International Journal of Organ Transplantation Medicine
Volume:5 Issue: 3, Summer 2014

Organ shortage is the greatest challenge facing the field of organ transplantation today. A variety of approaches have been implemented to expand the organ donor pool including live donation, a national effort to expand deceased donor donation, split organ donation, paired donor exchange, national sharing models and greater utilization of expanded criteria donors. Increased public awareness, improved efficiency of the donation process, greater expectations for transplantation, expansion of the living donor pool and the development of standardized donor management protocols have led to unprecedented rates of organ procurement and transplantation. Although live donors and donation after brain death account for the majority of organ donors, in the recent years there has been a growing interest in donors who have severe and irreversible brain injuries but do not meet the criteria for brain death. If the physician and family agree that the patient has no chance of recovery to a meaningful life, life support can be discontinued and the patient can be allowed to progress to circulatory arrest and then still donate organs (donation after circulatory death). Increasing utilization of marginal organs has been advocated to address the organ shortage.

T cell differentiation is dictated by a combination of T cell receptor (TCR) interaction with an antigen-bound major histocompatibility complex (MHC), and co-stimulatory molecules signal. The co-stimulatory signal can be positive or negative, and amplifying or diminishing the initial signal. However, the secondary co-stimulatory signal is not obligatory and its necessity is dictated, in part, by the stage of T cell development. In the field of transplantation, directing the T cell differentiation process can lead to therapeutic possibilities that promote allograft tolerance, and hinder unfavorable alloimmune responses. Therefore, understanding the details of T cell differentiation process, including the influence of co-stimulatory signals, is of paramount importance. It is important to note there is functional overlap between co-stimulatory molecules. It has been observed that some co-stimulatory signals have different effects on different T cell subsets. Hence, blockade of a co-stimulatory signal pathway, as part of a therapeutic regimen in transplantation, may have far reaching effects beyond the initial therapeutic intent and inhibit co-stimulatory signals necessary for desirable regulatory responses. In this review, co-stimulatory molecules involved in the differentiation of naïve T cells into T helper 1 (Th1), T helper 2 (Th2), T helper 17 (Th17), inducible regulatory T cells (iTregs), and T helper 9 (Th9) cells and their overlap are discussed.

Respiratory and renal insufficiencies are common dysfunctions during post-liver transplantation period that increase post-operative mortality and morbidity rates. Intra-operative fluid therapy is an important factor associated with pulmonary and renal insufficiency. To evaluate the relation between intra-operative fluid therapy and early renal and respiratory insufficiency after liver transplantation. In this randomized clinical study, 67 adult patients with end-stage liver disease who underwent orthotopic deceased donor liver transplantation were randomly allocated into two groups. The restricted fluid group, which received a controlled fluid administration of normal saline, 5 mL/kg/hr during anesthesia, and non-restricted fluid group received a controlled infusion of normal saline 10 mL/kg/hr during anesthesia. Early post-operative respiratory and renal insufficiency in both groups were assessed. The patients were monitored during the three stages of liver transplantation for their hemodynamic indices. The trial is registered with the Iranian Randomized Clinical Trial Registry, number IRCT2013101811662N4. The baseline demographic and clinical characteristics were similar in both studied groups. The prevalence of respiratory insufficiency in the non-restricted fluid group (15%) significantly (p=0.01) higher than that in the restricted fluid group (0%). The post-operative mean±SD serum creatinine was 1.0±0.1 mg/dL in the non-restricted fluid group and 1.1±0.2 in the restricted fluid group (p=0.43). No patients in the studied groups required post-operative continuous renal replacement therapy. Restricted crystalloid fluid administration during orthotropic liver transplantation though decreased post-operative chance of pulmonary insufficiency, did not increase renal dysfunction.

Tumors involving the root of the mesentery are generally regarded as “unresectable” with conventional surgical techniques. Resection with conventional surgery may end in life-threatening complications in these patients. Ex-vivo resection and auto-transplantation avoids excessive bleeding and prevents ischemic related damage to the small intestine and other organs. To share our experience of ex-vivo resection of the tumors with involvement of small bowel mesentery followed by small bowel auto-transplantation. In this study, medical records of all the patients who underwent ex-vivo resection and autotransplantation at our center were retrospectively analyzed. The most common indication for the procedure in our series was locally advanced pancreatic carcinoma. Our survival rate was 50% with a mean±SD follow-up of 10.1±9.8 (range: 0–26) months. Causes of early in-hospital mortality were multi-organ failure, sepsis, and cerebrovascular accident. Recurrence of disease was noted in one patient while one patient developed hepatic metastasis after 20 months of surgery. Ex-vivo resection of the tumor and auto-transplantation is the surgical treatment of choice for the locally advanced abdominal tumors involving the root of the mesentery.

Synchronous development of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) in a liver is an extremely rare event. Very few cases have so far been reported in the literature with such condition. Herein, we report on the first case of incidental diagnosis of synchronous HCC and CC in a patient with cryptogenic cirrhosis who underwent liver transplantation. The diagnosis was made after careful examination of the explanted liver.