Delacroix D L, Vaerman J P
J Immunol Methods. 1982;51(1):49-55. doi: 10.1016/0022-1759(82)90381-7.
The influence of size heterogeneity of IgA on its immunonephelometric (IN) assay was studied using highly purified preparations of monoclonal (MC) or polyclonal (PC) monomeric (M), dimeric (D), trimeric (T) and tetrameric (Q) IgA, as well as of secretory IgA (sIgA). Concentrations measured by optical density (OD) were compared to IN--concentrations obtained by using M as standards, on an equal weight basis. No significant difference was found between OD and IN concentrations of D, T, Q and sIgA were only slightly underestimated, with correction factors (CF) of 1.16, 1.20 and 1.24, respectively. The value of 1.24 for our sIgA sample (84% of 11S, 16% of 15S) could be due to the fact that secretory component represents about 20% of the mass of the sIgA molecule. IN seems a method of choice for measuring IgA concentrations in the range of microgram/ml, almost independently of the size of IgA.
使用高度纯化的单克隆（MC）或多克隆（PC）单体（M）、二聚体（D）、三聚体（T）和四聚体（Q）IgA以及分泌型IgA（sIgA）制剂，研究了IgA大小异质性对其免疫比浊法（IN）测定的影响。将通过光密度（OD）测量的浓度与以M作为标准品在等重量基础上获得的IN浓度进行比较。D、T、Q和sIgA的OD浓度与IN浓度之间未发现显著差异，sIgA仅略有低估，校正因子（CF）分别为1.16、1.20和1.24。我们的sIgA样本（11S的84%，15S的16%）的校正因子为1.24，可能是因为分泌成分约占sIgA分子质量的20%。对于微克/毫升范围内的IgA浓度测定，IN似乎是一种几乎不受IgA大小影响的首选方法。
