Effect of donor age on graft function and longterm survival of recipients undergoing living donor liver transplantation

BACKGROUND： Donor shortage is the biggest obstacle in organ transplantation. Living donor liver transplantation（LDLT） has been considered as a valuable approach to shortening waiting time. The objectives of this study were to investigate the feasibility of utilizing donors older than 50 years in LDLT and to evaluate the graft function and recipient survival.METHODS： All LDLT cases（n=159） were divided into the older（donor age ≥50 years, n=10） and younger（donor age 〈50 years,n=149） donor groups. Donor graft and recipient condition pre-,intra- and post-operation were compared between the two groups.In particular, graft functions and recipient survivals were analyzed.RESULTS： The median donor age was 58.5（52.5-60.0） years in the older donor group and 25.0（23.0-32.0） in the younger donor group. There was no significant difference in cold ischemic time, anhepatic phase and operation time between the older and younger donor groups（P〉0.05）. However, the volume of red blood cell transfused in operation was greater in the older donor group than in the younger donor group（1900 vs 1200 m L, P=0.023）. The 1-, 3- and 5-year graft survival rates were 90%, 80% and 80% for the older donor group, and 92%, 87% and 87% for the younger donor group, respectively（P=0.459）.The 1-, 3- and 5-year survival rates were 100%, 90% and 90% for recipients with older grafts, and 93%, 87% and 87% for those with younger grafts, respectively（P=0.811）.CONCLUSION： It is safe for a LDLT recipient to receive liver from donors older than 50 years, and there is no significant adverse effect on graft function and long-term patients’ survival.

Influence of donor age on the differentiation and division capacity of human adipose-derived stem cells

BACKGROUND Human adipose-derived stromal/stem cells(hASCs)are one of the most useful types of mesenchymal stromal/stem cells,which are adult multipotent cells with great therapeutic potential for the treatment of several diseases.However,for successful clinical application,it is critical that high-quality cells can be obtained.Diverse factors seem to be able to influence cell quality and performance,especially factors related to donors’intrinsic characteristics,such as age.Nevertheless,there is no consensus regarding this characteristic,and there is conflicting information in the literature.AIM To investigate the growth kinetics and differentiation potential of adipose-derived stem cells isolated from the lipoaspirates of elderly and young donors.METHODS hASCs were harvested from liposuctioned adipose tissue obtained from female donors(aged 20-70 years).Cells were distributed into two groups according to age range:old hASCs(oASCs,≥55 years,n=9)and young hASCs(yASCs,≤35 years,n=9).For each group,immunophenotypic characterization was performed by flow cytometry.Population doubling time was assessed over seven days.For adipogenic potential evaluation,lipid deposits were assessed after 7 d,14 d and 21 d of adipogenic induction.Osteogenic potential was verified by analyzing cell mineralization after 14 d,21 d and 28 d of osteogenic induction.mRNA expression of PPARγ2,CEBPA and Runx2 were detected by quantitative reverse transcription polymerase chain reaction.RESULTS hASCs were successfully obtained,cultured,and grouped according to their age:yASCs(26.33±4.66 years old)and oASCs(64.78±4.58 years old).After maintenance of the cells in culture,there were no differences in morphology between cells from the young and old donors.Additionally,both groups showed classical immunophenotypic characteristics of mesenchymal stem/stromal cells.The average doubling time indicated that yASCs(4.09±0.94 d)did not significantly differ from oASCs(4.19±1.29 d).Concerning differentiation potential,after adipogenic and osteogenic induction,yASCs and oASCs were able to differentiate to greater levels than the noninduced control cells.However,no differences were found in the differentiation efficiency of yASCs and oASCs in adipogenesis or osteogenesis.Additionally,the mRNA expression of PPARγ2,CEBPA and Runx2 were similar in yASCs and oASCs.CONCLUSION Our findings suggest that age does not seem to significantly affect the cell division or adipogenic or osteogenic differentiation ability of adipose-derived stem cells isolated from lipoaspirates.

Octogenarian liver grafts:Is their use for transplant currently justified?

AIMTo analyse the impact of octogenarian donors in liver transplantation.METHODSWe present a retrospective single-center study, performed between November 1996 and March 2015, that comprises a sample of 153 liver transplants. Recipients were divided into two groups according to liver donor age: recipients of donors ≤ 65 years (group A; n = 102), and recipients of donors ≥ 80 years (group B; n = 51). A comparative analysis between the groups was performed. Quantitative variables were expressed as mean values and SD, and qualitative variables as percentages. Differences in properties between qualitative variables were assessed by χ2 test. Comparison of quantitative variables was made by t-test. Graft and patient survivals were estimated using the Kaplan-Meier method.RESULTSOne, 3 and 5-year overall patient survival was 87.3%, 84% and 75.2%, respectively, in recipients of younger grafts vs 88.2%, 84.1% and 66.4%, respectively, in recipients of octogenarian grafts (P = 0.748). One, 3 and 5-year overall graft survival was 84.3%, 83.1% and 74.2%, respectively, in recipients of younger grafts vs 84.3%, 79.4% and 64.2%, respectively, in recipients of octogenarian grafts (P = 0.524). After excluding the patients with hepatitis C virus cirrhosis (16 in group A and 10 in group B), the 1, 3 and 5-year patient (P = 0.657) and graft (P = 0.419) survivals were practically the same in both groups. Multivariate Cox regression analysis demonstrated that overall patient survival was adversely affected by cerebrovascular donor death, hepatocarcinoma, and recipient preoperative bilirubin, and overall graft survival was adversely influenced by cerebrovascular donor death, and recipient preoperative bilirubin.CONCLUSIONThe standard criteria for utilization of octogenarian liver grafts are: normal gross appearance and consistency, normal or almost normal liver tests, hemodynamic stability with use of < 10 μg/kg per minute of vasopressors before procurement, intensive care unit stay < 3 d, CIT < 9 h, absence of atherosclerosis in the hepatic and gastroduodenal arteries, and no relevant histological alterations in the pre-transplant biopsy, such as fibrosis, hepatitis, cholestasis or macrosteatosis > 30%.

Evaluation of Regeneration Stock Alternatives for Optimization of Growth and Survival of Field-Grown Forest Trees

Successful reforestation depends on the use of stock material that has a high potential for growth and survival in the environment where it is out-planted. This study is aimed at raising awareness on plant traits that are useful in evaluating the reforestation potential of seedlings and cuttings. The authors reviewed relevant literature on the assessment of quality of seedlings and cuttings and on the comparison of field performance of the two stock types. Results indicated that root-collar diameter, shoot height, root mass, number of first-order lateral roots and shoot-root ratio are morphological parameters whereas root growth potential, water relations, photosynthetic capacity and dormancy status are physiological traits that could be used as a basis for rating and comparing the suitability of seedlings and cuttings for reforestation. There is a discrepancy among studies on the field performance of seedlings and cuttings. It is concluded that a combination of morphological and physiological parameters should be used in evaluating the relative value of cuttings and seedlings. In addition, the age of the parent plant of a cutting should be taken into consideration when comparing the reforestation potential of the two stock alternatives.

Biological character of human adipose-derived adult stem cells and influence of donor age on cell replication in culture

To investigate the biological character of human adipose-derived adult stem cells (hADAS cells) when cultured in vitro and the relationship between hADAS cell’s replication activity and the donor’s age factor, and to assess the stem cells as a new source for tissue engineering. hADAS cells are isolated from human adipose tissue of different age groups (from adolescents to olds: <20 years old, 21―40 years old, 41―60 years old and >61 years old groups). The protein markers (CD29, CD34, CD44, CD45, CD49d, HLA-DR, CD106) of hADAS cells were detected by flow cytometry (FCM) to identify the stem cell, and the cell cycle was examined for P20 hADAS cells to evaluate the safety of the subculture in vitro. The generative activity of hADAS cells in different age groups was also examined by MTT method. The formula “ log2T D = t logN t ? logN 0” was used to get the time doubling (TD) of the cells. The results showed that the cells kept heredity stabilization by chromosome analysis for at least 20 passages. The TD of these cells increased progressively by ageing, and the TD of the <20 years old group was lower than that of the >61 years old group (statistical analysis of variance (ANOVA), P=0.002, P<0.05). These find- ings suggested that a higher level of hADAS cells replication activity was found in the younger dona- tors, and they represent novel and valuable seed cells for studies of tissue engineering.