Editorial: liver transplantation in patients with non-alcoholic fatty liver disease and obesity-authors' reply

Systematic Assessment of Safety Threshold for Donor Age in Cadaveric Liver Transplantation

Background: Donor age affects allograft quality and the prognosis of recipients after liver transplantation (LT). Clinicians have assessed the quality of grafts from older donors based on their appearance and texture, with no reliable quantitative evidence. Our study aimed to assess the quantitative impact of donor age on post-transplant outcomes and its safety threshold for LT, based on the published literature.

Methods: Relevant studies were retrieved from the Embase, PubMed, and ISI Web of Science databases. Pooled dichotomous relative risks (RRs) were calculated using metan. Continuous RRs were calculated using a two-stage random-effects model.

Results: Eleven studies including 30,691 LT cases were included for further analysis. For categorical comparison, the RR of death within the first post-transplant year was significantly higher among patients who received grafts from older donors. Similarly, the RR of graft failure (GF) was increased within the 3 years after transplantation. For continuous comparison, advanced donor age affected transplant outcomes in a linear manner (P > 0.05). A 10-year increment in donor age was associated with RRs 1.10, 1.12, 1.15, 1.10, and 1.08 for 90-day, 180-day, 1-year, 3-year, and 5-year patient mortality and 1.08, 1.06, 1.10, 1.11, and 1.12, for 90-day, 180-day, 1-year, 2-year, and 3-year GF, respectively (all P < 0.05). A spline model showed that transplants using grafts from donors <43 years old were not associated with age-related risks (P > 0.05). The risk of GF was increased in subgroups with fewer LT cases, longer cold ischemic time, fewer male donors, and recipients with viral hepatitis (P < 0.05).

Conclusion: Donor age might affect post-LT outcomes in a dose-dependent manner. The safety threshold for donor age in terms of GF should be lowered to 43 years as an early warning for the guarantee of satisfactory outcomes. Clinicians should weigh the benefits against the risks carefully for patients receiving grafts from older donors. Further studies are warranted to investigate the mechanisms responsible for the relationship between donor age and graft quality.

Systematic review with meta-analysis: de novo non-alcoholic fatty liver disease in liver-transplanted patients

BACKGROUND

De novo non-alcoholic fatty liver disease (NAFLD) in liver-transplanted patients for cirrhosis not due to non-alcoholic steatohepatitis (NASH) is becoming a growing phenomenon.

AIMS

We performed a systematic review and evaluated the prevalence of this event and possible associated factors.

METHODS

A literature search in medical databases (PubMed, MEDLINE/OVIDSP, Science Direct and EMBASE) was performed in March 2017. Relevant publications were identified in most important databases. We estimated the pooled prevalence of NAFLD and NASH in patients with liver transplant. The data have been expressed as proportions/percentages, and 95% confidence intervals (CI) were calculated, using the inverse variance method. Odd ratios (OR) and 95% confidence intervals (95% CI) were estimated.

RESULTS

Twelve studies were selected, enrolling 2166 subjects overall undergoing post-liver transplant biopsy. The pooled weighted prevalence of de novo NAFLD was 26% (95% CI 20%-31%). The pooled weighted prevalence of NASH was 2% (95% CI 0%-3%). The highest prevalences of de novo NAFLD were found for patients transplanted for alcoholic cirrhosis (37%) and cryptogenic cirrhosis (35%) and for patients taking tacrolimus (26%). Tacrolimus showed a risk of NAFLD similar to ciclosporin (OR = 1.02, 95% CI 0.3-3.51).

CONCLUSIONS

Patients undergoing liver transplant are more prone to experience diabetes, hypertension or dyslipidaemia, and NAFLD may be an important element in this context. In this study, we show how the prevalence of NASH tends to remain significant and similar to the general population. Moreover, this study suggests a possible association with specific transplant indications. Further studies are required to confirm these findings.