Spuriously high free thyroxine with the Amerlite MAB FT4 assay.
In the Amerlite MAB FT4 assay, as stated by the manufacturer, FT4 values should be normal in patients with anti-thyroid hormone autoantibodies. The case of a 69 year old woman with a spuriously high FT4 using the Amerlite MAB FT4 assay is reported. Laboratory investigations showed that her spurious FT4 result was likely to have been caused by anti-thyroid hormone autoantibodies.
Lai
L C
LC
Department of Clinical Biochemistry, Freeman Hospital, Newcastle upon Tyne.
Day
J A
JA
Clark
F
F
Peaston
R T
RT
D000368:Aged; D000911:Antibodies, Monoclonal; D001323:Autoantibodies / Q000097:blood*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D013963:Thyroid Hormones / Q000276:immunology*; D013974:Thyroxine / Q000097:blood*
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D013963:Thyroid Hormones; D013974:Thyroxine