Hepatitis B virus reactivation associated with immunosuppressive therapy

During Solid Tumor Chemotherapy reactivation in chronic HBV without prophylaxis ranged from 4% to 68% (median, 25%). Risk of HBV reactivation depends on: HBV serologic status and type of immunosuppressive therapy. According to two parameter above mention, Risk of reactivation is very high when HBV reactivation was > 20 percent and High & moderate and low risk when HBV reactivation risk were 11-20 & 1 to 10 and <1 percent respectively. Most patients with HBV reactivation are asymptomatic, and the only manifestation is an increase in the HBV DNA level. Other patients can have a flare of their HBV infection. HBV reactivation is diagnosed when a patient with serologic evidence of HBV has: 1) A detectable HBV DNA level when they previously had undetectable HBV DNA. 2) A rise in HBV DNA of more than 2 log10 iu/ml in patients who had HBV DNA present at baseline. 3) In some studies, HBV reactivation is defined as a ≥10-fold increase in HBV DNA compared with baseline. 4) Reverse seroconversion (when a patient previously HBsAg-negative/anti-HBc-positive becomes HBsAg-positive). We recommend antiviral treatment for all patients who develop HBV reactivation. Tenofovir or entecavir for patients who are treatment-naïve is recommended.