Switzer S
J Clin Invest. 1967 Nov;46(11):1855-66. doi: 10.1172/JCI105676.
Sera from patients with extrahepatic biliary obstruction were found to have an abnormal lipoprotein (obstructive lipoprotein) which failed to react with antibodies to normal lipoproteins of d < 1.063. Preparations of this abnormal lipoprotein made by a combination of immunoprecipitation and multiple polyanion precipitations revealed a high content of free cholesterol (26%) and phospholipids (61%) but only trace amounts of cholesterol esters and triglycerides. Protein content varied from 13% to a corrected low of 5% when ultracentrifugation was also performed. Amino acid analyses of the latter preparations resembled that of lipoproteins of d < 1.006. The reasons underlying the apparent unreactivity of the abnormal lipoprotein were explored. No evidence could be found for soluble antigen-antibody complexes of gamma-globulin and the abnormal lipoprotein, nor for inhibition of antigen-antibody complex formation by serum factors. Purified preparations of obstructive lipoprotein did not react with antisera to high- or low-density lipoproteins prepared from normal sera. Moreover, rabbits immunized with the abnormal lipoproteins produced specific antibodies to this lipoprotein which reacted with a d < 1.006 lipoprotein in normal sera. All other lipoprotein fractions from normal sera were unreactive. It is not known whether this lipoprotein is abnormal by virtue of the presence of a unique peptide or because of secondary alterations in lipoprotein structure.
研究发现，肝外胆管梗阻患者的血清中存在一种异常脂蛋白（梗阻性脂蛋白），该脂蛋白不能与针对密度小于1.063的正常脂蛋白的抗体发生反应。通过免疫沉淀和多次聚阴离子沉淀相结合制备的这种异常脂蛋白，其游离胆固醇含量较高（26%），磷脂含量也较高（61%），但胆固醇酯和甘油三酯含量仅为微量。当同时进行超速离心时，蛋白质含量在13%至校正后的低至5%之间变化。对后一种制剂的氨基酸分析结果与密度小于1.006的脂蛋白相似。对这种异常脂蛋白明显无反应性的潜在原因进行了探究。未发现γ球蛋白与异常脂蛋白形成可溶性抗原-抗体复合物的证据，也未发现血清因子抑制抗原-抗体复合物形成的证据。纯化的梗阻性脂蛋白制剂不与由正常血清制备的抗高密度或低密度脂蛋白血清发生反应。此外，用异常脂蛋白免疫的兔子产生了针对这种脂蛋白的特异性抗体，该抗体与正常血清中密度小于1.006的脂蛋白发生反应。正常血清中的所有其他脂蛋白组分均无反应。尚不清楚这种脂蛋白是由于存在独特的肽而异常，还是由于脂蛋白结构的继发性改变所致。
