AIH linked to higher lymphoma, myeloma risks, but not to extrahepatic malignancy

Patients with autoimmune hepatitis (AIH) do not show an increased risk of overall extrahepatic malignancy compared with controls, but they appear to be at greater risk of lymphoma or myeloma, independent of immunosuppressant use, suggests a study.

A team of investigators used claims data from the Korean National Health Insurance Service database to pair patients diagnosed with AIH between 2007 and 2019 (n=7,382) in a 1:8 ratio with an age- and sex-matched control population (n=58,320).

The incidence rates and hazard ratios (HRs) of overall and specific extrahepatic malignancies were compared between the two groups. The impact of using immunosuppressants was also examined.

In total, 3,713 extrahepatic malignancies developed over a median follow-up of 5.2 years. Patients with AIH had a similar incidence rate of extrahepatic malignancy to matched controls (990.8 vs 937.6 cases per 100,000 person-years; HR, 0.93, 95 percent confidence interval [CI], 0.81–1.007; p=0.30).

However, the risk of hematologic malignancies, particularly lymphoma or myeloma (HR, 2.66, 95 percent CI, 1.70–4.17; p<0.001), was significantly higher among patients with AIH.  Notably, the use of glucocorticoids (HR, 0.74, 95 percent CI, 0.31–1.75; p=0.50) or azathioprine (HR, 2.12, 95 percent CI, 0.90–5.02; p=0.09) did not affect the risk of lymphoma or myeloma in this cohort.