Kuzuya H, Blix P M, Horwitz D L, Steiner D F, Rubenstein A H
Diabetes. 1977 Jan;26(1):22-9. doi: 10.2337/diab.26.1.22.
Serum levels of free and total insulin as well as total C-peptide immunoreactivity (C-peptide and proinsulin) and C- peptide were measured in insulin-treated diabetics with circulating insulin antibodies by the addition of polyethylene glycol (PEG) before and after acidification. PEG resulted in complete precipitation of insulin antibodies from serum and made it possible to measure free insulin in the supernatant. Incubation of serum at 37 degrees C. for two hours before addition of PEG resulted in values for free insulin that probably resembled the in-vivo levels most closely. The same method could also be used to remove proinsulin bound to circulating insulin antibodies and permitted the measurement of C-peptide in the supernatant. Clinical studies using this approach indicate that combined measurements of serum free and total insulin and C-peptide provide information that is helpful in understanding the contribution of endogenous and exogenous insulin to the course and metabolic control of insulin-requiring diabetic patients.
在有循环胰岛素抗体的胰岛素治疗糖尿病患者中，通过在酸化前后添加聚乙二醇（PEG）来测量游离胰岛素、总胰岛素以及总C肽免疫反应性（C肽和胰岛素原）和C肽的血清水平。PEG导致血清中的胰岛素抗体完全沉淀，从而能够测量上清液中的游离胰岛素。在添加PEG之前将血清在37℃孵育两小时，得到的游离胰岛素值可能最接近体内水平。同样的方法也可用于去除与循环胰岛素抗体结合的胰岛素原，并允许测量上清液中的C肽。使用这种方法的临床研究表明，联合测量血清游离胰岛素、总胰岛素和C肽可提供有助于理解内源性和外源性胰岛素对需要胰岛素治疗的糖尿病患者病程和代谢控制的贡献的信息。
