Lutheran Blood Group System

• Lutheran Blood Group System has an ISBT no. 005 with symbol LU
• Lutheran (Lu) Blood System has gene: BCAM; chromosome: 19
• There are 25 LU system antigens, but the most common includes the low-prevalence antigen Lua and the high-prevalence antigen Lub
• • Lu(a+b-); rare
  • Lu(a+b+); rare
  • Lu(a-b+); common
  • Lu(a-b-); extremely rare
• Lutheran (Lu) Antigens: Luᵃ and Luᵇ are poorly developed at birth, but have been detected on fetal RBCs as early as 10-12 weeks of gestation.
• Lutheran (Lu) Antigens: Luᵃ and Luᵇ have not been detected on platelets, lymphocytes, monocytes, or granulocytes
• Lutheran (Lu) Antigens: Luᵃ and Luᵇ are widely distributed in tissues: brain, lung, pancreas, placenta, skeletal muscle, and hepatocytes.
• Lutheran (Lu) Antigens: Luᵃ and Luᵇ are resistant to enzymes ficin and papain and to glycine-acid EDTA treatment and destroyed by enzymes trypsin and α-chymotrypsin.
• Anti-Luᵃ are often naturally occurring and can be IgM, IgG, or IgA and reacts best at 37C
• Anti-Luᵃ may demonstrate direct agglutination and show mixed-field reactivity and may also react at the AHG phase
• Anti-Luᵃ has no documented cases of immediate HTRs, but there are only rare and mild delayed HTRs due to anti-Luᵃ.
• Anti-Lub is IgM and IgA have been observed; but mostly IgG
• Anti-Lub is reactive at 37C and AHG phase and usually develop after RBC stimulation by transfusion or pregnancy
• Alloanti-Lub reacts with all cells tested except the autocontrol, and reactions are often weaker with Lu(a+b+)
• Anti-Lub has been implicated with shortened survival of transfused cells and post-transfusion jaundice, but severe or acute hemolysis has not been reported.
• Anti-Lu3 is rare antibody that reacts with all RBCs except Lu(a-b-)