• HLA forms part of the Major Histocompatibility Complex (MHC)
  • MHC antigens are integral for normal functioning of the immune response.
  • Essential role of HLA antigens lies in recognizing self-antigens for protection against micro-organisms and surveillance.
  • HLA typing is essential to the rejection that occurs during organ transplantation, and hematopoietic stem cell transplantation.
  • Found on the short arm of chromosome 6

  • Classified as HLA class I, class II, class III
  • Class I (HLA-A, B, C etc) & Class II (HLA-DR, DQ, DP etc): Important roles in immune recognition
  • Class III : Coding in same region as class I & II, but may not be important in transplantation