Immunosuppression in hepatitis B virus and hepatitis C virus transplants: special considerations

A risk assessment model of acute liver allograft rejection by genetic polymorphism of CD276

Background

Liver transplantation is an effective therapy for end‐stage liver diseases and acute liver failure. After the operation, however, recipients may suffer grafts loss induced by alloimmune reaction, which is termed as acute allograft rejection. The interaction between costimulatory molecules, CD276, and its ligand, TREML2, promotes T cell‐mediated immune response, as well as acute or chronic allograft rejection. Our research aimed at correlating genetic polymorphisms of CD276/TREML2 with acute rejection, and evaluating its prognostic value of acute rejection after liver transplantation.

Methods

The study enrolled a total of 388 recipients. Among them, acute allograft rejection was observed in 54 cases. We performed single nucleotide polymorphism genotyping of CD276, including rs11072431, rs11574495, rs12593558, rs12594627, rs2127015, rs3816661 and rs7176654, and TREML2, including rs4714431, rs6915083, rs7754593, and rs9394767 from preoperative peripheral blood genome DNA.

Results

We found rs2127015 of CD276, rs6915083 and rs7754593 of TREML2, and HBV infection as well were associated with acute rejection. And, rs2127015 influences CD276 expression. Moreover, we established a risk assessment model, composited by statistically proved risk factors.

Conclusion

By integrating both clinical and genetic variables, liver transplant recipients can be categorized into different risk groups, and might benefit from individualized therapies.

Prednisolone does not affect direct-acting antivirals against hepatitis C, but inhibits interferon-alpha production by plasmacytoid dendritic cells

BACKGROUND

Chronic hepatitis C virus (HCV) infection compromises long-term outcomes of liver transplantation. Although glucocorticosteroid-based immunosuppression is commonly used, discussion is ongoing on the effect of prednisolone (Pred) on HCV recurrence and response to antiviral therapy post transplantation. Recently, new drugs (direct-acting antivirals) have been approved for the treatment of HCV, however, it remains unknown whether their antiviral activity is affected by Pred. The aim of this study was to investigate the effects of Pred on the antiviral activity of asunaprevir (Asu), daclatasvir (Dac), ribavirin (RBV), and interferon-alpha (IFN-α), and on plasmacytoid dendritic cells (PDCs), the main IFN-α-producing immune cells.

METHODS

The effects of Pred and antiviral compounds were tested in both a subgenomic and infectious HCV replication model. Furthermore, effects were tested on human PDCs stimulated with a Toll-like receptor-7 ligand.

RESULT

Pred did not directly affect HCV replication and did not inhibit the antiviral action of Asu, Dac, RBV, or IFN-α. Stimulated PDCs potently suppressed HCV replication. This suppression was reversed by treating PDCs with Pred. Pred significantly decreased IFN-α production by PDCs without affecting cell viability. When Asu and Dac were combined with PDCs, a significant cooperative antiviral effect was observed.

CONCLUSION

This study shows that Pred acts on the antiviral function of PDCs. Pred does not affect the antiviral action of Asu, Dac, RBV, or IFN-α. This implies that there is no contraindication to combine antiviral therapies with Pred in the post-transplantation management of HCV recurrence.

Genetic polymorphism of interferon regulatory factor 5 (IRF5) correlates with allograft acute rejection of liver transplantation

BACKGROUND

Although liver transplantation is one of the most efficient curative therapies of end stage liver diseases, recipients may suffer liver graft loss opst-operation. IRF-5, a member of Interferon Regulatory Factors, functions as a key regulator in TLR4 cascade, and is capable of inducing inflammatory cytokines. Although TLR4 has been proved to contribute to acute allograft rejection, including after liver transplantation, the correlation between IRF5 gene and acute rejection has not been elucidated yet.

METHODS

The study enrolled a total of 289 recipients, including 39 females and 250 males, and 39 recipients developed acute allograft rejection within 6 months post-transplantation. The allograft rejections were diagnosed by liver biopsies. Genome DNA of recipients was extracted from pre-operative peripheral blood. Genotyping of IRF-5, including rs3757385, rs752637 and rs11761199, was performed, followed by SNP frequency and Hardy-Weinberg equilibrium analysis.

RESULTS

The genetic polymorphism of rs3757385 was found associated with acute rejection. G/G homozygous individuals were at higher risk of acute rejection, with a P value of 0.042 (OR = 2.34 (1.07-5.10)).

CONCLUSIONS

IRF5, which transcriptionally activates inflammatory cytokines, is genetically associated with acute rejection and might function as a risk factor for acute rejection of liver transplantations.

Hepatitis B recurrence after liver transplantation: a single center experiences and review the literature

BACKGROUND

Despite the advances in the treatment of chronic hepatitis B virus (HBV) infection, liver transplantation (LT) remains the only hope for many patients with end-stage liver diseases resulting from HBV.

OBJECTIVES

The aim of this study was to investigate the rate of HBV recurrence in cases that had undergone LT due to the HBV related liver cirrhosis.

PATIENTS AND METHODS

Forty-nine patients who underwent LT due to HBV related cirrhosis since 2001 to 2009 in Shiraz Organ Transplantation Center were enrolled in the present study. They were asked to complete the planned questionnaire and also to sign the informed consent in order to take part in this study. Post-transplant prophylaxis protocol against HBV recurrence was based on a hundred milligrams of lamivudine daily plus intramuscular injections of hepatitis B immune globulin (HBIG) with appropriate dosage to keep anti-HBs antibody titer above 300 IU/L and 100 IU/L in the first six months and afterwards, respectively. Blood samples were obtained and checked for HBsAg, HBeAg, and the titers of Anti -HBsAb as well as Anti- HBeAb with ELISA. A quantitative HBV DNA assay was also done on all samples (GENE-RAD® Real-time PCR).

RESULTS

There were 91.8% males and 8.2% females enrolled in the study. The duration of post-transplant prophylaxis ranged from 3 months to 8 years (mean 18.9 ± 19.3 months). HBsAg and HBeAg were positive in 24.5% and 2% of cases, respectively. Real-time PCR for HBV DNA were zero copies/mL in 91.8% of patients, none of which represented a positive value for HBV recurrence (Positive > 10,000 copies/mL). The mean Anti-HBs Ab titer was 231.7 ± 135.9 IU/L; it was above 100 IU/L in 71.4% of patients. Thirty-seven (75.5%) of the patients were taking tacrolimus plus mycophenolate mofetil, 6 (12.2%) were on cyclosporine plus mycophenolate mofetil, and 6 (12.2%) were taking sirolimus plus mycophenolate mofetil. HBsAg was detectable in seven patients taking tacrolimus plus mycophenolate mofetil (18.9%), in four patients taking cyclosporine plus mycophenolate mofetil (66.7%), and in one patient among the six who were taking sirolimus plus mycophenolate mofetil (16.7%). There was no significant statistical correlation between the presence of a positive value for HBsAg and the immunosuppression regimen or Anti HBsAb titer (P ˃ 0.05). Presence of a positive value for HBsAg was not predictive of a positive HBV DNA or its level in blood (P ˃ 0.05).

CONCLUSIONS

Post-transplant HBV prophylaxis with lamivudine and intramuscular HBIG with appropriate dosage to keep anti-HBs antibody titer above 300 IU/L in the first six months and above 100 IU/L afterwards is effective for prevention of HBV recurrence after LT.

Liver transplantation for HBV and management of reinfection

Follicular non-Hodgkin's lymphoma (NHL) represents the most common indolent lymphoma with a median survival of 10 years. A new prognostic index (FLIPI) provides prognostic information at diagnosis and at relapse. Initial treatments combining monoclonal antibody therapy using rituximab with chemotherapy appear to increase the response rate and decrease the risk of relapse with little increase in toxicity. Promising phase III trial results demonstrating improvements in outcome using rituximab have recently been reported. A number of phase II trials have also demonstrated encouraging activity combining radiolabeled antibodies in sequence with chemotherapy. The role of high-dose therapy and autologous transplantation is becoming more defined, with improvements in progression-free survival observed in the upfront and relapsed setting. The application of allogeneic transplantation, once restricted to young otherwise healthy patients has shown encouraging activity in older, relapsed, and refractory patients using nonmyeloablative conditioning regimens. These new treatment options make the management of newly diagnosed patients both exciting and a challenge.