Liver transplantation for metastatic liver malignancies

PURPOSE OF REVIEW: Liver transplantation is a validated treatment of primary hepatobiliary tumours. Over the last decade, a renewed interest for liver transplantation as a curative treatment of colorectal liver metastasis (CR-LM) and neuro-endocrine metastasis (NET-LM) has developed. RECENT FINDINGS: The ELTR and UNOS analyses showed that liver transplantation may offer excellent disease-free survival (ranging from 30 to 77%) in case of NET-LM, on the condition that stringent selection criteria are implemented. The interest for liver transplantation in the treatment of CR-LM has been fostered by the Norwegian SECA study. Five-year A 5-year survival rate of 60% could be reached. Despite the high recurrence rate (90%), one-third of patients were disease free following pulmonary surgery for metastases. SUMMARY: Liver transplantation will take a more prominent place in the therapeutic algorithm of CR-LM and NET-LM. Larger experiences are necessary to improve knowledge about tumour biology and to refine selection criteria. A multimodal approach adding neo and adjuvant medical treatment to the transplant procedure will be key to bring this oncologic transplant project into the clinical arena. The preserved liver function in these patients will allow a more deliberate access to split liver and living donation for these indications

Liver transplantation for secondary liver tumours.

Cautious expansion of indications for liver transplantation</jats:p

Dual adaptive model predictive control

We present an adaptive dual model predictive controller (dmpc) that uses current and future parameter-estimation errors to minimize expected output error by optimally combining probing for uncertainty reduction with control of the nominal model. Our novel approach relies on orthonormal basis-function models to derive expressions for the predicted distributions for the output and unknown parameters, conditional on the future input sequence. Propagating the exact future statistics enables reformulating the original stochastic problem into a deterministic equivalent that illustrates the dual nature of the optimal control but is nonlinear and nonconvex. We further reformulate the nonlinear deterministic problem to pose an equivalent quadratically-constrained quadratic-programming (qcqp) problem that state-of-the-art algorithms can solve efficiently, providing the exact solution to the probabilistically constrained finite-horizon dual control problem. The adaptive dmpc solves this qcqp at each sampling time on a receding horizon; the adaptation is a result of updating the parameter estimates used by the dmpc to decide the control input. The paper demonstrates the application of dmpc to a single-input single-output (siso) system with unknown parameters. In the simulation example, the parameter estimates converge quickly and the probing vanishes with increasing accuracy and precision of the estimates, improving the future control performance

Long‐term quality of life after liver transplantation for non‐resectable colorectal metastases confined to the liver

Background: Liver transplantation for patients with non-resectable colorectal liver metastases offers increased survival, with median overall survival of more than 5 years. The aim of this study was to compare quality of life before and up to 3 years after liver transplantation for colorectal liver metastases. Methods: Quality of life was assessed using the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire version 3.0. The patients received the questionnaire before and up to 3 years after liver transplantation. Results: Some 23 patients were included in the analysis. Three months after liver transplantation they reported reduced quality of life (global health status scale), physical function and role function, and increased dyspnoea. At 6 months, global health status, physical function and role function had returned to pretransplant values. Three years after liver transplantation all symptom and function scores were comparable to baseline values. Patients with high scores for fatigue, pain and appetite loss at baseline had reduced 3-year overall survival. Conclusion: Patients with non-resectable colorectal liver-only metastases receiving liver transplantation had good long-term quality of life. Patients with high symptom scores before transplantation had reduced 3-year overall survival

The effects of exendin-4 treatment on graft failure: An animal study using a novel revascularized minimal human islet transplant model

Islet transplantation has become a viable clinical treatment, but is still compromised by long-term graft failure. Exendin-4, a glucagon-like peptide 1 receptor agonist, has in clinical studies been shown to improve insulin secretion in islet transplanted patients. However, little is known about the effect of exendin-4 on other metabolic parameters. We therefore aimed to determine what influence exendin-4 would have on revascularized minimal human islet grafts in a state of graft failure in terms of glucose metabolism, body weight, lipid levels and graft survival. Introducing the bilateral, subcapsular islet transplantation model, we first transplanted diabetic mice with a murine graft under the left kidney capsule sufficient to restore normoglycemia. After a convalescent period, we performed a second transplantation under the right kidney capsule with a minimal human islet graft and allowed for a second recovery. We then performed a left-sided nephrectomy, and immediately started treatment with exendin-4 with a low (20μg/kg/day) or high (200μg/kg/day) dose, or saline subcutaneously twice daily for 15 days. Blood was sampled, blood glucose and body weight monitored. The transplanted human islet grafts were collected at study end point and analyzed. We found that exendin-4 exerts its effect on failing human islet grafts in a bell-shaped dose-response curve. Both doses of exendin-4 equally and significantly reduced blood glucose. Glucagon-like peptide 1 (GLP-1), C-peptide and pro-insulin were conversely increased. In the course of the treatment, body weight and cholesterol levels were not affected. However, immunohistochemistry revealed an increase in beta cell nuclei count and reduced TUNEL staining only in the group treated with a low dose of exendin-4 compared to the high dose and control. Collectively, these results suggest that exendin-4 has a potential rescue effect on failing, revascularized human islets in terms of lowering blood glucose, maintaining beta cell numbers, and improving metabolic parameters during hyperglycemic stress

Glial cell-line derived neurotrophic factor protects human islets from nutrient deprivation and endoplasmic reticulum stress induced apoptosis

One of the key limitations to successful human islet transplantation is loss of islets due to stress responses pre- and post-transplantation. Nutrient deprivation and ER stress have been identified as important mechanisms leading to apoptosis. Glial Cell-line Derived Neurotrophic Factor (GDNF) has recently been found to promote islet survival after isolation. However, whether GDNF could rescue human islets from nutrient deprivation and ER stress-mediated apoptosis is unknown. Herein, by mimicking those conditions in vitro, we have shown that GDNF significantly improved glucose stimulated insulin secretion, reduced apoptosis and proinsulin: insulin ratio in nutrient deprived human islets. Furthermore, GDNF alleviated thapsigargin-induced ER stress evidenced by reduced expressions of IRE1 alpha and BiP and consequently apoptosis. Importantly, this was associated with an increase in phosphorylation of PI3K/AKT and GSK3B signaling pathway. Transplantation of ER stressed human islets pre- treated with GDNF under kidney capsule of diabetic mice resulted in reduced expressions of IRE1 alpha and BiP in human islet grafts with improved grafts function shown by higher levels of human C-peptide post-transplantation. We suggest that GDNF has protective and anti-apoptotic effects on nutrient deprived and ER stress activated human islets and could play a significant role in rescuing human islets from stress responses

Microbubble contrast-enhanced ultrasound in the vascular evaluation after pancreas transplantation: a single-center experience

Background: Arterial and venous thrombosis are feared complications of pancreas transplantation (PTx). Microbubble contrast-enhanced ultrasound (CEUS) is a non-invasive imaging technique that can augment diagnostic capabilities of transplant organ perfusion. Purpose: To document the state to which CEUS can improve the vascular evaluation of PTx compared to conventional Doppler ultrasound (US) directly after surgery. Material and Methods: A total of 129 consecutive PTx in 128 adult patients were eligible for inclusion. The duodenal segment of the graft was anastomosed to the native duodenum. Within 12 h postoperatively, graft- circulation was monitored by Doppler US in 116 PTx performed in 116 patients (69 men, 47 women; mean age 41 years). CEUS was performed with a sulfur hexafluoride-containing contrast agent (SonoVue) intravenously if the examiner was not able to confirm normal graft circulation. Image quality was documented by two independent observers on a 4-point scale: 1 excellent; 2 minor diagnostic limitations; 3 major diagnostic limitations; and 4 non-diagnostic. Results: In the early postoperative phase, 79 (68%) of 116 PTx were examined with Doppler US only. Of these, 52 were of excellent quality (grade 1), 22 of good quality (grade 2), and five were of grade 3 or 4 quality. Thirty-seven (32%) examinations were supplemented by CEUS. CEUS significantly improved examination quality compared to Doppler US alone (median visualization score 1.5 vs. 2.5, respectively; P < 0.0001). Conclusion: CEUS can significantly improve vascular evaluation of PTx compared to Doppler US alone in the early postoperative phase

HLA variants related to primary sclerosing cholangitis influence rejection after liver transplantation

AIM: To investigate influence of human leukocyte antigen (HLA) and killer immunoglobuline-like receptor (KIR) genotypes on risks of acute rejection (AR) after liver transplantation (LTX). METHODS: In this retrospective study we included 143 adult donor-recipient pairs with a minimum of 6 mo follow-up after LTX for whom DNA was available from both donor and recipients. Clinical data, all early complications including episodes and severity of AR and graft/patient survival were registered. The diagnosis of AR was based on clinical, biochemical and histological criteria. All suspected episodes of AR were biopsy confirmed. Key classical HLA loci (HLA-A, HLA-B, HLA-C and HLA-DRB1) were genotyped using Sanger sequencing. 16 KIR genes were genotyped using a novel real time PCR approach which allows for determination of the diploid copy number of each KIR gene. Immunohistochemical staining for T (CD3), B (CD20) and natural killer (NK) cells (CD56 and CD57) were performed on liver biopsies from 3 different patient groups [primary sclerosing cholangitis (PSC), primary biliary cirrhosis and non-autoimmune liver disease], 10 in each group, with similar grade of AR. RESULTS: Fourty-four (31%) patients were transplanted on the basis of PSC, 40% of them had AR vs 24% in the non-PSC group (P = 0.04). No significant impact of donor-recipient matching for HLA and KIR genotypes was detected. In the overall recipient population an increased risk of AR was detected for HLA-B*08 (P = 0.002, OR = 2.5; 95%CI: 1.4-4.6), HLA-C*07 (P = 0.001, OR = 2.4; 95%CI: 1.4-4.0) and HLA-DRB1*03 (P = 0.03, OR = 1.9; 95%CI: 1.0-3.3) and a decreased risk for HLA-DRB1*04 (P = 0.001, OR = 0.2; 95%CI: 0.1-0.5). For HLA-B*08, HLA-C*07 and DRB1*04 the associations remained evident in a subgroup analysis of non-PSC recipients (P = 0.04, P = 0.003 and P = 0.02, respectively). In PSC recipients corresponding P values were 0.002, 0.17 and 0.01 for HLA-B*08, HLA-C*07 and DRB1*04, respectively. A dosage effect of AR prevalence according to the PSC associated HLA alleles was also notable in the total recipient population. For HLA-B*08 the frequency of AR was 56% in HLA-B*08 homozygous recipients, 39% in heterozygous recipients and 21% in recipients lacking HLA-B*08 (P = 0.02). The same was observed for the HLA-C*07 allele with AR in 57%, 27% and 18% in recipients being homozygous, heterozygous and lacking HLA-C*07 respectively (P = 0.003). Immunohistochemical analysis showed similar infiltration of T, B and NK cells in biopsies with AR in all three groups. CONCLUSION: We found significant associations between the PSC-associated HLA-B*08, HLA-C*07, HLA-DRB1*03 and HLA-DRB1*04 alleles and risk of AR in liver transplant recipients

Treatment with Tacrolimus and Sirolimus Reveals No Additional Adverse Effects on Human Islets In Vitro Compared to Each Drug Alone but They Are Reduced by Adding Glucocorticoids

Tacrolimus and sirolimus are important immunosuppressive drugs used in human islet transplantation; however, they are linked to detrimental effects on islets and reduction of long-term graft function. Few studies investigate the direct effects of these drugs combined in parallel with single drug exposure. Human islets were treated with or without tacrolimus (30 mu g/L), sirolimus (30 mu g/L), or a combination thereof for 24 hrs. Islet function as well as apoptosis was assessed by glucose-stimulated insulin secretion (GSIS) and Cell Death ELISA. Proinflammatory cytokines were analysed by qRT-PCR and Bio-Plex. Islets exposed to the combination of sirolimus and tacrolimus were treated with or without methylprednisolone (1000 mu g/L) and the expression of the proinflammatory cytokines was investigated. We found the following: (i) No additive reduction in function and viability in islets existed when tacrolimus and sirolimus were combined compared to the single drug. (ii) Increased expression of proinflammatory cytokines mRNA and protein levels in islets took place. (iii) Methylprednisolone significantly decreased the proinflammatory response in islets induced by the drug combination. Although human islets are prone to direct toxic effect of tacrolimus and sirolimus, we found no additive effects of the drug combination. Short-term exposure of glucocorticoids could effectively reduce the proinflammatory response in human islets induced by the combination of tacrolimus and sirolimus