放射性碘治疗后甲亢猫血清游离甲状腺素的化学发光免疫分析与平衡透析法比较。
Comparison of free thyroxine measurement by chemiluminescence and equilibrium dialysis following I therapy in hyperthyroid cats.
机构信息
Small Animal Department, Ghent University, Merelbeke, Belgium.
Department of Medical Imaging of Domestic Animals, Ghent University, Merelbeke, Belgium.
出版信息
J Feline Med Surg. 2020 Dec;22(12):1114-1120. doi: 10.1177/1098612X20906929. Epub 2020 Mar 31.
OBJECTIVES
The first objective was to assess correlation between free thyroxine (fT4) measurements by equilibrium dialysis (fT4ED; Antech Diagnostics) and a chemiluminescent enzyme immunoassay (fT4CEIA; IMMULITE 2000 Veterinary Free T4 [Siemens Healthcare Diagnostics Products]) in hyperthyroid, otherwise healthy, cats before (T0), and 1 month (T1) and 11-23 months (T2) after radioactive iodine (I) therapy. The second objective was to determine correlation between thyroid status based on fT4 (by both techniques) and the gold standard, thyroid scintigraphy.
METHODS
Thyroid status, including thyroid-stimulating hormone (TSH), total thyroxine (TT4) and fT4 serum concentrations, were assessed in 45 client-owned hyperthyroid cats before (T0), and 1 month (T1) and 11-23 months (T2) after I therapy. fT4 was determined by a chemiluminescent enzyme immunoassay (CEIA) and equilibrium dialysis (ED). Quantitative thyroid scintigraphy (with sodium 99m-Tc-pertechnetate) was performed at T2.
RESULTS
Spearman correlation between fT4CEIA and fT4ED was 0.81, 0.88 and 0.79 at T0, T1 and T2, respectively. fT4CEIA was consistently lower than fT4ED, with a median difference of -5.4 pmol/l ( <0.001) and -4.9 pmol/l ( <0.0001) at T1 and T2, respectively. At T2, all cats were identified as euthyroid based on thyroid scintigraphy. None of the cats were identified as being hypothyroid, based on serum TT4 and TSH measurements. Nine of 22 (40.9%) cats had an fT4CEIA below the reference interval (RI) at T2, whereas only 2/22 (9.1%) cats had an fT4ED concentration below the RI at T2.
CONCLUSIONS AND RELEVANCE
Good correlation exists between both assays at T1 and T2, but a significant systematic difference is noted at both time points. This could be an indication for reconsideration of the current RI, although further studies are warranted for assessing test accuracy (in otherwise healthy cats and cats with non-thyroidal illness). At this time, routine use of fT4CEIA after I therapy is not advised in feline patients.
目的
本研究的首要目的是评估平衡透析（fT4ED；Antech Diagnostics）和化学发光酶免疫分析（fT4CEIA；IMMULITE 2000 兽医游离 T4 [Siemens Healthcare Diagnostics Products]）检测甲状腺功能亢进、健康猫的游离甲状腺素（fT4）的相关性，评估方法为在放射性碘（I）治疗前（T0）、治疗后 1 个月（T1）和 11-23 个月（T2）检测游离甲状腺素（fT4）。第二个目的是评估基于两种技术（fT4ED 和 fT4CEIA）的甲状腺功能与金标准甲状腺闪烁扫描之间的相关性。
方法
在接受 I 治疗的 45 只患有甲状腺功能亢进的患宠前（T0）、治疗后 1 个月（T1）和 11-23 个月（T2）时，评估其甲状腺状态，包括促甲状腺激素（TSH）、总甲状腺素（TT4）和游离甲状腺素（fT4）血清浓度。通过化学发光酶免疫分析（CEIA）和平衡透析（ED）检测 fT4。在 T2 时进行定量甲状腺闪烁扫描（使用 99mTc-高锝酸钠）。
结果
T0、T1 和 T2 时，fT4CEIA 和 fT4ED 之间的 Spearman 相关系数分别为 0.81、0.88 和 0.79。fT4CEIA 始终低于 fT4ED，在 T1 和 T2 时，中位数差值分别为-5.4 pmol/L（<0.001）和-4.9 pmol/L（<0.0001）。在 T2 时，根据甲状腺闪烁扫描结果，所有猫均被认定为甲状腺功能正常。根据 TT4 和 TSH 测量结果，没有猫被认定为甲状腺功能减退。在 T2 时，22 只猫中有 9 只（40.9%）的 fT4CEIA 值低于参考区间（RI），而只有 2 只（9.1%）的猫的 fT4ED 值低于 RI。
结论和相关性
在 T1 和 T2 时，两种检测方法之间存在良好的相关性，但在两个时间点都存在显著的系统差异。这可能表明需要重新考虑当前的 RI，尽管还需要进一步的研究来评估检测的准确性（在健康猫和非甲状腺疾病猫中）。目前，不建议在接受 I 治疗后在猫中常规使用 fT4CEIA。
Zotero 插件