Human Leukocyte Antigen (HLA) System

Question 1

What are human leukocyte antigens?

Answer 1

Cell surface glycoproteins that are located on platelets and nucleated cells

Question 2

What cells are class I human leukocyte antigens found on? (HLA)

Answer 2

Platelets and nucleated cells

Mature RBCs have small amount

Question 3

What cells are class II human leukocyte antigens found on? (HLA)

Answer 3

B lymphs, monocyte/macrophages. activated T lymphs, dendritic cells

Question 4

What is the role of human leukocyte antigens?

Answer 4

These antigens contribute to self/non-self recognition, are involved in immune responses, and coordinate cellular and humoral responses

Question 5

Why is HLA an important consideration in Blood Bank practice?

Answer 5

After ABO, it is important for long-term survival of transplanted organs and it is the MOST important in hematopoietic progenitor cell transplantation.

Question 6

What diseases does HLA play a role in?

Answer 6

Immune-mediated platelet refractoriness
Febrile non-hemolytic transfusion rxn
TRALI
GVHD

Question 7

What system is used for parentage (paternity) testing?

Answer 7

HLA System

Question 8

What chromosome are the HLA system genes located on?

Answer 8

Short arm of chromosome 6 (major histocompatibility complex)

Question 9

What genes encode for the Class IA, B, and C HLA antigens?

Answer 9

HLA-A, HLA-B, HLA-C

Question 10

What do the genes HLA-A, HLA-B, HLA-C encode for?

Answer 10

Class IA, B, and C antigens

Question 11

What genes encode for the Class II HLA antigens?

Answer 11

HLA-DP, HLA-DQ, HLA-DR

Question 12

What do the genes HLA-DP, HLA-DQ, HLA-DR encode for?

Answer 12

Class II HLA antigens