Effects of Anti-thyroglobulin Antibody on the Measurement of Thyroglobulin: Differences Between Immunoradiometric Assay Kits Available.
- Author:
Byeong Cheol AHN
1
;
Ji Hyeong SEO
;
Jin Ho BAE
;
Shin Young JEONG
;
Jeongsoo YOO
;
Jin Hyang JUNG
;
Ho Yong PARK
;
Jung Guk KIM
;
Sung Woo HA
;
Jin Ho SOHN
;
In Kyu LEE
;
Jaetae LEE
;
June Sik PARK
;
Bo Wan KIM
;
Kyu Bo LEE
Author Information
1. Department of Nuclear Medicine, School of Medicine, Kyungpook National Unversity, Daegu, Korea. abc2000@mail.knu.ac.kr
- Publication Type:Original Article
- Keywords:
Thyroglobulin;
Anti-thyroglobulin antibody;
Immunoradiometric assay
- MeSH:
Diagnosis;
Follow-Up Studies;
Humans;
Immunoradiometric Assay*;
Thyroglobulin*;
Thyroid Gland;
Thyroid Neoplasms
- From:Korean Journal of Nuclear Medicine
2005;39(4):252-256
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: Thyroglobulin (Tg) is a valuable and sensitive tool as a marker for diagnosis and follow-up for several thyroid disorders, especially, in the follow-up of patients with differentiated thyroid cancer (DTC). Often, clinical decisions rely entirely on the serum Tg concentration. But the Tg assay is one of the most challenging laboratory measurements to perform accurately owing to antithyroglobulin antibody (Anti-Tg). In this study, we have compared the degree of Anti-Tg effects on the measurement of Tg between availale Tg measuring kits. MATERIALS AND METHODS: Measurement of Tg levels for standard Tg solution was performed with two different kits commercially available (A/B kits) using immunoradiometric assay technique either with absence or presence of three different concentrations of Anti-Tg. Measurement of Tg for patient's serum was also performed with the same kits. Patient's serum samples were prepared with mixtures of a serum containing high Tg levels and a serum containg high Anti-Tg concentrations. RESULTS: In the measurements of standard Tg solution, presence of Anti-Tg resulted in falsely lower Tg level by both A and B kits. Degree of Tg underestimation by A kit was more prominent than B kit. The degree of underestimation by B kit was trivial therefore clinically insignificant, but statistically significant. Addition of Anti-Tg to patient serum resulted in falsely lower Tg levels with only A kit. CONCLUSION: Tg level could be underestimated in the presence of anti-Tg. Anti-Tg effect on Tg measurement was variable according to assay kit used. Therefore, accuracy test must be performed for individual Tg-assay kit.
