TY - JOUR

T1 - Large Discrepancy in the Results of Sensitive Measurements of Thyroglobulin Antibodies in the Follow-Up on Thyroid Cancer

T2 - A Diagnostic Dilemma

AU - Nygaard, Birte

AU - Faber, Jens Oscar

AU - Bentzen, Jens

PY - 2012

Y1 - 2012

N2 - During follow-up on patients treated for differentiated thyroid cancer, thyroglobulin (Tg) antibodies can interfere with the Tg assay, making the use of Tg less reliable as a tumor marker. Purpose: To compare Tg and Tg autoantibodies (Tg- Ab) methods used in Denmark, regarding the number of patient samples being accepted for evaluating the result of a serum thyroglobulin (s-Tg) measurement. Design: 95 consecutive blood samples drawn from patients in 2006 in one center were selected according to the following criteria: s-Tg ! 1g/l and accepted BRAHMS Tg+ recovery test using 50 ng of Tg. Samples were retested with: (1) DPC IMMULITE 2000 Tg and Tg-Ab, (2) BRAHMS Tg and Tg-Ab on Kryptor, (3) BRAHMS Tg+ and Dynotest anti-Tg, (4) DELFIA hTg and recovery test using 25 ng of Tg, and (5) BRAHMS Tg+ with recovery test using 1 and 50 ng of Tg. Results: The number of patient samples that was not accepted for Tg evaluation varied from 2 to 26% when the reference values suggested by the manufacturers of the assay were used. When using the detection limit to the cutoff seen in epidemiological studies the number increased to 40%. Conclusion: We found large discrepancies in acceptance of patient samples for s-Tg evaluation, thus illustrating a diagnostic dilemma.

AB - During follow-up on patients treated for differentiated thyroid cancer, thyroglobulin (Tg) antibodies can interfere with the Tg assay, making the use of Tg less reliable as a tumor marker. Purpose: To compare Tg and Tg autoantibodies (Tg- Ab) methods used in Denmark, regarding the number of patient samples being accepted for evaluating the result of a serum thyroglobulin (s-Tg) measurement. Design: 95 consecutive blood samples drawn from patients in 2006 in one center were selected according to the following criteria: s-Tg ! 1g/l and accepted BRAHMS Tg+ recovery test using 50 ng of Tg. Samples were retested with: (1) DPC IMMULITE 2000 Tg and Tg-Ab, (2) BRAHMS Tg and Tg-Ab on Kryptor, (3) BRAHMS Tg+ and Dynotest anti-Tg, (4) DELFIA hTg and recovery test using 25 ng of Tg, and (5) BRAHMS Tg+ with recovery test using 1 and 50 ng of Tg. Results: The number of patient samples that was not accepted for Tg evaluation varied from 2 to 26% when the reference values suggested by the manufacturers of the assay were used. When using the detection limit to the cutoff seen in epidemiological studies the number increased to 40%. Conclusion: We found large discrepancies in acceptance of patient samples for s-Tg evaluation, thus illustrating a diagnostic dilemma.

U2 - 10.1159/000341362

DO - 10.1159/000341362

M3 - Journal article

C2 - 24783019

VL - 1

SP - 193

EP - 197

JO - European Thyroid Journal

JF - European Thyroid Journal

SN - 2235-0640

ER -