Quantification de l'AgHBs : nouvel outil virologique pour la prise en charge de l'hépatite B chronique

There has been recent renewed interest in HBsAg titering due to newly standardized and performant quantitative assays and also to new powerful antiviral drugs leading to HBsAg loss. The clearance of HBsAg is the ultimate goal of treatment and is considered as “cure”. HBsAg titering may be a useful and economic tool to manage patients with chronic HBV, in complamentary with HBV DNA levels. HBsAg titers differ significantly during the natural history of HBV infection, progressively declining from immune tolerance to inactive phase. The combination of HBsAg < 1 000 IU/mL and HBV DNA < 2 000 IU/mL accurately identifies true inactive carriers. During antiviral treatment, HBsAg levels decline more rapidly in patients under peg-interferon (Peg-IFN) than in those under nucleos(t)ide analogues, and in responders to peg-IFN compared to non responders suggesting individalized response-guided therapy in patients under Peg-IFN. Early stopping rules for patients not responding peg-IFN according to a lack of any HBsAg decline could optimize treatment management. However, before future stopping rules according to treatment algorithms can be applied in clinical practice, additional prospective studies are needed to validate the clinical utility of these kinetics of HBsAg declines during the natural history of infection and during therapy course to define the HBsAg cut off levels and the best timing of clinical relevance.