MTX Doubles Hepatotoxicity Risk in Psoriasis Patients Save

A study from the University of Pennsylvania Perelman School of Medicine was published in the Journal of Investigative Dermatology showing that the risk of incident liver disease doubled when patients with psoriasis (PsO) or psoriatic arthritis (PsA) take methotrexate (MTX), but not when MTX is used in rheumatoid arthritis. (Citation source https://buff.ly/2i9qizC)

This was a comparative cohort study of patients with psoriasis (N=197,130), PsA (N=12,308), RA (N=54,251), and matched controls (N=1,279,754). Researchers calculated the adjusted hazard ratios for any liver disease in these patients with or without systemic therapy (ST).  Liver disease was defined as any liver disease, non-alcoholic fatty liver disease (NAFLD), and cirrhosis (any etiology).

 Overall, 6% of psoriasis patients were prescribed systemic therapy, as were 53% of people with psoriatic arthritis and 61% of people with rheumatoid arthritis. MTX was the most commonly prescribed ST. 

The Liver Disease Hazard ratios were: 

Incident NAFLD was highest in patients with PsO prescribed a ST (2.23) and PsA with ST (2.11). Risk of cirrhosis was highest among patients with PsO with an ST (2.62) and PsA without a ST (3.15).

Increasing body surface area in PsO further increased the prevalence of liver disease and cirrhosis (p for trend <0.001).

More so than RA, PsO and PsA are associated with liver disease, particularly NAFLD and cirrhosis, and this was true even among patients without systemic therapy exposure.

Compared to people without chronic inflammatory diseases, people with psoriasis were 37% more likely to develop liver disorders. When psoriasis patients took methotrexate, they had roughly twice  (67%) the odds of liver damage.  For rheumatoid arthritis, there was no increased risk of liver disease when people took methotrexate, but when they didn’t they had 49% higher odds of liver damage.

There was no data on deaths from liver disease in this study