Human Leukocyte Antigen (HLA) is found on which of the following?

Human Leukocyte Antigen (HLA) molecules are indeed found on the surface membranes of almost all cells in the body. They play a crucial role in the immune system by helping the body distinguish between self and non-self substances. HLA molecules are primarily involved in presenting peptide fragments derived from proteins to T-cells, which are an integral part of the immune response.

This widespread presence on cell membranes extends beyond just white blood cells. While white blood cells have a significant concentration of HLAs, other cell types, including those of the liver, kidney, and even some epithelial cells, also express these molecules. This feature is pivotal for the functioning of the immune system, particularly in organ transplantation and tissue matching, where compatibility between the HLA types of donor and recipient can greatly influence the success of the procedure.

In contrast, mature red blood cells do not express HLA molecules, which is significant because it affects how they are treated by the immune system. The presence of HLA only on white blood cells is a common misconception, as it implies exclusivity to immune cells when, in reality, it encompasses a broader range of cell types. Additionally, stating that HLA is only found in plasma is incorrect, as HLAs are membrane proteins and