Israel Medical Association Journal

Background: Pulmonary disease is the most frequent cause of morbidity and mortality in cystc fibrosis patients. New techniques such as non-invasive positive pressure ventilation have resulted in prolongation of life expectancy in CF[1] patients with end-stage lung disease.

Objectives: To determine the role of NIPPV[2] in CF patients awaiting lung transplantation.

Methods: Between 1996 and 2001 nine CF patients (5 females) with end-stage lung disease were treated with bi-level positive airway pressure ventilation in the "spontaneous" mode.

Results: The patients' mean age at initiation of BiPAP[3] was 15 years (range 13–40 years) and the mean duration of BiPAP usage was 8 months (range 3–16 months). Four patients underwent successful lung transplantation, three patients died while awaiting transplantation, and the remaining two are still on NIPPV while waiting for transplantation. Patients' body mass index increased significantly (P < 0.05) during BiPAP therapy (from 16.1 to 17.2 kg/m²). Blood pH, p_aCO₂, and bicarbonate improved significantly (from 7.31 to 7.38, 90.8 to 67.2 mmHg, and 48.9 to 40.3 mEq/L, respectively). Pulmonary function tests were not affected by BiPAP usage. The patients experienced a significant alleviation in morning headaches and improvement in quality of sleep (P < 0.003). There were no major complications during BiPAP usage.

Conclusions: We demonstrated that long-term NIPPV can stabilize and improve physiologic parameters such as ventilation, arterial blood gases and body mass index, as well as subjective symptoms such as sleep pattern, daily activity level, and morning headaches in CF patients with end-stage lung disease. Further prospectively controlled studies are needed to evaluate the potential of BiPAP therapy and its influence on morbidity and mortality in the post-lung transplantation period.

Background: The prognosis of patients with fulminant hepatic failure without timely liver transplantation is dismal. Given the limited availability of cadaveric organs for urgent transplantation in Israel, adult-to-adult living-donor segmental liver transplantation may be the only alternative.

Objectives: To report our initial experience with urgent lifesaving LDLT[1] in this unique scenario.

Methods: Three adult patients with FHF[2] (two of unknown etiology, one with paracetamol intoxication) were transferred from other institutions and admitted to our intensive care unit. Initial treatment and monitoring included intracranial pressure monitoring and hepatic dialysis using the Molecular Adsorbent Recirculating System. Expeditious potential donor selection included medical, psychosocial and surgical evaluation. Liver volume and vascular anatomic compatibility were assessed with computed tomography angiography.

Results: Between July and October 2003 we performed three procedures of urgent adult-to-adult LDLT. The donors (two uncles, one sister) underwent hepatic resection (two right lobes, one left lateral segment) and recovered well. The recipients underwent total hepatectomy with caval preservation, followed by lobar grafting. All recipients recovered and are alive with good liver function and without any neurologic complications.

Conclusions: Urgent adult-to-adult living-donor segmental liver transplantation can be performed safely and timely as a lifesaving procedure in the setting of comatose patients with FHF.

Since both major forms of diabetes involve inadequate function of pancreatic beta cells, intensive research is ongoing to better understand how beta cells perform their complex role of secreting the hormone insulin in response to physiologic needs. Identification and characterization of pancreatic transcription factors has revealed that they play a crucial role not only in maintenance of mature beta-cell function but also at multiple stages in pancreatic development. Furthermore, recent reports have revealed their potential to convert non-beta cells into insulin-producing cells, which in some cases can function to ameliorate diabetes in experimental animals. The ability to translate these successes to the clinic will require a detailed mechanistic understanding of the molecular basis of action of these proteins. Specific gene regulation in beta cells involves the action of multiple transcription factors recruited to the promoter and functioning synergistically to activate transcription, in part through recruitment of co-activator proteins and components of the basal transcriptional machinery. In addition, the process involves modification of chromatin structure, the details of which are beginning to be elucidated. Our ability to modulate gene expression patterns may lead to developing ways to provide an unlimited supply of functional beta cells for transplantation, permitting a dramatic improvement in therapeutic options for diabetes.

Type 1 diabetes mellitus is caused by an autoimmune destruction of pancreatic islet beta cells, leading to insulin deficiency. Beta-cell replacement is considered the optimal treatment for type 1 diabetes, however it is severely limited by the shortage of human organ donors. An effective cell replacement strategy depends on the development of an abundant supply of beta cells and their protection from recurring immune destruction. Stem/progenitor cells, which can be expanded in tissue culture and induced to differentiate into multiple cell types, represent an attractive source for generation of cells with beta-cell properties: insulin biosynthesis, storage, and regulated secretion in response to physiologic signals. Embryonic stem cells have been shown to spontaneously differentiate into insulin-producing cells at a low frequency, and this capacity could be further enhanced by tissue culture conditions, soluble agents, and expression of dominant transcription factor genes. Progenitor cells from fetal and adult tissues, such as liver and bone marrow, have also been shown capable of differentiation towards the beta-cell phenotype in vivo, or following expression of dominant transcription factors in vitro. These approaches offer novel ways for generation of cells for transplantation into patients with type 1 diabetes.

In recent years, umbilical cord blood has emerged as an alternative source of hematopoietic progenitors (CD34+) for allogeneic stem cell transplantation, mainly in patients who lack an human leukocyte antigen-matched marrow donor. Since 1998, about 2,500 patients have received UCB[1] transplants for a variety of malignant and non-malignant diseases. The vast majority of recipients were children with an average weight of 20 kg, however more than 500 UCB transplantations have already been performed in adults. The “naive” nature of UCB lymphocytes may explain the lower incidence and severity of graft versus host disease encountered in UCBT[2] compared to the allogeneic transplant setting. Furthermore, UCB is rich in primitive CD16^-CD56⁺⁺ natural killer cells, which possess significant proliferative and cytotoxic capacities and can be expanded using interleukin-12 or 15, so as to mount a substantial graft versus leukemia effect. The major disadvantage of UCB is the low yield of stem cells, resulting in higher graft failure rates and slower time to engraftment compared to bone marrow transplantation. A rational approach thus involves ex vivo expansion of UCB-derived hematopoietic precursors.

Background: An organ sharing system should achieve fairness and optimal graft longevity. Balancing between social and utilitarian considerations is a sensitive ethical, public and medical issue that requires a means to examine the consequences of any allocation policy or planned changes thereof.

Objective: To evaluate the performance and applicability of a computerized simulation model by examining the impact of two opposing organ allocation policies (social or utilitarian) on predicted organ distribution regarding age, waiting time, recipient sensitization measured by panel reactive antibody level and overall donor-recipient tissue matching (measured by the number of HLA antigen mismatches).

Methods: Using a computerized simulation model, virtual donors and recipients were emulated and organs were allocated according to either social algorithms or utilitarian policies. The resulting number of HLA mismatches, PRA[1], age, and waiting time distributions were compared between allocation strategies.

Results: Simulating allocation of 7,000 organs to 17,000 candidate recipients and implementing social policies yielded donor-recipient compatibility comparable to utilitarian policies (0–1 mm: 19.4% vs. 28%) while allocating 66.7% of organs to long waiters (>48 months).

Conclusion: This computerized simulation model is a valuable tool for decision-makers establishing or modifying organ allocation policies.

Background: Recent advances in immunosuppressive therapy have led to a substantial improvement in the outcome of kidney transplantation. Living unrelated donors may become a source of additional organs for patients on the kidney waiting list.

Objectives: To study the impact of combination of calcineurin inhibitors and mycophenolate-mofetile, together with steroids, on outcomes of living related and unrelated transplants. 

Methods: Between September 1997 and January 2000, 129 patients underwent living related (n=80) or unrelated (n=49) kidney transplant. The mean follow-up was 28.2 months. Immunosuppressive protocols consisted of MMF[1] with cyclosporine (41%) or tacrolimus (59%), plus steroids. Patient and graft survival data, rejection rate, and graft functional parameters were compared between the groups.

Results: LUD[2] recipients were older (47.8 vs. 33.6 years) with higher number of re-transplants (24.5% vs. 11.2% in LRD[3] recipients, P < 0.05). Human leukocyte antigen matching was higher in LRD recipients (P < 0.001). Acute rejection developed in 28.6% of LUD and 27.5% of LRD transplants (P = NS). Creatinine levels at 1, 2 and 3 years post-transplant were 1.6, 1.7 and 1.7 mg/dl for LRD patients and 1.5, 1.5 and 1.3 mg/dl for LUD recipients (P = NS). There was no difference in patient survival rates between the groups. One, 2 and 3 year graft survival rates were similar in LRD (91.3%, 90% and 87.5%) and LUD (89.8%, 87.8% and 87.8%) recipients.

Conclusions: Despite HLA[4] disparity, rejection and survival rates of living unrelated transplants under current immunosuppressive protocols are comparable to those of living related transplants.