Methotrexate (MTX) is often the primary medication to treat various rheumatic diseases (RDs) because of its low cost and its demonstrated efficacy in controlling disease activity. However, a concern has been the potential for hepatic fibrosis associated with long-term MTX usage. This study investigated the association between cumulative MTX intake and development of liver fibrosis by utilizing noninvasive transient elastography (FibroScan).

All patients with inflammatory arthritis treated with MTX were offered screening with FibroScan. A certified technician measured liver stiffness after patients adhered to a fast. Relevant clinical information was obtained by patient survey and medical records review. The population was divided into quartiles based on participants' cumulative dosage of MTX.

Five hundred twenty patients with RD were included in this study. The prevalence of stages F3 or F4 liver fibrosis was 13.3% in the control group and 12.7% in the entire sample. Compared with subgroup 1 (control with cumulative MTX exposure of ≤ 499 mg), MTX subgroups 2 to 4 were not significantly correlated with higher FibroScan scores ( = 0.82, 0.59, and 0.18, respectively). In multivariable linear regression analysis, statistically significant factors for liver stiffness were BMI, waist circumference, male sex, and age.

No significant correlation between the cumulative MTX dosage and liver stiffness, even at high MTX doses, was observed. The analyses showed significant correlations between the FibroScan score and BMI. These findings were reassuring in that current rheumatology practice appears to be safe and effective in screening for liver fibrosis in patients on long-term low-dose MTX therapy.