Studies evaluating xanthine oxidoreductase (XOR) activities in comprehensive liver diseases are scarce, and different etiologies have previously been combined in groups for comparison. To accurately evaluate XOR activities in liver diseases, the plasma XOR activities in etiology-based comprehensive liver diseases were measured using a novel, sensitive, and accurate assay that is a combination of liquid chromatography and triple quadrupole mass spectrometry to detect [¹³C₂, ¹⁵N₂]uric acid using [¹³C₂, ¹⁵N₂]xanthine as a substrate. We also mainly evaluated the association between the plasma XOR activities and parameters of liver tests, purine metabolism-associated markers, oxidative stress markers, and an inflammation marker. In total, 329 patients and 32 controls were enrolled in our study. Plasma XOR activities were generally increased in liver diseases, especially in the active phase, such as in patients with hepatitis C virus RNA positivity, those with abnormal alanine transaminase (ALT) levels in autoimmune liver diseases, and uncured hepatocellular carcinoma patients. Plasma XOR activities were numerically highest in patients with acute hepatitis B. Plasma XOR activities were closely correlated with parameters of liver tests, especially serum ALT levels, regardless of etiology and plasma xanthine levels. Our results indicated that plasma XOR activity might reflect the active phase in various liver diseases.

A 44-year-old woman with multiple sclerosis (MS) receiving interferon (IFN)-beta-1a treatment was admitted to a local hospital for severe icterus and liver injury. She was transferred to our university hospital because fulminant hepatitis (FH) was suspected. She was diagnosed with acute-type FH based on hepatic coma, severe liver injury and liver failure, and she received plasma exchange and continuous hemodiafiltration therapy. On hospital day 6, she died from liver failure despite intensive care. An autopsy revealed histological findings consistent with FH. Physicians should monitor the hepatic function of MS patients receiving IFN-beta-1a treatment, as serious events can occur in rare cases.