Ito Y, Kuroda Y, Enomoto H
Nihon Naibunpi Gakkai Zasshi. 1980 Jun 20;56(6):786-803. doi: 10.1507/endocrine1927.56.6_786.
We examined the method of radioimmunoassay of the Disc T4 (dried blood spot T4) for the purpose of mass screening of neonatal hypothyroidism and tried the parallel assay of T4 and TSH in dried blood spotted on filter paper at the fifth day of life, and we compared the results. By changing the volumes of T4 antibody and T4 antigen solutions, it is possible to measure thyroxine using two discs 3mm in diameter. Disc T4 values obtained in 45 unknown samples by this method were in good correlation with serum T4 values of the same subjects (Y = 0.97X + 0.06). The coefficients of variation were 5.6 to 18.9% in the range of 5.3 to 10.7 micrograms/100ml of Disc T4 (within assay), and 7.9 to 20.8% in the range of 2.4 to 10.3 micrograms/100ml of Disc T4 (between assay). We measured both Disc T4 and Disc TSH of 26,067 newborn infants born between June 1978 and May 1979. Out of 26,067 measurements, four cases of primary hypothyroidism, fourteen cases of TBG deficiency and two cases of transient hypothyroidism were discovered. Out of the four cases of primary hypothyroidism, three showed low Disc T4 (1.3 to 4.0 micrograms/100ml) and high Disc TSH (200 to 240 micromicrons/ml), one showed normal Disc T4 (7.1 micrograms/100ml) and high Disc TSH (30 micromicrons/ml). It was thought the last case might be mild hypothyroidism. In 14 cases of TBG deficiency, Disc T4 was not detectable to 3.4 micrograms/100ml while Disc TSH was within the normal range. In two cases of transient hypothyroidism, Disc T4 measurements showed normal range (6.5, 10.6 micrograms/100ml), and Disc TSH showed high values (41, 120 micromicrons/ml). Therefore, Disc TSH was more sensitive and showed less false positive cases than did Disc T4 for screening hypothyroidism. Although no secondary hypothyroidism existed in the 26,067 measurements, it continues to be important to measure Disc T4 for the discovery of secondary or tertiary hypothyroidism.
为了对新生儿甲状腺功能减退症进行大规模筛查，我们研究了干血斑T4（Disc T4）的放射免疫测定方法，并尝试在出生后第5天对滤纸上的干血斑进行T4和TSH的平行测定，然后比较结果。通过改变T4抗体和T4抗原溶液的体积，可以使用两个直径为3mm的圆盘来测量甲状腺素。用这种方法在45个未知样本中获得的Disc T4值与同一受试者的血清T4值具有良好的相关性（Y = 0.97X + 0.06）。在Disc T4为5.3至10.7微克/100ml范围内（批内），变异系数为5.6%至18.9%，在Disc T4为2.4至10.3微克/100ml范围内（批间），变异系数为7.9%至20.8%。我们对1978年6月至1979年5月出生的26067名新生儿进行了Disc T4和Disc TSH的测定。在26067次测量中，发现了4例原发性甲状腺功能减退症、14例TBG缺乏症和2例暂时性甲状腺功能减退症。在4例原发性甲状腺功能减退症中，3例显示Disc T4低（1.3至4.0微克/100ml）和Disc TSH高（200至240微微克/ml），1例显示Disc T4正常（7.1微克/100ml）和Disc TSH高（30微微克/ml）。认为最后一例可能是轻度甲状腺功能减退症。在14例TBG缺乏症中，Disc T4在不可检测至3.4微克/100ml之间，而Disc TSH在正常范围内。在2例暂时性甲状腺功能减退症中，Disc T4测量显示在正常范围内（6.5、10.6微克/100ml），而Disc TSH显示高值（41、120微微克/ml）。因此，在筛查甲状腺功能减退症时，Disc TSH比Disc T4更敏感且假阳性病例更少。虽然在26067次测量中没有继发性甲状腺功能减退症，但测量Disc T4对于发现继发性或三发性甲状腺功能减退症仍然很重要。
