Effect of donor-recipient age matching in living donor liver transplantation. Transplant Proc. 2015;47:718-722. [PMID: 25891717 DOI: 10.1016/j.transproceed.2015.01.022]

Non-invasive molecular biomarkers for monitoring solid organ transplantation: A comprehensive overview

Solid organ transplantation is a life-saving intervention for individuals with end-stage organ failure. Despite the effectiveness of immunosuppressive therapy, the risk of graft rejection persists in all viable transplants between individuals. The risk of rejection may vary depending on the degree of compatibility between the donor and recipient for both human leucocyte antigen (HLA) and non-HLA gene-encoded products. Monitoring the status of the allograft is a critical aspect of post-transplant management, with invasive biopsies being the standard of care for detecting rejection. Non-invasive biomarkers are increasingly being recognized as valuable tools for aiding in the detection of graft rejection, monitoring graft status and evaluating the efficacy of immunosuppressive therapy. Here, we focus on the importance of molecular biomarkers in solid organ transplantation and their potential role in clinical practice. Conventional molecular biomarkers used in transplantation include HLA typing, detection of anti-HLA antibodies, killer cell immunoglobulin-like receptor genotypes, and anti-MHC class 1-related chain A antibodies, which are important for assessing the compatibility of the donor and recipient. Emerging molecular biomarkers include the detection of donor-derived cell-free DNA, microRNAs (regulation of gene expression), exosomes (small vesicles secreted by cells), and kidney solid organ response test, in the recipient's blood for early signs of rejection. This review highlights the strengths and limitations of these molecular biomarkers and their potential role in improving transplant outcomes.

Impact of Older Donor Age on Recipient and Graft Survival After LDLT: The US Experience

BACKGROUND

The impact of selecting older donors for living donor liver transplantation (LDLT) in the United States is incompletely studied, particularly in light of the recent expansion of LDLT nationally.

METHODS

Adult LDLTs from January 01, 2005 to December 31, 2019 were identified using the United Network for Organ Sharing database. Multivariable Cox models evaluated living donor (LD) age as a predictor of LDLT recipient and graft survival. The impact of increasing donor age on recipient outcomes was compared between LD and deceased donor recipients. Donor postoperative outcomes were evaluated.

RESULTS

There were 3539 LDLTs at 65 transplant centers during the study period. Despite the recent expansion of LDLT, the proportion of LDs aged ≥50 y was stable. There were no clinically significant differences in recipient or donor characteristics by LD age group. LD age ≥50 y was associated with an adjusted hazard ratio of 1.49 ( P = 0.012) for recipient survival and 1.61 ( P < 0.001) for graft survival (vs LDs aged 18-29 y). The negative impact of increasing donor age on graft survival was more profound after LDLT than deceased donor liver transplantation (interaction P = 0.019). There was a possible increased rate of early donor biliary complications for donors >55 y (7.1% versus 3.1% for age <40 y; P = 0.156).

CONCLUSIONS

Increasing LD age is associated with decreased recipient and graft survival, although older donors still largely yield acceptable outcomes. Donor outcomes were not clearly impacted by increasing age, though this warrants further study.

Update on liver transplantation-newer aspects

Liver transplantation (LT) remains the only therapeutic option offering gold standard treatment for end-stage liver disease (ESLD) and acute liver failure (ALF), as well as for certain early-stage liver tumors. Currently, the greatest challenge facing LT is the simple fact that there are not enough adequate livers for all the potential patients that could benefit from LT. Despite efforts to expand the donor pool to include living and deceased donors, organ shortage is still a major problem in many countries. To solve this problem, the use of marginal liver grafts has become an inevitable choice. Although the definition of marginal grafts or criteria for expanded donor selection has not been clarified yet, they are usually defined as grafts that may potentially cause primary nonfunction, impaired function, or late loss of function. These include steatotic livers, older donors, donors with positive viral serology, split livers, and donation after cardiac death (DCD). Therefore, to get the best outcome from these liver grafts, donor-recipient selection should be vigilant. Alcohol- related liver disease (ALD) is one of the most common indications for LT in Europe and North America. Traditionally, LT for alcoholic liver disease was kept limited for patients who have achieved 6 months of abstinence, in part due to social and ethical concerns regarding the use of a limited resource. However, the majority of patients with severe alcoholic hepatitis who fail medical therapy will not live long enough to meet this requirement. Besides, the initial results of early liver transplantation (ELT) without waiting for 6 months of abstinence period are satisfactory in severe alcoholic hepatitis (SAH). It will be important to take care of these patients from a newer perspective.

[High donor age for liver transplantation : Tackling organ scarcity in Germany]

BACKGROUND

Liver transplantation is the only curative treatment option for patients with end-stage liver disease; however, the 40% decline of available organ donors in recent years in Germany necessitates the optimization of available resources and possibly extending the criteria to older donors.

MATERIAL AND METHODS

All 2652 livers made available to the Charité Universitätsmedizin Berlin from 2010 to 2016 were retrospectively analyzed and the clinical outcome of 526 liver transplantations during this time frame were evaluated.

RESULTS

The median age of donors of transplanted organs increased from 49.3 years in 2010 to 57.3 years in 2016 (p = 0.02). Organs from donors ≥65 years were more frequently discarded than organs from younger donors (n = 344, 18.4% vs. n = 220, 28.1%; p = 0.005). Moreover, the older donors had higher rates of diabetes mellitus and hepatic steatosis. Organs from older donors had a higher donor risk index (2.8 vs. 2.2; p < 0.001) and were transplanted more often in patients with preserved liver function and hepatocellular carcinoma and liver cirrhosis (n = 121, 74.7% of indications). The 3‑year survival after liver transplantation from donors ≥65 and ≥80 years old was not significantly reduced in comparison to younger donors; however, there was an increased retransplantation rate (28.6%; p = 0.005) after transplantation of organs from donors ≥80 years old.

CONCLUSION

Despite conservative organ acceptance there were higher rates of retransplantation after transplantation from very old donors. In the light of an increasing scarcity of suitable organs this mandates caution and highlights the need for adequate assessment instruments for marginal donor organs before transplantation.

Advances in liver transplantation allocation systems

With the growing number of patients in need of liver transplantation, there is a need for adopting new and modifying existing allocation policies that prioritize patients for liver transplantation. Policy should ensure fair allocation that is reproducible and strongly predictive of best pre and post transplant outcomes while taking into account the natural history of the potential recipients liver disease and its complications. There is wide acceptance for allocation policies based on urgency in which the sickest patients on the waiting list with the highest risk of mortality receive priority. Model for end-stage liver disease and Child-Turcotte-Pugh scoring system, the two most universally applicable systems are used in urgency-based prioritization. However, other factors must be considered to achieve optimal allocation. Factors affecting pre-transplant patient survival and the quality of the donor organ also affect outcome. The optimal system should have allocation prioritization that accounts for both urgency and transplant outcome. We reviewed past and current liver allocation systems with the aim of generating further discussion about improvement of current policies.