Ultrasound ARFI Shows No Increased Liver Fibrosis Risk in RA Patients on Methotrexate

This longitudinal study aimed to assess liver stiffness in patients with rheumatoid arthritis (RA) who were receiving methotrexate (MTX) monotherapy using non-invasive, ultrasound-based elastography, specifically Acoustic Radiation Force Impulse (ARFI) imaging. A total of 23 MTX-naive patients were included, with baseline evaluations carried out between July 2018 and April 2019, and follow-up measurements taken after an average of 2.6 years. The primary outcome was the mean shear wave velocity, which was measured using ARFI from 10 valid readings per patient. The study’s findings revealed that liver stiffness, as determined by ARFI, did not increase over the follow-up period. In fact, the mean shear wave velocity decreased from 1.07 m/s (SD = 0.23) at baseline to 0.97 m/s (SD = 0.16) at follow-up, a statistically significant difference (P = 0.013). Additionally, the changes in liver stiffness could not be predicted by factors such as inflammation markers, disease activity, BMI, age, sex, or the use of non-steroidal anti-inflammatory drugs (NSAIDs), as regression analysis showed no significant predictors (corrected R² = 0.344; P = 0.296). These results suggest that MTX monotherapy does not increase the risk of liver fibrosis over time in RA patients. The study supports the use of ARFI as a reliable, non-invasive tool for assessing liver stiffness and highlights that long-term MTX use does not adversely affect liver health, contradicting previous concerns about potential liver damage. This research provides valuable insights for clinicians monitoring RA patients under MTX treatment, demonstrating the importance of using non-invasive techniques to ensure liver health in this population.