Unexplained High Activity of Aspartate Aminotransferase in an Asymptomatic Pediatric Patient

• Main Authors: Wajiha Maan, Qurratul Ann Warsi, Avideh Rashed, Manoochehr Karjoo
• Format: Article
• Language: English
• Published: Mashhad University of Medical Sciences 2017-10-01
• Series: International Journal of Pediatrics
• Subjects: Alanine; alkaline phosphatase; Aspartate Aminotransferase; Child; macro-enzymes
• Online Access: http://ijp.mums.ac.ir/article_9103_42dae51d73b54ac65687fc741da5a03f.pdf

Elevated enzyme activities in plasma may at times be attributed to the presence of macro-enzymes. The macro-enzymes are often serum enzymes in complex with immunoglobulins, resulting in a greater molecular mass that cannot be filtered by renal glomeruli and are, hence, retained in the plasma. The aspartate aminotransferase (AST) can exist as a macro-enzyme, although it has been rarely reported. We describe a pediatric patient with persistently elevated serum AST activity, due to macro-enzyme formation between AST and an immunoglobulin. This is to highlight the importance of early diagnosis of macro-AST in an otherwise asymptomatic pediatric patient with isolated AST-elevation and to avoid unnecessary costly testing.