HLA antigens are used for which purposes?

• A. Tissue compatibility and paternity testing
• B. Blood type matching
• C. Liver function testing
• D. Vitamin D status

Answer: (A)

HLA antigens are highly variable cell-surface proteins that determine whether immune cells recognize another person’s cells as self. The main use is to assess tissue compatibility for transplantation: the closer the HLA match between donor and recipient, the lower the risk of graft rejection and graft-versus-host disease. Because HLA alleles are inherited, HLA typing can also contribute to paternity testing, though modern DNA testing provides more definitive results. These antigens aren’t used for blood type matching (which relies on ABO and Rh antigens), nor for assessing liver function or vitamin D status.