Evaluation of the first automated thyroglobulin assay.
The aim of this study was to investigate technical and analytical performance of the first automated thyroglobulin (Tg) assay (DPC-Immulite; Diagnostic Products Corporation, Los Angeles, USA). In imprecision studies using several human serum pools ranging from 21 to 58 replicates, a coefficient of variation of 9.0% was obtained at a mean Tg concentration of 0.84 ng/ml and of 6.1% at a Tg concentration of 62.1 ng/ml. In a method comparison with a non-automated assay (BRAHMS LUMItest Tg, BRAHMS, Berlin, Germany) using 383 sera of 303 patients with thyroid carcinoma, regression analysis according to Passing and Bablock yielded in the following equation: Immulite Tg = 1.6 x BRAHMS Tg-0.1 ng/ml (Pearson's r = 0.979). Sera obtained from 59 patients with thyroid carcinoma enabled comparative follow-up studies; in all cases qualitative agreement was found with regard to increase or decrease of serum Tg; in eight cases, however, Tg was detected with the Immulite assay but not with the BRAHMS assay. Further follow-up proved the presence of thyroid tissue in these patients. From these and further methodological data (dilution linearity, interference studies, carry-over study, high-dose hook properties, and short report time) it is concluded that the DPC-Immulite Tg assay meets the requirements of routine diagnostic use.
Vogeser
M
M
Institute of Clinical Chemistry, Klinikum Grosshadern, Ludwig-Maximilians-Universität Munich, Germany. mvogeser@klch.med.uni-muenchen.de
Knesewitsch
P
P
Jacob
K
K
Seidel
D
D
D001331:Automation; D005069:Evaluation Studies as Topic; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood*; D013959:Thyroid Diseases / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood
D013954:Thyroglobulin