Clinical features and immune mechanisms directly linked to the altered liver function in patients with rheumatoid arthritis

BACKGROUND

The aim of this study was to explore the impact of arthritis on liver function using different approaches in vivo and in vitro.

METHODS

A cross-sectional study was performed on 330 non-obese/non-T2DM subjects: 180 RA patients, 50 NAFLD non-RA patients, and 100 healthy donors (HDs). A longitudinal study was conducted on 50 RA patients treated with methotrexate for six months. Clinical and laboratory parameters and markers of liver disease were collected. Mechanistic studies were carried out in both the CIA mouse model and hepatocytes treated with anti-citrullinated protein antibodies (ACPAs).

RESULTS

RA patients have an increased risk of suffering from liver disease independent of obesity or T2DM. This risk was associated with factors such as insulin resistance, autoantibodies, inflammation, and component C3. Methotrexate treatment for six months was associated with liver abnormalities in those newly-diagnosed patients having CV risk factors. ACPAs induced a defective hepatocyte function, promoting IR and inflammation. The induction of arthritis in mice caused the infiltration of immune cells in the liver and increased inflammatory, apoptotic, and fibrotic processes.

CONCLUSION

RA patients may experience mild to moderate liver inflammation due to the infiltration of T, B cells, and macrophages, and the action of ACPAs. This is independent of obesity or diabetes and linked to systemic inflammation, and disease activity levels. The negative effects of methotrexate on liver function could be restricted to the concomitant presence of cardiovascular risk factors.

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.

Diagnostic potential of NETosis-derived products for disease activity, atherosclerosis and therapeutic effectiveness in Rheumatoid Arthritis patients

OBJECTIVES

1) To assess the association of NETosis and NETosis-derived products with the activity of the disease and the development of cardiovascular disease in RA; 2) To evaluate the involvement of NETosis on the effects of biologic therapies such as anti-TNF alpha (Infliximab) and anti-IL6R drugs (Tocilizumab).

METHODS

One hundred and six RA patients and 40 healthy donors were evaluated for the occurrence of NETosis. Carotid-intimae media thickness was analyzed as early atherosclerosis marker. Inflammatory and oxidative stress mediators were quantified in plasma and neutrophils. Two additional cohorts of 75 RA patients, treated either with Infliximab (n = 55) or Tocilizumab (n = 20) for six months, were evaluated.

RESULTS

NETosis was found increased in RA patients, beside myeloperoxidase and neutrophil elastase protein levels. Cell-free nucleosomes plasma levels were elevated, and strongly correlated with the activity of the disease and the positivity for autoantibodies, alongside inflammatory and oxidative profiles in plasma and neutrophils. Moreover, ROC analyses showed that cell-free nucleosomes levels could identify RA patients showing early atherosclerosis with high specificity. RA patients treated either with IFX or TCZ for six months exhibited decreased generation of NETs. Concomitantly, clinical parameters and serum markers of inflammation were found reduced. Mechanistic in vitro analyses showed that inhibition of NETs extrusion by either DNase, IFX or TCZ, further abridged the endothelial dysfunction and the activation of immune cells, thus influencing the global activity of the vascular system.

CONCLUSIONS

NETosis-derived products may have diagnostic potential for disease activity and atherosclerosis, as well as for the assessment of therapeutic effectiveness in RA.