Association of Alanine Aminotransferase Flares to Hepatitis B Surface Decline During Tenofovir Alone or With Pegylated Interferon Alfa

We aimed to determine whether the intensity of alanine aminotransferase (ALT) flares during antiviral therapy is associated with the level of hepatitis B surface antigen (HBsAg) decline.Quantitative HBsAg was determined during tenofovir monotherapy or tenofovir plus peginterferon alfa-2a in 201 participants with hepatitis B e antigen-positive or -negative chronic hepatitis B. A multivariable analysis identified factors associated with a shorter time to reduction in HBsAg.Fifty flares occurred during treatment of which 74% were moderate (ALT >5-10 × upper limit of normal) or severe (ALT >10 × upper limit of normal). These flares were associated with greater HBsAg decline compared with no flares. Significantly faster times to HBsAg decline >1 log 10 IU ( P = 0.04) and to HBsAg level <100 IU/mL ( P = 0.01) were observed with severe flares.Flare severity is a potentially important factor associated with shorter time to HBsAg reduction. These findings can be useful when evaluating HBsAg response to evolving hepatitis B virus therapies.