Under informed consent, 1 8 cases Napabucasin price switched to Peg IFN a-2a plus adefovir, 5 continued therapy with telbivudine, 1 1 refused to receive treatment and 10 followed the suggestion to stopped treatment. The durations of treatment are from 48 to 96 weeks. Results Among 1 8 cases switched to Peg IFN a-2a plus adefovir, 15(83.3%) achieved complete virological response (HBV DNA<20IU/ml),

9(50%) achieved HBeAg clearance or sero-conversion with HBV DNA<20IU/ml, 5(27.8%) achieved HBsAg clearance(HBsAg <0.05IU/ml) or seroconversion with HBeAg loss and HBV DNA<20IU/ml, 1 did not achieve virological response, and 2 lost to follow-up. 3 patients who achieved HBsAg seroconversion had stopped antiviral therapy GPCR & G Protein inhibitor with HBsAb titers greater than 300IU/L persistently. Conclusions Based on postpartum ALT elevation, decrease of HBeAg titer and reduction of HBV DNA, switching to IFN-based regimen may achieve high rates of response after childbirth in pregnant HBV carriers who

received nucleoside analogs for PTMCT . The mechanism may be associated with recovery of immune function after childbirth and enhancement of immune function by antiviral therapy in the third trimester of pregnancy. Disclosures: The following people have nothing to disclose: Junfeng Lu, Xinyue Chen, Yali Liu, Hongwei Zhang, Lina Ma, Hua Zhang Switch in HBV genotypes is well known on interferon therapy. Whether prolonged Tenofovir therapy introduces genotype switches in patients (pts) during treatment is not known. Eighty-Eight chronic hepatitis B pts with raised ALT (>1.5 x ULN) and histologically proven chronic hepatitis, this website receiving tenofovir as per protocol were followed up every 6 months. HBV genotypes were studied if pts had at least two follow-ups (n=67) . Of these pts, 17 were treatment exposed (Lamivudine 12, Adefovir 3, Lamivudine + Adefovir 2). HBV Polymerase/surface region sequences from 67 pts were subjected to phylogenetic,

recombination analysis and inter-genotype (change of genotype), intra-genotype (change of subgenotype), recombination were determined in follow-up samples and compared to baseline. Majority of pts were male (n 58). Median HBV DNA was 3.1×106 IU/ml. HBeAg was +ve in 38 (56.7%). At baseline, HBV genotypes were : A 14 (20.8%), D 52 (77.6%) and C 1 (1.5%) with predominance of sub-genotype A1, C1 and D1. Twenty-two of 67 (32.8%) pts experienced inter-genotype switches. Six pts experienced switch in genotype at 6 months and 7 at 1 year, 3 at 1.5 year, 4 at 2 year and 2 pts at 2.5 years. The trend of genotype switch was more often detected from A to D [13 (92.8%), baseline HBeAg +ve: 9; HBeAg -ve 4] as compared to genotype D to A [9 (17.3%) baseline HBeAg +ve: 2; HBeAg -ve: 7] (P <0.002). Of 22 pts, in 3 change in HBeAg coincided with genotype switch i.e. [HBeAg +ve, Genotype A converted to HBeAg -ve, genotype D in one ], [HBeAg -ve, genotype D reverted to HBeAg +ve, genotype A in 2 pts].