Low baseline HBsAg levels were associated with HBsAg clearance (40% for baseline HBsAg levels ≤ 20 IU/mL and 2% for levels > 20 IU/mL, P < 0.05). Interestingly, a 50% decrease in the HBsAg level from the baseline to week 12 was associated with a reduced likelihood of HBV DNA reactivation in patients with serum HBV DNA levels that were undetectable at the baseline (PPV = 89.5%).43 This raises the possibility that we might be able to identify those HCV/HBV-coinfected patients who are likely to experience HBV reactivation and may need additional therapy with

NAs. HBsAg declines during NA therapy appear more apparent in HBeAg-positive patients than HBeAg-negative patients, Selleckchem Inhibitor Library at least in the short term (Table 3). Although differences in the inclusion criteria preclude a comparison of HBsAg reduction across studies, one study involving both HBeAg-positive patients and HBeAg-negative patients showed that a substantial HBsAg decline during entecavir (ETV) therapy was restricted to HBeAg-positive patients.29 BVD-523 nmr A small study from Korea showed that a decrease > 1 log10 IU/mL in serum HBsAg levels during therapy (5 of 28 patients) was associated with a much higher cumulative incidence of HBeAg loss (80% versus 30%, P = 0.034) after 1

year of ETV therapy.28 Notably, one study showed that the HBsAg decline during ETV therapy was restricted to patients with baseline ALT levels greater than or equal to 2 times the upper limit of normal (P = 0.007), and it was most profound in those who lost HBeAg.29 This suggests that the HBsAg decline might be linked to increased immunological activity. HBsAg seroclearance is sometimes reported during NA therapy in HBeAg-positive patients. With tenofovir (TDF), HBsAg seroclearance rates of 3%, 6%, and 8% were reported after 1, 2, and 3 years of therapy in HBeAg-positive patients, but seroclearance was not observed in HBeAg-negative patients.44 HBsAg seroclearance rates for HBeAg-positive patients treated with ETV or LAM after 96 weeks on treatment and 24 weeks off therapy were 5%

and 3%, respectively.45 Recent studies have shown that a rapid decline in HBsAg levels during the first year of NA therapy learn more in HBeAg-positive patients is associated with a higher probability of HBsAg seroclearance: 8 of 32 patients with a rapid HBsAg decline > 1 log10 IU/mL during telbivudine (LdT) therapy achieved HBsAg clearance in year 3, whereas 0 of 56 patients with steady HBsAg levels achieved this (P = 0.0024).30 Similarly, patients with HBsAg loss during TDF therapy, who were most frequently infected with genotype A or D, exhibited a rapid HBsAg decline, and the HBV DNA decline pattern in patients with or without HBsAg loss was similar.31 There would be a considerable advantage in being able to determine whether a patient could stop NA therapy after a successful response.