Usefulness of noninvasive diagnostic procedures for assessment of methotrexate hepatotoxicity in patients with rheumatoid arthritis.

Methotrexate (MTX) is recommended as a first-line treatment for rheumatoid arthritis (RA). There are no strict guidelines regarding monitoring for liver damage in RA patients. This study aimed to evaluate noninvasive diagnostic procedures in assessing liver fibrosis in RA patients. Ninety-six RA patients were recruited for this study. The procollagen III N-terminal peptide (PIIINP) serum level was measured in all patients. The Enhanced Liver Fibrosis score (ELF-1) was calculated for 82 patients. Transient elastography (TE) was performed in 91 patients, those examined were divided into two groups: a study and control group, comprising patients with and without risk factors for liver fibrosis, respectively. The TE result correlated only with the body mass index-BMI (p < 0.05); there was no correlation with the cumulative MTX dose (p = 0.33). The TE result was significantly higher in those with risk factors for liver fibrosis than in those without risk factors (TE result >  = 7.1 kPa 28/42 vs 13/41, HR = 2.103, Mann-Whitney U test, approximately 0.02). There was a positive correlation between the PIIINP level and body weight (p = 0.028), cumulative MTX dose (p = 0.007), RA activity (p = 0.028) and diabetes mellitus (DM) (p = 0.001). There was a positive correlation between the ELF-1 score and age (p < 0.001), cumulative MTX dose (p = 0.007) and RA activity (p < 0.001). The PIIINP level and ELF-1 score are not organ specific, and readings may vary depending on RA activity. TE is organ specific and can be performed by a skilled ultrasonographer might be useful to assess actual liver condition.