Diagnostic performance of transient elastography for detection of methotrexate-induced liver injury using Roenigk classification in Asian patients with psoriasis: a retrospective study

Liver biopsy, the gold standard for monitoring methotrexate-induced liver fibrosis in psoriasis patients, has potential morbidity and mortality. Transient elastography (TE) has been widely used as an alternative non-invasive method. Currently, psoriasis-specific data of TE comparing to Roenigk histopathology is lacking. This retrospective study assessed the diagnostic performance of TE in the detection of methotrexate-induced liver injury and liver fibrosis in Asian psoriasis patients. Risk factors that associated with liver injury by TE and histopathology were also determined. Psoriasis patients who had received methotrexate and undergone both TE and liver biopsy (gold standard) examinations between 2005 and 2016 were enrolled. Ten of 41 patients developed methotrexate-induced liver injury (Roenigk grade ≥3a) and two of them had significant liver fibrosis (Metavir fibrosis stage ≥2). Area under the receiver operating characteristic curve (AUROC = 0.78) indicated that TE was capable of identifying patients with and without liver injury. Using a cut-off TE value of 7.1 kilopascal (kPa), this ultrasound-based elastography yielded 50% sensitivity and 83.9% specificity for detecting methotrexate-induced liver injury and had 50% sensitivity and 76.9% specificity for identifying significant liver fibrosis. A total cumulative dosage of methotrexate, age, gender, metabolic syndrome, and metabolic components were not significantly associated with TE values ≥7.1 kPa and Roenigk grade ≥3a. Thus, using clinical context, laboratory information, and a cut-off TE value of 7.1, TE is an attractable non-invasive tool for identify psoriasis patients who have a low probability of methotrexate-induced liver injury and significant liver fibrosis. Liver biopsy can be reserved for selected patients.