Evaluation of response rates to antiviral drugs with novel markers in the treatment of chronic hepatitis B

Hepatitis B virus (HBV) infection is a global health problem, and HBV viralreplication is related to increasing morbidity and mortality. Although new antiviral drugshave entered into use in our country and the world, achieving the loss of HbsAg targetedwith existing antiviral agents is still problematic. Many factors involving the host and virusaffect response to treatment in chronic hepatitis B (CHB) infection, and these are importantwhen deciding on treatment. Markers of response to treatment in CHB have not yet beenfully established, and new ideas are being proposed every day. The effect of treatmentresponse markers on permanent virological response has also not been fully described. Oneof the latest proposals in treatment response markers is the quantification and analysis ofHbsAg and HbeAg. The aim of this study was to evaluate the effectiveness of antiviraldrugs in patients receiving treatment for CHB and to investigate the relations betweenresponses to months of treatment and to determine permanent response markers, as well asinvestigating new response markers.This study was performed at the KTU Medical Faculty Department of InfectiousDiseases and Clinical Microbiology between 1 April, 2007, and 31 December, 2010. Weplanned to evaluate the response rates of patients started on potent antiviral treatment fromsubjects diagnosed with chronic HBV and monitored at the infectious diseases polyclinic.Patients? virological, biochemical and serological response rates at weeks 12, 24, 48, 96and 144 of monitoring and the correlations between these responses were investigated.Novel response markers were defined as a fall in HbeAg levels in HbeAg positive patientsand early virological response (EVR). Data obtained were transferred to SPSS.One hundred seventeen patients, 72 started on entecavir (ETV) and 45 on tenofovir(TDF), were included. Patients? virological response rates at weeks 12, 24, 48, 96 and 144were 95.8%, 20.8%, 68%, 75.4% and 66.7%, respectively, in the group given ETV and86.6%, 20%, 71.1% and 78.6%, respectively, in the group given TDF. No difference wasdetermined between the groups in terms of response rates. EVR(+) was determined in92.3% of patients, and response was achieved in 72.2% of these patients after 48 weeks. Asignificant correlation was determined between the decrease in HBV-DNA levels at 12weeks and response at 48 weeks (p=0.023). A significant correlation was also determinedbetween a fall in the 62 HbeAg(+) patients? HBV DNA levels pre-treatment and on the 24thand 48th weeks of treatment and the fall in HbeAg titers (r=0.32 p=0.017, r=034 p=0.01).In conclusion, no difference was determined in terms of efficacy between potentantivirals in the treatment of CHB. EVR, used as a response predictor in IFN-basedtreatments, shows that the log decrease in HBV DNA at the 12th week can be used as aresponse marker in oral antiviral agents. In addition, with the determination of a positivecorrelation between the fall in HbeAg titers and a fall in HBV DNA levels in HbeAg(+)patients we determined that HbeAg titer monitoring can be used as a novel monitoringparameter.