Significance of serum HBV RNA in non‐cirrhotic HBeAg‐negative chronic hepatitis B patients who discontinue effective antiviral therapy

HBV RNA is considered as a promising predictor in patients who discontinue nucleos(t)ide analogues (NAs). We determined HBV RNA levels in non‐cirrhotic HBeAg‐negative patients who discontinued NAs and assessed their predictability for 12‐month outcomes. Fifty‐seven patients of DARING‐B study were included. HBV RNA levels were determined in stored monthly serum samples drawn at 0–3 months after end of therapy (EOT). Other markers previously determined in the same cohort including hepatitis B core‐related antigen (HBcrAg) were also assessed. HBV RNA at EOT was detectable in 7% of patients, who developed virological/clinical relapse and required retreatment at month 2; in patients with undetectable EOT HBV RNA, 12‐month cumulative rates of virological relapse, clinical relapse and retreatment were 68%, 28% and 21%, respectively (p ≤ 0.008). HBV RNA at month‐1 after EOT was detectable in 19% of patients being associated with higher probability only of virological relapse (p = 0.001). HBV RNA levels correlated significantly to HBV DNA, HBcrAg, ALT and interferon‐induced protein‐10, but not HBsAg levels. Combined EOT HBV RNA and HBcrAg detection and/or HBsAg >1000 IU/ml was associated only with higher probability of retreatment having higher sensitivity and lower specificity than HBV RNA alone. In conclusion, serum HBV RNA is detectable in a minority of non‐cirrhotic HBeAg‐negative patients under effective long‐term NAs therapy offering low sensitivity but 100% specificity for early retreatment due to severe clinical relapses after NA discontinuation. The combinations of EOT HBV RNA with HBcrAg and/or high HBsAg levels increase sensitivity but decrease specificity for prediction of retreatment after NAs withdrawal.