P128 A composite score consisting of both cccDNA transcriptional activity biomarkers and immunological markers in serum refines HBeAg-negative chronic hepatitis B phases

HBeAg-negative chronic hepatitis B (CHB) is a variable disease with phases determined by HBV DNA and ALT levels: ‘infection’ phase (HBV DNA 20000 IU/ml & elevated ALT). Over 30% HBeAg-negative patients fall within a ‘grey zone’ (HBV DNA 2000–20000 IU/ml & normal ALT). Novel serological markers of cccDNA transcriptional activity: hepatitis B core-related antigens (HBcrAg) & pre-genomic HBV RNA (pgRNA) are relevant in separating HBeAg-negative patients (‘infection’ vs. ‘hepatitis’) and so reducing the number of indeterminate ‘grey zone’ patients. As CHB is an immune-mediated disease, the pro-inflammatory chemokine CXCL10 and soluble (s)PD-1 (exhaustion marker) levels may refine HBeAg-negative phases further. Combining these serum markers to create a composite score may increase our ability to stratify HBeAg-negative phases.To compare serological, virological and immunological markers in HBeAg-negative patients and determine whether these markers are able to refine HBeAg-negative CHB phases based on HBV DNA & ALT levels (‘infection’, ‘grey zone’ & ‘hepatitis’) and create a composite score.MethodsSerum samples from a cross-sectional cohort of 562 untreated HBeAg-negative patients (median age 38yrs, 204 males) were tested for diagnostic markers: HBV DNA (Roche TaqMan,IU/ml), quantHBsAg (Abbott Architect,IU/ml), biochemical (ALT,IU/L) and further tests were performed for the biomarkers: HBcrAg (CLEIA Fujirebio,log10U/ml), pgRNA (Abbott Diagnostics dual-target real-time-PCR assay, LLQD= 0.4 log10U/ml), CXCL10 & sPD-1 serum levels by ELISA [pg/ml]. Patients were divided into 3 groups based on HBV DNA levels: ‘infection’ (20000IU/ml) phases. The results were compared by AUC-ROC, univariate and multivariate analysis. The scoring system for the composite score was calculated using only markers with AUC-ROC>0.7.ResultsPatients in ‘infection’ phase (n=293) have lowest levels in all markers in contrast to ‘grey zone’ (n=215) & ‘hepatitis’ (n=54) phase patients by univariate analysis (figure 1). However, only HBV DNA, HBcrAg, pgRNA, CXCL10 and sPD-1 levels differed between groups by multivariate and AUC-ROC analysis (figure 1). The cut offs for the composite score were: HBcrAg (