TRPA1 and Pruritus: Cholestatic itch has been linked to bile acids, bilirubin, progesterone metabolites, and lysophosphatidic acid (LPA).2–6 LPA is a bioactive phospholipid with diverse biological functions.7 Autotaxin catalyzes the hydrolysis of lysophosphatidylcholine (LPC) to LPA, and it has been demonstrated that levels of autotaxin and LPA correlate with itch intensity in patients with cholestatic liver disease.2 In addition, a recent study suggested that LPA induces itch via TRPV1 and TRPA1.8