van Wijk Xander M R, Magee Catherine A, Wu Alan H B, Tana Michele M, Lynch Kara L
Department of Laboratory Medicine, University of California, San Francisco, Zuckerberg San Francisco General, San Francisco, CA, USA.
San Francisco Department of Public Health, Zuckerberg San Francisco General, San Francisco, CA, USA.
Clin Chim Acta. 2016 Dec 1;463:1-3. doi: 10.1016/j.cca.2016.10.011. Epub 2016 Oct 11.
Macro-aspartate aminotransferase (macroAST) is a high molecular weight form of AST that is usually formed through association with immunoglobulin (Ig) in the circulation. As a result of reduced inactivation, clearance or excretion, AST values are persistently increased. This can lead to problems interpreting these values and diagnosing the patient, especially if clinicians are not aware of this phenomenon.
For a case of suspected macroAST, we compared three simple methods: polyethylene glycol precipitation, ultrafiltration, and Ig depletion using protein A and G.
All three methods were consistent with a diagnosis of macroAST.
The protein A and G method was straightforward and provided unambiguous results. However, given the affinity of protein A and protein G, it likely only detects AST-IgG macrocomplexes.
巨天冬氨酸转氨酶（macroAST）是天冬氨酸转氨酶的一种高分子量形式，通常通过在循环中与免疫球蛋白（Ig）结合形成。由于灭活、清除或排泄减少，天冬氨酸转氨酶值持续升高。这可能导致解读这些值和诊断患者出现问题，尤其是当临床医生不了解这种现象时。
对于一例疑似macroAST的病例，我们比较了三种简单方法：聚乙二醇沉淀法、超滤法以及使用蛋白A和G的Ig去除法。
所有三种方法均与macroAST的诊断一致。
蛋白A和G法操作简单且结果明确。然而，鉴于蛋白A和蛋白G的亲和力，它可能仅检测到AST-IgG巨复合物。
