血清人胰岛素样生长因子结合蛋白-3放射免疫测定法的建立及其临床应用

Radioimmunoassay of human insulin like growth factor binding protein 3 in serum and its clinical application

目的 建立特异的血清胰岛素样生长因子结合蛋白３（ＩＧＦＢＰ３） 放射免疫测定法（ＲＩＡ），并初步应用于临床。方法 用ＩＧＦＢＰ３ 免疫兔子，制备兔抗ＩＧＦＢＰ３ 血清。以乳过氧化物酶法进行１２５Ｉ标记ＩＧＦＢＰ３ 。建立ＩＧＦＢＰ３ ＲＩＡ，并做方法学的检验，测定健康成人和肢端肥大症、生长激素缺乏症（ＧＨＤ） 及肝硬化和慢性肾功能不全（ＣＲＦ） 患者的血清ＩＧＦＢＰ３ 水平。结果 ＩＧＦＢＰ３ ＲＩＡ的最小可测值为（１６－９ ±２－４） μｇ／Ｌ。兔抗ＩＧＦＢＰ３ 血清与ＩＧＦＢＰ３ 结合的亲和常数为７－９ ×１０１０ Ｌ／ｍｏｌ，与ＩＧＦＢＰ１、ＩＧＦＢＰ２、胰岛素样生长因子１（ＩＧＦ１） 和人生长激素（ｈＧＨ） 均无交叉反应。ＩＧＦＢＰ３ＲＩＡ 准确性好，高中低３ 个剂量的平均回收率为９８－７％ ，批内及批间平均ＣＶ分别为（７－８ ±３－５） ％ 和（１０－８±３－１）％ 。８８ 例健康成人血清ＩＧＦＢＰ３ 水平为（３－１±０－５） ｍｇ／Ｌ，４９ 例活动性肢端肥大症及１９例ＣＲＦ患者血清ＩＧＦＢＰ３ 水平分别为（１６－８ ±９－９） 和（１３－２ ±３－６） ｍｇ／Ｌ，均与健康成人水平无重叠。１２９ ?

Objective To establish a specific radioimmunoassay (RIA) for serum level of human insulin like growth factor binding protein 3 (IGFBP 3) and study serum IGFBP 3 levels in normal adults and some pathophysiological states Methods IGFBP 3 antibody was raised and iodinated IGFBP 3 was made with lactoperoxidase as a tracer, then set up the RIA for human serum IGFBP 3 Serum levels of normal adults, patients suffered from acromegaly, growth hormone deficiency (GHD), liver cirrhosis and chronic renal failure (CRF) were tested Results The minimal detectable range of this IGFBP 3 RIA was (16 9±2 4) μg/L The affinity constant is 7 9×10 10 L/mol, without cross reactivity with IGFBP 1, IGFBP 2, insulin like growth factor 1 (IGF 1) and human growth hormone (hGH) The mean rate of recovery was 98 7%, and the mean coefficients of variation for intra and interbatch assay were (7 8±3 5)% and (10 8±3 1)% respectively The mean serum levels of IGFBP 3 in 88 normal adults were (3 1 ±0 5) mg/L (range 2 0～4 0 mg/L), while that in 49 active acromegalics were (16 8±9 9) mg/L (range 5 6～42 8 mg/L) and in 19 CRF were (13 2±3 6) mg/L (range 9 8～25 0 mg/L), none of them was overlapping the normal adult levels The mean serum IGFBP 3 levels of 129 GHD and 18 liver cirrhosis were (1 6 ±0 9) mg/L (range 0 4～3 7 mg/L) and (2 4±0 7) mg/L (range 1 2～3 7 mg/L) respectively, all of them were overlapping the lower level of serum IGFBP 3 of normal adults Conclusions This RIA is easy to use, can detect wide range of serum IGFBP 3, has high specificity and good reproducibility Serum IGFBP 3 assay is very useful in diagnosis of the hyper , normal and hypo secretory state of hGH