Review Examines Interaction Between 2 Distinct Liver Diseases

A recent study reviewed the interaction between autoimmune hepatitis (AIH) and metabolic-associated fatty liver disease (MAFLD), which affects about 25% of people worldwide.

Both conditions may coexist and may react to each other in a synergistic fashion, impacting both progression and response to therapies. One challenge in diagnosing the 2 liver conditions is that there is no specific biomarker, either for the diseases alone or together.

The authors said the prevalence of MAFLD among patients with AIH is unknown, but that estimates range from 17% to 30%. Even less is known about the prevalence of AIH in MAFLD, and in both of the available studies available for analysis, the number of patients with a confirmed diagnosis of AIH after a liver biopsy fell.

The higher prevalence of coexistent MAFLD/AIH in patients with AIH can be explained by the higher prevalence of MAFLD overall as compared with the generally lower prevalence of AIH, they said.

MAFLD appears to have an effect on AIH. A small retrospective US study showed that patients with MAFLD/AIH were more likely to have cirrhosis and had worse clinical outcomes when compared with patients with AIH alone. Having both conditions was linked to a relative risk for liver-related mortality of 7.65 in patients with MAFLD/AIH and 2.55 for liver-related adverse outcomes compared with AIH alone. Worse outcomes were also seen with both conditions in larger studies conducted in the United States and Japan.

There is a lack of data about treatment when the 2 conditions are present, the authors said. In one of the aforementioned studies, patients with MAFLD and AIH were significantly more likely to receive ursodeoxycholic acid, while they were less likely to receive prednisolone, compared with AIH alone.

While the presence of autoantibodies are required to diagnose AIH, their effect on MAFLD is unclear. Patients with MAFLD have been reported to have a higher presence of autoantibodies than the general population, but the clinical significance of that is not know. The authors said the while the topic needs more research, “the available evidence suggests that patients with MAFLD/AIH have differential natural history, with potential bidirectional synergistic interaction between both conditions.”

In addition, more studies are needed to understand “the shared genetic basis between AIH and MAFLD.” One study in AIH has shown that PNPLA3-rs738409 variant GG, a strong risk variant for MAFLD, is a strong predictor for time to liver transplantation or death. The same study showed that TM6SF2-rs58542926 was linked with steatosis in AIH patients, but not with fibrosis progression.

Treatment requires a multidisciplinary approach tailored to each patient and may involve corticosteroids, prednisolone, budesonide, and immunosupressive agents, the authors said. Therapy must also include dietary changes, weight loss, exercise, and abstaining from alcohol.

Reference

Metabolic-associated fatty liver disease and autoimmune hepatitis: An overlooked interaction. Gabera Y, AbdAllah M, Salamac A, Sayedd M, Alem SA, Nafadyc S. Expert Rev Gastroenterol Hepatol. Published online July 15, 2021. doi: 10.1080/17474124.2021.1952867