Aim

To assess predictors of alanine aminotransferase (ALT) elevation in methotrexate (MTX) treated rheumatoid arthritis (RA) patients, and to describe the monitoring of liver enzymes, including handling and outcome of elevated ALT.

Methods

All RA patients starting MTX in January, 2005 to April, 2013 at a rheumatology clinic, (Uppsala University Hospital, Sweden) were identified from electronic medical records. Clinical and laboratory data were obtained from medical records, supplemented by telephone interviews. Predictors for ALT >1.5× over the upper limit of normal (ULN) were identified by multiple regression analysis.

Results

The study comprised 213 RA patients starting MTX. During a mean follow‐up of 4.3 years, 6288 ALT tests were performed; 7% of tests with ALT were >ULN. ALT >1.5× ULN was observed in 44 (21%) patients and the strongest predictor was a pre‐treatment elevation of ALT (adjusted odds ratio = 6.8, 95% CI 2.2‐20.5). Recurrent elevations occurred in 70% of patients who continued treatment, and the proportion was similar in those with and without interventions, for example MTX dose reduction (67% vs 73%, P = 0.43). Seven patients (3%) permanently stopped MTX due to ALT elevation, and two were eventually diagnosed with non‐alcoholic fatty liver disease. No patient developed hepatic failure.

Conclusion

Only a small number of ALT tests performed during MTX therapy in RA capture an elevation. A pre‐treatment elevation of ALT was the strongest predictor for early and recurrent ALT elevations during therapy. This study supports a more individualized approach to monitoring and handling of ALT elevations during MTX therapy in RA than recommended in current guidelines.