Transplantation最新文献

The observation decades ago that inflammatory injuries because of an alloimmune response might be present even in the absence of concomitant clinical impairment in allograft function conduced to the later definition of subclinical rejection. Many studies have investigated the different subclinical rejections defined according to the Banff classification (subclinical T cell-mediated rejection and antibody-mediated rejection), overall concluding that these episodes worsened long-term allograft function and survival. These observations led several transplant teams to perform systematic protocolar biopsies to anticipate treatment of rejection episodes and possibly prevent allograft loss. Paradoxically, the invasive characteristics and associated logistics of such procedures paved the way to investigate noninvasive biomarkers (urine and blood) of subclinical rejection. Among them, several research teams proposed a blood gene signature developed from cohort studies, most of which achieved excellent predictive values for the occurrence of subclinical rejection, mainly antibody-mediated rejection. Interestingly, although all identified genes relate to immune subsets and pathways involved in rejection pathophysiology, very few transcripts are shared among these sets of genes, highlighting the heterogenicity of such episodes and the difficult but mandatory need for external validation of such tools. Beyond this, their application and value in clinical practice remain to be definitively demonstrated in both biopsy avoidance and prevention of clinical rejection episodes. Their combination with other biomarkers, either epidemiological or biological, could contribute to a more accurate picture of a patient's risk of rejection and guide clinicians in the follow-up of kidney transplant recipients.

Background: Kidney transplantation is a widely used treatment for end-stage kidney disease. Nevertheless, the incidence of acute kidney injury (AKI) in deceased donors poses a potential hazard because it significantly increases the risk of delayed graft function and potentially exerts an influence on the kidney allograft outcome. It is crucial to develop a diagnostic model capable of assessing the existence and severity of AKI in renal grafts. However, no suitable kidney injury markers have been developed thus far.

Methods: We evaluated the efficacy of the molecular probe NPO-B, which selectively responds to cysteine, as a new diagnostic tool for kidney injury. We used an in vitro model using ischemia/reperfusion injury human kidney-2 cells and an in vivo ischemia/reperfusion injury mouse model. Additionally, cysteine was investigated using urine samples from deceased donors and living donors to assess the applicability of detection techniques to humans.

Results: This study confirmed that the NPO-B probe effectively identified and visualized the severity of kidney injury by detecting cysteine in both in vitro and in vivo models. We observed that the fluorescence intensity of urine samples measured using NPO-B from the deceased donors who are at a high risk of renal injury was significantly stronger than that of the living donors.

Conclusions: If implemented in clinical practice, this new diagnostic tool using NPO-B can potentially enhance the success rate of kidney transplantation by accurately determining the extent of AKI in renal grafts.

Background: New diagnostic criteria have recently been established to classify small-for-size syndrome (SFSS) after living donor liver transplantation into 3 groups based on severity. This study aimed to evaluate the clinical impact of grade A SFSS and identify the mortality risk.

Methods: We collected data from 406 patients diagnosed with grade A SFSS after living donor liver transplantation. Grade A SFSS is characterized by total bilirubin >5 mg/dL on postoperative day (POD) 7 or total bilirubin >5 mg/dL or ascites >1 L/d on POD 14. After propensity score matching, 193 patients were categorized into the up-trend group, down-trend group, and ascites group, with 43 patients (22.3%) in the up-trend group (total bilirubin on POD 7 < POD 14), 107 patients (55.4%) in the down-trend group (total bilirubin on POD 7 > POD 14), and 43 patients (22.3%) in the ascites group (only satisfying ascites criteria).

Results: There was no significant difference in survival between patients with grade A SFSS and those without SFSS ( P  = 0.152). The up-trend group showed a higher 90-d mortality rate than the down-trend and ascites groups ( P  = 0.025). The 1-y survival rate differed significantly between the groups (87.6%, 91.9%, and 97.7%, respectively; P  = 0.044). The independent risk factors for survival were up-trend of total bilirubin, recipient age (65 y and older), model for end-stage liver disease score (≥30), and ABO incompatibility. Patients with ≥2 risk factors had worse survival rates than those with none and only 1 risk factor ( P  < 0.001).

Conclusions: Although the survival rate was comparable between the grade A SFSS and non-SFSS cohorts, the up-trend group showed worse survival. Aggressive interventions should be considered for up-trend patients with risk factors.

Background: For patients who have difficulty controlling blood glucose even with insulin administration, xenogeneic islet cells, including human stem cell-derived pancreatic islets (hSC-islet) and porcine islets, have garnered attention as potential solutions to challenges associated with donor shortages. For the development of diabetes treatment modalities that use cell transplantation therapy, it is essential to evaluate the efficacy and safety of transplanted cells using experimental animals over the long term.

Methods: We developed permanent diabetic immune-deficient mice by introducing the Akita (C96Y) mutation into the rodent-specific Insulin1 gene of NOD/Shi-scid IL2rγc null (NOG) mice ( Ins1 C96Y/C96Y NOG). Their body weight, nonfasting blood glucose, and survival were measured from 4 wk of age. Insulin sensitivity was assessed via tolerance tests. To elucidate the utility of these mice in xenotransplantation experiments, we transplanted hSC-islet cells or porcine islets under the kidney capsules of these mice.

Results: All male and female homozygous mice exhibited persistent severe hyperglycemia associated with β-cell depletion as early as 4 wk of age and exhibited normal insulin sensitivity. These mice could be stably engrafted with hSC-islets, and the mice that received porcine islet grafts promptly exhibited lowered blood glucose levels, maintaining blood glucose levels below the normal glucose range for at least 52 wk posttransplantation.

Conclusions: The Ins1C96Y/C96Y NOG mouse model provides an effective platform to assess both the efficacy and safety of long-term xenograft engraftment without the interference of their immune responses. This study is expected to contribute essential basic information for the clinical application of islet cell transplantation.

Background: Ex situ machine perfusion of the donor liver, such as dual hypothermic oxygenated machine perfusion (DHOPE), is increasingly used in liver transplantation. Although DHOPE reduces ischemia/reperfusion-related complications after liver transplantation, data on cost-effectiveness are lacking. Our objective was to evaluate the cost-effectiveness of DHOPE in donation after circulatory death (DCD) liver transplantation.

Methods: We performed an economic evaluation of DHOPE versus static cold storage (SCS) based on a multicenter randomized controlled trial in DCD liver transplantation (DHOPE-DCD trial; ClinicalTrials.gov number, NCT02584283). All patients enrolled in the 3 participating centers in the Netherlands were included. Costs related to the transplant procedure, hospital stay, readmissions, and outpatients treatments up to 1 y posttransplant were calculated. The cost for machine perfusion was calculated using 3 scenarios: (1) costs for machine perfusion, (2) machine perfusion costs plus costs for personnel, and (3) scenario 2 plus depreciation expenses for a dedicated organ perfusion room.

Results: Of 119 patients, 60 received a liver after DHOPE and 59 received a liver after SCS alone. The mean total cost per patient up to 1 y posttransplant was €126 221 for the SCS group and €110 794 for the DHOPE group. The most significant reduction occurred in intensive care costs (28.4%), followed by nonsurgical interventions (24.3%). In cost scenario 1, DHOPE was cost-effective after 1 procedure. In scenarios 2 and 3, cost-effectiveness was achieved after 25 and 30 procedures per year, respectively.

Conclusions: Compared with conventional SCS, machine perfusion using DHOPE is cost-effective in DCD liver transplantation, reducing the total medical costs up to 1 y posttransplant.