title: Liver injury induced by levothyroxine in a patient with primary hypothyroidism.
abstract: We report a patient with primary hypothyroidism, who developed hepatocellular injury due to levothyroxine, synthetic thyroxine. A 63-year-old male was admitted to our hospital due to elevation of liver enzymes. The patient was diagnosed as having hypothyroidism and had been treated with levothyroxine for almost two months until admission. Drug-induced liver injury induced due to levothyroxine was suspected and liver enzymes were rapidly decreased after discontinuation of levothyroxine and dried thyroid powder, also containing thyroxine. Synthetic triiodothyronine, the deiodinated form of levothyroxine was administered instead, and was well tolerated by the patient. The drug-induced lymphocyte stimulation test (DLST) using levothyroxine was negative. Since triiodothyronine which structurally resembles levothyroxine did not cause liver injury, and DLST using levothyroxine was negative, it is unlikely that levothyroxine itself was targeted by the immune system. Rather, we assume that the complex of levothyroxine as the hapten and liver-related macromolecules in the body as the carrier might have acquired antigenicity in this patient and subsequently resulted in liver injury.
authors.affiliation: Department of Medicine, Teikyo University School of Medicine, Tokyo.
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Kawakami
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Negoro
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Morisawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Mikami
authors.forename: Makoto
authors.initials: M
authors.lastname: Hojo
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Satoko
authors.initials: S
authors.lastname: Uegaki
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Aiso
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Taro
authors.initials: T
authors.lastname: Ishii
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kuyama
authors.forename: Toshio
authors.initials: T
authors.lastname: Fukusato
authors.forename: Hajime
authors.initials: H
authors.lastname: Takikawa
mesh_terms: D056486:Chemical and Drug Induced Liver Injury; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis / Q000188:drug therapy*; D008107:Liver Diseases / Q000175:diagnosis / Q000628:therapy; D008297:Male; D008875:Middle Aged; D013974:Thyroxine / Q000009:adverse effects*; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000627:therapeutic use
chemical_list: D014284:Triiodothyronine; D013974:Thyroxine