Au cours de ce travail, nous nous sommes intéressés à l'impact de l'exposition à la ciclosporine A (CsA) sur la signalisation angiogénique dans le carcinome à cellules rénales (renal cell carcinoma – RCC) qui représente la deuxième cause de cancer chez les patients transplantés rénaux. Nous avons examiné in vitro l'impact de l'exposition à la CsA sur la réponse UPR (Unfolded Protein Response) et la régulation des protéines sécrétées en portant un intérêt particulier à la régulation du VEGF (Vascular Endothelial Growth factor). Nous confirmons l'effet de la CsA sur la protéostase et montrons que l'activation de l'UPR par la CsA, conduisant à une augmentation de la production de VEGF en hypoxie, pourrait participer à l'agressivité des tumeurs. Nous proposons de rechercher certains biomarqueurs de l'UPR chez les patients ayant développé un RCC post-transplantation afin d'examiner de façon plus approfondie l'altération de la protéostase et la régulation de l'UPR dans ce contexte. Dans le domaine de la médecine personnalisée, d'autres approches comme la pharmacogénétique sont désormais utilisées dans la pratique médicale. Dans ce contexte, nous avons évalué l'intérêt du génotypage du VEGF dans une cohorte de patients transplantés rénaux. Nous montrons que le polymorphisme VEGF 936 C>T est associé de façon significative au risque de développer un RCC post-transplantation. Même s'il est évident que des études supplémentaires doivent être menées, nos résultats indiquent que le génotypage de VEGF 936 C>T pourrait être envisagé pour améliorer la gestion des traitements immunosuppresseurs chez les patients identifiés comme étant à risque de développer un RCC post-transplantation / In this work, we investigated the impact of cyclosporine A (CsA) exposure on angiogenic signalling in renal cell carcinoma (RCC), the second mostly observed cancer in renal transplanted patients. We examined in vitro the effect of CsA exposure on the Unfolded Protein Response (UPR) and the regulation of secreted proteins with a focus on VEGF (Vascular Endothelial Growth Factor) regulation. We confirm the effect of CsA on proteostasis and we show that the activation of UPR by CsA, leading to an increased VEGF hypoxic expression, could contribute to the aggressiveness of tumours. We propose to investigate a list of candidate UPR biomarkers in patients who have developed a post-transplant RCC in order to confirm the alteration of proteostasis and the UPR activation in this context. In the field of personalized medicine, other approaches such as pharmacogenetics are now used in medical practice. In this context, we evaluated the VEGF genotyping in a cohort of renal transplanted patients. We show that VEGF 936 C>T is significantly associated with the risk of developing a post-transplant RCC. Although it is evident that additional studies need to be conducted, our results indicate that VEGF 936 C>T genotypes might be useful to classify patients according to their post-transplant RCC risk in order to improve immunosuppressive drugs management

No description available.

It has been reported that the presence of Fc receptor blocking antibodies is associated with normal pregnancy and improved cadaver donor renal transplant survival. The demonstration of the development of such antibody activity in the animal model during one or more pregnancies and the effect of these pregnancies on the survival of a subsequent renal allograft form the major aims of the studies presented in this thesis.A microsurgical laboratory was therefore established at Aberdeen University and the rat renal transplant model developed. Fc receptor blocking activity was assessed using the EA inhibition assay.The results indicate that:I Fc receptor blocking activity was not found in the sera of virgin rats.2 Significant levels of these antibodies were only found after two pregnancies and they occurred in 50% of such cases3 Primiparous animals and those multiparous animals which did not develop EA inhibiting activity rejected renal allografts from the paternal strain in the same time as virgin animals.4 Only multiparous rats sharing over 30% EA inhibition failed to reject transplants carrying paternal specificities. Those animals were capable of rejecting grafts from third party donors suggesting that the Fc receptor blocking antibodies were directed towards paternal antigens.It is therefore suggested that Fc receptor blocking activity occurring as a result of pregnancy in the rat renal transplant model may enhance a renal allograft from the paternal strain. These antibodies may therefore represent a form of donor specific immunosuppression.

Class of 2012 Abstract / Specific Aims: To compare and evaluate the therapies prescribed, the incidence of adverse drug events, and the time to clinical cure in transplant patients with a cytomegalovirus (CMV) infection at an academic medical center before and during the foscarnet nationwide shortage. Methods: This study was a retrospective chart review to compare CMV treatment prescribed and clinical outcomes in pediatric and adult transplant patients at an academic medical center. Transplant patients were evaluated over a 16 month time period between December 2009 and March 2011. The average dose (mg/kg) and prevalence ganciclovir, foscarnet, and cidofovir prescribed in transplant patients with CMV infection were evaluated. Additionally, the incidence of adverse drug events including acute renal dysfunction and myelosuppression were characterized. Main Results: There were 30 subjects diagnosed with CMV disease during the evalutaion period. Of all of the patients treated for CMV before the shortage, 79% received ganciclovir, 43% received foscarnet, and 21% received cidofovir. Following the shortage in September 2010, the usage of the antiviral agents changed to 100%, 25%, and 13% respectively. Overall the usage of ganciclovir increased while the usage of foscarnet decreased when there was a shortage of medication. Conclusions: The antiviral prescribing patterns changed significantly during the foscarnet shortage. The average dose and incidence of ganciclovir increased which likely contributed to serious adverse events. Due to the limited amount of patients treated for CMV and the short time frame, clinical cure could not be determined at this time. Drug shortages are a serious problem and significantly influence patient outcomes.

Class of 2012 Abstract / Specific Aims: The primary aim of this study was to determine the incidence of posaconazole and voriconazole concentration monitoring that occurs in transplant patients receiving antifungal prophylaxis therapy. The secondary aim was to determine whether voriconazole and posaconazole serum concentrations were used for dose adjustments. Methods: Patients status post either a liquid or solid organ transplant over the age of 1 year who received invasive fungal infection prophylaxis with either posaconazole or voriconazole between the dates of February 1, 2010 through January 31, 2011 while admitted to academic medical center were included in this descriptive retrospective study. This study has been approved by the Institutional Review Board. Data collected on each subject included demographic information, type of transplant, posaconazole or voriconazole concentrations, and duration and dosage adjustments. Main Results: 54 subjects were identified who received either voriconazole or posaconazole for fungal prophylaxis after transplant. For subjects who were prescribed posaconazole (N = 8), concentration monitoring was performed in 50% of subjects and 0% of posaconazole dose adjustments were based on concentrations. For subjects who were prescribed voriconazole, concentration monitoring and dose adjustments based on voriconazole concentrations were performed in 20% and 78% of subjects respectively. Adverse outcomes associated with the use of antifungal therapy were reported in 0% of the posaconazole therapy group and 17% of the voriconazole therapy group. Conclusions: Both posaconazole and voriconazole concentrations were obtained from patients who were receiving antifungal therapy for invasive fungal infection prophylaxis. Adjustments of prophylactic doses are not well characterized.

No description available.

Graft versus Host Disease (GvHD) is one of the main complications patients face after receiving a bone marrow transplant. Between 40-60% of bone marrow transplant recipients develop GvHD, with consequent systemic inflammation/fibrosis, reduced quality of life, graft failure, and mortality. We have previously demonstrated that donor-derived C5 is involved in the initiation and propagation of GvHD. Current approaches to inhibition of C5 share a serious flaw of indiscriminately blocking production of a mediator that is crucial for host defense. Targeted therapies to block C5 in specific cells, or anatomical sites, are the only way in which to achieve therapeutic benefit without compromising host defenses. Three lentiCRISPR v2-dCas9 gene editing viral constructs were created to selectively cleave the complement C5 gene, at three different sites. Our objective was to knockout complement C5 function in infected donor BM cells in a GVHD mouse model. Each of the three lentiCRISPR plasmids was separately co-cultured with PMDG2 and PSPAX2, in human embryonic kidney (HEK) 293T cells. Resultant viral particles were able to transfer the Cas-9 endonuclease gene into donor BM cells in vitro with a transduction efficiency of 52%. Treated donor BM cells were then retro-orbital injected into irradiated recipient mice. Control mice were transplanted following the same protocol excluding the lentiCRISPR treatment of BM. The lentiCRISPR treatment group demonstrated significantly lower total airway resistance (p = 0.05) and higher lung compliance (p = 0.014) when compared to the control group. When compared to the saline treated group however the lentiCRISPR group showed significantly higher total airway resistance (p = 0.004) and significantly lower lung compliance (p = 0.014). These results taken together suggest a possible reduction in GvHD severity in mice that received the lentiCRISPR treatment. This study can serve as a starting point for the development of this novel treatment of GvHD. / Thesis / Master of Science (MSc)

No description available.

These two studies investigate the immune responses of lung and kidney transplant recipients to the influenza vaccine. The study involving kidney transplant recipients developed a novel flow cytometry assay to measure cell-mediated immunity in response to influenza vaccination. The activation of T-cells was assessed through the change in T-cell production of interferon gamma after vaccination. In lung transplant recipients, the study examined the formation of de novo anti-HLA antibodies following influenza vaccination. Anti-HLA antibodies were classified as donor-specific or not. The study in kidney transplant recipients found that the influenza vaccine is effective at stimulating the immune response and producing long-lived memory in these patients, as evidenced by high baseline T-cell activity. The study of lung transplant recipients found that receiving the influenza vaccine did not result in the production of anti-HLA antibodies. Both studies found vaccine to be safe for use in these populations. / Experimental Medicine

No / Aims: An increasing dialysis population and insufficient supply of transplant organs necessitate that patients are carefully evaluated prior to registration on the national waiting list to ensure effective utilization of a scarce resource. We have assessed listing practice in two renal units within the North of England Transplant Alliance. Methods: Demographic, ethnic and clinical data were recorded at initiation of dialysis for patients from two northern English cities, Bradford (n = 209) and Hull (n = 202) between 1994 ¿ 2000. Patients were stratified by two co-morbidity scoring systems. Multivariate and survival analyses were undertaken by registration status. Results: Overall, 159 patients were registered onto the waiting list. Stratification by co-morbidity predicted listing at high and low risk, but with overlap at medium scores. There was no difference in overall co-morbid burden between the two centers (p = 0.161 and 0.316, respectively, for two scoring systems). Logistic regression analysis demonstrated a center effect, Hull having an odds ratio for listing of 0.48 compared to Bradford (p = 0.041). Short- and medium-term survival in the listed group was high regardless of co-morbid score (22 vs 174 deaths in the non-listed group). In this cohort, five patients died with grafts, another three died whilst active on the waiting list. The remaining 14 patients had been removed from the list prior to death. Summary: Co-morbidity scoring schemes are unlikely to be sophisticated enough to accurately identify those who would most benefit from transplantation, and the value of clinical judgment is well-shown in this study. Standardization of registration will result in more equitable allocation of organs. However, this study has demonstrated that there are differences in listing practices even within a single alliance. Continuous assessment will allow judicious removal from the waiting list of patients who have developed an unacceptable co-morbid burden.