Hepatitis B Splice-Generated Protein Antibodies in Syrian Chronic Hepatitis B Patients: Incidence and Significance

BACKGROUND Previous studies have suggested hepatitis B splice-generated protein (HBSP), when expressed, is involved in the pathogenesis of HBV infection. OBJECTIVES We aimed to evaluate anti-HBSP incidence and association with several HBV infection parameters in a group of Syrian chronic hepatitis B patients. PATIENTS AND METHODS Eighty treatment-naïve HBsAg-positive adult chronic hepatitis B patients' sera were included in our prospective targeted study. Liver function, virological and histological tests results were obtained from patients' medical files. Three variants of a 20-mer HBSP-derived peptide were designed based on HBV genome sequences obtained from Syrian patients' sera (GenBank Accession No. JN257148-JN257217). Microtiter plate wells were coated with the synthetic peptides and used to detect anti-HBSP antibodies by an optimized indirect enzyme-linked immunosorbent assay (ELISA). Samples were considered positive when showed optical density (OD) values higher than the cut-off value for at least one peptide variant. RESULTS Seven out of eighty (9%) CHB patients were positive for anti-HBSP antibodies. Mean OD values were not significantly different between HBeAg-positive and -negative patients (P > 0.05). OD values showed weak positive correlation with ALT and AST values (P < 0.05), and weak to moderate positive correlation with liver biopsy staging ranks (P < 0.05). No significant correlation was revealed with viral load values or liver biopsy grading ranks (P > 0.05). CONCLUSIONS We introduced an anti-HBSP antibodies ELISA, designed for locally circulating HBV strains. Correlation observed of Anti-HBSP with liver fibrosis staging regardless of viral replication and liver inflammation suggests anti-HBSP antibodies as possible indicator for HBV-associated liver fibrosis.