IgG3 is the dominant subtype of anti-isoniazid antibodies in patients with isoniazid-induced liver failure.
Isoniazid (INH) therapy is associated with a significant incidence of idiosyncratic liver failure. We recently reported eight cases of INH-induced liver failure in which patients had antidrug and anticytochrome P450 antibodies. However, it was unclear what role these antibodies play in the mechanism of INH-induced liver injury. Here, we report that the dominant isotype of anti-INH antibodies was IgG, with IgG3 being the dominant subtype. IgG3 antibodies are associated with a Th1-type immune response and fix complement. IgG3 antibodies have been associated with other forms of liver injury and may play a pathogenic role in INH-induced liver injury.
Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto , Toronto, Ontario M5S 1A8, Canada.
Imir G
IG
Metushi
William M
WM
Lee
Jack
J
Uetrecht
D000995:Antitubercular Agents / Q000009:adverse effects* / Q000276:immunology*; D056486:Chemical and Drug Induced Liver Injury / Q000097:blood / Q000276:immunology / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007538:Isoniazid / Q000009:adverse effects* / Q000276:immunology*; D008099:Liver / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D017093:Liver Failure / Q000097:blood / Q000139:chemically induced* / Q000276:immunology / Q000473:pathology
D000995:Antitubercular Agents; D007074:Immunoglobulin G; D007538:Isoniazid