Failure of hepatitis B vaccination to induce either humoral or cellular immune response after liver transplantation for hepatitis B related cirrhosis

Cyclosporine combined with nonlytic interleukin 2/Fc fusion protein improves immune response to hepatitis B vaccination in a mouse skin transplantation model

BACKGROUND

Improving immune responses to vaccination in immunosuppressed patients is extremely important. Previously, we observed that cyclosporine (CsA) combined with a nonlytic interleukin (IL)-2/fragment crystallizable (Fc) fusion protein induces immune tolerance to mouse skin transplantations. In the present study, we asked whether this combination improved hepatitis B (HBV) vaccine efficacy in immunosuppressed mice while also prolonging skin graft survival.

METHODS

After C57BL/6 mice received DBA/2 skin grafts, they were administered a 14-day course of CsA (30 mg/kg intraperitoneal) combined with IL-2/Fc (1 μg, intraperitoneal). HBV vaccine (2 μg) was injected intramuscularly on the day of skin transplantation. On day 14, the serum levels of hepatitis B surface antibody (HBsAb), IL-4, IL-10, interferon (IFN-γ), and IL-2 were measured by enzyme-linked immunosorbent assay. We assessed the percentages of CD4(+)CXCR5(+) follicular T helper cells, CD4(+)FoxP3(+) regulatory T cells (Treg) and expressions of IL-17, IL-21, FoxP3, Bcl-6 in the spleen. Animals were divided into four groups: control, vaccine-treated, CsA + vaccine-treated, CsA + IL-2/Fc + vaccine-treated hosts.

RESULTS

Combination therapy significantly increased HBsAb levels and also prolonged skin graft survival. Serum levels of Th1 cytokines IL-2 and IFN-γ were significantly higher in the combination group, while Th2 cytokines, IL-4 and IL-10 were lower. Combined treatment increased the percentage of Treg and the expression of Foxp3 and IL-21, meanwhile inhibiting the expression of Bcl-6. But the percentage of Tfh did not significantly change among the groups.

CONCLUSIONS

These observations suggested that a combination of CsA and IL-2/Fc fusion protein enhanced immune responses after HBV vaccination and prolonged skin graft survival.

Hepatitis B and C in liver transplantation: new strategies to combat the enemies

Hepatitis B immune globulin-free therapeutic regimens with a nucleos(t)ide analogue (NUC) or NUC combinations after liver transplantation (LT) are currently being investigated for their efficacy and safety as HBV re-infection prophylaxis in clinical studies. Recurrence rates differ among these studies as most of them are limited by a non-randomised study design, small sample size, lack of long-term data and varying time intervals for the switch from combined to purely virostatic prophylaxis. Post-transplant pre-emptive antiviral therapy with pegylated IFN and ribavirin is associated with low sustained virological response rates and was found to have no advantage over treatment of manifest HCV re-infection. Safety and efficacy of triple antiviral therapy including boceprevir or telaprevir in patients with manifest HCV re-infection are currently under investigation in clinical trials. Relevant drug interactions have been shown to occur during calcineurin inhibitor (CNI) and concomitant triple antiviral therapy, which vary with type of CNI and choice of HCV protease inhibitor. Newer direct-acting antivirals with lower or minimal toxicity, when used in combination with immunosuppressives, are worthy of further study in LT patients. This review focuses on hot topics in the management of hepatitis B and C patients before and after LT and offers a critical summarised selection of the corresponding relevant studies published in the current literature or presented at recent liver congresses.

Prevention of hepatitis B recurrence after living donor liver transplantation: primary high-dose hepatitis B immunoglobulin monotherapy and rescue antiviral therapy

The prevention of hepatitis B virus (HBV) recurrence is essential after liver transplantation in patients infected with HBV. We evaluated the efficacy of primary high-dose hepatitis B immunoglobulin (HBIG) monotherapy and rescue antiviral therapy in 639 HBV-infected adult patients who underwent living donor liver transplantation (LDLT) between February 1997 and December 2004. The overall 5-year survival rate was 80.7%, and recurrence of hepatocellular carcinoma was the most common cause of late mortality. Pretransplant HBV replication was observed in 392 (61.3%) patients. The interval of 10,000-IU HBIG administration to maintain antibody to hepatitis B surface antigen > 500 IU/L was 30 days in 11.4% patients, 40 to 50 days in 72.1%, and 60 days in 16.5%. At the last follow-up, 3.9% of the patients without HBV recurrence were receiving combination therapy. Overall 1-year, 3-year, 5-year, and 10-year HBV recurrence rates were 1.4%, 5.5%, 7.3%, and 8.5%, respectively. HBV recurrence occurred after a mean of 25.7 +/- 16.4 months after LDLT. After HBV recurrence, 5 of 9 patients died from rapidly progressive liver failure before treatment with adefovir, and only 1 of 29 patients died after treatment with adefovir. Need for frequent HBIG infusions (< or =30 days), active pretransplant HBV replication, and hepatocellular carcinoma recurrence were significant risk factors for HBV recurrence and indications for combination therapy. Our posttransplant HBV prophylaxis regimen resulted in a 5-year HBV recurrence rate of 7.3% and a mortality rate of 13.2% after HBV recurrence, showing the effectiveness of high-dose HBIG monotherapy and rescue antiviral therapy.

Viral hepatitis after liver transplantation

Recurrence of the original liver disease following liver transplantation is a typical complication in viral hepatitis. Recent advances, particularly the development of strategies to prevent or effectively treat hepatitis B, have led to substantial improvements in the post-transplantation outcome of hepatitis B candidates. While the efficacy of antivirals to treatrecurrent hepatitis C has improved in recent years, there is as yet no therapy to universally prevent recurrent infection, and tolerability of antivirals remains a matter of concern.