Frequency of hepatitis B virus reactivation in cancer patients undergoing cytotoxic chemotherapy: a prospective study of 626 patients with identification of risk factors

Risk of hepatitis B reactivation in patients treated with direct-acting antivirals for hepatitis C

The recent introduction of direct-acting antiviral drugs (DAAs) for treatment of the hepatitis C virus (HCV) has greatly improved the management of HCV for infected patients. These viral protein inhibitors act rapidly, allowing HCV clearance and increasing the sustained virological response rates. However, hepatitis B virus (HBV) reactivation has been reported in HCV/HBV co-infected patients. Hepatitis B reactivation refers to an abrupt increase in the HBV and is well-documented in patients with previously undetected HBV DNA due to inactive or resolved HBV infection. Reactivation can occur spontaneously, but in most cases, it is triggered by various factors. Reactivation can be transient, without clinical symptoms; however, it usually causes a hepatitis flare. HBV reactivation may occur regardless of HCV genotype and type of DAA regimen. HBV screening is strongly recommended for co-infected HCV/HBV patients before initiation and during DAA therapy regardless of HBV status, HCV genotype and class of DAAs used. HBV reactivation can be prevented with pretreatment screening and prophylactic treatment when necessary. Additional data are required to evaluate the underlying mechanisms of HBV reactivation in this setting.

Chemotherapy-related reactivation of hepatitis B infection: Updates in 2013

Hepatitis B reactivation is a potentially serious complication of anticancer chemotherapy, which occurs during and after therapy. This condition affects primarily hepatitis B surface antigen (HBsAg)-positive patients, but sometimes HBsAg-negative patients can be at risk, based only on evidence of past infection or occult infection with a low titer of detectable hepatitis B virus (HBV) DNA. The clinical outcomes vary with the different degrees of virologic and biochemical rebound, ranging from asymptomatic elevations in liver enzymes to hepatic failure and even death. Despite the remarkable advancement in the treatment of chronic hepatitis B over the past decade, proper strategies for the prevention and management of HBV reactivation remain elusive. Moreover, with the increasing use of rituximab in patients with lymphoma, HBV reactivation in occult or past infections has become increasingly problematic, especially in HBV-endemic regions. This review addresses the current knowledge on the clinical aspects and management of chemotherapy-related HBV reactivation, updates from recent reports, several unresolved issues and future perspectives.

Mycobacterium avium subspecies paratuberculosis in the etiology of Crohn’s disease, cause or epiphenomenon?

The origin of inflammatory bowel disease is unknown. Attempts have been made to isolate a microorganism that could explain the onset of inflammation, but no pathological agent has ever been identified. Johne’s disease is a granulomatous chronic enteritis of cattle and sheep caused by Mycobacterium avium subspecies paratuberculosis (MAP) and shows some analogies with Crohn’s disease (CD). Several studies have tried to clarify if MAP has a role in the etiology of CD. The present article provides an overview of the evidence in favor and against the “MAP-hypothesis”, analyzing the methods commonly adopted to detect MAP and the role of antimycobacterial therapy in patients with inflammatory bowel disease. Studies were identified through the electronic database, MEDLINE, and were selected based on their relevance to the objective of the review. The presence of MAP was investigated using multiple diagnostic methods for MAP detection and in different tissue samples from patients affected by CD or ulcerative colitis and in healthy controls. On the basis of their studies, several authors support a close relationship between MAP and CD. Although increasing evidence of MAP detection in CD patients is unquestionable, a clear etiological link still needs to be proven.

Hepatitis B and inflammatory bowel disease: Role of antiviral prophylaxis

Hepatitis B virus (HBV) is a very common infection worldwide. Its reactivation in patients receiving immunosuppression has been widely described as being associated with significant morbidity and mortality unless anti-viral prophylaxis is administered. Treatment in inflammatory bowel disease (IBD) patients has changed in recent years and immunosuppression and biological therapies are now used more frequently than before. Although current studies have reported an incidence of hepatitis B in inflammatory bowel disease patients similar to that in the general population, associated liver damage remains an important concern in this setting. Liver dysfunction may manifest in several ways, from a subtle change in serum aminotransferase levels to fulminant liver failure and death. Patients undergoing double immunosuppression are at a higher risk, and reactivation usually occurs after more than one year of treatment. As preventive measures, all IBD patients should be screened for HBV markers at diagnosis and those who are positive for the hepatitis B surface antigen should receive antiviral prophylaxis before undergoing immunosuppression in order to avoid HBV reactivation. Tenofovir/entecavir are preferred to lamivudine as nucleos(t)ide analogues due to their better resistance profile. In patients with occult or resolved HBV, viral reactivation does not appear to be a relevant issue and regular DNA determination is recommended during immunosuppression therapy. Consensus guidelines on this topic have been published in recent years. The prevention and management of HBV infection in IBD patients is addressed in this review in order to address practical recommendations