ITIH4: Effective Serum Marker, Early Warning and Diagnosis, Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a highly lethal malignant tumor evolved from cirrhosis. It is quite significant to seek accurate, easy markers for early warning and diagnosis of HCC. Through prospective cohort follow-up study and mass spectrometry, we discovered and verified a serum marker valuable for early warning and diagnosis. Follow-up observation was performed on cirrhosis patients. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was adopted to detect the serums of patients, and the serum polypeptides with a potential value in early HCC warning and diagnosis were screened. Electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF-MS/MS) was exploited to identify these screened polypeptides. Moreover, the serum marker concentration was determined by ELISA to validate the clinical value of the serum marker. Among 109 cirrhosis patients followed up for two years, 29 patients (26.6%) finally progressed into HCC. MALDI-TOF MS shows that the concentration of a 3155.66Da polypeptide was significantly different between the patients that progressed into HCC and those not. Through MS/MS identification, it is confirmed that the polypeptide is inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4). The serum ITIH4 concentrations in two groups were measured with ELISA and compared with Alpha-fetoprotein (AFP). Results show that serum ITIH4 and AFP concentrations were negatively correlated (r=-0.263, p=0.0006), and the ITIH4 concentration had a significant intergroup difference (p=0.000). Receiver operating characteristic (ROC) curve indicates that its predictive value (area under the curve, AUC) is 0.667, superior to AFP. For the patients progressing into HCC, serum samples were separately collected when they were recruited and diagnosed as cirrhosis. Measurement on these samples reveals that ITIH4 was declining during the progression of HCC (p=0.006). By virtue of mass spectrometry, we discovered and identified a biomarker valuable for early HCC warning and diagnosis. This marker overperforms the commonly used AFP, demonstrating a bright prospect.