LTC4LTD4LTE4
LTC4, LTD4 and LTE4 are a closely related group of lipid mediators collectively known as cysteinyl leukotrienes (CysLTs). They are derived from arachidonic acid through the 5-lipoxygenase pathway in leukocytes and other cells of the immune system. The synthesis begins with the formation of the unstable epoxide LTA4, which is converted to LTC4 by the enzyme LTC4 synthase through the conjugation of glutathione. LTC4 is then released and rapidly and sequentially converted to LTD4 and LTE4 by extracellular peptidases, yielding increasingly stable molecules. LTE4 is the most stable of the trio and is commonly measured in urine as a systemic marker of CysLT production.
As signaling mediators, CysLTs act on two G-protein coupled receptors, CysLT1 and CysLT2. LTD4 has the highest
Clinical relevance: CysLTs play a significant role in asthma and allergic rhinitis and are particularly elevated
Measurement and biomarkers: urinary LTE4 is commonly used as a noninvasive biomarker of systemic CysLT production;