BB MBG

• DIEGO (DI) System


  Composed of 22 antigens; 3 Independent pairs: Antithetical antigens: Dia/Dib , Wra /Wrb and Wu/DISK
• Diego antigens

  Carried on band 3, a major integral RBC membrane glycoprotein
• Band 3

  • Also known as the red cell anion exchanger (AE-1) or solute carrier family-4, anion exchanger, member 1 (SLC4A1)
  • Located at Chromosome 17
• Dia

  Rare in most populatipopulationson, but is polymorphic in people of Mongolian ancestry
• Dia /Dib polymorphism

  Located on the last (seventh) extracellular loop of the protein
• Wra

  Low prevalence
• Wrb

  High prevalence, associated with an amino acid substitution on the fourth external loop
• Diego antibodies

  • Sometimes IgM, but usually IgG
  • Reactive in the indirect antiglobulin test
  • Can cause HTR's and HDFN
• Cartwright (Yt) System


  Named the first antibody marker and used the last letter "t" in the patient's last name: "Cartwright"
• Yta

  High prevalence
• Ytb

  Low prevalence
• Yt phenotypes

  • Yt(a+b-) COMMON
  • Yt(a+b+) COMMON
  • Yt(a-b+) rare
• Yt antigens

  Represented an amino acid substitution on the glycosylphosphatidylinositol (GPI)-linked RBC glycoprotein acetylcholinesterase (AChE) - enzymes involved in neurotransmission
• Yt antigens are located on Chromosome 7 and do not cause HDFN
• Xg System


  • Discovered in the serum of multiple transfused man
  • High prevalence in female (89%) than male (66%)
  • Controlled by X-linked gene (located on the X chromosome)
  • Named after the X Chromosome and g "Grand rapids" where the patient was treated
• Anti-Xga


  IgG reactive in the IAT and sensitive to enzymes but not DTT treatment; not been associated with HTR or HDN
• Scianna (SC) System


  Composed of the three antigens: Sc1, Sc2, and Sc3
• Anti-Sc1 and anti-Sc2 antibodies


  • Most are IgG, red cell stimulated and react in indirect antiglobulin testing
  • Not implicated with Hemolytic transfusion reaction
• Anti-Sc3

  • Characterized as IgG, red cell stimulated and reacting in the IAT phase of testing
  • Linked to cause a mild transfusion reactions
• SC gene

  • Located at chromosome 1
  • The product of the gene is a protein called Erythroid membrane associated protein (ERMAP)
• ERMAP

  RBC adhesion protein
• Scianna Ab


  Causes mild HDFN
• Dombrock (DO) System


  • Antigen Do^a and Do^b
  • Gregory (Gy^a), Holley (Hy) and Joseph (Jo^a )
• Anti-Do^a and Anti-Do^b

  • Described as IgG, red cell-stimulated antibodies that react primarily in indirect antiglobulin test w/ PEG or Enzyme enhancement
  • Not associated with HDFN
  • Reported to cause delayed HTR
• Antibodies to Gy^a, Hy and Jo^a

  • All are characterized as IgG, red cell stimulated
  • IAT: reactive
  • Do not cause HDFN, but has been described to cause moderate transfusion reaction
• Dombrock antigens


  • Carried on a mono-ADP-ribosyltransferase 4 (ART4)
  • Attached to the RBC membrane by a GPI anchor
• Gene coding for dombrock located at chromosome 12
• Colton (CO) System


  Composed of three antigens: Co^a , Co^b, and Co3 (formerly Co^ab)
• CO antigen

  Have been located on the transport protein known as channel-forming integral protein (CHIP)
• CHIP

  Forms the primary erythrocyte water channel and is responsible for water permeability
• CHIP and the Co antigen

  • Expressed in the tissue of the proximal and descending tubules and the collecting duct of the kidney
  • Account for the 80% of water reabsorption
• Anti-Co^a and Anti-Co^b


  Associated with Acute to delayed transfusion reactions
• Anti-Co3

  Causing severe HDFN
• CHIDO/ROGERS (CH/RG) System


  Includes 9 antigens, which are subdivided into: 6 Ch antigens, 2 Rh antigens, and WH antigen
• Alleles for RG and CH

  Have been located on two closely linked genes known as C4A (CH) and C4B (RG) on Chromosome 6
• Antigens product

  Have been demonstrated on the C4d fragments of the C4A (CHIDO) and C4B (ROGERS) glycoproteins of the C4 complement components
• Anti-Ch/Rg


  Stimulated usually in multi-transfused individuals lacking one or more of the corresponding antigens; antibodies are IgG and weakly reactive in IAT
• Gerbich (GE) System


  Complex system that is composed of three high incidence: Ge2, Ge3 and Ge4; and four-low incidence: Wb, Ls^a, An^a, and Dh^a
• GE antigens


  Inherited on chromosome 2 and are expressed on glycophorin C (GPC) and/or glycophorin D (GPD)
• Leach phenotype (GE:-2,-3,-4)


  Present with a change in erythrocyte morphology in the form of Elliptocyte