Nikolić J A
INEP Institute for the Application of Nuclear Energy, Zemun, Beograd.
Glas Srp Akad Nauka Med. 1992(42):57-73.
Alpha-fetoprotein (AFP) is a specific glycoprotein which is synthesised in the fetal liver and released into the blood stream together with the closely related protein, albumin. It has been proposed that AFP functions as a carrier of essential fatty acids to certain developing cells and as a possible immunosuppressor. In man its synthesis is under the strict and complicated control of transcription of a single gene on chromosome 4. The concentration of AFP in fetal serum is greatest at about 13 weeks gestation and then decreases up to birth. During pregnancy AFP passes into the amniotic fluid and also across the placenta, so that the concentration of AFP in maternal serum increases during pregnancy in a characteristic way. Greater than normal increases may indicate certain pathological states in the fetus. Serum concentrations of AFP in the newborn infant decrease rapidly to reach levels typical for adults (< 10 micrograms/L) usually by the end of the first year. Raised concentrations of serum AFP appear in a large proportion of patients with primary hepatoma and in a smaller percentage of patients with other malignant diseases (tumours of the testis, ovary, bronchi, gastrointestinal tract). In addition, increases in serum AFP are found in other illnesses accompanied by damage to hepatocytes in the liver (hepatitis, cirrhosis etc.). Certain differences in the structure of the oligosaccharide portion of the molecule have been shown between AFP synthesized by benign or by malignant cells and between AFP synthesised by hepatocytes or by cells of endodermal origin. These differences have been used as an aid in the diagnosis of liver diseases where serum AFP is elevated. Since AFP is not strictly specific for a certain type of carcinoma, its determination is primarily used in medicine for monitoring the effects of therapy and surgery on the course of malignant conditions which initially showed increased levels of serum AFP.
甲胎蛋白（AFP）是一种特殊的糖蛋白，在胎儿肝脏中合成，并与密切相关的蛋白质白蛋白一起释放到血流中。有人提出，AFP作为必需脂肪酸的载体，运输到某些发育中的细胞，并可能作为一种免疫抑制剂。在人类中，其合成受位于4号染色体上的单个基因转录的严格而复杂的控制。胎儿血清中AFP的浓度在妊娠约13周时最高，然后在出生前逐渐降低。在怀孕期间，AFP进入羊水并穿过胎盘，因此孕妇血清中AFP的浓度以一种特征性的方式增加。高于正常水平的增加可能表明胎儿存在某些病理状态。新生儿血清中AFP的浓度迅速下降，通常在第一年末达到成人典型水平（<10微克/升）。大多数原发性肝癌患者血清AFP浓度升高，其他恶性疾病（睾丸、卵巢、支气管、胃肠道肿瘤）患者中AFP浓度升高的比例较小。此外，在伴有肝细胞损伤的其他疾病（肝炎、肝硬化等）中也发现血清AFP升高。已显示良性或恶性细胞合成的AFP以及肝细胞或内胚层来源细胞合成的AFP在分子寡糖部分的结构上存在某些差异。这些差异已被用于辅助诊断血清AFP升高的肝脏疾病。由于AFP对某一类型的癌症并不具有严格的特异性，其测定主要用于医学领域，以监测治疗和手术对最初血清AFP水平升高的恶性疾病病程的影响。
