Altered serum N-glycomics in chronic hepatitis B patients

Background We previously reported on serum N-glycans as markers for the diagnosis of cirrhosis in patients with chronic hepatitis C infection. Our present study aimed to evaluate the use of serum glycan markers for the diagnosis of liver fibrosis in patients with chronic hepatitis B infection. Methods Patients with hepatitis B virus (HBV) infection (n=173) were diagnosed by clinical laboratory analysis and histological examination. Liver fibrosis was staged using Ishak score. N-glycan profiles of serum proteins were determined by DNA sequencer-based carbohydrate analytical profiling. Results We found that in HBV patients, like in hepatitis C virus patients, several serum N-glycans were altered during the development of liver fibrosis. We found higher levels of total agalactosylated biantennary glycans in fibrosis patients with HBV infection than in healthy controls. The biantennary (NA2) and the triantennary (NA3) N-glycans decreased significantly (P < 0.001) with increased severity of fibrosis. The diagnostic power of serum glycan marker (GlycoFibroTest) [area under the curve (AUC)=0.735) was similar to that of FibroTest (AUC=0.740) for discriminating between moderate and advanced fibrosis (F3-F6) from non- or mild fibrosis (F0-F2). However, GlycoFibroTest (AUC=0.740) was slightly better than FibroTest (AUC=0.696) for distinguishing fibrotic patients (F1 or more) from non-fibrotic patients (F0). Conclusions The assay for serum glycan profiling showed satisfactory reproducibility and is a non-invasive blood test for the diagnosis of liver fibrosis. The changes of N-glycan level in serum can be used to monitor or follow-up the progress of fibrosis using specific N-glycan markers.