Elecsys® Thyrotropin (TSH) Assay Evaluated

Abstract

Immunoassays on the fully automated Elecsys® 2010 analyzer (Boehringer Mannheim, Meylan, France) involve the electrochemiluminescent reaction of Ru(II) Tris(bipyridyl) with tripropylamine combined with a magnetic microparticle separation after short incubation times with low sample volumes [1] . The thyrotropin (TSH) assay, which requires a high sensitivity [2] , has an 18-min incubation time and 50-μL sample volume. In the present study we assessed the analytical and clinical performances of this TSH assay during 5 weeks in June and July of 1996. Assays were performed in singleton according to the manufacturer’s instructions with two different lot numbers. Results were compared with those of the Immulite TSH3G assay (Behring Diagnostic, Rueil Malmaison, France). The procedures were performed in accordance with the Helsinki Declaration of 1975, as revised in 1983. Interassay reproducibility was assessed by repeated analysis (n = 12) of 12 patients’ frozen sera and of the TSH3G Immulite control serum. CVs were 0.06 mU/L, 10.4% at TSH of 0.018 mU/L, and 14.9% at TSH of 0.014 mU/L. “Functional sensitivity” (CV = 20%) was <0.014 mU/L; therefore Elecsys TSH can be …