Calcineurin inhibition and disease recurrence in the hepatitis C virus-positive liver transplant recipient

Liver transplantation for primary biliary cirrhosis in a hepatitis endemic region: a single-center Asian experience

From March 1984 to November 2008, we performed 539 primary liver transplantations (LTs). Nineteen (19, 3.5%) were transplanted for end-stage liver disease secondary to primary biliary cirrhosis (PBC). There were 17 (89%) female and 2 (11%) male recipients. The overall mean age was 50.3 ± 6.3 yr. The mean model for end-stage liver disease, and Child-Turcotte-Pugh scores were 20.7 ± 2.1, and 11.0 ± 0.5, respectively. There were 2 (11%) United Network for Organ Sharing status 3, 16 (84%) 2B, and 1 (5%) 2A patients. Fourteen patients (14, 73.7%) underwent living donor LT, and five patients (26.3%) received deceased donor LT. The primary immunosuppression consisted of cyclosporine (n = 5) and tacrolimus (n = 14). Liver function returned to normal one month after transplantation. The overall mean follow-up was 5.8 ± 0.8 yr (range, four months to 15.7 yr). The overall one-, three-, and five-yr survival rates were 94.7%, 89.2%, and 89.2%, respectively. Without hepatitis B virus (HBV) prophylaxis, one patient acquired de novo HBV infection after receiving a graft from an anti-HBc(+) donor. Another patient developed recurrent hepatitis C infection and expired 25 months after transplantation. Our results showed that HBV prophylaxis was effective not only against de novo infection, but it also worked on pre-transplant HBV carrier with PBC and helped in virus clearance.

The acquisition time of infection: a determinant of the severity of hepatitis C virus-related liver disease in renal transplant patients

BACKGROUND

The aim of this study was to compare the clinical and histopathological course of HCV infection acquired before and during or after renal transplantation.

METHODS

According to HCV status, 197 RT patients were divided into three groups. At the time of RT, anti-HCV antibody was positive in 47 patients (pre-RT HCV group). In 27 patients, in whom anti-HCV negative at the time of RT, anti-HCV and/or HCV RNA was found to be positive following an ALT elevation episode after RT (post-RT HCV group). Both anti-HCV and HCV RNA were negative at all times in remaining 123 patients (control group).

RESULTS

Liver biopsy was performed in 31 of 47 patients in pre-RT and 24 of 27 in post-RT HCV group after RT. Duration of follow-up was similar in all groups with a mean of 7.1 +/- 4.0 yr. Ascites and encephalopathy were seen in only post-RT HCV group (22%). Histological grade (6.5 +/- 2.7 vs. 4.1 +/- 1.4) and stage (2.0 +/- 1.5 vs. 0.8 +/- 0.8) was significantly severe in post-RT HCV group (p < 0.01). Three patients died due to liver failure in post-RT HCV group.

CONCLUSIONS

HCV infection acquired during or after RT shows a severe and rapidly progressive clinicopathological course, which is significantly different from pre-transplant anti-HCV positive patients.

Cellular models for the screening and development of anti-hepatitis C virus agents

Investigations on the biology of hepatitis C virus (HCV) have been hampered by the lack of small animal models. Efforts have therefore been directed to designing practical and robust cellular models of human origin able to support HCV replication and production in a reproducible, reliable and consistent manner. Many different models based on different forms of virions and hepatoma or other cell types have been described including virus-like particles, pseudotyped particles, subgenomic and full length replicons, virion productive replicons, immortalised hepatocytes, fetal and adult primary human hepatocytes. This review focuses on these different cellular models, their advantages and disadvantages at the biological and experimental levels, and their respective use for evaluating the effect of antiviral molecules on different steps of HCV biology including virus entry, replication, particles generation and excretion, as well as on the modulation by the virus of the host cell response to infection.

Correlation between liver fibrosis and inflammation in patients transplanted for HCV liver disease

Hepatitis C virus (HCV) re-infection after liver transplantation (LT) is characterized by an accelerated disease progression in recent years with unclear mechanisms. We evaluate the relationship between progression of liver fibrosis and histological necro-inflammation in HCV recipients, according to age of transplant. Fifty-five patients transplanted (1993-2002) for HCV liver disease, were included in the study. Recipients were retrospectively stratified in three different age of transplant, of 40 months each: group 1) from January 1993 to May 1996; group 2) from June 1996 to august 1999; group 3) from September 1999 to December 2002. Grading (necro-inflammation) and staging (fibrosis) scores were evaluated in liver biopsies at 1, 2 and 3 years from LT (Ishak classification). For all age of transplant the main factor associated with fibrosis progression, was grading score (p < 0.05). However mean staging score for each point of grading increased from 0.3 +/- 0.2 in older LT to 0.7 +/- 0.5 in newer ones (p = 0.01). In conclusion in HCV-LT patients (1) liver fibrosis is strictly associated to histological necro-inflammation; (2) the proportion of this relationship has been changing in recent years since newer LT patients, show an increased amount of fibrosis in comparison with the older ones, for similar grading score.

NIM811, a nonimmunosuppressive cyclosporine analogue, suppresses collagen production and enhances collagenase activity in hepatic stellate cells

BACKGROUND/AIMS

A recent decrease in patient survival has been reported among hepatitis C virus (HCV)-infected liver transplant recipients and this may be attributable to progression of fibrosis. We reported previously that cyclosporine suppressed the proliferation of, and collagen production in, hepatic stellate cells (HSCs). Here, we investigated the effects of NIM811, a cyclosporine analogue, on cell growth, collagen production and collagenase activity in HSCs.

METHODS

Rat HSCs and human HSC-derived TWNT-4 cells were cultured for the study. The expression of collagen, matrix metalloproteinase 1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) and collagenase activity was evaluated. Cell proliferation and apoptosis were measured. Phosphorylation of mitogen-activated protein kinases (MAPKs), Smad2 and Smad3 was evaluated. The expression of the tumour growth factor-beta (TGF-beta)-receptor and Smad7 genes was also evaluated.

RESULTS

NIM811, as well as cyclosporine, suppressed the transcription and synthesis of collagen and stimulated the production of MMP-1 with a concomitant enhancement of collagenase activity, although it did not change the expression of TIMP-1. NIM811 inhibited proliferation without induction of apoptosis. In the MAPKs and TGF-beta signalling pathways, NIM811 enhanced the phosphorylation of JNK and p38, but not extracellular signal-regulated kinases 1 and 2, and suppressed the phosphorylation of Smad2 and Smad3, accompanied by increased Smad7 transcription and decreased TGF-beta-receptor transcription.

CONCLUSION

These findings demonstrate that NIM811 not only suppresses collagen production and proliferation but also increases collagenase activity. These effects are accompanied by inhibition of TGF-beta signalling pathways.

A cyclosporine-based immunosuppressive regimen may be better than tacrolimus for long-term liver allograft survival in recipients transplanted for hepatitis C

Rapid recurrence of severe hepatitis C (HCV) after liver transplantation is a major barrier to survival of the transplanted liver. While cyclosporine (CsA) in vitro has been shown to suppress HCV replication, an effect is not seen with tacrolimus (Tac). Evidence is inconsistent whether or how this translates to clinical practice. To expand the evidence on this issue, we analyzed graft survival and histological outcomes after liver transplantation for HCV hepatitis.

METHODS

Using our longitudinal database (1991 onward) graft outcomes for all liver transplant recipients with HCV were evaluated (105 grafts in 97 patients). Severe activity, severe fibrosis, and graft survival were analyzed. All liver biopsies were scored (blinded) according to the Ludwig scale. Immunosuppression was based on prednisone and a calcineurin inhibitor (Tac n = 89, 85%; CsA n = 15, 14%). Comparisons of outcomes using CsA versus Tac therapy were done using survival analysis via the log-rank test.

RESULTS

Graft survival was significantly better in the CsA group. Although there was no apparent difference in severe activity (grade 2), there was a statistically significant difference in graft survival without fibrosing cholestatic hepatitis (P = .01) and a trend toward a difference in fibrosis-free survival (P = 0.1). The rate of sustained response to antiviral therapy was twice as high in the CsA group, 50% versus 22% (P = 0.16; NS).

CONCLUSIONS

Graft survival in liver transplant recipients with HCV may be greater with CsA-based immunosuppression. There may also be a lower rate of fibrosing cholestatic hepatitis in this group.

Patterns of recurrent hepatitis C after liver transplantation in a recent cohort of patients

Clinicopathologic trends of recurrent hepatitis C after liver transplantation (LT) in hepatitis C (HCV) patients seem to have changed in recent years. Our aims were to define the current post-LT patterns of HCV recurrence and identify features of diagnostic and/or prognostic significance. Detailed analysis was performed on 92 HCV patients who underwent LT from June 1999 to December 2003 and survived early post-LT period. The study patients were grouped, as follows: no histologic recurrence (n = 31), "typical" recurrent HCV (n = 52), and post-LT autoimmune-like hepatitis ("AIH-like") (n = 9). The typical and AIH-like groups had mostly common features with post-LT progressive fibrosis (stage > or =2) more frequent in the latter. Based on post-LT progressive fibrosis (stage > or =2), the 2 post-LT hepatitis categories were regrouped as progressive (n = 24) and nonprogressive (n = 37). High viral counts, HCV genotype 1, and native liver inflammation grade 2 or higher with plasmacytic periseptitis were more frequent in progressive cases than nonprogressive or nonrecurrent cases. Sex mismatch of male recipient and female donor was more common in nonrecurrent group. Overall, death rate was comparable in all groups; however, post-LT HCV-related deaths were more common in progressive cases. In conclusion (1) two thirds (66.2%) of HCV patients developed histologic hepatitis after LT with either typical or AIH-like features; (2) progressive fibrosis was seen in 39.3% of patients with post-LT hepatitis and 26% of the entire study group and was more frequent in AIH-like cases; (3) inflammation grade 2 or higher with plasmacytic periseptitis in native livers may be a predictor of post-LT progressive fibrosis; and (4) male recipient/female donor combination was more common in nonrecurrent cases.

Retrospective Study of the Effects of Cyclosporine in Comparison With Azathioprine on Renal Transplant Recipients Infected With Hepatitis C Virus

A recent report noted that cyclosporine (CsA) inhibits replication of the hepatitis C virus (HCV) in vitro. Thus, CsA may be a superior immunosuppressant for renal transplant recipients infected with HCV. In the present retrospective study, we assessed whether CsA reduced the clinical impact of HCV infection among those patients. A total of 405 renal transplants were performed between 1973 and 2005, of whom we studied 189 who received CsA-based immunosuppression (CsA group) vs 108 who received an azathioprine-based regimen (AZA group). There were 44 HCVAb carriers and 145 noncarriers in the CsA group, and 41 carriers and 67 noncarriers in the AZA group. Our results showed that patient survival rate was significantly worse among HCVAb carriers than among noncarriers, as the overall survival rates were 82.9% and 90.9%, respectively, after 10 years and 71.5% and 85.7%, respectively, after 20 years (P = .0003). Patient survival rates were also significantly worse in HCVAb carriers than in noncarriers in both groups, which were 83.2% and 95.0%, respectively, after 10 years, and 74.7% and 88.8%, respectively, after 20 years (P = .0147) in the CsA group, and 82.9% and 83.6%, respectively, after 10 years and 70.7% and 80.6%, respectively, after 20 years (P = .0171) in the AZA group. Conversely, no significant difference was seen in patient survival rate for HCVAb carriers between the two groups (83.2% vs 82.9% at 10 years, and 74.7% vs 70.7% at 20 years, P = .8195). Our results confirmed that HCV infection has a negative impact on the long-term survival of renal transplant patients who receive either a CsA-based or an AZA-based regimen, suggesting that CsA does not have a positive impact on HCV carriers.

Mycophenolic acid inhibits hepatitis C virus replication and acts in synergy with cyclosporin A and interferon-alpha

BACKGROUND & AIMS

Chronic hepatitis C virus (HCV) infection is the leading indication for liver transplantation. Clinical evidence suggests that particular immunosuppressive agents can have an influence on HCV recurrence. Cyclosporine A (CsA) specifically inhibits HCV replication through blocking the viral RNA polymerase enzyme NS5B. In this study, we investigated the effect of mycophenolic acid (MPA) and other immunosuppressants on HCV replication.

METHODS

MPA and other compounds were tested in vitro using an HCV-replication model containing a luciferase reporter gene.

RESULTS

At clinically relevant concentrations (1.0-6.0 microg/mL), MPA inhibited HCV replication to approximately 75%. CsA and interferon (IFN)-alpha also showed inhibition in a dose-dependent manner. In these short-term (18 hours) experiments, MPA did not inhibit cell proliferation or induce cell death, which could have accounted for the antiviral effect. In contrast to the antiviral activity of MPA against West Nile virus, the effect of MPA on HCV replication was guanosine independent. When combined, MPA and CsA showed significant synergistic inhibition of replication, reaching maximum inhibition of approximately 90% at the highest doses. Synergistic effects were observed with suboptimal concentrations of IFN-alpha with MPA or CsA. The kinetics of HCV inhibition by MPA, CsA, and IFN-alpha were clearly distinct, with earliest effects seen with IFN-alpha. No specific inhibitory effects were observed with tacrolimus or rapamycin.

CONCLUSIONS

The immunosuppressive drug MPA is as potent as CsA as an inhibitor of HCV replication. MPA was shown to have a distinct anti-HCV mechanism of action, independent of cell proliferation and guanosine depletion.

Pharmacological targeting of catalyzed protein folding: the example of peptide bond cis/trans isomerases

Peptide bond isomerases are involved in important physiological processes that can be targeted in order to treat neurodegenerative disease, cancer, diseases of the immune system, allergies, and many others. The folding helper enzyme class of Peptidyl-Prolyl-cis/trans Isomerases (PPIases) contains the three enzyme families of cyclophilins (Cyps), FK506 binding proteins (FKBPs), and parvulins (Pars). Although they are structurally unrelated, all PPIases catalyze the cis/trans isomerization of the peptide bond preceding the proline in a polypeptide chain. This process not only plays an important role in de novo protein folding, but also in isomerization of native proteins. The native state isomerization plays a role in physiological processes by influencing receptor ligand recognition or isomer-specific enzyme reaction or by regulating protein function by catalyzing the switch between native isomers differing in their activity, e.g., ion channel regulation. Therefore elucidating PPIase involvement in physiological processes and development of specific inhibitors will be a suitable attempt to design therapies for fatal and deadly diseases.

Review article: hepatitis C virus and calcineurin inhibition after renal transplantation

The impact of hepatitis C virus on patient and graft survival after renal transplantation remains controversial. However, recent studies have given emphasis on the detrimental role of hepatitis C on long-term patient and graft survival after renal transplantation. Various mechanisms can promote the lower survival in hepatitis C virus-positive recipients, i.e. post-transplant diabetes mellitus, liver disease and infections. Novel evidence has been accumulated showing the inhibitory activity of ciclosporin on the hepatitis C virus replication rate in human hepatocytes; ciclosporin has been shown in vitro to suppress hepatitis C virus replication as effectively as interferon alpha. This effect has not been seen with tacrolimus and is separate from its immunosuppressive activity. Data from patients with normal kidney function or after bone marrow transplantation show that ciclosporin inhibits hepatitis C virus replication. It appears that the progression of liver fibrosis is slower in hepatitis C virus-positive liver transplant recipients treated with ciclosporin than tacrolimus. In contrast, the clinical outcome of hepatitis C in hepatitis C virus-positive patients after liver transplantation treated with ciclosporin vs. tacrolimus has given mixed results. No information after renal transplantation is available. Various parameters can promote the worsening of hepatitis C after renal transplantation but choice of calcineurin inhibition is one of the few risk factors that can potentially be modified by the physician. Prospective, comparative trials of ciclosporin and tacrolimus with large size and adequate follow-up after renal transplantation are in progress.

Exogenous administration of immunomodulatory therapies in hematopoietic cell transplantation: an infectious diseases perspective

PURPOSE OF REVIEW

In contrast to the recipient of a solid organ transplantation, the immunological competence of recipients of hematopoietic cell transplantation does not correlate well with the administration of non-corticosteroid immunosuppressive agents. This apparent paradox reflects the unique and dynamic conglomeration of factors that affect immune reconstitution after hematopoietic cell transplantation. The following is the second part of a review of the recent primary literature regarding exogenous immunomodulatory influences as they pertain to infections in the setting of hematopoietic cell transplantation.

RECENT FINDINGS

The main themes of published primary research from 2004 to the present include the influence of exogenously administered immunomodulatory agents on infectious complications after hematopoietic cell transplantation.

SUMMARY

The use of immunomodulatory agents such as monoclonal antibodies directed against lymphocyte antigens in the treatment of hematopoietic malignancy has greatly expanded during the past decade. Separate trials of the potential utility of these agents, particularly in the reduction of graft-versus-host disease, in the setting of hematopoietic cell transplantation have yielded encouraging results. Given the infancy of these new approaches, it is not possible to make definitive statements regarding the relative risk of serious infection with each therapy. It is clear that a reduction in regimen-related non-infectious complications or mortality does not necessarily ensure a reduction in clinically significant infections. Improvements in early diagnostic and therapeutic options for these infections now bring us to an era of understanding pathogens such as cytomegalovirus as probes of the functional reconstitution of immunity.