Neopterin

Neopterin is a small molecule produced by immune cells, specifically macrophages, in response to infections or immune system activation. Its levels in blood or urine increase when the body is fighting an infection, inflammation, or certain diseases involving immune response. Measuring neopterin helps doctors assess immune system activity and can aid in diagnosing and monitoring conditions like infections, autoimmune diseases, and some cancers. It serves as a useful marker for detecting ongoing immune activation, providing insights into how the body is responding to various health challenges.