The Clinical Significance Of Up-converting Phosphor Immunochromatography In Detecting Hepatitis B Virus’ Large Envelope Protein In Various Types Of Chronic Liver Disease

Objective:To compare and contrast up-converting phosphor immunochromatography (UPT-LF) and enzyme-linked immunosorbent assay (ELISA) in detecting hepatitis B virus’ large envelope protein (HBV-LP) and explore the clinical significance of HBV-LP variations in serum of chronic hepatitis B (CHB), liver cirrhosis (LC) and primary hepatic carcinoma (PHCC) patients.Methods:Up-converting phosphor (UCP) is used as a tracer agent in combination with immunochromatography to make quantitative test strips for hepatitis B surface antigen protein. A new UPT-based immunochromatographic technology is employed to detect hepatitis B virus’ large envelope protein (HBV-LP) in serum of260CHB,190LC and45PHCC patients; chemiluminescence is adopted to detect HBeAg; real-time fluorescent quantitative PCR is utilized to detect hepatitis B virus’ DNA (HBV DNA).60samples of healthy patients are selected for comparison, whose HBV-LP in serum is detected through UPT-LF and ELISA. Results:1. HBV-LP quantitative test strips are produced based on up-converting phosphor immunochromatography (UPT-LF). The test strips are proven well-functioning, as the lowest detection limit is around0.1U/ml, cut-off is around1.0U/ml, both inter and intra assay variations (CV%) are lower than15%..2. A UPT-LF-based test shows that HBV-LP of each of the60healthy samples is lower than1U/ml, and specificity is100%. An ELISA-based test shows that59healthy serum samples are HBV-LP negative and1such sample is HBV-LP positive, and specificity is98.3%.3. HBV-LP detection is conducted among495serum samples of hepatitis B patients through both UPT-LF and ELISA. The coincidence rate of both detection methods is91.7%. The positive rate of HBV-LP is58.5%and59.5%respectively by UPT-LF and by ELISA.4. In terms of positive HBV-LP concentration level, the majority of CHB patients fall into high concentration group (>40U/ml); LC and PHCC patients predominantly fall into low concentration group (<10U/ml).5. CHB patients, LC patients and PHCC patients are all ranked in descending order in terms of the positive rates of HBeAg, HBV DNA and HBV-LP; the positive rates of HBeAg and HBV DNA in LC and PHCC patients are lower than those in CHB patients and the difference is statistically significant (P<0.01).6. Within the groups of LC and PHCC patients, the positive rate of HBV-LP is significantly higher than those of HBV DNA and HBeAg and the difference is statistically significant (P<0.05). Conclusions:As a swift and reliable method in detecting HBV-LP levels, up-converting phosphor immunochromatography (UPT-LF) has better specificity than enzyme-linked immunosorbent assay (ELISA). HBV-LP detection is of great value in diagnosing chronic liver disease and monitoring treatment effects.