Older age and liver transplantation: a review

Delayed transplantation of human neural precursor cells improves outcome from focal cerebral ischemia in aged rats

Neural precursor cell (NPC) transplantation may have a role in restoring brain function after stroke, but how aging might affect the brain's receptivity to such transplants is unknown. We reported previously that transplantation of human embryonic stem cell (hESC)-derived NPCs together with biomaterial (Matrigel) scaffolding into the brains of young adult Sprague-Dawley rats 3 weeks after distal middle cerebral artery occlusion (MCAO) reduced infarct volume and improved neurobehavioral performance. In this study, we compared the effect of NPC and Matrigel transplants in young adult (3-month-old) and aged (24-month-old) Fisher 344 rats from the National Institute on Aging's aged rodent colony. Distal MCAO was induced by electrocoagulation, and hESC-derived NPCs were transplanted into the infarct cavity 3 weeks later. Aged rats developed larger infarcts, but infarct volume and performance on the cylinder and elevated body swing tests, measured 6-8 weeks post-transplant, were improved by transplantation. We conclude that advanced age does not preclude a beneficial response to NPC transplantation following experimental stroke.

Ageing, telomeres, senescence, and liver injury

Populations in developed countries continue to grow older and an understanding of the ageing process to allow healthy ageing carries important medical implications. Older individuals are more susceptible to most acquired liver disorders and more vulnerable to the consequences of liver disease. Accordingly, age is a critical determinant of outcome for hepatitis C virus infection and liver transplantation. In this review we describe changes in the ageing liver and discuss mechanisms of senescence at the cellular level. In particular, we focus on mechanisms by which inflammation, oxidative stress, and oncogenic stress accelerate cellular senescence. In the setting of chronic hepatic injury and inflammation, cellular senescence functions as an essential stress-response mechanism to limit the proliferation of damaged cells and reduce the risk of malignancy, but this benefit is achieved at the expense of senescence-related organ dysfunction. The dual role of cell senescence in chronic liver disease will make this an intriguing but challenging area for future clinical interventions.

Analysis of liver transplant outcomes for United Network for Organ Sharing recipients 60 years old or older identifies multiple model for end-stage liver disease-independent prognostic factors

Older recipient age is associated with worse posttransplant survival. Although the median age of liver disease patients undergoing orthotopic liver transplantation (OLT) continues to rise, prognostic factors for posttransplant survival specific to older patients have not been defined. To address this issue, the United Network for Organ Sharing/Organ Procurement and Transplantation Network outcome database was searched to identify prognostic factors for the 8070 liver recipients 60 years old or older who underwent transplantation from 1994 to 2005. Prognostic factors were assessed with univariate analysis and multivariate modeling. The 5 strongest prognostic variables (ventilator status, diabetes mellitus, hepatitis C virus, creatinine levels >/=1.6 mg/dL, and recipient and donor age >or=120 years) were aggregated to define a novel older recipient prognostic score (ORPS). The overall 1- and 5-year posttransplant survival rates were 83% and 67%, respectively. The risk model, created by the assignment of 1 point to each ORPS factor, stratified patient outcomes into distinct prognostic groups at the 1-, 3-, and 5-year posttransplant time points (P < 0.001). The 5-year survival rates for patients with ORPS values of 0, 1, and 2 points were 75%, 69%, and 58%, respectively. Patients who underwent transplantation with an ORPS > 2 points consistently experienced 5-year survival rates of less than 50%. In conclusion, in liver transplant recipients 60 years old or older, the ORPS was able to predict significant and clinically relevant differences in posttransplant survival. By optimization of donor selection for recipients over the age of 60 years, clinical utilization of the ORPS model may enhance organ utilization for all patients awaiting OLT.

Outcomes after liver transplant in patients aged 70 years or older compared with those younger than 60 years

OBJECTIVE

To compare mortality, graft loss, and postoperative complications after liver transplant in older patients (> or =70 years) with those in younger patients (<60 years).

PATIENTS AND METHODS

Outcomes for 42 patients aged 70 years or older who underwent liver transplant were compared with those of 42 matched controls younger than 60 years. All patients underwent transplants between March 19, 1998, and May 7, 2004. Information was collected on patient characteristics, comorbid conditions, laboratory results, donor and operative variables, medical and surgical complications, and mortality and graft loss.

RESULTS

Preoperative characteristics were similar across age groups, except for creatinine (P=.01) and serum albumin (P=.03) values, which were higher in older patients, and an earlier year of transplant in younger patients (P<.001). Intraoperatively, older patients required more erythrocyte transfusions (P=.04) and more intraoperative fluids (P=.001) than did younger patients. Postoperatively, bilirubin level (P=.007) and international normalized ratios (P=.01) were lower in older patients, whereas albumin level was higher (P<.001). The median follow-up was 5.1 years (range, 0.1-8.5 years). Compared with younger patients, older patients were not at an increased risk of death (relative risk, 1.00; 95% confidence interval, 0.43-2.31; P>.99) or graft loss (relative risk, 1.17; 95% confidence interval, 0.54-2.52; P=.70). The frequency of other complications did not differ significantly between age groups, although older patients had more cardiovascular complications.

CONCLUSION

Five-year mortality and graft loss in older recipients were comparable with those in younger recipients, suggesting that age alone should not exclude older patients from liver transplant.

Outcome of acute liver failure in the elderly

Older age is considered a poor prognostic factor in acute liver failure (ALF) and may still be considered a relative contraindication for liver transplantation for ALF. We aimed to evaluate the impact of older age, defined as age > or = 60 years, on outcomes in patients with ALF. One thousand one hundred twenty-six consecutive prospective patients from the US Acute Liver Failure Study Group registry were studied. The median age was 38 years (range, 15-81 years). One thousand sixteen patients (90.2%) were younger than 60 years (group 1), and 499 (49.1%) of these had acetaminophen-induced ALF; this rate of acetaminophen-induced ALF was significantly higher than that in patients > or = 60 years (group 2; n = 110; 23.6% with acetaminophen-induced ALF, P < 0.001). The overall survival rate was 72.7% in group 1 and 60.0% in group 2 (not significant) for acetaminophen patients and 67.9% in group 1 and 48.2% in group 2 for non-acetaminophen patients (P < 0.001). The spontaneous survival rate (ie, survival without liver transplantation) was 64.9% in group 1 and 60.0% in group 2 (not significant) for acetaminophen patients and 30.8% in group 1 and 24.7% in group 2 for non-acetaminophen patients (P = 0.27). Age was not a significant predictor of spontaneous survival in multiple logistic regression analyses. Group 2 patients were listed for liver transplantation significantly less than group 1 patients. Age was listed as a contraindication for transplantation in 5 patients. In conclusion, in contrast to previous studies, we have demonstrated a relatively good spontaneous survival rate for older patients with ALF when it is corrected for etiology. However, overall survival was better for younger non-acetaminophen patients. Fewer older patients were listed for transplantation.

Liver transplantation: from Child to MELD

The widespread availability of transplantation in most major medical centers in the United States, together with a growing number of transplant candidates, has made it necessary for primary care providers, especially internal medicine and family practice physicians to be active in the clinical care of these patients before and after transplantation. This review provides an overview of the liver transplantation process, including indications, contraindications, time of referral to a transplant center, the current organ allocation system, and briefly touches on the expanding field of living donor liver transplantation.

Potential utility of xenobiotic mitogens in the context of liver regeneration in the elderly and living-related transplantation

Although liver regeneration occurring after partial hepatectomy (PH) is greatly reduced in aged mice, liver hyperplasia induced by xenobiotic mitogens was found to be age independent. Here, we investigated the potential utility of mitogens in stimulating liver regeneration in old mice subjected to two-third PH. Although virtually no hepatocytes entered S phase 48 h after PH, pretreatment (2 h prior to surgery) with 1,4-bis(2-(3,5-dichloropyridyloxy)benzene (TCPOBOP), a ligand of constitutive androstane receptor, induced an increase of bromodeoxyuridine incorporation and enhanced the expression of cyclin D1, cyclin A and proliferating cell nuclear antigen . Next, we investigated the potential utility of mitogens in the context of donor conditioning prior to living-related transplantation. Three days after TCPOBOP administration to intact young mice, an almost doubling of the liver mass and DNA content occurred; the regenerative response to two-third resection of the TCPOBOP-induced hyperplastic liver was similar to that of mice subjected to PH alone, suggesting that an increased liver mass at the time of surgery does not inhibit the regenerative capacity. The present results suggest that mitogen-induced hyperplasia is a promising tool in conditions characterized by reduced regenerative capacity, such as in the elderly, or when a rapid increase of liver mass is required, such as in living-related transplantation.

Our experience in liver transplantation in patients over 65 yr of age

OBJECTIVES

The aim of this study was to analyze short- and long-term results of liver transplantation (LT) in patients over 65 yr.

MATERIAL AND METHODS

Between 1996 and 2004, 386 patients underwent 415 LT at our center. The main indication for LT was post-necrotic cirrhosis in 59%, followed by hepatocellular carcinoma (HCC) over cirrhosis in 33%. Half of the patients (53%) were hepatitis C virus (HCV) +. Overall, 72 patients were >65 yr of age. Actuarial survival, causes of mortality and postoperative complications were compared between groups: patients under and over 65 yr. Risk factors for poor outcome in patients over 65 yr were also analyzed.

RESULTS

The older group had more patients at Child A stage, more HCC as an indication for LT and more HCV (+) patients, p < 0.05. No differences were observed in donor and surgery characteristics, except for lower multi-transfusion and higher incidence of grafts with steatosis in the older group (p < 0.05). Actuarial survival at one, three, five and 10 yr was 82%, 75%, 72%, and 70% for the <65 yr group vs. 77%, 66%, 55%, and 55% for the >65 yr group (p = 0.03). Main causes of mortality in patients >65 yr were recurrence of underlying disease and medical causes. In the older age group, fewer infections (p = ns) and rejections (p = 0.017) occurred in the postoperative period. Risk factor for poor outcome in the group of patients over 65 yr in multivariate analyses was pre-LT renal insufficiency (odds ratio 3.5, p = 0.002, 95% confidence interval 1.58-7.82).

CONCLUSION

Results in patients >65 yr are comparable to those <65 yr if older LT candidates are carefully selected. Overimmunosuppression should be avoided in older candidates, as its effects could worsen the pre-existing diseases common in elderly patients.

Allogeneic hematopoietic stem cell transplantation in the elderly

The development of reduced intensity or non-myeloablative conditioning (NST) in preparation for allogeneic stem cell transplantation (SCT) revolutionized the field and led to reconsideration of the dogma of upper age limit that was set up by the transplant centers as an eligibility parameter. Analysis of the literature data showed that NST regimens are associated with decreased transplant related mortality, and graft-versus-host disease, in comparison with standard myeloablative conditioning, in patients above the age of 50-55 years, or in younger patients with significant comorbidities. However we have to mention, that our considerations are based on the retrospective analysis of the literature data, and that well controlled prospective randomized studies are needed in order to definitely assess the role of NST. Comorbidity indices might be proved as the most important parameters for the choice of the most proper regimen for each patient in need and should be included in future trials.

Impact of age older than 60 years in living donor liver transplantation

BACKGROUND

Living donor liver transplantation (LDLT) was extended to adults in recent years and more recently to older patients. The impact of donor age, analysis of preoperative risk factors for older LDLT recipients, and comparison of the complication rate between older and younger recipients were analyzed.

METHODS

Subjects included patients who underwent LDLT at Kyoto University Hospital from October 1996 to December 2005. Twenty-three donors were 60 years of age or older, and 411 were younger than 60 years of age. Fifty-two recipients were 60 years of age or older and 410 were younger than 60 years of age.

RESULTS

Postoperative recovery of liver function for donors and recipient/graft survival were not influenced by donor age. Hospital stay was longer in the donors 60 years of age or older than those younger than 60 years of age (P=0.02). The 5-year survival rates were 78.7% in recipients 60 years of age or older and 69.3% in younger recipients (P=0.26). Among preoperative risk factors for recipient survival rate, fulminant hepatic failure and preoperative status in the intensive care unit were significant (P<0.05). There were no significant differences in the incidence of postoperative complications for recipients.

CONCLUSIONS

Selected right lobe donors from individuals who were 60 years of age or older showed a similar postoperative course compared with younger donors. Moreover, LDLT is feasible for patients 60 years of age or older who do not require care in the intensive care unit or do not have fulminant hepatic failure.

Anemia in liver transplant recipients undergoing antiviral treatment for recurrent hepatitis C

Adherence to antiviral therapy is essential to achieve sustained virological responses in patients treated for hepatitis C. An important limitation to use of appropriate doses of ribavirin is development of anemia. The aim of this study is to identify risk factors associated with anemia in liver transplant recipients undergoing treatment for recurrent hepatitis C virus (HCV). Retrospective analysis was performed on 115 adult liver transplantation (LT) recipients who received antiviral treatment. Anemia was defined as hemoglobin of <10 gm/dL or the use of erythropoietin replacement therapy. Variables found to be significant in univariate analysis were further studied in multivariate analysis. The mean (+/- standard deviation [SD]) age of our cohort was 52.1 (+/- 8.8) yr. Anemia developed in 44 patients (38.3%). Mean (+/- SD) onset of anemia was 8.9 (+/- 6.8) weeks after initiation of antiviral therapy. A total of 30 patients (26%) required erythropoietin replacement, at a mean (+/- SD) of 7.9 (+/- 6.0) weeks after start of antiviral treatment. A total of 27 patients (24%) required ribavirin dose reduction, at a mean (+/- SD) time to dose reduction of 8.1 (+/- 6.3) weeks. In univariate analysis, body mass index (BMI) (P < 0.01), mycophenolate mofetil use (P = 0.05), trimethoprim-sulfamethoxazole (P = 0.02), and age (P = 0.02) were statistically significant. In conclusion, in multivariate analysis, BMI (P < 0.01) and age (P = 0.02) were found to be independent predictors of anemia. Anemia is common in liver transplant recipients treated for recurrent HCV. Special vigilance is required for older patients and patients with a low BMI.

Current indications and contraindications for liver transplantation

Survival rates after liver transplantation have improved steadily because of earlier referral and timely evaluation, judicious patient selection, improved surgical techniques, superior immunosuppressive regimens, and effective prevention of perioperative opportunistic infections. Indications and contraindications for liver transplantation are undergoing constant modifications with the goal of improving survival and functional status of patients who have end-stage liver disease or acute liver failure. Potential candidates for liver transplantation should meet minimal listing criteria and not have contraindications to liver transplantation. Currently, the Model for End-stage Liver Disease score is used for organ allocation, but it may have future application in patient-selection criteria.

Increased ischemic injury in old mouse liver: an ATP-dependent mechanism

Although livers exhibit only minimal morphologic changes with age, how older livers tolerate pathologic conditions such as normothermic ischemia is unknown. Young 6-week-old mice and old 60-week-old mice underwent 60 minutes of hepatic ischemia and various periods of reperfusion. Markers of hepatocyte injury, hepatic energy content, and mitochondrial function were determined. Ischemic preconditioning and glucose injection were evaluated as protective strategies against reperfusion injury in old mice. Reperfusion injury was far worse in old mice compared with mice in the young control group. Ischemic preconditioning was highly protective against reperfusion injury in young but not in old mice. Older livers had dramatically reduced adenosine triphosphate (ATP) levels and glycogen contents. The low intrahepatic energy level in old mice was associated with a reduced mitochondrial ATP production. Preoperative injection of glucose restored the intrahepatic ATP content and protected against reperfusion injury. Furthermore, glucose injection restored the protective effect of ischemic preconditioning, resulting in additive protection when both strategies were combined. Aging of the liver is associated with mitochondrial dysfunction and decreased intrahepatic energy content, resulting in poorer tolerance against ischemic injury. Improving intrahepatic ATP levels in old livers by glucose injection protects the old liver against ischemic injury and restores the protective effects of ischemic preconditioning.

Selección de candidatos para trasplante hepático

Liver transplantation is the treatment of choice in acute and irreversible chronic liver failure of distinct etiologies. Because of the current shortage of donor organs, careful selection of candidates for transplantation is required. In addition to specific prognostic models, there are general models, such as the Child-Pugh classification and the MELD system, which are useful in determining the optimal timing of liver transplantation in most patients with cirrhosis. Once the need for transplantation has been determined and the possibility of other available therapeutic measures has been ruled out, a multidisciplinary evaluation should be performed to assess the patient's suitability for this procedure. This evaluation must rule out the presence of medical, surgical or psychological factors that could compromise patient or graft survival, making transplantation futile. The present review analyzes the most frequent contraindications to transplantation, as well as the most important aspects of pretransplantation evaluation.

Risk stratification of adult patients undergoing orthotopic liver transplantation for fulminant hepatic failure

BACKGROUND

Orthotopic liver transplantation (OLT) is an effective treatment for fulminant hepatic failure (FHF), but postOLT mortality is higher for patients with FHF than for patients with other indications for OLT. In the current study, a large cohort of patients who underwent OLT for FHF was evaluated to develop and validate a system useful for estimating postOLT patient survival.

METHODS

The 1,457 patients who underwent OLT for FHF in the United States between 1988 and 2003 were enrolled through the UNOS database. This group was divided into a modeling group (n=972) and a crossvalidation group (n=486). With a multivariate regression analysis, the modeling group was used to identify clinical parameters that had a significant association with postOLT survival. This regression analysis was used to create a scoring system that was subsequently assessed in the crossvalidation group.

RESULTS

Four risk factors were identified with the multivariate analysis: 1) body mass index > or = 30 kg/m2; 2) serum creatinine > 2.0 mg/dL; 3) recipient age > 50 years old; and 4) history of life support. By assigning points based on the number of risk factors present, the scoring system was able to differentiate between low-risk patients (5-year survival, 81%) and high-risk patients (5-year survival, 42%). The relative risk of postOLT mortality increased by approximately 150% for each additional point.

CONCLUSION

The scoring system risk-stratified the crossvalidation group and accurately predicted postOLT survival. A scoring system utilizing clinical and demographic information readily available prior to OLT may help predict the probability of survival after OLT for FHF.

An Overview of Solid Organ Transplantation

Once a medical curiosity, solid organ transplantation is now a commonplace occurrence, with more than 27,000 procedures performed in the United States in 2004 alone. This article offers an overview of the various solid organ transplant procedures to provide a context within which subsequent articles on pulmonary complications can be viewed.

Older liver graft transplantation, cholestasis and synthetic graft function

Older liver grafts are often discarded because of conservative selection criteria. We report on our clinical experience with graft-age related outcome. Patients transplanted with livers older than 70 years (70.2-80.2 years, n = 38) were compared with controls transplanted with livers younger than 70 years. Pairs were matched for age, gender, indication and cold ischemic time. Mean donor age was 73.4 +/- 2 vs. 39 +/- 16 years. Patient and graft survival did not differ between both groups after 1-year follow-up (P = 0.19 and P = 0.24 respectively). Retransplantation rate was 10.5% vs. 5.3% (P = 0.40). Initial poor function occurred in two patients in the study group versus four patients in the control group (P = 0.69). The incidence of rejection episodes was comparable. Parameters of cholestasis and protein synthesis showed no difference 1-year post-transplant. Mean age of donor organs in matched pairs group B was near by half of that in the older donor group A (39.0 vs. 73.4 years). Post-transplant outcome as indicated by patient and graft survival was comparable between both groups. Donor organ age had no impact on postoperative organ function. We recommend to accept liver grafts from organ donors older than 70 years to expand the donor pool.