Methotrexate therapy is not associated with increased liver stiffness and significant liver fibrosis in rheumatoid arthritis patients: A cross-sectional controlled study with real-time two-dimensional shear wave elastography.

OBJECTIVE

To explore the significance of the association between treatment with methotrexate (MTX) and liver stiffness in rheumatoid arthritis (RA) patients.

METHODS

We enrolled 140 consecutive RA patients under MTX treatment (MTX-treated RA; mean treatment duration: 6.2 years; mean MTX cumulative dose: 4.67 g), 33 RA patients naive to MTX (MTX-naive RA) and 100 age and sex-matched healthy blood donors (HD). Liver stiffness was assessed by real time two-dimensional shear wave elastography, with values ≥7.1 Kilopascals (kPa) defining significant liver fibrosis.

RESULTS

kPa values in HD (4.32 ± 0.7) were lower than that in MTX-naive RA (4.92 ± 0.8) and MTX-treated RA (4.85 ± 0.9, p < .0005 for trend). On the contrary, the difference in kPa between MTX-naive and MTX-treated RA was not significant (p = .89). Similarly, liver stiffness was not significantly different across strata of cumulative MTX dose (4.95 ± 0.7 kPa in MTX <1 g, 4.90 ± 1.1 kPa in MTX 1-3 g and 4.80 ± 0.9 in MTX >3 g, p = .610). Significant liver fibrosis was diagnosed in 4 patients in the MTX-treated RA (highest kPa value = 7.6; no liver function test abnormalities or clinical signs of hepatic failure) and in none in both the MTX-naive RA and HD groups (p = .145).

CONCLUSION

Liver stiffness values, although within the normal range, are significantly higher in RA patients vs. controls, irrespective of MTX treatment. RA patients taking MTX do not have a higher prevalence of significant liver fibrosis when compared to MTX naive RA patients and the general population.