Prevalence of Aminotransferase Macroenzymes in Rheumatoid Arthritis Patients and Impact on Their Management

INTRODUCTION: Rheumatoid arthritis (RA) treatment can be hepatotoxic, but liver enzymes can be falsely elevated due to macroenzyme presence. Macroenzymes are often found in autoimmune diseases, but prevalence and effect on treatment is unclear. This study aimed to determine aminotransferase macroenzyme prevalence and effect in RA patients. MATERIALS AND METHODS: This study included consecutive RA patients without liver disease sent for laboratory tests. Samples with elevated AST or ALT were processed for macroenzymes. Presence was determined using polyethylene glycol precipitation (PEG). RESULTS: Out of 126 patients, 21 had elevated aminotransferase levels. Due to liver disease, 6 patients were excluded, another 3 were unavailable for informed consent, leaving 12 patients for inclusion. Out of 12 patients, 1 had increased AST levels, 2 increased ALT levels, and 9 both. Macro-ALT was detected in 5/11 patients, 1 also had macro-AST. Out of 5 patients with macroenzymes, treatment change was seen in 3/5 patients, imaging in 2/5, both in 2/5. CONCLUSION: Elevated liver enzymes in RA patients is not always indicative of hepatotoxicity, as shown by the fact that about half of patients in our study had macroenzymes detected. Before assuming drug hepatotoxicity and changing treatment or ordering imaging, rheumatologists could consider macroenzyme presence.