Decoding clinical and molecular pathways of liver dysfunction in Psoriatic Arthritis: Impact of cumulative methotrexate doses.

Background: The occurrence of liver abnormalities in Psoriatic Arthritis (PsA) has gained significant recognition. Identifying key factors at the clinical and molecular level can help to detect high-risk patients for non-alcoholic fatty liver disease in PsA.

Objectives: to investigate the influence of PsA and cumulative doses of methotrexate on liver function through comprehensive in vivo and in vitro investigations.

Methods: A cross-sectional study involving 387 subjects was conducted, 200 patients with PsA, 87 NAFLD-non-PsA patients, and 100 healthy donors (HDs), age and sex-matched. Additionally, a retrospective longitudinal study was carried out, including 83 PsA patients since initiation with methotrexate. Detailed clinical, and laboratory parameters along with liver disease risk were analyzed. In vitro, experiments with hepatocyte cell line (HEPG2) were conducted.

Results: PsA patients present increased liver disease risk associated with the presence of cardiometabolic comorbidities, inflammatory markers, onychopathy, and psoriasis. The treatment with PsA serum on hepatocytes encompassed inflammatory, fibrotic, cell stress, and apoptotic processes. At the molecular level, methotrexate impacts liver biology, although the cumulative doses did not affect those alterations, causing any potential damage to liver function at the clinical level. Finally, anti-PDE-4 or anti-JAK decreased the inflammatory profile induced by PsA serum on hepatocytes.

Conclusion: 1)This study identifies the complex link between liver disease risk, comorbidities, and disease-specific features in PsA patients. 2)Methotrexate dose in PsA patients had no significant effect on liver parameters, confirmed by hepatocyte in vitro studies. 3)Anti-PDE-4 and anti-JAK therapies show promise in reducing PsA serum-induced hepatocyte activation, potentially aiding liver complication management.