Histokompatibilitetsfaktorer

Histokompatibilitetsfaktorer, also known as HLA (Human Leukocyte Antigen) in humans, are a set of proteins found on the surface of cells in the body. These proteins play a crucial role in the immune system's ability to distinguish between the body's own cells and foreign invaders. Think of them as identification markers for your cells.

The HLA system is highly polymorphic, meaning there are many different versions of these genes within the human population. This diversity is essential for the survival of the species, as it ensures that at least some individuals will have HLA types that can recognize and respond to a wide range of pathogens.

When a foreign substance, like a virus or bacterium, enters the body, immune cells called T cells recognize the foreign antigens presented by HLA molecules on infected cells. This recognition triggers an immune response to eliminate the threat.

Due to their role in immune recognition, HLA types are critically important in organ transplantation. If the HLA types of the donor and recipient are not a good match, the recipient's immune system may recognize the transplanted organ as foreign and attack it, leading to rejection. Therefore, HLA typing is a vital step in matching donors and recipients for transplants. Variations in HLA genes are also associated with various autoimmune diseases and allergies.