Evolution of immunosuppression in liver transplantation: contribution of cyclosporine

End-stage heart failure: The future of heart transplant and artificial heart

In the last decades, outcomes significantly improved for both heart transplantation and LVAD. Heart transplantation remains the gold standard for the treatment of end stage heart failure and will remain for many years to come. The most relevant limitations are the lack of grafts and the effects of long-term immunosuppressive therapy that involve infectious, cancerous and metabolic complications despite advances in immunosuppression management. Mechanical circulatory support has an irreplaceable role in the treatment of end-staged heart failure, as bridge to transplant or as definitive implantation in non-transplant candidates. Although clinical results do not overcome those of HTx, improvement in the new generation of devices may help to reach the equipoise between the two therapies. This review will go through the evolution, current status and perspectives of both therapeutics.

Recipient Age and Mortality After Liver Transplantation: A Population-based Cohort Study

BACKGROUND

The feasibility of liver transplantation (LT) in elderly recipients remains a topic of debate.

METHODS

This cohort study evaluated the impact of recipient's age on LT outcome between January 2007 and May 2016 covered by the Korean National Health Insurance system (n = 9415). Multilevel regression models were used to determine the impact of recipient's age on in-hospital and long-term mortality after LT.

RESULTS

All patients had a first LT, with 2473 transplanted with liver from deceased donors (DD) and 6942 from living donors. The mean age was 52.2 ± 9.0 years. Most LT were performed on patients in their 50s (n = 4290, 45.6%) and 0.9% (n = 84) of the LT was performed on patients older 70 years. The overall in-hospital mortality was 6.3%, and the 3-year mortality was 11.3%. The in-hospital mortality included, 13.5% associated with DDLT and 3.7% involved living donor LT. When compared with that for patients aged 51 to 55 years, the risk of death among recipients older than 70 years was about fourfold higher after adjusting for baseline liver disease (odds ratio, 4.1; 95% confidence interval, 2.21-7.58), and was nearly threefold higher after adjusting for baseline liver disease and perioperative complications (odds ratio, 2.92; 95% confidence interval, 1.37-6.24). Also, the cost of LT increased significantly with age.

CONCLUSIONS

The data show that age remains an important risk factor for LT, suggesting that LT should be considered with caution in elderly recipients.

Tolerance and chimerism and allogeneic bone marrow/stem cell transplantation in liver transplantation

The liver has particular tolerogenic properties that allow its spontaneous acceptance in some animal species. Liver structure is considered to favor a tolerogenic environment. The peripheral tolerance mechanisms also play a role in spontaneous tolerance to liver graft. In a clinical setting, the main challenge nowadays facing liver transplantation is minimization of immunosuppression with the goal of donor-specific tolerance. Mechanisms involved in tolerance to transplanted organs are complex and partly unknown. A significant mechanism in tolerance induction is chimerism. Chimerism can be induced through transplantation of allogeneic donor bone marrow/stem cells under appropriate host conditioning. This review focuses on the tolerance mechanisms in liver transplantation and highlights the role of chimerism and allogeneic bone marrow/stem cell transplantation in tolerance development.

Review of the early diagnoses and assessment of rejection in vascularized composite allotransplantation

The emerging field of vascular composite allotransplantation (VCA) has become a clinical reality. Building upon cutting edge understandings of transplant surgery and immunology, complex grafts such as hands and faces can now be transplanted with success. Many of the challenges that have historically been limiting factors in transplantation, such as rejection and the morbidity of immunosuppression, remain challenges in VCA. Because of the accessibility of most VCA grafts, and the highly immunogenic nature of the skin in particular, VCA has become the focal point for cross-disciplinary approaches to developing novel approaches for some of the most challenging immunological problems in transplantation, particularly the early diagnoses and assessment of rejection. This paper provides a historically oriented introduction to the field of organ transplantation and the evolution of VCA.

Liver transplant outcomes in HIV-infected patients: a systematic review and meta-analysis with synthetic cohort

OBJECTIVES

The relative success of liver transplantation in those with HIV compared to HIV-uninfected individuals remains a point of intense debate. We aimed to evaluate the effectiveness of liver transplantation in HIV-hepatitis co-infected patients using a meta-analysis and individual patient data meta-analysis as a synthetic cohort.

METHODS

We searched MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE (inception to 2010), AMED, CINAHL, TOXNET, Development and Reproductive Toxicology, Hazardous Substances Databank, Psych-info and relevant conferences. We included cohort studies and individual case-reports evaluating survival of co-infected transplant patients. We abstracted data on cohort and case demographics and outcomes. We pooled cohorts using a random-effects analysis and created a synthetic cohort of cases using individual patient data. We confirmed this with the pooled cohort analysis.

RESULTS

We included 15 cohort studies and 49 case series with individual patient data. At 12 months, 84.4% [95% confidence interval (CI) 81.1-87.8%] of patients had survived. Within the HIV-infected population evaluated, HIV-hepatitis B virus (HBV) co-infection was associated with optimal survival. In an adjusted model, individuals positive for HBV were 8.28 (95% CI 2.26-30.33) times more likely to survive when compared to those without HBV. Further, individuals with an undetectable HIV viral load at the time of transplantation were 2.89 (95% CI 1.41-5.91) times more likely to survive when compared to those with detectable HIV viremia. Hepatitis C virus was not a predictor of patient survival when adjusted for by other key predictors [0.54 (95% CI 0.17-1.80)].

The prevalence and natural history of untreated isolated central perivenulitis in adult allograft livers

Central perivenulitis (CP) in the allograft liver can be associated with portal-based acute cellular rejection and autoimmune hepatitis or can occur in isolation (isolated CP). Although several studies have demonstrated the significance of CP, the prevalence and natural history of untreated isolated CP have not been well studied. We examined 100 adult allograft liver recipients who had long-term follow-up, had routine protocol biopsies, and received no treatment for isolated CP. Isolated CP was identified in 28 (28%) patients. It occurred late at a mean of 658 days. Interestingly, patients with late isolated CP (defined as >3 months posttransplant) usually manifested only mildly to modestly elevated liver function tests. However, late isolated CP was associated with prior and subsequent allograft complications. Nearly all (94%) cases of late isolated CP occurred in patients who had early episodes of CP and/or acute cellular rejection. Of 13 patients who developed adverse outcomes in their allografts (zone 3 fibrosis in 10, de novo autoimmune hepatitis in 3, and ductopenia in 3), all experienced episodes of prior CP, and 12 (92%) had late CP; 1 patient required retransplant for chronic rejection, but all were alive within the last year. In summary, "transplant-associated" isolated CP occurs in 28% of adult patients, early CP is predictive of late CP, and late CP (often present as isolated CP) is associated with long-term liver injury in some patients.

Short-term induction therapy with anti-thymocyte globulin and delayed use of calcineurin inhibitors in orthotopic liver transplantation

The appropriate time point for starting immunosuppressive treatment with calcineurin inhibitors after orthotopic liver transplantation (OLT) has been a subject of debate. The aim of the study was to analyze the effects of anti-thymocyte globulin (ATG) induction therapy on rejection, renal function, infection, tumor rate, and survival. We retrospectively analyzed 391 patients after OLT who had either received calcineurin inhibitors immediately after OLT (n = 129) or after an initial short-term Thymoglobulin induction therapy (n = 262). The 1-year acute rejection rate was 14.5% vs. 31.8% in favor of ATG (P = 0.0008). Rejection grades and the need for treatment also differed significantly (7.3% vs. 23.3%; P = 0.001). Serum creatinine at transplantation was similar in both groups (1.14 mg/dL vs.1.18 mg/dL; P = NS). Postoperative hemofiltration was less frequently seen after induction therapy (P < 0.05). Reduced renal function at 1 year was commonly observed, but serum creatinine (1.26 mg/dL vs. 1.37mg/dL; P = 0.015) and glomerular filtration rate (81 mL/min vs. 75 mL/min; P = 0.02) were far better in the ATG group. Undesired side effects occurred at a similar rate in both groups. Five-year patient survival was also similar in the 2 groups (70.1% and 74.3%; P > 0.05). Short-term ATG induction therapy with delayed administration of calcineurin inhibitors led to a more favorable rejection rate and an improved clinical course in case of a rejection episode. It has beneficial effects on renal function immediately after OLT as well as later, and no additional harmful effects.

Barriers preventing liver transplantation in Canadians with HIV-infection--perceptions of HIV specialists

Liver transplantation is a life-saving procedure with demonstrated utility. There are accumulating data indicating that this procedure is helpful in HIV-infected patients as well. Liver transplantation is currently largely unavailable to those living with HIV in Canada. Understanding the obstacles to this procedure is the first step to increasing access. Between August 2005 and November 2005, HIV physicians, one from each Canadian HIV Trials Network site, were asked to complete a quantitative questionnaire on adult liver transplant access and need. Forty-six per cent (16 of 35) of sites responded. A median 20% of the nearly 12,700 HIV patients followed at these sites had concurrent liver disease (20% caused by hepatitis C virus, 5% caused by hepatitis B virus and 5% were alcohol-related). On average, two patients per site were thought to be appropriate candidates for liver transplant evaluation. Eighty per cent of respondents anticipated increased need for liver transplantation over the next five years. Organ supply was universally identified as the chief obstacle to transplantation in patients with HIV. Other key issues included risk of hepatitis C virus reinfection and transplant surgical team willingness. Based on these data, it is believed that these issues should be the focus of efforts designed to increase access to transplantation in Canadians with end-stage liver disease and concurrent HIV.

Short-term versus long-term induction therapy with antithymocyte globulin in orthotopic liver transplantation

T-cell depletion is an essential aspect of clinical immunosuppression. The aim of the present study was to compare the efficacy of two dosage regimens in this setting. We retrospectively compared 246 patients (group 1) who received a 10-day antithymocyte globulin (ATG) induction protocol with 226 patients (group 2) who received a 3-day protocol. The 6-month rejection rate was 22.3% in group 1 and 12.7% in group 2 (P = 0.03). The sub-analysis showed a higher rejection rate in patients with cholestatic disease (P = 0.01), who were more numerous in group 1. This resulted in an overall difference between the groups. Rates of de novo malignancies and recurrent hepatocellular carcinoma were identical. Viral infection rates were 16% and 18%, respectively (P > 0.5). The rates of bacterial and fungal infection were also similar (37% vs. 42%, P > 0.1). However, infection and ATG administration are independent risk factors for survival. A lower rate of fatal infection was observed in group 2 (P = 0.01), while the 10-day ATG regimen had a detrimental effect on patients who had infection (P < 0.0001). Our results strongly support the application of 3-day ATG induction therapy regimen after orthotopic liver transplantation, as it is associated with the same rejection rate as long-term ATG induction therapy, without the negative survival effect of the latter due to lethal infection.

Avoiding calcineurin inhibitors in the early post-operative course in high-risk liver transplant recipients: The role of extracorporeal photopheresis

The aim of this work is to report on the results of a single-center, prospective study on the feasibility of calcineurin-inhibitor (CNI)-staggered immunosuppression by use of extracorporeal photopheresis (ECP) in liver transplant (LT) recipients at risk of renal and neurological complications. Patients were matched on a 1:1 basis with historical controls on standard CNI immunosuppression. ECP patients were treated with ECP plus antimetabolites and/or steroids, while CNIs were withheld until clinically indicated. Thirty-six patients were evaluated: 18 ECP patients and 18 controls. ECP was tolerated in 100% of cases. CNI were introduced at a median of 8 days (4-55) in 17 ECP patients, while one patient was on a fully CNI-sparing regimen 22 months after LT. Acute rejection occurred in 27.7% patients in ECP (5/18) versus 16.7% in controls (3/18) (P = ns) with a shorter time to rejection in ECP (36 +/- 31.3 days vs. 83.6 +/- 65.6 days; P = ns). All rejection episodes were amenable to medical treatment. Neurological and renal complications occurred in 22.2% (4/18) of patients in either group, but led to in-hospital mortality in 3 patients among controls versus 1 in ECP (P = ns). One-, 6-, and 12-month survival rates were 94.4, 88.1, and 88.1% in ECP versus 94.4, 77.7, and 72.2% among controls (P < 0.0001). ECP seems to allow for management of high-risk LT recipients in the early post-transplant course and reduction of CNI-related mortality. Continued data validation is favored to assess the impact of ECP on long-term graft and patient survival.

FK778 and Tacrolimus Prevent the Development of Obliterative Airway Disease After Heterotopic Rat Tracheal Transplantation

BACKGROUND

The effectiveness of the novel immunosuppressive agent FK778 and of tacrolimus to prevent the development of obliterative airway disease (OAD) was investigated in an animal model.

METHODS

Tracheae from Brown-Norway donors were heterotopically transplanted in the greater omentum of Lewis rats. Recipients were treated for 28 days with FK778 (5 or 20 mg/kg), tacrolimus (1 or 4 mg/kg) or combination regimens at varying doses (5 + 1 mg/kg, 10 + 2 mg/kg or 20 + 4 mg/kg). Grafts were harvested and processed for histologic and immunohistochemical evaluation. Lymphocyte surface antigen expression was quantified and in vitro smooth muscle cell (SMC) proliferation assays were performed.

RESULTS

In untreated recipients, very large amounts of infiltrating CD4+, CD8+ and ED1+ mononuclear cells were observed in the peritracheal region with epithelial loss and complete luminal obliteration. Granulation tissue consisted of alpha-actin-positive cells and collagen-rich fibrosis. FK778 and tacrolimus as well as combination regimens of both agents dose-dependently inhibited peritracheal infiltration and luminal obliteration. Only tacrolimus-treated recipients showed preserved luminal epithelial coverage with airway goblet cells, whereas, in animals that received FK778, no epithelium was found. Both agents equally suppressed in vivo lymphocyte CD25 expression. Only FK778-treated animals were completely free of adverse drug side effects. FK778 but not tacrolimus showed potent anti-proliferative effects on SMC in vitro.

CONCLUSIONS

Although both agents proved effective to prevent OAD development, histology revealed major differences. The anti-proliferative potency of FK778 on SMC may be an important mechanism of action. Combination regimens showed favorable drug interaction and allowed dose reduction of both agents to achieve maximal immunosuppressive efficacy.

[Pediatric liver transplantation]

There are no differences in results between pediatric liver transplantation and liver transplantation in adults. The reverts of the liver disease prior to transplantation (particularly the need of intensive care is the best predictor of perspective mortality. Therefore, liver transplantation in children should be indicated prior a severe decompensation of the disease.