外周血甲状腺球蛋白mRNA对分化型甲状腺癌的诊断价值

Evaluation of thyroglobulin mRNA in peripheral blood of patients with differentiated thyroid carcinoma after remnant ablation

目的探讨外周血甲状腺球蛋白（Tg） mRNA在分化型甲状腺癌（DTC）复发或转移中的诊断价值。方法经术后病理检查诊断为DTC且已完全去除残留甲状腺组织，于2006年4月-2007年2月进行随访的162例DTC患者，均进行左旋甲状腺素（l—T4）替代治疗。应用反转录．聚合酶链反应（RT—PCR）技术对患者外周血中Tg mRNA进行检测，分析Tg mRNA表达阳性率与患者TNM分期等临床特征的关系；应用电化学发光免疫分析（ECLIA）仪测定血清Tg和抗Tg抗体（TgAb），分别以〉1ug／L和〉10^4U／L为阳性判断标准。以随访时^131Ⅰ全身显像、胸部X线、颈部超声、CT扫描等检查确诊病灶为复发或转移“金标准”，比较Tg mRNA和Tg诊断DTC复发或转移的诊断效能。结果外周血TgmRNA和血清Tg监测DTC复发或转移的灵敏度分别为86．61％和53．57％，差异有统计学意义瓴。=29．153，P〈0．001）。52例TgAb阳性患者中，检测外周血Tg mRNA和血清Tg的灵敏度分别为86．54％和0，差异有统计学意义（X^2=79．322，P〈0．001）。外周血Tg mRNA的表达与TNM分期呈明显正相关（Kendall相关系数为0．515，P〈0．001），与年龄、性别、肿瘤组织学类型及转移灶的分布无相关性（Kendall相关系数分别为0．020，0．069，0．050，0．028，P均〉0．05）。结论外周血Tg mRNA可作为监测DTC复发或转移的指标，其灵敏度高于血清Tg，特别适合于TgAb阳性的DTC患者。

Objective The aim of this study was to evaluate the diagnostic value of thyroglobulin （Tg） mRNA in peripheral blood samples of patients with differentiated thyroid carcinoma （DTC） after remnant ablation. Methods Tg mRNA was detected by reverse transcription-polymerase chain reaction （ RT-PCR） in peripheral blood of 162 patients. SPSS 13.0 was used for date analysis. Results The Tg mRNA assay had higher sensitivity than the conventional serum Tg measurement [ 86.61% （97/112 ） vs 53.57% （60/112） , X^2 = 29. 153, P 〈 0.001 ] which was the ＂gold standard＂ for the identification of recurrence or metastases. In the anti-Tg antibodies （TgAh） positive DTC patients, the sensitivity of Tg mRNA was higher than that of serum Tg [86.54% （45/52） vs 01 in identifying recurrent or metastatic thyroid disease （X^2 = 79. 322, P 〈0.001 ）. There was a significantly positive correlation between Tg mRNA expression and the clinical stages （Kendall correlation coefficient = 0.515, P 〈 0.001 ）. There was no difference of Tg mRNA expression in peripheral blood among ages, sex, pathological types and location of metastases, respectively （ Kendall correlation coefficient = 0.020, 0.069, 0. 050 and 0. 028 ; all P 〉 0.05 ）. Conclusions Circulating Tg mRNA is a more sensitive marker than serum Tg in identifying recurrent or metastatic DTC, particularly in patients during levo-thyroxine （l-T4 ） therapy and with TgAh-positive. The DTC patients who have positive expression of Tg mRNA indicates poor prognosis.