A QUICK METHOD TO DETECT CIRCULATING ANTITHYROID HORMONE AUTOANTIBODIES

The aim of this study was to evaluate the feasibility of a chromatogra phic method to easily detect circulating anti-thyroid hormone autoanti bodies (THBA), to calculate their affinity constant and the total thyr oid hormone (TH) levels in presence of THBA. This method was applied t o sera from 4 subject with suspected THBA and 20 controls (10 normal s ubjects and 10 patients with thyroid dysfunctions). After a short incu bation with (125)l-T3 or T4 tracer solution containing 8-anilino-1-nap hthalenesulfonic acid as inhibitor of the binding of TH to plasma prot eins without affecting THBA binding, the samples were chromatographied on prepacked Sephadex LH 20 columns and eluted with TRIS buffer to se parate free TH from THBA-bound TH. Samples were considered THBA positi ve when radioactivity values in TRIS eluates were higher than in contr ols. THBA-bound TH were subsequently eluted with methanol and used to calculate the total TH present in patients with THBA. After a validati on test using two standardized methods, we propose this method to quic kly detect THBA in samples with suspected spuriously high values of fr ee and total TH.