Korean J Gastroenterol.  2001 Aug;38(2):124-127.

A Case of Isolated Aspartate Aminotransferase Elevation Due to Macroenzyme Formation with Immunoglobulin M

• Lee CK
• Kim MH
• Kim BH
• Suh JT
• Han YS
• Lee DK
• Dong SH
• Kim HJ
• Chang YW
• Lee JI
• Chang R

Abstract

Aspartate aminotransferase (AST) has rarely been reported to complex with immunoglobulins, resulting in an elevation in AST level. Thus, this condition should be considered in patients with asymptomatic isolated elevation of AST to avoid the misinterpretation of the test result and unnecessary diagnostic procedures. We experienced a case of isolated and persistent elevation of serum AST without other abnormal laboratory findings in a 26-year-old healthy woman. In spite of extensive investigation including liver biopsy, no definite cause for the abnormality could be discovered. Using the polyethylene glycol precipitation test, the PAGE test, and the immunoglobulin precipitation test, we identified the IgM-AST complex formation responsible for the elevation of serum AST. Clinically, the awareness and detection of this macroenzyme formation can obviate unnecessary diagnostic workup.

Keyword

Macroenzyme; Macro - AST; IgM - AST complex

MeSH Terms

Adult
Aspartate Aminotransferases*
Aspartic Acid*
Biopsy
Female
Humans
Immunoglobulin M*
Immunoglobulins*
Liver
Polyethylene Glycols
Aspartate Aminotransferases
Aspartic Acid
Immunoglobulin M
Immunoglobulins
Polyethylene Glycols