic transfusion reaction
  10. When must HLA be matched for and why?
    • Must be matched for organ, tissue, bone marrow, and stem cell transplant donors and recipients
    • If not matched correctly, a severe graft-vs-host disease results
  11. What do platelet membranes have that cause problems when transfusing?
    Membranes have protein antigens
  12. What clinical conditions result from transfusing?
    • Neonatal alloimmune thrombocytopenia
    • Posttransfusion purpura
  13. What antibodies react with platelet protein antigens?
    • ABO
    • HLA-specific
    • Platelet-specific
  14. Where is the antibody binding site found?
    In the variable region of the heavy and light chains
  15. What antibody is:
    Composed of 5 basic immunoglobulin units (pentamer)
    Can activate complement
    Cannot cross the placenta due to its size
    React optimally at room temp or below
    Usually clinically insignificant
    IgM antibodies
  16. What antibody is:
    Single immunoglobulin unit
    Normally cannot activate complement unless 2 molecules are present
    Can cross the placenta
    Reacts optimally at 37 degrees celcius
    Typically clinically significant
    Capable of causing transfusions reactions or HDN (hemolytic disease of the newborn)
    IgG antibodies
  17. What are antigen-antibody complexes held together by?
    • Electrostatic charges
    • Hydrogen bonding
    • Hydrophobic bonding
    • Van der Waals forces
  18. What removes antigen-antibody complexes?
    Reticuloendothelial system (spleen, liver, and lymph nodes)
  19. What are the 2 stages that some antigen-antibody complexes require for detection?
    • Sensitization: antibody attaches to the antigen but does not produce visible agglutination or hemolysis
    • Lattice formation: random collisions of antibody coated RBCs link antibodies together to form visual agglutination
  20. What factors affect the first stage of agglutination - sensitization?
    • Serum to cell ratio
    • Reaction temp
    • Incubation time
    • pH
  21. What factors affect the 2nd stage of agglutination - lattice formation?
    • Reaction temp
    • Incubation time
    • pH
    • Repelling negative charges
  22. What is another indication of antibody-antigen reactions and is caused by complement?
    Hemolysis
  23. What is the term for the process of cell division that results in the same number of chromosomes in the new and old cells?
    Mitosis
  24. What is the term for the process of cell division that occurs in gametes resulting in 1/2 the chromosomes in each new cell?
    Meiosis
  25. What is the term for the smalled unit of inheritance?
    Gene
  26. What is the term for the site on the chromosome where specific genes are located?
    Genetic locus
  27. What is the term for alternative forms of a gene?
    Alleles
  28. What is the term for opposite form of a gene, different allele?
    Antithetical
  29. What is the term for having 2 or more possible alleles at a locus?
    Polymorphic
  30. What is the term of having equal expression of both alleles in a phenotype?
    Codominant
  31. What is the term for genes expressed with equal frequency in males and females, on non-sex chromosomes?
    Autosomal
  32. What is the term for:
    Carried on the X chromosome
    No father to son transmission
    Will be expressed if passed from father to daughter or from mother to son
    Sex-linked dominant
  33. What is the term for:
    Carried on the X chromosome
    Males inherit it from carrier mothers
    Traits are exhibited most commonly in males (hemophilia)
    Females can exhibit the trait but must inherit it from both carrier mother and affected father
    Sex-linked recessive
  34. What Mendelian Inheritance Principle is when 2 members of a single gene pair pass from one generation to the next in separate gametes?
    Law of Independent Segregation
  35. What Mendelian Inheritance Principle is when traits inherited from different chromosomes expressed separately and discretely?
    Law of Independent Assortment
  36. What is the term for agglutination reactions that are generally stronger for homozygous cells and slightly weaker for heterozygous cells?
    Dosage effect
  37. What is the term for when genes are inherited on the same chromosome?
    Cis
  38. What is the term for when genes are inherited on separate chromosomes?
    Trans
  39. What is the term for a set of genes inherited via one of the 2 parental gametes?
    Haplotype
  40. What is the term for genes that do not produce a detectable product?
    Amorphic
  41. What is the calculation for determining the percentage of compatible units, if a person has mulitple antibodies?


    If there are multiple antibodies, multiple each fraction together to get the bottom number
  42. Where are ABO antigens found on?
    • RBCs
    • Lymphs
    • Plts
    • Tissue cells
    • Bone marrow
    • Organs
  43. What are ABO antigens made of and when are they developed?
    • Glycolipid or glycoprotein
    • Developed in utero at 5-6 weeks of gestation
    • Full expression of ABO antigens occurs between 2-4 years of age
  44. What is the building block of A and B antigens?
    H antigen
  45. How does the H antigen build the ABO antigens?
    • H antigen acts as the acceptor molecule for the 2 sugars that make up the A and B antigens
    • A blood type: H antigen with N-acetylgalactosamine attached
    • B blood type: H antigen with D-galactose attached
    • O blood type: H antigen with NO additional sugars attached
  46. What does the subgroup A1 express on the RBC?
    Possesses both A and A1 antigens on the RBC surface
  47. What does the subgroup A2 possess on the RBC?
    Expresses only the A antigen on the RBC surface
  48. How can subgroups of A be detected?
    Detected by polyclonal Anti-A,B
  49. What reagent detects subgroup subgroup A1?
    Anti-A1 Lectin
  50. If a weak subgroup of A donates blood that is transfused to group O patient, what will happen?
    Intravascular hemolysis
  51. Who produces Anti-A and Anti-B and why?
    • Produced by humans who lack the corresponding antigens
    • Lack of exposure to naturally occurring substances that resemble A and B antigens
  52. What type of antibody are Anti-A and Anti-B and what can they activate?
    • IgM
    • Can activate complement
  53. What types of problems cause issues with forward type grouping?
    • Acquired B phenotype
    • Polyagglutination
    • Rouleaux
    • ABO subgroups
    • Transfusion of non-type specific blood
    • Bone marrow or stem cell transplants
  54. What types of problems cause issues with reverse type grouping?
    • A subgroups with Anti-A1
    • Cold alloantibodies
    • Cold autoantibodies
    • Rouleaux
    • Newborn or elderly person
  55. What phenotype is a person who inherits hh genotype?
    Bombay (Oh) Phenotype
  56. What blood type can a Bombay patient be transfused with and why?
    • Only Bombay group blood
    • Patients have alloanti-H, which is capable of activating complement and causing a hemolytic transfusion reaction
  57. What are the 2 alleles that produce secretor status?
    • Se
    • se
  58. What alleles that are inherited are capable of expressing ABO and H antigens in their secretions?
    Se
Author
ncrook
ID
212975
Card Set
Immunohematology
Description
Overview, Genetics, ABO and H Blood Group Systems, Rh
Updated