1994 Volume 23 Issue 1 Pages 1-7
For sensitive measurement of the anti-thyroglobulin antibody in serum, a two-step sandwich chemiluminescence enzyme immunoassay (CLEIA) was developed. This method uses a microplate as a solid phase, peroxidase as a labeling enzyme, and luminol and an enhancer as chemiluminescence reagents. The CLEIA allowed absolute levels of the antibody to be measured over a wide range (from 100 to 100,000 ng/ml). The results of this assay correlated with those from a dual antibody radioimmunoassay (RIA) 1), revealed a correlation coefficient of 0.64 and regression equation of Y=21.6X-160 (N=20). There was poor agreement between the results from the two assays at high concentrations. The upper limit of the normal range for blood anti-thyroglobulin antibody was 195 ng/ml. Antibody levels significantly lower than this concentration were found to cause underestimation of serum thyroglobulin levels. Serum anti-thyroglobulin antibody levels were determined for 30 patients who had been checked periodically for serum thyroglobulin after surgical resection of thyroid cancer. Levels higher than 200 ng/ml were found for 6 of these patients. In these cases, the serum thyroglobulin levels seemed to be underestimated because of the presence of high levels of anti-thyroglobulin antibody. These findings indicate the necessity of measurement of the levels of both anti-thyroglobulin antibody and thyroglobulin for early detection of recurrence after surgical resection of thyroid cancer.
