A pilot study of salivary N-glycome in HBV-induced chronic hepatitis,cirrhosis, and hepatocellular carcinoma

Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus (HBV), which can lead to chronic liver disease and put people at high risk of death from cirrhosis of the liver and liver cancer. However, little is known about the correlation of salivary N-linked glycans related to HBV-infected liver diseases. Here we investigated N-linked glycome in saliva from 200 subjects (50 healthy volunteers (HV), 40 HBV-infected patients (HB), 50 cirrhosis patients (HC), and 60 hepatocellular carcinoma patients (HCC) using MALDI-TOF/TOF-MS. Representative MS spectra of N-glycans with signal-to-noise ratios >6 were annotated using the GlycoWorkbench program. A total of 40, 47, 29, and 33 N-glycan peaks were identified and annotated from HV, HB, HC, and HCC groups, respectively. There were 15 N-glycan peaks (e.g., m/z 1647.587, 1688.613 and 2101.755) were present in all groups. Three N-glycan peaks (m/z 2596.925, 2756.962, and 2921.031) were unique in HV group, 2 N-glycan peaks (m/z 1898.676 and 1971.692) were unique in HB group, 5 N-glycan peaks (m/z 1954.677, 2507.914, 2580.930, 2637.952, and 3092.120) were unique in HC group, and 3 N-glycan peaks (m/z 2240.830, 2507.914, and 3931.338) were unique in HCC group. The proportion of fucosylated N-glycans was apparently increased in the HCC group (84.8%) than in any other group (73.1% ± 0.01), however, the proportion of sialylated N-glycans was decreased in HCC group (12.1%) than in any other group (17.23% ± 0.003). Our data provide pivotal information to distinguish between HBV-associated hepatitis, cirrhosis and HCC, and facilitate the discovery of biomarkers for HCC during its early stages based on precise alterations of N-linked glycans in saliva.