Introduction Macro aspartate aminotransferase (macro-AST) has rarely reported as benign cause for increased plasma AST activities (ASAT). Highly specialized chromatography or electrophoresis were proposed for diagnosing macro-AST. We aimed to present a easy method for macro-AST.

Case Report We report here three cases of 18-month-old and 11-year-old two girls and 5-year-old boy with an isolated chronic asymptomatic elevation of the plasma ASAT. Our patients had no relevant past medical history and no family history of liver pathologies. They have high AST levels respectively 64 IU/L(0–40), 123 IU/L, 75 IU/L. They did not have hepatomegaly or splenomegaly. Several and regular controls of the liver function tests confirmed the asymptomatic isolated elevation of ASAT with values varying between 50 and 120 IU/L. The viral serologies for hepatitis were always unremarkeble. ASMA, LKM, ceruloplasmine, anti-gliadin antibodies, TSH, FT4, alpha-1 antitripsin and abdominal sonographic imaging were normal. We took blood two tubes of 1 ml of blood samples from each patients and from 3 healthy controls. We studied AST levels of one tubes and other tubes were studied after 6 days of refrigerated storage (4° C). We reported 1–3% of loss of AST activity in our patients and 30–35% of loss of AST activity in control group (Table 1). As a result very low loss of AST activity of our patients supported that our patients have macro AST.

• Download figure
• Open in new tab
• Download powerpoint

Abstract 700 Table 1

Conclusion Physicians should be aware of macro-AST as a cause of plasma AST activity elevations. Several laboratory techniques were proposed for diagnosing macro-AST. Some require highly specialized chromatography or electrophoresis. Other have more simple prosedures based on immunoprecipitation of macroenzymes by polyethyleneglycol. There was a simple method as we reported in our three patients.