Objective To test whether the tryptophan metabolism was abnormal in newly diagnosed ITP patients as well as in these patients after treatment with dexamethasone.Methods Newly diagnosed patients with ITP between Jan 2014 and May 2015 were enrolled,including14 females and 11 males,with a median age of 57 years Objective To test whether the tryptophan metabolism was abnormal in newly diagnosed ITP patients as well as in these patients after treatment with dexamethasone. Methods Newly diagnosed patients with ITP between Jan 2014 and May 2015 were enrolled, including 14 females and 11 males, with a median age of 57 years