Bloodbanking

• The ABO system is the most important blood group system.
• Genetics is important in blood banking as it plays a crucial role in the modern blood banking system, determining how genes and traits are inherited, especially in different blood group systems with specific inheritance patterns
• Deoxyribonucleic Acid (DNA) is the genetic material found within the cell nucleus, with two fundamental roles: replicating itself exactly before cell division and providing instructions for building every protein in the body
• In DNA, base pairing involves Adenine binding with Thymine (A - T) and Guanine binding with Cytosine (G-C)
• Ribonucleic Acid (RNA) is located outside the nucleus and carries out orders of protein synthesis issued by DNA, with bases Adenine, Guanine, Cytosine, and Uracil, and in RNA, base pairing involves Adenine binding with Uracil (A - U) and Guanine binding with Cytosine (G-C)
• Contrast the different forms of RNA:

  • mRNA: Messenger RNA takes information from DNA to ribosomes where proteins are made
  • rRNA: Ribosomal RNA delivers amino acids to the ribosome
  • tRNA: Transfer RNA delivers amino acids to the ribosome, with the anticodon matching the codon on the mRNA strand
• Every cell in our body is important for protein synthesis because it contains DNA and RNA, with enzymes being made out of proteins
• A gene is a segment of DNA arranged along the chromosome at a specific position called locus, with genes at a specific locus that differ in their nucleotide sequence called alleles, leading to homozygous and heterozygous genotypes with different antigen expression levels
• Genotype represents the total genetic composition of an individual, while phenotype represents the detectable or expressed characteristics of genes, with the physical expression of inherited traits being the dominant gene
• Antigens are any foreign material that enters our body and induces the production of antibodies, with antibodies being produced in response to antigens, categorized into polyclonal/monoclonal, naturally occurring/immune, alloantibodies/hetero antibodies/autoantibodies
• Blood group antibodies may be characterized by factors like epitope and variable region diversity, mode of sensitization, expected or unexpected presence in routine samples, isotypes class, activity (warm or cold-reactive), clinical significance, alloantibody or autoantibody specificity, serum titer, and chemical reactivity
• Alloantibody or autoantibody specificity, serum titer, and chemical reactivity are factors that influence immunoglobulins
• 1. ME reagents are used to detect antibodies and enhance media or reagents
• In the primary immune response, IgM is produced
• IgG is the most efficient at binding complement
• In the secondary immune response, IgG is produced:

  • Acute phase: IgM
  • Chronic phase: IgG
• Chromosomal locations of major blood group systems:

  • Chromosome 1: Rh, Duffy
  • Chromosome 4: MNS
  • Chromosome 7: Kell
  • Chromosome 9: ABO
  • Chromosome 18: Kidd
  • Chromosome 19: H, Lewis, Lutheran
  • Chromosome 22: P1
• ABO blood group system:

  • First human blood group system discovered
  • Types: A (2nd common), B (3rd common), AB (Least common), O (Most common)
• ABO forward grouping:

  • Detects the ABO blood group of an individual
  • Uses Anti-A and Anti-B reagents
  • Results in positive agglutination or negative agglutination
• ABO reverse grouping:

  • Confirms the blood type after forward typing
  • Uses A-cells and B-cells
  • Results in different reactions based on blood group
• Serologic grading for macroscopic evaluation:

  • Grades range from 0 to 4+ based on agglutination levels
• Major ABO genotypes and phenotypes:

  • A1, A2, A1B, A2B, B, O with possible genotypes
• Inheritance of ABO genes:

  • Described by Bernstein in 1924
  • Follows Mendelian genetics with genotypes and phenotypes
• Attachment is a strong reciprocal emotional bond between an infant and a primary caregiver

  
• Schaffer and Emerson's 1964 study on attachment:

  • Aim: identify stages of attachment / find a pattern in the development of an attachment between infants and parents
  • Participants: 60 babies from Glasgow
  • Procedure: analysed interactions between infants and carers
  • Findings: babies of parents with 'sensitive responsiveness' were more likely to have formed an attachment
• Freud's superego is the moral component of the psyche, representing internalized societal values and standards
• Traits or characteristics that are always expressed when present in a heterozygous state:

  • A, B gene

  
• Traits or characteristics that are NOT always expressed when the dominant gene is present:

  • O gene
  • Do not expect it to be expressed when inherited in heterozygous
  • Considered as an amorph gene or silent gene, only indicates the absence of the Ag
• The Law of Mendelian genetics
• The mother is BO, heterozygous
• The father is AO, heterozygous

  • The children can be blood type A, blood type AB, blood type B, and blood type O
• Use punnett square for easier understanding of inheritance and to determine the percentage of offspring with a specific phenotype or genotype
• Practice question #1:

  • Mother: homozygous A (AA)
  • Father: heterozygous B (BO)
  • Possible outcomes: AB = 50%, AO = A = 50%
• Practice question #2:

  • Mother: AO
  • Father: AO
  • Possible outcomes: AO = A = 75%, OO = 25%
• Practice question #3:

  • Mother: group O = OO
  • Child: group B = BO or BB
  • Which blood types exclude paternity: O
• Formation of ABH antigens:

  • Genes at three separate loci: ABO, Hh, and Se
  • Produces specific glycosyltransferases (enzymes) that add sugars to the basic precursor substance
• Comparison of Type 1 and Type 2 Precursor Chains:

  • Type 1: Originates in plasma, controlled by H, A, B genes
  • Type 2: Synthesized on erythrocytic precursors, controlled by H, A, B genes
• Formation of H antigen:

  • H gene produces L-fucosyltransferase that attaches L-Fucose to the precursor substance to form H Ag
• Formation of A antigen:

  • A gene produces N-acetylgalactosaminyltransferase which attaches N-acetyl-D-galactosamine to the H antigen
• Formation of AB antigen:

  • Similar process to A and B antigens, but with differences in antigenic sites