PDL1nivåer

PDL1nivåer refers to the levels of programmed death-ligand 1 (PD-L1) found in a patient's tumor cells or immune cells. PD-L1 is a protein that plays a crucial role in the immune system's ability to distinguish between self and non-self. In healthy individuals, PD-L1 acts as a checkpoint, helping to prevent the immune system from attacking healthy tissues. It does this by binding to the PD-1 receptor on T-cells, which then signals the T-cell to disengage and not mount an immune response.

However, some cancer cells exploit this mechanism by overexpressing PD-L1 on their surface. This allows them to "hide" from the immune system, effectively evading T-cell detection and destruction. By binding to PD-1 on T-cells, the cancer cells can suppress the anti-tumor immune response, enabling tumor growth and progression.

Measuring PDL1nivåer is therefore an important diagnostic and prognostic tool, particularly in the context of cancer immunotherapy. Specific types of immunotherapy, known as immune checkpoint inhibitors, target the PD-1/PD-L1 pathway. These drugs work by blocking the interaction between PD-1 and PD-L1, thereby releasing the brakes on the immune system and allowing T-cells to recognize and attack cancer cells.

The level of PD-L1 expression can predict a patient's likelihood of responding to these immunotherapies. Higher PDL1nivåer are generally associated with a better response rate to PD-1/PD-L1 inhibitor therapy. Consequently, testing PDL1nivåer is often a prerequisite for initiating such treatments for certain cancers, including melanoma, non-small cell lung cancer, and urothelial carcinoma. The specific thresholds for determining "high" or "low" PDL1 expression can vary depending on the cancer type and the assay used.