采用多种抗原测定静注人免疫球蛋白(pH4)中抗体Fc段生物学活性的初探

目的初步探讨采用多种抗原测定静注人免疫球蛋白(IVIG)(pH4)中抗体的Fc段生物学活性,了解IVIG中抗体的Fc段生物学活性。方法采用补体活化的经典途径中免疫复合物激活补体的方法,将不同浓度的麻疹病毒、风疹病毒、乙肝表面抗原(HBsAg)、破伤风类毒素、脑膜炎球菌P64k外膜蛋白和白喉类毒素6种抗原分别致敏人O型血红细胞形成红细胞-抗原结合物;然后,6种致敏红细胞分别与IVIG孵育,与特异性抗体形成红细胞-抗原-抗体复合物;最后,此复合物与补体反应,在541 nm波长处读取吸光值,并绘制溶血反应动力学曲线,分别计算IVIG中针对上述6种抗原IgG的Fc段生物学活性。采用此方法,用6种抗原致敏的红细胞测定IVIG的Fc段生物学活性10次,验证此方法的重复性。结果麻疹病毒、风疹病毒、HBsAg、破伤风类毒素和脑膜炎球菌P64k外膜蛋白致敏的红细胞分别与供试品和补体反应后,测定的溶血反应动力学曲线较平缓,而白喉类毒素致敏的红细胞与供试品和补体反应后,测定的溶血反应动力学曲线下降明显,呈典型的"S"型曲线。计算结果显示,IVIG中针对此六种抗原的抗体Fc段生物学活性相对于参考品均大于80%。Fc段生物学检测方法重复性较好。结论采用多种抗原分别致敏红细胞,可以用来检测IVIG中多种抗体的Fc段生物学活性,为深入了解IVIG制品中的多种抗体的Fc段生物学活性奠定了基础。

Determination on biologic activity of Fc fragment in intravenous immunoglobulin(pH4) by using multiple antigens

Objective To determine biologic activity of Fc in IVIG(pH4) by using different antigens,and to understand biologic activity of Fc fragment of various IgG in IVIG(pH4).Methods The classical complement activation was carried out in determinination biological activity of Fc fragment in IVIG(pH4) by using 6 different antigens coupled-tanned red blood cells(RBC),respectively.First,It is by preparation of measles vaccines,rubella vaccines,HBsAg,tetanus toxin,P64k outer membrane protein of Meningococcus and diphtheria toxin coupling to RBC respectively.Then IVIG were added to the antigen coupled RBC to form a complex(antigen sensitized RBC and antibody).Finally,the complement was added to the complex.Measurement biologic activity of the Fc was by means of detection in 541 nm and making curves for haemolysis.Analysis was performed for 10 times by using 6 different antigen with different concentration coupled RBC,respectively.Verification was carried out in confirmation of the repetition for biologic activity of Fc in IVIG.Results The haemolysis curves were in slope lines for 5 different antigens(measles vaccines,rubella vaccines,HBsAg,tetanus toxin,and p64k protein on outer membrane protein of Meningococcus)coupled RBC.However,haemolysis curve for diphtheria toxoid coupled RBC was very typical and formed a classical "S"curve.The biologic activity of Fc fragment in IVIG could reach to more than 80% by using of 6 different antigens in comparison of reference materials.The test for repetition of biologic activity of Fc in IVIG was in a normal range.Conclusion Determination on biologic activity for Fc fragment in IVIG was attempted by using multiple antigens in this study,which provided a primary basis in this aspect.