Comparison of noninvasive screening tools for hepatic fibrosis, association with methotrexate cumulative dose, and risk factors in psoriasis patients.

Methotrexate (MTX) is a first-line systemic psoriasis therapy with risk of liver fibrosis. Noninvasive tools for liver fibrosis screening are Fibroscan®, Fibrosis-4 (FIB-4) index, and aspartate aminotransferase-to-platelet ratio (APRI) index. To compare Fibroscan®, FIB-4, and APRI in detecting fibrosis, determine association of fibrosis with MTX cumulative dose, and explore risk factors for fibrosis. A case-control study involving psoriasis patients aged ≥18 years with MTX cumulative dose ≥1 g, with age and sex-matched MTX naïve psoriasis patients was performed. Noninvasive tools were used to assess liver fibrosis. Sixty-one patients on MTX and 54 controls participated. Fibroscan® detected fibrosis in 22 (36.1%) patients on MTX compared to 11 (19.6%) controls (p = 0.05). FIB-4 predicted fibrosis in 13 (21.3%) patients on MTX and in 10 (17.9%) controls (p = 0.64) while APRI diagnosed 7 (11.5%) versus 7 (12.5%), p = 0.65. No significant correlation between Fibroscan® assessed liver stiffness and MTX cumulative dose (p = 0.47). Independent risk factors for liver fibrosis were MTX use with raised alanine aminotransferase (OR = 68.56, 95% CI 8.26; 568.86, p < 0.001), diabetes mellitus (OR = 30.35, 95% CI 7.52; 122.42, p < 0.001), and raised BMI (obese patients OR = 8.26, 95% CI 1.73-39.43, p = 0.02; overweight patients OR = 6.29, 95% CI 1.28-30.99, p = 0.01). Liver fibrosis occurred in both MTX naïve and MTX-treated psoriasis patients. Fibroscan® detected higher prevalence of liver fibrosis compared to FIB-4 and APRI. Cumulative MTX does not correlate with fibrosis severity. Fibroscan® is recommended prior to MTX therapy and at regular intervals especially among patients with diabetes and increased BMI.