Reduced doses of hepatitis B immunoglobulin protect against hepatitis B virus infection recurrence after liver transplantation

HBV recurrence lowered by lamivudine/HBIG combination therapy in liver transplant patients: ten-year experience

BACKGROUND

Lamivudine and hepatitis B immunoglobulin (HBIG) are widely used to treat patients with hepatitis B recurrence after liver transplantation. However, the outcomes are inconclusive. The present study was undertaken to evaluate the effect of combined therapy on patients with hepatitis B recurrence after liver transplantation.

METHODS

Twenty-two patients with hepatitis B recurrence after liver transplantation from August 2000 to October 2011 were enrolled in this study. Of these patients, 16 received lamivudine plus HBIG (combination therapy group) and 6 were treated with lamivudine alone (lamivudine-treated group). The clinical features were matched in the two groups. HBV recurrence parameters, HBsAg clearance rate, patient survival rate, and survival time were compared.

RESULTS

The average time of follow-up was 47.2 months (range 13-99). Significant difference was noted in the HBsAg clearance rate in the lamivudine-treated and combination therapy groups (50% vs 93.8%, P<0.05). There was no significant difference in the time of HBV recurrence, patient survival rate and survival time between lamivudine-treated and combination therapy groups (P>0.05).

CONCLUSION

Compared with lamivudine monotherapy, combination therapy significantly increased the HBsAg clearance rate in patients with HBV recurrence after liver transplantation.

Liver transplantation for hepatitis B virus. Pre-emptive and peri-operative prophylaxis

In the past, reinfection of the graft by hepatitis B virus (HBV) after liver transplantation for HBV-related liver disease was often followed by severe liver damage and reduced survival. The long-term administration of hepatitis B immunoglobulin (HBIG) dramatically reduced this risk. However, this procedure was ineffective in most patients with active viral replication pre-transplant. The use of lamivudine in the pre-transplant setting partially solved this problem. The emergence of resistant mutants to lamivudine was also solved by the addition of adefovir. At present, combination therapy by oral antivirals pre-transplant and HBIG plus the same drugs post-transplant achieves nearly 100% of protection against graft reinfection. In a recent study, a new intravenous HBIG, Niuliva has shown high efficacy in achieving protective anti-HBs levels after liver transplantation for HBV-related liver diseases, as well as a good safety profile. Using combination therapies, the doses of HBIG can be reduced or even stopped after several weeks or months post-transplant, continuing with oral antivirals alone. The recently introduced antivirals achieve a very high antiviral potency and low risk of resistance. This may further increase the efficacy in preventing graft reinfection in the post-liver transplantation setting.

Lamivudine or lamivudine combined with hepatitis B immunoglobulin in prophylaxis of hepatitis B recurrence after liver transplantation: a meta-analysis

There is a controversy over whether the different outcomes of prophylaxis of hepatitis B virus (HBV) recurrence are attributable to different treatments. A systematic review and a meta-analysis were conducted to evaluate lamivudine monotherapy and combined therapy of lamivudine and hepatitis B immunoglobulin (HBIG) in HBV infected liver recipients. A fixed effects model was used for statistical pooling of relative risks (RR) for the different outcomes. Six articles (551 patients) fulfilled the inclusion criteria. Statistically significant differences were observed between lamivudine monotherapy and lamivudine + HBIG therapy in hepatitis B recurrence [P < 0.0001; RR = 0.38; 95% CI (0.25, 0.58)], YMDD mutant [P = 0.002; RR = 0.40; 95% CI (0.23, 0.72)] and hepatitis B recurrence in HBV-DNA positive patients before orthotopic liver transplantation [P < 0.00001; RR = 0.31; 95% CI (0.21, 0.45)]. No significant differences were observed in patient survival [P = 0.59; RR = 1.02; 95% CI (0.95, 1.09)], graft survival [P = 0.56; RR = 1.02; 95% CI (0.95, 1.09)] and diseases leading to death between the two groups [HBV recurrence leading to death: P = 0.05; RR = 0.47; 95% CI (0.22, 1.02); hepatocellular carcinoma recurrence leading to death: P = 0.13; RR = 0.34; 95% CI (0.09, 1.36)]. In conclusion, combination of lamivudine and HBIG can effectively decrease the recurrence rate of HBV and the incidence of YMDD mutant, but it can not improve patient survival and graft survival significantly. Well-designed large-sample trials are needed to evaluate the efficiency of combined therapy of lamivudine and HBIG in prophylaxis of HBV recurrence in liver graft recipients.

Human monoclonal antibody against Hepatitis B virus surface antigen (HBsAg)

Hepatitis B virus (HBV) is one of the main pathogens responsible for hepatitis and hepatocellular carcinoma. Human plasma-derived Hepatitis B immune globulin (HBIG) is being used for prophylactic and liver transplantation currently. However, it may be necessary to replace a HBIG with a recombinant one because of limited availability of human plasma with high anti-HBsAg antibody titer and possible contamination of human pathogens. A Chinese hamster ovary (CHO) cell line, HB-C7A, was established which produces a fully human IgG1 that binds HBsAg. The HB-C7A exhibits approximately 2600 units/mg of antibody. The affinity (K(a)) of HB-C7A is 1.1 x 10(8) M(-1) by Biacore analysis and estimated 6.7-fold higher than that of Hepabig (a plasma-derived HBIG from Green Cross Corp., Yongin, Korea) by competition ELISA. The HB-C7A recognizes the conformational "a" determinant of HBsAg and binds HBV particle more efficiently than the Hepabig. The HB-C7A binds to HBV-infected human liver tissue but does not bind to normal human tissues. This HB-C7A has several advantages compared to plasma-derived Hepabig such as activity, safety and availability.

Protocol liver biopsies in long-term management of patients transplanted for hepatitis B-related liver disease

AIM: To evaluate the long-term histological outcome of patients transplanted for HBV-related liver disease and given HBIg prophylaxis indefinitely after LT.

METHODS: Forty-two consecutive patients transplanted for hepatitis B were prospectively studied. HBsAg, HBV-DNA and liver function tests were evaluated in the serum 3, 6 and 12 mo after LT and then yearly. LB was obtained 6 and 12 mo after LT and yearly thereafter. Chronic hepatitis (CH) B after LT was classified as minimal, mild, moderate or severe.

RESULTS: HBV recurred in 7/42 (16.6 %) patients after 6-96 mo of follow-up. A hundred and eighty-seven LB were evaluated. Four of 7 patients with graft reinfection, all with unknown HBV DNA status before LT, developed cirrhosis at 12-36 mo of follow-up. Of the 122 LB obtained from 28 HBsAg+/HCV- recipients with no HBV recurrence after LT, all biopsies were completely normal in only 2 patients (7.1 %), minimal/non-specific changes were observed in 18 (64.2 %), and at least 1 biopsy showed CH in the remaining 8 (28.5 %). Twenty-nine LB obtained from 7 patients transplanted for HBV-HCV cirrhosis and remaining HBsAg- after LT revealed recurrent CH-C. Actuarial survival was similar in patients with HBsAg+ or HBsAg- liver diseases.

CONCLUSION: Though protocol biopsies may enable the detection of graft dysfunction at an early stage, the risk of progression and the clinical significance of these findings remains to be determined.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

A randomized study comparing lamivudine monotherapy after a short course of hepatitis B immune globulin (HBIg) and lamivudine with long-term lamivudine plus HBIg in the prevention of hepatitis B virus recurrence after liver transplantation

BACKGROUND/AIMS

To compare the efficacy in preventing hepatitis B virus (HBV) recurrence of lamivudine vs. lamivudine plus hepatitis B immune globulin (HBIg) after a short course of HBIg and lamivudine in liver transplanted chronic hepatitis B patients.

METHODS

Forty-six patients with HBV cirrhosis received lamivudine before liver transplantation and were then randomized to receive lamivudine plus HBIg for 1 month followed by lamivudine or both drugs for 17 months.

RESULTS

Thirty-two patients were transplanted and 29 were randomized to receive combination therapy (15 cases) or lamivudine monotherapy (14 cases). HBV DNA was undetectable in all cases (17 induced by lamivudine therapy) at the time of liver transplantation. After 18 months of follow-up, all patients survived without HBV recurrence: hepatitis Bs antigen and HBV DNA were negative; however, HBV DNA was detected by polymerase chain reaction in four cases (three with HBIg plus lamivudine and one with lamivudine). Alanine aminotransferase levels were normal except in six cases (one HCV and two HDV coinfections). There were no drug-related adverse events.

CONCLUSIONS

Lamivudine monotherapy after a short course of lamivudine and HBIg is equally as efficacious in preventing HBV recurrence as HBIg plus lamivudine during the first 18 months after liver transplantation. This strategy is more economic and convenient to administer than long-term HBIg plus lamivudine.