Trong nghiên cứu đầu tiên của Sanchez-Fueyo et al., 56 17 bệnh nhân có nguy cơ thấp đối với HBV tái phát (không replicative trước khi cấy ghép, HBIg cho ít nhất 18 tháng mà không có bằng chứng của nhiễm trùng HBV allograft, và liều thấp ức chế miễn dịch) đã được chủng ngừa HBV tại trung bình là 30 tháng sau cấy ghép. | 350 Chapter 22 after 1 year of treatment and 1-year patient survival reached 92 .50 Combination prophylaxis with low doses of intramuscular HBIg and lamivudine has also been shown to be highly effective Table with recurrence rates of 10 in most 34 44 51-55 Higher rates of recurrence are typically found in patients who have developed lamivudine resistance prior to This strategy is becoming the standard of care in most transplant programmes. However the best protocol is still unknown as doses routes type and lengths of administration vary substantially from centre to centre. Moreover the amount of HBIg infused ranges from 2800 to 80 000 IU during the first week and from 7600 to 200 000 IU during the first year. Some centres continue to use the intravenous . route while others switch to the intramuscular . injection. Fixed . or . HBIg doses are utilized in some centres while others prefer to individualize this therapy to achieve predefined serum anti-HBs concentrations. Finally some centres continue HBIg indefinitely while others stop HBIg at different time intervals from transplantation. Future studies are needed to assess these aspects in particular the benefits of fixed versus individualized therapy and the need for indefinite versus limited durations of HBIg therapy. Long-term prophylactic therapy At present the main unanswered question relates to long-term prophylaxis. In patients receiving combination therapy there is a need to define the optimal duration of HBIg. Two different approaches have been investigated. The first is active HBsAg vaccination with the aim of inducing active immunity against HBV without the need for additional antiviral treatment. Results from preliminary studies are disparate 56-59 with good results being achieved in some studies and poor response to HBV vaccination observed in others. Reasons for these apparently discrepant results likely include differences in study populations differences
