Başkent Üniversitesi Yayınları
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Item Impact of Donor and Recipient Age on Allograft Tolerance(Başkent Üniversitesi, 2009-06) Martins, Paulo N.The elderly represent the fastest growing segment of the population with end-stage organ disease and the use of aged grafts increased exponentially. Since aging of the immune system, or "immunosenscence" is generally associated with weaker immune responses, one might expect the elderly to be less reactive against transplanted organs than younger patients and therefore to show better results in terms of transplant outcome. Paradoxically, however, experimental studies and clinical data of organ transplantation show that old age of either the recipient or the donor is associated with poorer outcomes. On the other hand transplant tolerance is easier to be induced in the neonatal period. One potential reason for this discrepancy may lie in the effects of immunosenescence on the induction of tolerance. While the impact of aging on acute and chronic allograft rejection has been extensively studied, its role on establishing transplant tolerance is not well known. Since tolerance is an active process, and not just the absence of an immune response, the immunologic changes associated with the aging process may interfere with graft survival. In experimental and clinical transplantation, most successful tolerance induction protocols have been tested on young individuals, using grafts from young donors. However, some experiments that have utilized aged animals have demonstrated resistance to tolerance induction. Extrapolation of these results to humans suggests that protocols for clinical tolerance induction may not be effective in the elderly and may need to be revised for this population. The resistance to achieving immunological tolerance with aging is complex and multifactorial. Here, we review the age associated changes that may interfere with immunologic tolerance. Understanding this phenomenon may help in developing novel therapeutic approaches to reverse the crucial dysfunctions of the aging immune system and achieve effective tolerance regimens for the elderly.Item Fatal Acute Purulent Pericarditis in a Patient with Renal Transplant: A Case Report(Başkent Üniversitesi, 2009-03) Mohsin, Nabil; Abbas, Pakkayara; Ehab, Mohammad; Amitabh, Jha; Budruddin, MohammadObjectives: Acute purulent pericarditis is a life-threatening disease, although it is becoming uncommon in the era of antibiotics. Materials and Methods: We present a case of fatal acute massive purulent pericarditis in a kidney transplant recipient. Results: A 46-year-old woman had an unrelated commercial renal transplant in 2003. She had a history of diabetes mellitus and hepatitis C infection. Kaposi sarcoma developed in the posttransplant period. Her last admission was prompted by the development of acute rejection confirmed by transplant biopsy, and she was treated with intravenous methylprednisolone. Three days before her death, thrombophlebitis of the right forearm was noted. We postulate that this could have been the source of the fulminant purulent pericarditis, as the organism in the pericardial fluid was Staphylococcus aureus, a common pathogen in thrombophlebitis. She was initially resuscitated after cardiac arrest but died shortly after. Conclusions: Severe purulent pericarditis in the immunocompromised patient can occur abruptly. The source of infection may show minimal signs and symptoms. Thrombophlebitis and other apparently minor infections should not be overlooked in such patients.Item TEST(2025) TESTItem Risk Factors of Long-Term Graft Loss in Renal Transplant Recipients with Chronic Allograft Dysfunction(Başkent Üniversitesi, 2010-12) Khalkhali, Hamid Reza; Kazemnejad, Anoushirvan; Hajizadeh, Ebrahim; Ghafari, AliBackground: Graft loss owing to chronic allograft dysfunction is a major concern in renal transplant recipients. We assessed the affect of immune and nonimmune risk factors on death-censored graft loss in renal transplant recipients with chronic allograft dysfunction. Materials and Methods: We performed a retrospective, single-center study on 214 renal transplant recipients with chronic allograft dysfunction among 1534 renal transplant recipients at the Urmia University Hospital from 1997 to 2005. Data registry includes details from all renal transplants. The renal transplant recipient information is regularly updated to determine current graft function, graft loss, or renal transplant recipient’s death. The selection criteria were a functional renal allograft for at least 1 year and a progressive decline in allograft function. Results: Increasing donor age (RR=1.066; P < .001), recipient age (RR=1.021, P = .0), recipient weight (RR=1.024; P = .029), and waiting time on dialysis to transplant. (RR=1.047; P = .006), pretransplant hypertension (RR=3.126; P < .001), pretransplant diabetes (RR=5.787; P < .001), delayed graft function (RR=6.087; P < .001), proteinuria (RR=2.663; P = .001), posttransplant diabetes (RR=2.285; P = .015), posttransplant hypertension (RR=2.047; P = .017), and AR (RR=3.125; P < .001). Patients in stage 2 at the beginning of chronic allograft dysfunction relative to stage 1 (RR=4.823; P < .001) and patients in stage 3 at the beginning of chronic allograft dysfunction relative to stage 1 (RR=123.06; P < .001) were significant risk factors for death-censored graft loss. Using mycophenolate mofetil versus azathioprine reduced death-censored graft loss (RR=0.499; P ≤ .001). Conclusion: We found that age of donor, pretransplant hypertension, pretransplant diabetes, type of immunosuppression (mycophenolate mofetil vs azathioprine), delayed graft function, proteinuria, and stage of allograft dysfunction at the start of chronic allograft dysfunction are the major risk factors for late renal allograft dysfunction.Item Liver Transplant in a Patient with Active Pulmonary Tuberculosis(Başkent Üniversitesi, 2010-09) Yankol, Yucel; Kalayogl, Munci; Acarli, Koray; Alan, Servet; Kanmaz, Turan; Kocak, Burak; Topaloglu, SerdarObjectives: Immunosuppressive treatment generally increases the severity of active infection. Therefore, liver transplant is contraindicated in the presence of active tuberculosis. Despite the importance of supportive treatment, liver transplant is the only treatment for fulminant hepatic failure. Materials and Methods: We report a case of successful liver transplant for fulminant hepatic failure in the presence of active tuberculosis infection. Results: We immediately performed a liver transplant from a live donor. The patient received low-dose immunosuppressive treatment and antituberculosis treatment. The patient was cured and discharged on the 25th day after surgery. We stopped antituberculosis treatment 10 months after discharge. The patient has been followed for 32 months after transplant with normal graft function and has been free of pulmonary tuberculosis infection. Conclusions: Liver transplant can be performed in cirrhotic patients with active infections, such as tuberculosis, as a life-saving procedure.Item Hand-Assisted Laparoscopic Donor Nephrectomy in Patients With Aberrant Inferior Vena Caval Anatomy(Başkent Üniversitesi, 2010-09) Dellen, David van; Inston, Nicholas G.; Ready, Andrew R.Objectives: Hand-assisted laparoscopic donor nephrectomy has become an established technique for live-donor organ retrieval. In most cases, the left kidney is removed because of its more favorable anatomic relations, particularly with the major abdominal vessels. Materials and Methods: We present 2 cases of live donation in which a hand-assisted laparoscopic approach was used to remove the right kidney as indicated by the presence of aberrant vascular anatomy, 1 being situs inversus totalis, the other a left-sided inferior vena cava. Results: A 41-year-old woman and a 51-year-old man underwent assessment for live-kidney donation. During preoperative investigation, they underwent magnetic resonance imaging that demonstrated situs inversus totalis and a left-sided inferior vena cava. No contraindications to live donation were found during the investigation. In both cases, a right donor nephrectomy was performed owing to an anatomically longer right renal vein. Living donation proceeded without complication in both cases, and both patients had uneventful recoveries. Conclusions: Abnormalities in vascular anatomy should not be considered an absolute contraindication to donation, even by the hand-assisted laparoscopic donor approach. The use of magnetic resonance scanning preoperatively allows detailed planning of the approach required.Item Influence of Hypothermia and Cardioplegic Solutions on Expression of α-Gal Epitope on Porcine Aortic Endothelial Cells(Başkent Üniversitesi, 2010-09) Keller, Miriam; Brenner, Paolo; Reichart, Bruno; Schmoeckel, Michael; Beiras-Fernandez, Andresbjectives: The Galα1-3Galβ1-4GlcNAc-R is the major antigen on pig tissue bound by human xenoreactive natural antibodies in xenotransplant. We have investigated in vitro the influence of hypothermic storage with cardioplegic solutions on expression of Galα1-3Galβ1-4GlcNAc-Rs and hyperacute xenograft rejection. Materials and Methods: To analyze effects of hypothermia on the Galα1-3Galβ1-4GlcNAc-Rs, cultured porcine aortic endothelial cells were exposed to a temperature of 4°C for 1 hour, 4 hours, and 6 hours. Cell cultures of the control groups were incubated at the same time at 38°C. To investigate the influence of cardioplegic solutions on the Galα1-3Galβ1-4GlcNAc-Rs, porcine aortic endothelial cells were exposed to 4°C for 4 hours in the presence of University of Wisconsin solution or histidine-tryptophan-ketoglutarate solution. Cells of the control groups were cooled at 4°C for 4 hours without cardioplegic solution. After treatment, porcine aortic endothelial cells were submitted to fluorescence-activated cell sorter. Results: Hypothermia of 4°C showed no significant effect on the quantity of Galα1-3Galβ1-4GlcNAc-Rs. However, the treatment of porcine aortic endothelial cells with University of Wisconsin solution resulted in a highly significant reduction of Galα1-3Galβ1-4GlcNAc-Rs by 50% (P = .006). Treatment of porcine aortic endothelial cells with histidine-tryptophan-ketoglutarate solution decreased α-Gal quantity significantly by 32% (P = .011). Conclusions: Our data offer new perspectives in the prevention of hyperacute, humoral xenograft rejection by reducing the Galα1-3Galβ1-4GlcNAc-Rs after exposure to different cardioplegic solutions.Item A Comparative Study on Suture Versus Cuff Anastomosis in Mouse Cervical Cardiac Transplant(Başkent Üniversitesi, 2010-09) Zhou, Yiming; Chen, Zongyou; Qian, Shiguang; Xiang, Jianbin; Gu, XiaodongObjectives: To compare the cuff technique to traditional suture technique in establishing cervical heart transplant model in mice. Materials and Methods: Eighty transplants were performed by 1 surgeon, 40 using the cuff technique, and 40 using the suture technique, under the same circumstances. Results: The cuff approach was significantly superior to conventional suture anastomosis in higher surgical successful rate, less surgery, and less ischemic time (P < .05). Suture anastomosis required an intensive microsurgical training and at least a 16× surgical microscope, while the cuff anastomosis required less learning time and a 10× surgical microscope. Conclusions: The cuff technique is the preferred method in cervical heart transplant model in mice.Item Thrombotic Microangiopathy in Allogeneic Stem Cell Transplantation in Childhood(Başkent Üniversitesi, 2010-09) Erbey, Fatih; Tanyeli, Atila; Uckan, Duygu; Cetin, Mualla; Yilmaz, Sema; Kuskonmaz, Baris; Bayram, IbrahimObjectives: We define the incidence, risk factors, and mortality rates for the occurrence of thrombotic microangiopathy in 50 children who underwent transplants between January 2006 and June 2008 at 2 Turkish pediatric centers. Materials and Methods: The diagnosis of thrombotic microangiopathy was done according to the reports of International Working Group in 2007. Results: Fifty patients (27 male and 23 female; age range, 3 months to 18 years) were included. Patients with malignant and nonmalignant diseases were 13 (26%) and 37 (74%). Myeloablative and nonmyeloablative conditioning regimens were used in 29 (58%) and 21 patients (42%). Bone morrow was used as the source of stem cells in 32 patients (62%) and peripheral blood was used in 18 patients (36%). Thrombotic microangiopathy was seen in 3 of 50 cases (6%). Thrombotic microangiopathy developed in 3 of 18 patients in whom peripheral blood was used as the source of stem cells while none of 32 patients who had bone marrow as the source developed thrombotic microangiopathy (P < .05). Conclusions: Using peripheral blood as a source of stem cells is a risk factor for development of thrombotic microangiopathy.Item Estimated Glomerular Filtration Rate in Patients With Surgically Acquired Single Kidney Compared With Patients With Congenital Single Kidney: Implications For Kidney Transplant From Live Donors(Başkent Üniversitesi, 2010-09) Bob, Flaviu; Vernic, Corina; Gadalean, Florica Nicoleta; Gluhovschi, Gheorghe; Trandafirescu, Virginia; Petrica, Ligia; Velciov, Silvia; Bozdog, Gheorghe; Gluhovschi, CristinaObjectives: The pathophysiology of the single kidney is involved in the evolution toward end-stage renal disease. Furthermore, most data suggest that the renal function of the donor is maintained after nephrectomy. This study sought to analyze the difference between surgically acquired single kidney and the congenital single kidney, regarding kidney function at a similar moment in time of the existence of a single kidney. Materials and Methods: Two groups were enrolled in this study. Group A consisted of 28 patients with surgically acquired single kidney, time from nephrectomy was 30.23 ± 10.82 years; mean age, 54.42 ± 14.99 years. Group B consisted of 20 patients with a congenital single kidney (mean age, 30.3 ± 10.43 years). We assessed glomerular filtration rate (Modification of Diet in Renal Disease 4 Study Equation) and the presence of classic and nonclassic risk factors for chronic kidney disease. Results: The estimated glomerular filtration rate showed no statistically significant difference between the 2 groups. Conclusions: Our study did not show any influence of surgical nephrectomy on the evolution of kidney function. Kidney function in the surgically acquired single kidney was similar to the kidney function in the congenital single kidney at a comparable time interval. Our results have potential favorable implications for kidney transplant from living donors.