The unsolved problem of organ allocation in times of organ shortage: the German solution?

Graft-derived Cell-free DNA as a Noninvasive Biomarker of Cardiac Allograft Rejection: A Cohort Study on Clinical Validity and Confounding Factors

BACKGROUND

Circulating graft-derived cell-free DNA (dd-cfDNA) is a new marker of cardiac allograft damage that is used for noninvasive rejection diagnostics. We performed dd-cfDNA (%) in heart transplant recipients during the first posttransplant year.

METHODS

In 87 patients, serial dd-cfDNA determination at predefined time-points was performed in 770 single samples. dd-cfDNA fraction (%) was measured using an established universal droplet digital polymerase chain reaction method, providing same-day turn-around. Rejection was diagnosed according to clinical parameters and biopsies.

RESULTS

Median dd-cfDNA (%) was high (5.36%) immediately after reperfusion and decreased to a median (interquartile range) of 0.10% (0.05%-0.24%) in clinically stable patients by postoperative day 10. Compared to dd-cfDNA (%) samples in clinically stable patients, values were higher (P < 0.001) in biopsy-proven rejection ISHLT 1R (0.42% [0.15%-0.53%]) and 2R rejection (0.84% [0.39%-0.97%]). Moreover, dd-cfDNA (%) was already significantly increased 9-30 days before biopsy-proven rejection (0.36% [0.20%-0.61%]). An as yet unknown finding was a slightly, but significantly (P < 0.0001) higher dd-cfDNA (%) value in samples of stable patients with pericardial effusions (PEs) (n = 94; 0.18% [0.07%-0.30%]) compared to samples of non-PE patients (n = 132; 0.07% [0.04%-0.17%]). Using a cutoff of 0.35%, sensitivity and specificity of dd-cfDNA for cardiac rejection were 0.76 and 0.83 (area under the curve [AUC] ROC-curve: 0.81 [95% confidence interval, 0.73-0.89]). Omitting PE samples from the control group yielded an AUC of 0.86 [95% confidence interval, 0.76-0.95]. Samples drawn <12 hours after endomyocardial biopsy showed high (0.40% [0.15%-1.21%]) dd-cfDNA values, also in ISHLT0R (0.36% [0.10%-0.60%]).

CONCLUSIONS

dd-cfDNA plasma values were significantly associated with cardiac rejection. However, PE or improper sampling (eg, shortly after biopsy) should be considered as confounders for rejection diagnoses using dd-cfDNA.

The experiences of adult heart, lung, and heart-lung transplantation recipients: A systematic review of qualitative research evidence

Aim

To review evidence about the experience of being the recipient of a donated heart, lungs, or heart and lungs.

Design

A systematic review (registered with PROSPERO: CRD42017067218), in accordance with PRISMA guidelines.

Data sources

Seven databases and Google Scholar were searched in May 2017 and July 2019 for papers reporting English-language research that had used qualitative methods to investigate experiences of adult recipients.

Review methods

Quality was assessed and results were analysed thematically.

Results

24 papers (reporting 20 studies) were eligible and included. Their results were organised into three chronological periods: pre-transplant (encompassing the themes of ‘dynamic psychosocial impact’, ‘resources and support’), transplant (‘The Call’, ‘intensive care unit’), and post-transplant (‘dynamic psychosocial impact’, ‘management’, ‘rejection’). Sub-themes were also identified. It was evident that contemplating and accepting listing for transplantation entailed or amplified realisation of the precipitating illness’s existential threat. The period surrounding transplantation surgery was marked by profound, often surreal, experiences. Thereafter, although life usually improved, it incorporated unforeseen challenges. The transplantation clinic remained important to the recipient. The meaning of the clinic and its staff could be both reassuring (providing care and support) and threatening (representing onerous medical requirements and potential organ rejection).

Conclusion

This review has implications for the psychosocial care of transplant recipients and indicates the need for further research to gain insight into the experience of receiving a donated heart and/or lung.

Impact

Medical consequences of heart and lung transplantation are well documented; this is the first systematic review of research using qualitative methods to investigate the experience of heart, lung, and heart-and-lung transplantation. The psychosocial impact of transplantation was found to be dynamic and complex, with notable features evident before, during, and after transplantation. Clinic staff remained significant to recipients. It is clear that recipients need continuing psychosocial as well as medical support.

Measures influencing post-mortem organ donation rates in Germany, the Netherlands, Spain and the UK : A systematic review

BACKGROUND

German post-mortem organ donation rates have been declining since 2010. Several transplantation scandals led to a negative portrayal of organ donation in the media. Spain, the UK and the Netherlands achieved a rise in organ donation rates while retaining organ donation legislation.

METHODS

A systematic review of publications focusing on (1) organ donation legislation, (2) data on post-mortem organ donation rates and (3) measures to increase post-mortem organ donation rates in Europe was conducted in November 2017 in PubMed, PsycINFO and Web of Science. Quality parameters of the World Bank and the World Health Organization (WHO) were studied to analyze national health services, frequent causes of death and life expectancy.

RESULTS

Quality parameters of national health services were similar in all countries. The Netherlands and Germany have an opt in system. An increase of 37.4% in post-mortem organ donation rates from 2008 to 2015 in the UK was accomplished through the establishment of a donation task force, adopting parts of the Spanish model, while maintaining an opt in system. Spain has the highest organ donation rate worldwide (39.7 per million persons in 2015). The implementation of transplantation coordinators and the change in legislation in Germany in 2012 has so far shown no effect. Public awareness of organ donation in the Netherlands increased following various information campaigns.

CONCLUSION

Donation after cardiac death (DCD), expanded donor criteria, increasing public awareness and introduction of an organ donor register should be discussed as measures to increase organ donation rates in Germany.

Immediately Functioning Grafts from Brain-Dead Donors Treated with Extracorporeal Membrane Oxygenation

A brain-dead donor experienced repeated cardiac arrests followed by severe hypotension requiring multiple vasoactive agents. These events were associated with severe lactic acidosis and dysregulated kidney function in the donor. A 10-hour treatment with extracorporeal membranous oxygenation was instituted, which was able to hemodynamically stabilize the donor. This treatment protocol resulted in the procurement of 2 viable kidney grafts transplanted into 2 recipients, who had immediate kidney graft function and excellent serum creatinine levels upon hospital discharge. These results are all the more significant considering that both cases involved long cold ischemia times, and one of the recipients had diabetes and was receiving his second kidney graft.

Impact of Donor Arterial Partial Pressure of Oxygen on Outcomes After Lung Transplantation in Adult Cystic Fibrosis Recipients

INTRODUCTION

Donor PaO2 levels are used for assessing organs for lung transplantation (LTx), but survival implications of PaO2 levels in adult cystic fibrosis (CF) patients receiving LTx are unclear.

METHODS

UNOS registry data spanning 2005-2013 were used to test for associations of donor PaO2 with patient survival and bronchiolitis obliterans syndrome (BOS) in adult (age ≥ 18 years) first-time LTx recipients diagnosed with CF.

RESULTS

The analysis included 1587 patients, of whom 1420 had complete data for multivariable Cox models. No statistically significant differences among donor PaO2 categories of ≤200, 201-300, 301-400, or >400 mmHg were found in univariate survival analysis (log-rank test p = 0.290). BOS onset did not significantly differ across donor PaO2 categories (Chi-square p = 0.480). Multivariable Cox models of patient survival supported the lack of difference across donor PaO2 categories. Interaction analysis found a modest difference in survival between the two top categories of donor PaO2 when examining patients with body mass index (BMI) in the lowest decile (≤16.5 kg/m(2)).

CONCLUSIONS

Donor PaO2 was not associated with survival or BOS onset in adult CF patients undergoing LTx. Notwithstanding statistically significant interactions between donor PaO2 and BMI, there was no evidence of post-LTx survival risk associated with donor PaO2 below conventional thresholds in any subgroup of adults with CF.

Survival in Adult Lung Transplant Recipients Receiving Pediatric Versus Adult Donor Allografts

BACKGROUND

Recent evidence showed that pediatric donor lungs increased rates of allograft failure in adult lung transplant recipients; however, the influence on survival is unclear.

METHODS

The United Network for Organ Sharing (UNOS) database was queried from 2005 to 2013 for adult lung transplant recipients (≥18 years) to assess survival differences among donor age categories (<18 years, 18 to 29 years, 30 to 59 years, ≥60 years).

RESULTS

Of 12,297 adult lung transplants, 12,209 were used for univariate Cox models and Kaplan-Meier (KM) analysis and 11,602 for multivariate Cox models. A total of 1,187 adult recipients received pediatric donor lungs compared with 11,110 receiving adult donor organs. Univariate and multivariate Cox models found no difference in survival between donor ages 0 to 17 and donor ages 18 to 29, whereas donor ages 60 and older were significantly associated with increased mortality hazard, relative to the modal category of donor ages 30 to 59 (adjusted hazard ratio = 1.381; 95% confidence interval = 1.188% to 1.606%; p < 0.001). Interactions between recipient and donor age range found that the oldest donor age range was negatively associated with survival among middle-aged (30 to 59) and older (≥60) lung transplant recipients.

CONCLUSIONS

Pediatric donor lung allografts were not negatively associated with survival in adult lung transplant recipients; however, the oldest donor age range was associated with increased mortality hazard for adult lung transplant recipients.

[Individualized stem cell therapy]

Stem cells are attributed with having a great potential in regenerative medicine. Pluripotent stem cells are particularly interesting because they can be multiplied indefinitely and also differentiated under defined conditions. Currently, cardiomyocytes can be differentiated very effectively from pluripotent stem cells, making the former an attractive starting material for cardiac disease modeling in a culture dish (patient in a dish) and cell based-therapy in heart failure. The rapid biotechnological advances made in recent years now enable these concepts to be translated into clinical applications.