Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
Clin Chem Lab Med. 2011 Jun;49(6):1025-7. doi: 10.1515/CCLM.2011.155. Epub 2011 Mar 11.
This study evaluated the impact of thyroglobulin (Tg) antibodies (TgAb) interference on Tg measurements performed with a second-generation immunometric Tg assay, in comparison to a first-generation method.
Five serum pools without detectable TgAb and containing measurable Tg concentrations were obtained from DTC patients and mixed with sera from patients with measurable TgAb, but undetectable Tg concentrations. Tg and TgAb concentrations were measured by the first- and the second-generation Tg immunoassays and Tg-recovery was also evaluated for both assays.
The decrease in Tg concentrations in the presence of TgAb was more pronounced in the first-generation Tg assay (41.6%) compared with the second-generation assay (31.4%) (p<0.01). Accordingly, the mean Tg-recovery values were 51.4% in the first-generation Tg assay and 68.8% in the second-generation (p<0.01). Measurable Tg concentrations were found in all sera using the second-generation assay, but not the first-generation method.
Our preliminary results indicate that an undetectabIe Tg concentration measured using the second-generation assay is unlikely to be a false-negative result induced by TgAb-interferences.
本研究评估了甲状腺球蛋白 (Tg) 抗体 (TgAb) 干扰对第二代免疫测定法与第一代方法检测 Tg 时的影响。
从 DTC 患者中获得 5 个无 TgAb 可检测且 Tg 浓度可测量的血清池，并与 TgAb 可测量但 Tg 浓度不可检测的患者血清混合。使用第一代和第二代 Tg 免疫测定法分别测量 Tg 和 TgAb 浓度，并评估两种测定法的 Tg 回收率。
与第二代测定法（31.4%）相比，第一代测定法（41.6%）中 TgAb 存在时 Tg 浓度的下降更为明显（p<0.01）。因此，第一代 Tg 测定法的平均 Tg 回收率为 51.4%，第二代为 68.8%（p<0.01）。使用第二代测定法可在所有血清中检测到可测量的 Tg 浓度，但第一代方法不行。
我们的初步结果表明，使用第二代测定法检测到的不可测量的 Tg 浓度不太可能是由 TgAb 干扰引起的假阴性结果。
