title: Thyrotoxicosis factitia masquerading as recurrent Graves' disease: endogenous antibody immunoassay interference, a pitfall for the unwary.
abstract: Antibody interference in immunoassays is an underestimated problem, which has the potential to cause patient harm and waste health-care resources. We report a case where thyroglobulin antibodies generated a false-positive thyroglobulin result delaying the diagnosis of thyrotoxicosis factitia masquerading as recurrent Graves' disease. A high index of clinical suspicion and good laboratory-clinician communication underpins effective clinical and laboratory strategies to detect potentially erroneous laboratory results due to endogenous antibody interference in immunoassays.
authors.affiliation: Department of Diabetes and Endocrinology, New Cross Hospital, Wolverhampton, UK.
authors.forename: V R
authors.initials: VR
authors.lastname: Jahagirdar
authors.forename: P
authors.initials: P
authors.lastname: Strouhal
authors.forename: G
authors.initials: G
authors.lastname: Holder
authors.forename: R
authors.initials: R
authors.lastname: Gama
authors.forename: B M
authors.initials: BM
authors.lastname: Singh
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D006111:Graves Disease / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D007118:Immunoassay; D013954:Thyroglobulin / Q000276:immunology; D013971:Thyrotoxicosis / Q000175:diagnosis* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D013954:Thyroglobulin