Amelioration of renal damage by administration of anti-thymocyte globulin to potential donors in a brain death rat model

Role of biobanks in transplantation

The establishment of bio-banks together with high throughput technologies, such as genomics, transcriptomics and proteomics has opened new frontiers in biomarker discovery and the development of systems biology approaches to identifying key pathways that could be exploited to improve outcomes of solid organ transplantation. One of the major challenges in organ donation has been the lack of access to large scale well characterised material to facilitate projects that aim to characterise injury to donor organs and identify biomarkers. This may have hampered research in the field of organ donation by not allowing researchers to materials of high quality and lower pre-analytical variability. We describe in this manuscript the need for bio-banks in organ donation, research opportunities and the particular challenges in establishing such an initiative.

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We address:

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The main challenges in transplantation.

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Underpinning cellular processes of injury and repair.

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The role of biobanks can be used in transplantation.

Oxidative stress and apoptosis in a pig model of brain death (BD) and living donation (LD)

Background

As organ shortage is increasing, the acceptance of marginal donors increases, which might result in poor organ function and patient survival. Mostly, organ damage is caused during brain death (BD), cold ischemic time (CIT) or after reperfusion due to oxidative stress or the induction of apoptosis. The aim of this study was to study a panel of genes involved in oxidative stress and apoptosis and compare these findings with immunohistochemistry from a BD and living donation (LD) pig model and after cold ischemia time (CIT).

Methods

BD was induced in pigs; after 12 h organ retrieval was performed; heart, liver and kidney tissue specimens were collected in the BD (n = 6) and in a LD model (n = 6). PCR analysis for NFKB1, GSS, SOD2, PPAR-alpha, OXSR1, BAX, BCL2L1, and HSP 70.2 was performed and immunohistochemistry used to show apoptosis and nitrosative stress induced cell damage.

Results

In heart tissue of BD BAX, BCL2L1 and HSP 70.2 increased significantly after CIT. Only SOD2 was over-expressed after CIT in BD liver tissue. In kidney tissue, BCL2L1, NFKB, OXSR1, SOD2 and HSP 70.2 expression was significantly elevated in LD. Immunohistochemistry showed a significant increase in activated Caspase 3 and nitrotyrosine positive cells after CIT in BD in liver and in kidney tissue but not in heart tissue.

Conclusion

The up-regulation of protective and apoptotic genes seems to be divergent in the different organs in the BD and LD setting; however, immunohistochemistry revealed more apoptotic and nitrotyrosine positive cells in the BD setting in liver and kidney tissue whereas in heart tissue both BD and LD showed an increase.

Evaluation of histological damage of solid organs after donor preconditioning with thymoglobulin in an experimental rat model

Rabbit anti-rat thymoglobulin (rATG) administered to donors with brain death (BD) may improve organs quality. We explored the effects of rATG administered to BD donors in the histology of heart, lungs and small bowel in a rat experimental model. Animals were randomly assigned to 3 groups: V (n=5) no BD, 2h ventilation; BD (n=5) BD and 2h ventilation; BD and rATG: BD, 2h ventilation, rATG (10mg/kg) after BD diagnosis. Histopathological damage scores were based on neutrophil infiltration, airway epithelial cell damage, interstitial edema, hyaline membrane formation, and pulmonary hemorrhage (lungs); neutrophil infiltration and interstitial edema (heart); Park score (bowel). Lung damage was significantly lower in BD+rATG group: V 5 ± 1.6; BD 11.25 ± 0.5, BD+rATG 6.5 ± 1.9 (p<0.01). Heart: V 2.0 ± 0.81; BD 4.75 ± 1.25 and BD+rATG 3.5 ± 1.7 (p>0.05). Small bowel: BD 2.25 ± 0.96 vs. BD+rATG 1.00 ± 1.15 (n.s.). Histological damage amelioration in lung and attenuation tendency in heart and small bowel encourages research of cytoprotective strategies to improve organ viability.