BACKGROUND Macro-aspartate aminotransferase(AST), a macroenzyme, is a high-molecular mass complex formed by self-polymerization or association with other serum components that are difficult for the kidney to clear, le...BACKGROUND Macro-aspartate aminotransferase(AST), a macroenzyme, is a high-molecular mass complex formed by self-polymerization or association with other serum components that are difficult for the kidney to clear, leading to the isolated elevation of serum AST activity. Cases of macro-AST formation are rare, with only 3 published in the English language literature up to September 2019 in China. In this paper, we present a case in which an asymptomatic woman with persistent isolated elevated AST was confirmed as having macro-AST by the polyethylene glycol precipitation method.CASE SUMMARY A 34-year-old woman was referred to our clinic for elevated AST levels with normal levels of other liver-associated enzymes on November 12, 2018. Her AST level of liver function test had been abnormal for 7 mo before she came to the clinic. The patient was asymptomatic with a normal physical examination. There was no relevant family history and no alcohol consumption or smoking. She had a several-month history of traditional Chinese medical taking and had stopped it 1 year prior. The laboratory tests in our clinic showed only the elevation of AST(89.5 U/L) with no other significant abnormalities. We performed the precipitation technique with polyethylene glycol to confirm the presence of macro-AST. Then for almost a year, her AST level still fluctuated in the abnormal range.CONCLUSION This case highlights that clinical physicians should be familiar with this rare condition of persistent isolated AST elevation due to the presence of macro-AST to avoid unnecessary investigation and patient anxiety.展开更多
文摘BACKGROUND Macro-aspartate aminotransferase(AST), a macroenzyme, is a high-molecular mass complex formed by self-polymerization or association with other serum components that are difficult for the kidney to clear, leading to the isolated elevation of serum AST activity. Cases of macro-AST formation are rare, with only 3 published in the English language literature up to September 2019 in China. In this paper, we present a case in which an asymptomatic woman with persistent isolated elevated AST was confirmed as having macro-AST by the polyethylene glycol precipitation method.CASE SUMMARY A 34-year-old woman was referred to our clinic for elevated AST levels with normal levels of other liver-associated enzymes on November 12, 2018. Her AST level of liver function test had been abnormal for 7 mo before she came to the clinic. The patient was asymptomatic with a normal physical examination. There was no relevant family history and no alcohol consumption or smoking. She had a several-month history of traditional Chinese medical taking and had stopped it 1 year prior. The laboratory tests in our clinic showed only the elevation of AST(89.5 U/L) with no other significant abnormalities. We performed the precipitation technique with polyethylene glycol to confirm the presence of macro-AST. Then for almost a year, her AST level still fluctuated in the abnormal range.CONCLUSION This case highlights that clinical physicians should be familiar with this rare condition of persistent isolated AST elevation due to the presence of macro-AST to avoid unnecessary investigation and patient anxiety.
