Patients with autoimmune thyroid disease including Hashimoto’s thyroiditis and Grave’s disease occasionally develop autoantibodies to T4 and T3. These autoantibodies interfere with the measurement of T4 and T3 immunoassay. Thus abnormal or disparate T4 and T3 concentrations may be due to autoantibodies.
No special preparation required
Sample by 7th of the month; Report after 2–3 weeks