title: The canals of hering might represent a target of methotrexate hepatic toxicity.
abstract: Methotrexate treatment for psoriasis is known to cause hepatic fibrosis in some patients, which might progress to cirrhosis. The fine, radiating, fibrous septa developing in this setting have a distribution that is reminiscent of the location of the canals of Hering (coH). To assess the possibility of fibrous obliteration of the coH in patients receiving methotrexate, we developed a staining technique by combining an immunohistochemical stain for cytokeratin 7 with a modified Masson trichrome. Sixteen biopsy specimens from 7 patients were evaluated. The biopsies had a variety of histologic changes, including steatosis, anisonucleosis, multinucleation, chronic inflammation, bile duct damage, and ductular reaction. Fibrosis was present in 13 biopsy specimens (81%) and was mild in 7, moderate in 3, and severe in 3 specimens. Compared with normal (control) liver specimens, biopsy specimensfrom patients receiving methotrexate had decreased numbers of coH (1.9 +/- 0.8 vs 5.2 +/- 1.7; P < .025). In specimens with moderate or severe fibrosis, fibrous septa sometimes extended along the coH. These findings suggest that scarring of the coH might be a consequence of the toxic effects of methotrexate.
authors.affiliation: Department of Pathology, Aristotle University Medical School, Thessaloniki, Greece.
authors.forename: Prodromos
authors.initials: P
authors.lastname: Hytiroglou
authors.forename: Hillel
authors.initials: H
authors.lastname: Tobias
authors.forename: Romil
authors.initials: R
authors.lastname: Saxena
authors.forename: Martha
authors.initials: M
authors.lastname: Abramidou
authors.forename: Constantine S
authors.initials: CS
authors.lastname: Papadimitriou
authors.forename: Neil D
authors.initials: ND
authors.lastname: Theise
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000473:pathology; D008297:Male; D008727:Methotrexate / Q000633:toxicity*; D008875:Middle Aged; D011565:Psoriasis / Q000188:drug therapy
chemical_list: D007166:Immunosuppressive Agents; D008727:Methotrexate