Efficacy and Safety of Everolimus and Mycophenolic Acid With Early Tacrolimus Withdrawal After Liver Transplantation: A Multicenter Randomized Trial

SIMCER was a 6-mo, multicenter, open-label trial. Selected de novo liver transplant recipients were randomized (week 4) to everolimus with low-exposure tacrolimus discontinued by month 4 (n = 93) or to tacrolimus-based therapy (n = 95), both with basiliximab induction and enteric-coated mycophenolate sodium with or without steroids. The primary end point, change in estimated GFR (eGFR; MDRD formula) from randomization to week 24 after transplant, was superior with everolimus (mean eGFR change +1.1 vs. -13.3 mL/min per 1.73 m² for everolimus vs. tacrolimus, respectively; difference 14.3 [95% confidence interval 7.3-21.3]; p < 0.001). Mean eGFR at week 24 was 95.8 versus 76.0 mL/min per 1.73 m² for everolimus versus tacrolimus (p < 0.001). Treatment failure (treated biopsy-proven acute rejection [BPAR; rejection activity index score >3], graft loss, or death) from randomization to week 24 was similar (everolimus 10.0%, tacrolimus 4.3%; p = 0.134). BPAR was more frequent between randomization and month 6 with everolimus (10.0% vs. 2.2%; p = 0.026); the rate of treated BPAR was 8.9% versus 2.2% (p = 0.055). Sixteen everolimus-treated patients (17.8%) and three tacrolimus-treated patients (3.2%) discontinued the study drug because of adverse events. In conclusion, early introduction of everolimus at an adequate exposure level with gradual calcineurin inhibitor (CNI) withdrawal after liver transplantation, supported by induction therapy and mycophenolic acid, is associated with a significant renal benefit versus CNI-based immunosuppression but more frequent BPAR.

Reduced-dose tacrolimus with mycophenolate mofetil vs. standard-dose tacrolimus in liver transplantation: a randomized study

We conducted a multicenter randomized study in liver transplantation to compare standard-dose tacrolimus to reduced-dose tacrolimus with mycophenolate mofetil to reduce the occurrence of tacrolimus side effects. Two primary outcomes (censored criteria) were monitored during 48 weeks post-transplantation: occurrence of renal dysfunction or arterial hypertension or diabetes (evaluating benefit) and occurrence of acute graft rejection (evaluating risk). Interim analyses were performed every 40 patients to stop the study in the case of increased risk of graft rejection. One hundred and ninety-five patients (control: 100; experimental: 95) had been included when the study was stopped. Acute graft rejection occurred in 46 (46%) and 28 (30%) patients in control and experimental groups, respectively (HR = 0.59; 95% CI: [0.37-0.94]; p = 0.024). Renal dysfunction or arterial hypertension or diabetes occurred in 80 (80%) and 61 (64%) patients in control and experimental groups, respectively (HR = 0.68; 95% CI: [0.49-0.95]; p = 0.021). Renal dysfunction occurred in 42 (42%) and 23 (24%) patients in control and experimental groups, respectively (HR = 0.49; 95% CI: [0.29-0.81]; p = 0.004). Leucopoenia (p = 0.001), thrombocytopenia (p = 0.017) and diarrhea (p = 0.002) occurred more frequently in the experimental group. Reduced-dose tacrolimus with mycophenolate mofetil reduces the occurrence of renal dysfunction and the risk of graft rejection. This immunosuppressive regimen could replace full-dose tacrolimus in adult liver transplantation.

Low rejection rates with tacrolimus-based dual and triple regimens following liver transplantation

We studied the outcome of 345 liver transplant patients who received tacrolimus-based immunosuppressive therapy either as a dual regimen (with corticosteroids, n=172) or as a triple regimen (with corticosteroids and azathioprine, n=173) for 3 months after transplantation (3-month cohort). A further analysis was conducted for the first 195 patients randomised (dual n=100, triple n=95) who were followed up for 12 months after transplantation (12-month cohort). For the 3-month cohort, patient survival was 90.7% (dual) and 91.9% (triple), graft survival after 3 months was 88.4% (dual therapy) and 89.6% (triple therapy). Acute rejections were experienced by 67/172, 39.0% of patients on dual therapy and by 60/173, 34.7% of patients on triple therapy; corticosteroid-resistant rejections were reported in 9 patients (5.2%) in either treatment group. The overall safety profile was similar for the two treatment groups. Significant differences, however, were found for thrombocytopenia (dual 13/172, 7.6%, triple 37/173, 21.4%, p<0.001) and leukopenia (dual 4/172, 2.3%, triple 24/173, 13.9%, p<0.001). For the 12-month cohort, patient survival was 85.6% (dual) and 88.4% (triple) after 1 year. Graft survival was 81.7% (dual) and 85.2% (triple) 12 months after transplantation. Acute rejections were reported for 38/100, 38.0% of patients on dual therapy and 36/95, 37.9% of patients on triple therapy, corticosteroid-resistant rejections were 7/100, 7.0% (dual) and 7/95, 7.4% (triple) of patients. In the 12-month cohort, no significant differences in the safety profiles of the treatment groups were found. We conclude that both tacrolimus-based dual and triple drug regimens provide effective and safe immunosuppression following orthotopic liver transplantation.

Natural killer cell and alphabeta and gammadelta lymphocyte traffic into the liver graft immediately after liver transplantation

BACKGROUND

The persistence and migration of donor leukocytes has been well established, but cellular kinetics immediately after revascularization and the potential relevance of these different lymphocyte populations to spontaneous tolerance remain unclear. During the early hours of revascularization, there is a transitory "congestion" of the liver graft, which is evidence of an early phase that we have termed "first cellular contact."

METHODS

We have carried out by flow cytometry a prospective comparative study of the peak kinetics of lymphocyte subpopulations contained in: (a) peripheral blood and liver grafts at the time of multi-organ extraction from 14 brain-dead donors, (b) recipient peripheral blood before transplantation, and (c) recipient peripheral blood and liver grafts after (t=2 h) declamping and vascularization of the liver graft.

RESULTS

Before transplantation, the liver grafts contained large numbers of natural killer (NK) and NK-like cells with early lymphocyte activation. Immediately after revascularization, there was an influx of recipient NK and NK-like cells into the liver.

CONCLUSIONS

NK and CD3+CD56+ (NK-like) cells flooding into the liver graft immediately after revascularization could rapidly destroy allogeneic cells. However, spontaneous tolerance and the persistence of donor lymphocytes after orthotopic liver transplant could be a result of donor TCRalphabeta NK1.1 liver graft lymphocytes, which may be involved in the destruction of CD8+ T lymphocytes that would have received the apoptosis signal, and to NK and NK-like cell inhibition via inhibitory NK receptors. The decrease in gammadelta T lymphocytes in the two compartments suggests a mechanism of recirculation and capture in other lymphoid organs.

Evaluation of efficacy of liver transplantation in alcoholic cirrhosis using matched and simulated controls: 5-year survival. Multi-centre group

BACKGROUND/AIMS

Alcoholic cirrhosis is the most common cause of liver transplantation in US males. The limited number of donor livers calls for "prioritisation", favouring those patients who will benefit most. The aim was to assess the efficacy of liver transplantation in patients with alcoholic cirrhosis.

METHODS

We compared the survival of 169 transplanted patients with two conservatively treated control groups, one of 169 patients matched for prognostic factors (age, cirrhosis severity, bleeding history) and one of 169 simulated patients.

RESULTS

The probability of survival to 5 years in the transplanted group was 66% (95% confidence interval 58-74%) vs. 52% (44-60; p = 0.03) in the matched group and 54% (51-57; p = 0.01) in the simulated controls. Transplantation was associated with survival (relative risk = 1.51; p = 0.02), independently of risk score (risk = 2.07; p<0.001), indication, period of inclusion, centre experience, and alcohol abstinence. Patients with severe disease (Pugh C11-15) benefited most in terms of 5-year survival: 58% (44-72) vs. 31% (17-45; p = 0.008) in the matched and 35% (30-40; p<0.001) in the simulated control groups. For patients at lower risk there was no significant difference.

CONCLUSIONS

Liver transplantation increases the 5-year survival of patients with severe alcoholic cirrhosis. In patients at lower risk, efficacy of transplantation should be confirmed by longer follow-up or by randomised trial.

In vitro infection of adult normal human hepatocytes in primary culture by hepatitis C virus

In vitro infection of adult normal human hepatocytes in primary culture has been performed for investigating the replication cycle of hepatitis C virus (HCV) in differentiated cells. Hepatocytes were prepared from liver tissue resected from donors who tested negative for HCV, and inoculation was performed 3 days after plating with 33 HCV serum samples of different virus load and genotype. The presence of intracellular HCV RNA, detected by a strand-specific rTth RT-PCR assay, was used as evidence of infection. A kinetics analysis of HCV replication revealed that intracellular negative-strand RNA appeared at day 1 post-infection with a maximum level at days 3 and 5, followed by a decrease until day 14. At day 5, we estimated that the copy level of viral RNA was amplified at least 15-fold in infected cells. The level of intracellular HCV RNA in response to different serum samples was reproducible from one hepatocyte culture to another, suggesting that there is no inter-individual variability in the susceptibility of hepatocytes to HCV infection. These findings indicate that adult human hepatocytes in primary culture retain their susceptibility to in vitro HCV infection and support HCV RNA replication. This model should represent a valuable tool for the study of initial steps of the HCV replication cycle and for the evaluation of antiviral molecules.

Contribution of primary cultures of adult human hepatocytes to the pathophysiology of hepatocellular carcinoma

BACKGROUND/AIMS

The mechanisms of hepatocarcinogenesis are still poorly understood. The development of hepatocellular carcinoma has recently been shown to be associated with increased DNA synthesis in cirrhosis. The aim of this work was to determine whether the high rate of hepatocyte regeneration observed in cirrhotic liver with hepatocellular carcinoma is associated with the presence of a growth factor that could be detectable in the serum.

METHODS

Adult human hepatocytes in primary culture, allowing the evaluation of the release of circulating hepatotrophic factors, were used. These cultures were treated for 48 h with serum from patients with cirrhosis with and without hepatocellular carcinoma, from patients with liver metastasis, and from healthy subjects. The rate of DNA synthesis in these cultures was assessed by measuring the amount of [3H]-thymidine incorporation into genomic DNA.

RESULTS

On average, the synthesis of DNA was increased 2.5-, 2.2-, 2.1-, and 2.3-fold, respectively, in response to serum from patients with cirrhosis with hepatocellular carcinoma, from patients with cirrhosis without hepatocellular carcinoma, from patients with liver metastasis, and from healthy subjects.

CONCLUSIONS

We conclude that the hepatotrophic activity of the serum is not significantly different in patients with cirrhosis with or without hepatocellular carcinoma. These results suggest that the increased DNA synthesis in hepatocytes of cirrhotic liver with hepatocellular carcinoma might be due to proliferative factor(s) acting by paracrine or autocrine pathways.

Hepatitis B virus (HBV)-specific in vitro antibody production by peripheral blood mononuclear cells (PBMC) after vaccination by recombinant hepatitis B surface antigen (rHBsAg)

To study the immunization induced by rHBsAg, we analysed the in vitro antibody production (IVAP) to HBsAg by PBMC from 18 subjects vaccinated by two injections on days 0 and 30. HBsAg-specific IVAP was detectable in all subjects after both the first and the second injection, and lasted for about 10 days and then disappeared. However, when the spontaneous HBsAg-specific IVAP became negative, HBsAg stimulation of PBMC cultures induced again a specific HBsAg IVAP. Cultures of cell populations separated by erythrocyte rosetting or Percoll density centrifugation showed that the cells responsible for spontaneous secretion, after in vivo stimulation, were low-density B lymphocytes. High-density B lymphocytes were involved in anti-HBs production induced by in vitro stimulation when spontaneous secretion disappeared. These data suggest that the IVAP test could be a source of important information along with serologic analysis for exploration of the immune response to hepatitis B vaccine.