Collins John, Ritter Detlef, Bacon Bruce R, Landt Michael, Creer Michael H
Departments of Pathology and Laboratory Medicine, Saint Louis University School of Medicine, St Louis, MO 63110, USA.
Liver. 2002 Dec;22(6):501-6. doi: 10.1034/j.1600-0676.2002.01689.x.
Persistent elevation of aspartate aminotransferase (AST) activity in serum due to the presence of a macroenzyme form of AST (macro-AST) may lead to diagnostic confusion in many clinical conditions, particularly those associated with chronic liver disease. We describe a case of macro-AST arising in an adult female with a false-positive hepatitis C virus (HCV) RNA test result that was not accompanied by other biochemical or histologic evidence of liver disease. The presence of macro-AST in serum was confirmed utilizing size-exclusion, high performance liquid chromatography (HPLC) and Protein G-agarose beads to precipitate immune complexes of AST and immunoglobulin G followed by centrifugation and AST activity measurements in the supernatant. A brief review of the clinical enzymology of AST and methods used to quantify serum macro-AST activity is provided.
由于天冬氨酸氨基转移酶（AST）的巨酶形式（macro-AST）导致血清中AST活性持续升高，在许多临床情况下可能会导致诊断混淆，尤其是与慢性肝病相关的情况。我们描述了一例发生在成年女性中的macro-AST病例，该病例丙型肝炎病毒（HCV）RNA检测结果呈假阳性，且未伴有其他肝病的生化或组织学证据。利用尺寸排阻、高效液相色谱（HPLC）和蛋白G琼脂糖珠沉淀AST和免疫球蛋白G的免疫复合物，随后离心并测量上清液中的AST活性，从而证实了血清中存在macro-AST。本文简要回顾了AST的临床酶学以及用于定量血清macro-AST活性的方法。
