Kidney injury molecule-1 (KIM-1) (also known as TIM-1 and HAVCR) is a type 1 transmembrane glycoprotein found on activated CD4+ T cells, especially Th2 cells, and dedifferentiated proximal tubule epithelial cells. In humans, KIM-1 levels are very low or undetectable in normal samples, but following drug toxicity or ischemic damage to the kidney, the 85 kD, mucin-rich extracellular region of this molecule is shed and detected at elevated levels in urine, serum, and plasma. Therefore, KIM-1 is a suitable renal biomarker capable of early detection and progressive monitoring of acute kidney injury beyond traditional injury markers such as serum creatinine (SCr) and blood urea nitrogen (BUN) which lack specificity and sensitivity. KIM-1 has also been implicated in the development of atopic airway disease (asthma) and Th2-biased autoimmune responses.
