[Clinical, biochemical and epidemiological features of macro-AST preceding inflammatory bowel disease diagnosis by several years]

INTRODUCTION

An isolated elevation of aspartate aminotransferase (AST) is a diagnostic issue. Macro-aspartate aminotransferase (macro-AST) corresponds to the formation of complexes between AST and immunoglobulins.

CASE REPORT

We report the case of a patient with macro-AST identified several years before the onset of inflammatory bowel disease (IBD). A 6-year retrospective analysis in our laboratory identified only one case out of 42 540 adult patients.

CONCLUSION

The objective of this work is to increase awareness of this benign disorder among clinicians and biologists, as well as to aid in prescribing only the required tests.

[Macro-AST and myeloma: An incidental association?]

INTRODUCTION

Macro-AST is recognized as a classical aetiology of isolated and persistent increase of serum aspartate aminotransferase (AST) levels. Macro-AST are high molecular weight complexes associating AST and a macromolecule, often an immunoglobulin. Although those macroenzymes of unknown pathogenesis are usually non-pathogenic, association with several diseases, including autoimmune diseases and liver diseases has been described.

CASE REPORT

We report here the case of a 45-year-old patient with previously normal liver enzymes in whom an AST elevation and an IgA monoclonal gammopathy were discovered concomitantly. Following the diagnosis of multiple myeloma, we could evidence in the patient's serum a complex between AST and the monoclonal IgA. AST levels course followed closely the progression of monoclonal gammopathy.

CONCLUSION

This is the first report demonstrating a clear link between macro-AST and a monoclonal gammopathy.