Prevention of lamivudine-resistant hepatitis B recurrence after liver transplantation with entecavir plus tenofovir combination therapy and perioperative hepatitis B immunoglobulin only

Application of nucleoside analogues to liver transplant recipients with hepatitis B

Hepatitis B is a common yet serious infectious disease of the liver, affecting millions of people worldwide. Liver transplantation is the only possible treatment for those who advance to end-stage liver disease. Donors positive for hepatitis B virus (HBV) core antibody (HBcAb) have previously been considered unsuitable for transplants. However, those who test negative for the more serious hepatitis B surface antigen can now be used as liver donors, thereby reducing organ shortages. Remarkable improvements have been made in the treatment against HBV, most notably with the development of nucleoside analogues (NAs), which markedly lessen cirrhosis and reduce post-transplantation HBV recurrence. However, HBV recurrence still occurs in many patients following liver transplantation due to the development of drug resistance and poor compliance with therapy. Optimized prophylactic treatment with appropriate NA usage is crucial prior to liver transplantation, and undetectable HBV DNA at the time of transplantation should be achieved. NA-based and hepatitis B immune globulin-based treatment regimens can differ between patients depending on the patients’ condition, virus status, and presence of drug resistance. This review focuses on the current progress in applying NAs during the perioperative period of liver transplantation and the prophylactic strategies using NAs to prevent de novo HBV infection in recipients of HBcAb-positive liver grafts.

Diagnostic and therapeutic progress of multi-drug resistance with anti-HBV nucleos(t)ide analogues

Nucleos(t)ide analogues (NA) are a breakthrough in the treatment and management of chronic hepatitis B. NA could suppress the replication of hepatitis B virus (HBV) and control the progression of the disease. However, drug resistance caused by their long-term use becomes a practical problem, which influences the long-term outcomes in patients. Liver transplantation is the only choice for patients with HBV-related end-stage liver disease. But, the recurrence of HBV after transplantation often caused by the development of drug resistance leads to unfavorable outcomes for the recipients. Recently, the multi-drug resistance (MDR) has become a common issue raised due to the development and clinical application of a variety of NA. This may complicate the antiviral therapy and bring poorly prognostic outcomes. Although clinical evidence has suggested that combination therapy with different NA could effectively reduce the viral load in patients with MDR, the advent of new antiviral agents with high potency and high genetic barrier to resistance brings hope to antiviral therapy. The future of HBV researches relies on how to prevent the MDR occurrence and develop reasonable and effective treatment strategies. This review focuses on the diagnostic and therapeutic progress in MDR caused by the anti-HBV NA and describes some new research progress in this field.

KASL Clinical Practice Guidelines: Management of chronic hepatitis B

The guideline on the management of chronic hepatitis B (CHB) was first developed in 2004 and revised in 2007 by the Korean Association for the Study of the Liver (KASL). Since then there have been many developments, including the introduction of new antiviral agents and the publications of many novel research results from both Korea and other countries. In particular, a large amount of knowledge on antiviral resistance--which is a serious issue in Korea--has accumulated, which has led to new strategies being suggested. This prompted the new guideline discussed herein to be developed based on recent evidence and expert opinion.

TARGET POPULATION

The main targets of this guideline comprise patients who are newly diagnosed with CHB and those who are followed or treated for known CHB. This guideline is also intended to provide guidance for the management of patients under the following special circumstances: malignancy, transplantation, dialysis, coinfection with other viruses, pregnancy, and children.

The option of HBIG-free prophylaxis against recurrent HBV

Since the early 1990's, hepatitis B immune globulin (HBIG) has been central to the prevention of hepatitis B virus (HBV) recurrence after liver transplantation. When used in combination with oral nucleos(t)ide analogues, HBIG prevents reinfection with HBV in ⩾90% of transplant recipients. While HBIG is highly efficacious, its use is undermined by its high cost. Because of this limitation, there have been many studies of alternative regimens seeking to minimize the dose or duration of HBIG without sacrificing low HBV recurrence rates. Toward that goal, lower dose intramuscular HBIG in combination with oral nucleos(t)ide analogues has been shown to be highly efficacious in preventing disease recurrence and represents a significant cost savings when compared with high dose intravenous administration. The withdrawal of HBIG after a defined course of combination HBIG and oral antivirals has also been shown to be effective, particularly if combination antiviral therapy is used. The ability to achieve undetectable HBV DNA levels pre-transplantation in the majority of patients may contribute to the high efficacy of these HBIG "light" regimens. Additionally, the success of antiviral rescue therapy for those patients who fail prophylaxis and develop recurrent HBV infection post-transplant has provided the impetus to move increasingly towards HBIG-free approaches. New techniques to detect occult HBV in hepatic and extrahepatic sites may allow clinicians to define a subgroup of patients in whom withdrawal of HBIG or all prophylaxis may be applicable.

Risk factors for infection after liver transplantation

Infection is a common cause of morbidity and mortality after liver transplantation. Risk factors relate to transplantation factors, donor and recipient factors. Transplant factors include ischaemia-reperfusion damage, amount of intra-operative blood transfusion, level and type of immunosuppression, rejection, and complications, prolonged intensive care stay with dialysis or ventilation, type of biliary drainage, repeat operations, re-transplantation, antibiotics, antiviral regimen, and environment. Donor risk factors include infection, prolonged intensive care stay, quality of the donor liver (e.g. steatosis), and viral status. For the recipient the most important are MELD score >30, malnutrition, renal failure, acute liver failure, presence of infection or colonisation, and immune status for viruses like cytomegalovirus. In recent years it has become clear that genetic polymorphisms in innate immunity, especially the lectin pathway of complement activation and in Toll-like receptors importantly contribute to the infection risk after liver transplantation. Therefore, the risk for infections after liver transplantation is a multifactorial problem and all factors need attention to reduce this risk.