Mathews K P, Herschbach J H, Chambers S L, Zuraw B L
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037, USA.
J Clin Lab Anal. 1995;9(3):196-203. doi: 10.1002/jcla.1860090309.
Measurement of C1-r-C1-s-(C1 inh)2 complexes in serum or plasma by enzyme-linked immunosorbent assay (ELISA) has been proposed as a relatively convenient and sensitive means for assessing C1 activation. However, interference by unactivated C1q (r-s)2 at low serum or plasma dilutions has resulted in estimates that vary widely with the degree of serum or plasma dilution. Precipitating the interfering C1q (r-s)2 with 6% polyethylene glycol has been proposed to resolve this problem, but here it is shown that this procedure also precipitates or coprecipitates some of the C1-r-C1-s-(C1 inh)2 complexes. Satisfactory results have been achieved without PEG precipitation by testing high plasma dilutions under conditions where there is a sufficient excess of anti-C1s coating the microtitration plate wells that removal of C1q (r-s)2 is not necessary. Optimizing conditions for quantitating these complexes at high dilution have been investigated. The mean normal EDTA plasma C1-r-C1-s-(C1 inh)2 complex measurement was 36.6 +/- 7.0 (S.D.) ELISA units with a 95% confidence interval of 19.5-47.6u. Besides providing a sensitive assay for C1 activation, measuring C1-r-C1-s-(C1 inh)2 complexes may help to clarify the pathophysiologic mechanisms resulting from C1 inh deficiency under various conditions.
通过酶联免疫吸附测定（ELISA）检测血清或血浆中的C1-r-C1-s-（C1 inh）2复合物，已被提议作为评估C1活化的一种相对便捷且灵敏的方法。然而，在低血清或血浆稀释度下，未活化的C1q（r-s）2会产生干扰，导致检测结果随血清或血浆稀释程度而有很大差异。有人提议用6%聚乙二醇沉淀干扰性的C1q（r-s）2来解决这个问题，但本文表明该方法也会沉淀或共沉淀一些C1-r-C1-s-（C1 inh）2复合物。在微滴定板孔中包被有足够过量抗C1s的条件下，通过检测高血浆稀释度，无需去除C1q（r-s）2，不进行聚乙二醇沉淀也能获得满意结果。已对在高稀释度下定量这些复合物的优化条件进行了研究。正常EDTA血浆中C1-r-C1-s-（C1 inh）2复合物的平均测量值为36.6±7.0（标准差）ELISA单位，95%置信区间为19.5 - 47.6u。除了为C1活化提供一种灵敏的检测方法外，检测C1-r-C1-s-（C1 inh）2复合物可能有助于阐明在各种情况下C1 inh缺乏所导致的病理生理机制。
