HBV pregenome RNA as a predictor of spontanous HBeAg seroconversion in HBeAg-positive chronic hepatitis B patients

BACKGROUND: Previous studies have indicated that HBV pregenome RNA (HBV pgRNA) could predict HBeAg seroconversion among the chronic hapatitis B (CHB) patients treated with pegylated interferon (Peg-IFN) or nucleos(t)ide analogues (NAs). However, the data about the prediction of HBV pgRNA for spontaneous HBeAg seroconversion is limited. METHODS: One hundred thirteen CHB patients with HBeAg-positive in the immune active phase were followed up for 76 weeks without antiviral treatment. Based on the laboratory test results of liver function, HBeAg, anti-HBe, and HBV DNA at week 76, patients were assigned to two groups: spontaneous HBeAg seroconversion (group A, n = 18) and non-spontaneous HBeAg seroconversion group. Among the latter group, 36 patients were selected as controls (group B, n = 36). RESULTS: At week 12, between group A and group B, there was a significant difference in the level of HBV pgRNA (group A 6.35 ± 1.24 log(10) copies/ml and group B 7.52 ± 0.79 log(10) copies/ml, P = 0.001), and the difference enlarged at week 28. The receiver operating characteristic curves (AUROCs) of the HBV pgRNA level and the ∆HBV pgRNA at week 28 were 0.912 (P = 0.001, 95% CI: 0.830–0.994), and 0.934 (P = 0.001, 95% CI: 0.872–0.996), respectively. The optimal cutoffs of HBV pgRNA and the reduction from baseline (∆HBV pgRNA) at week 28 for spontaneous HBeAg seroconversion prediction were 5.63 log(10) copies/ml and 1.85 log(10) copies/ml, respectively. The positive predictive value and negative predictive value of HBV pgRNA and ∆HBV pgRNA at week 28 were 86.7% and 87.2%, 87.5% and 89.5%, respectively. And the combination of the HBV pgRNA level and the HBV pgRNA decreased could provide better prediction. CONCLUSIONS: HBV pgRNA is a sound predictor for spontaneous HBeAg seroconversion among the CHB patients in immune active phase. Dynamic monitoring of HBV pgRNA is helpful for clinical treatment decision.