Utilization of livers donated after circulatory death for transplantation - An international comparison

BACKGROUND & AIMS

Liver graft utilization rates are a hot topic due to the worldwide organ shortage and the increasing number of transplant candidates on waiting lists. Liver perfusion techniques have been introduced in several countries, and may help to increase the organ supply, as they potentially enable the assessment of livers before use.

METHODS

Liver offers were counted from donation after circulatory death (DCD) donors (Maastricht type III) arising during the past decade in eight countries, including Belgium, France, Italy, the Netherlands, Spain, Switzerland, the UK, and the US. Initial type-III DCD liver offers were correlated with accepted, recovered and implanted livers.

RESULTS

A total number of 34,269 DCD livers were offered, resulting in 9,780 liver transplants (28.5%). The discard rates were highest in the UK and US, ranging between 70 and 80%. In contrast, much lower DCD liver discard rates, e.g. between 30-40%, were found in Belgium, France, Italy, Spain and Switzerland. In addition, we observed large differences in the use of various machine perfusion techniques, as well as in graft and donor risk factors. For example, the median donor age and functional donor warm ischemia time were highest in Italy, e.g. >40 min, followed by Switzerland, France, and the Netherlands. Importantly, such varying risk profiles of accepted DCD livers between countries did not translate into large differences in 5-year graft survival rates, which ranged between 60-82% in this analysis.

CONCLUSIONS

Overall, DCD liver discard rates across the eight countries were high, although this primarily reflects the situation in the Netherlands, the UK and the US. Countries where in situ and ex situ machine perfusion strategies were used routinely had better DCD utilization rates without compromised outcomes.

IMPACT AND IMPLICATIONS

A significant number of Maastricht type III DCD livers are discarded across Europe and North America today. The overall utilization rate among eight Western countries is 28.5% but varies significantly between 18.9% and 74.2%. For example, the median DCD-III liver utilization in five countries, e.g. Belgium, France, Italy, Switzerland, and Spain is 65%, in contrast to 24% in the Netherlands, UK and US. Despite this, and despite different rules and strategies for organ acceptance and preservation, 1- and 5-year graft survival rates remain fairly similar among all participating countries. A highly varying experience with modern machine perfusion technology was observed. In situ and ex situ liver perfusion concepts, and application of assessment tools for type-III DCD livers before transplantation, may be a key explanation for the observed differences in DCD-III utilization.

Location and allocation: Inequity of access to liver transplantation for patients with severe acute-on-chronic liver failure in Europe

There is growing evidence that liver transplantation (LT) is the most effective treatment for acute-on-chronic liver failure grade-3 (ACLF-3). This study examines whether and how this evidence translates into practice by analyzing the variability in intensive care unit (ICU) admissions, listing strategies, and LT activity for patients with ACLF-3 across transplantation centers in Europe. Consecutive patients who were admitted to the ICU with ACLF-3, whether or not they were listed and/or transplanted with ACLF-3, between 2018 and 2019 were included across 20 transplantation centers. A total of 351 patients with ACLF-3 were included: 33 had been listed prior to developing ACLF-3 and 318 had not been listed at the time of admission to the ICU. There was no correlation between the number of unlisted patients with ACLF-3 admitted to the ICU and the number listed or transplanted while in ACLF-3 across centers. By contrast, there was a correlation between the number of patients listed and the number transplanted while in ACLF-3. About 21% of patients who were listed while in ACLF-3 died on the waiting list or were delisted. The percentage of LT for patients with ACLF-3 varied from 0% to 29% for those transplanted with decompensated cirrhosis across centers (average = 8%), with an I² index of 68% (95% confidence interval, 49%-80%), showing substantial heterogeneity among centers. The 1-year survival for all patients with ACLF-3 was significantly higher in centers that listed and transplanted more patients with ACLF-3 (>10 patients) than in centers that listed and transplanted fewer: 36% versus 20%, respectively (p = 0.012). Patients with ACLF-3 face inequity of access to LT across Europe. Waitlisting strategies for patients with ACLF-3 influence their access to LT and, ultimately, their survival.

Liver transplantation for patients with acute-on-chronic liver failure (ACLF) in Europe: Results of the ELITA/EF-CLIF collaborative study (ECLIS)

BACKGROUND & AIMS

Liver transplantation (LT) has been proposed as an effective salvage therapy even for the sickest patients with acute-on-chronic liver failure (ACLF). This large collaborative study was designed to assess the current clinical practice and outcomes of patients with ACLF who are wait-listed for LT in Europe.

METHODS

This was a retrospective study including 308 consecutive patients with ACLF, listed in 20 centres across 8 European countries, from January 2018 to June 2019.

RESULTS

A total of 2,677 patients received a LT: 1,216 (45.4%) for decompensated cirrhosis. Of these, 234 (19.2%) had ACLF at LT: 58 (4.8%) had ACLF-1, 78 (6.4%) had ACLF-2, and 98 (8.1%) had ACLF-3. Wide variations were observed amongst countries: France and Germany had high rates of ACLF-2/3 (27-41%); Italy, Switzerland, Poland and the Netherlands had medium rates (9-15%); and the United Kingdom and Spain had low rates (3-5%) (p <0.0001). The 1-year probability of survival after LT for patients with ACLF was 81% (95% CI 74-87). Pre-LT arterial lactate levels >4 mmol/L (hazard ratio [HR] 3.14; 95% CI 1.37-7.19), recent infection from multidrug resistant organisms (HR 3.67; 95% CI 1.63-8.28), and renal replacement therapy (HR 2.74; 95% CI 1.37-5.51) were independent predictors of post-LT mortality. During the same period, 74 patients with ACLF died on the waiting list. In an intention-to-treat analysis, 1-year survival of patients with ACLF on the LT waiting list was 73% for ACLF-1 or -2 and 50% for ACLF-3.

CONCLUSION

The results reveal wide variations in the listing of patients with ACLF in Europe despite favourable post-LT survival. Risk factors for mortality were identified, enabling a more precise prognostic assessment of patients with ACLF.

LAY SUMMARY

Acute-on-chronic liver failure (ACLF) is a severe clinical condition for which liver transplantation is an effective therapeutic option. This study has demonstrated that in Europe, referral and access to liver transplantation (LT) for patients with ACLF needs to be harmonised to avoid inequities. Post-LT survival for patients with ACLF was >80% after 1 year and some factors have been identified to help select patients with favourable outcomes.

Protective Role of Tacrolimus, Deleterious Role of Age and Comorbidities in Liver Transplant Recipients With Covid-19: Results From the ELITA/ELTR Multi-center European Study

BACKGROUND AND AIMS

Despite concerns that liver transplant (LT) recipients may be at increased risk of unfavorable outcomes from COVID-19 due the high prevalence of co-morbidities, immunosuppression and ageing, a detailed analysis of their effects in large studies is lacking.

METHODS

Data from adult LT recipients with laboratory confirmed SARS-CoV2 infection were collected across Europe. All consecutive patients with symptoms were included in the analysis.

RESULTS

Between March 1 and June 27, 2020, data from 243 adult symptomatic cases from 36 centers and 9 countries were collected. Thirty-nine (16%) were managed as outpatients while 204 (84%) required hospitalization including admission to the ICU (39 of 204, 19.1%). Forty-nine (20.2%) patients died after a median of 13.5 (10-23) days, respiratory failure was the major cause. After multivariable Cox regression analysis, age >70 (HR, 4.16; 95% CI, 1.78-9.73) had a negative effect and tacrolimus (TAC) use (HR, 0.55; 95% CI, 0.31-0.99) had a positive independent effect on survival. The role of co-morbidities was strongly influenced by the dominant effect of age where comorbidities increased with the increasing age of the recipients. In a second model excluding age, both diabetes (HR, 1.95; 95% CI, 1.06-3.58) and chronic kidney disease (HR, 1.97; 95% CI, 1.05-3.67) emerged as associated with death CONCLUSIONS: Twenty-five percent of patients requiring hospitalization for COVID-19 died, the risk being higher in patients older than 70 and with medical co-morbidities, such as impaired renal function and diabetes. Conversely, the use of TAC was associated with a better survival thus encouraging clinicians to keep TAC at the usual dose.

A Bayesian methodology to improve prediction of early graft loss after liver transplantation derived from the liver match study

BACKGROUND

To generate a robust predictive model of Early (3 months) Graft Loss after liver transplantation, we used a Bayesian approach to combine evidence from a prospective European cohort (Liver-Match) and the United Network for Organ Sharing registry.

METHODS

Liver-Match included 1480 consecutive primary liver transplants performed from 2007 to 2009 and the United Network for Organ Sharing a time-matched series of 9740 transplants. There were 173 and 706 Early Graft Loss, respectively. Multivariate analysis identified as significant predictors of Early Graft Loss: donor age, donation after cardiac death, cold ischaemia time, donor body mass index and height, recipient creatinine, bilirubin, disease aetiology, prior upper abdominal surgery and portal thrombosis.

RESULTS

A Bayesian Cox model was fitted to Liver-Match data using the United Network for Organ Sharing findings as prior information, allowing to generate an Early Graft Loss-Donor Risk Index and an Early Graft Loss-Recipient Risk Index. A Donor-Recipient Allocation Model, obtained by adding Early Graft Loss-Donor Risk Index to Early Graft Loss-Recipient Risk Index, was then validated in a distinct United Network for Organ Sharing (year 2010) cohort including 2964 transplants. Donor-Recipient Allocation Model updating using the independent Turin Transplant Centre dataset, allowed to predict Early Graft Loss with good accuracy (c-statistic: 0.76).

CONCLUSION

Donor-Recipient Allocation Model allows a reliable donor and recipient-based Early Graft Loss prediction. The Bayesian approach permits to adapt the original Donor-Recipient Allocation Model by incorporating evidence from other cohorts, resulting in significantly improved predictive capability.

Bone marrow hypoplasia complicating tacrolimus (FK506) therapy

Tacrolimus (FK506)-induced hematological toxicity, which has rarely been reported in transplant recipients, may result in anemia episodes, reported mainly in kidney and heart transplant recipients, sporadic cases of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, red cell aplasia (4 reported cases), and generalized bone marrow suppression (only 1 reported case). We describe a case of a liver transplant recipient with pancytopenia that appeared during immunosuppressive therapy with tacrolimus. This patient suffered from progressive anemia, leukopenia with severe neutropenia, and mild thrombocytopenia; bone marrow biopsy showed hypoplasia (20% of cellularity) without dysplasia. Bone marrow recovery was made possible by suspending tacrolimus and changing to immunosuppression with cyclosporine A, despite the two drugs being very similar in their mechanism of immunosuppression. Contrary to previously reported cases (pure red cell aplasia and bone marrow hypoplasia), the recovery of hemoglobin and neutrophil values was slow after tacrolimus suspension, even though in the first month transfusions were no longer necessary.