Eotaxin expression and eosinophil infiltrate in the liver of patients withdrug-induced liver disease

Background: Drug-induced liver disease is due to intrinsic or idiosyncratic hepatotoxins. Liver parenchyma is then infiltrated by immunocompetent cell s. Eosinophils are primarily tissue leukocytes which are attracted into tis sues by various chemoattractants, including chemokines. The aim of this stu dy was to study eosinophils in the livers of patients with drug-induced liv er disease. Methods: Immunohistochemical studies with antibodies against eosinophil cat ionic proteins (major basic protein, eosinophil-derived neurotoxin and eosi nophil cationic protein), cytokines (interleukin 5 (IL-5), interleukin 3 (I L-3) and granulocyte-macrophage colony stimulating factor (GM-CSF)) and che mokines (eotaxin and RANTES (Regulated upon Activation Normal T cell Expres sed and Secreted)) were performed to assess the in situ activation of the l iver-infiltrating eosinophils of 14 patients with drug-induced liver diseas e and 19 controls. Results: Eosinophils were only observed in patients with drug-induced liver disease. Eosinophils were morphologically normal when hepatitis was due to paracetamol whereas eosinophils had granular changes when hepatitis was du e to an idiosyncratic hepatotoxin. Eotaxin was detected in all patients wit h drug-induced liver disease, whereas RANTES was detected in three of them. IL-5, IL-3 or GM-CSF were not detected. Conclusions: In patients with drug-induced liver disease, the recruitment o f eosinophils in the liver may depend on eotaxin expression. Eosinophil cha nges may vary according to the type of drug. (C) 2001 European Association for the Study of the Liver. Published by Elsevier Science B.V. All rights r eserved.