Risk of liver disease in patients with psoriasis, psoriatic arthritis, and rheumatoid arthritis receiving methotrexate: a population-based study.

Abstract Background Patients with psoriatic disease may be more susceptible to methotrexate hepatotoxicity than those with rheumatoid arthritis (RA) but direct evidence is lacking. Objective To compare liver disease risk among patients with psoriasis (PsO), psoriatic arthritis (PsA), and RA receiving methotrexate Methods In a population-based cohort study, Danish individuals with PsO, PsA, or RA receiving methotrexate during 1997-2015 were compared with respect to four outcomes: mild liver disease, moderate-to-severe liver disease, cirrhosis, and cirrhosis-related hospitalization. Results Among 5,687, 6,520, and 28,030 individuals with PsO, PsA, and RA, respectively, the incidence rate of any liver disease was greatest for PsO, followed by PsA, and lowest for RA. Compared to patients with RA, patients with PsO were 1.6-3.4 times more likely to develop one of the liver disease outcomes while those with PsA were 1.3-1.6 times more likely to develop mild liver disease and cirrhosis after adjustment for demographics, smoking, alcohol use, comorbidities, and methotrexate dose. Limitations Confounding by unmeasured variables, misclassification and surveillance bias Conclusion PsO, PsA, and RA differentially influence liver disease risk in the setting of methotrexate use independent of other major risk factors. More conservative monitoring should be considered in patients receiving methotrexate for psoriatic disease, particularly PsO.