Showing papers on "Transplantation published in 1999"

Comparison of Mortality in All Patients on Dialysis, Patients on Dialysis Awaiting Transplantation, and Recipients of a First Cadaveric Transplant

Abstract: Background The extent to which renal allotransplantation — as compared with long-term dialysis — improves survival among patients with end-stage renal disease is controversial, because those selected for transplantation may have a lower base-line risk of death. Methods In an attempt to distinguish the effects of patient selection from those of transplantation itself, we conducted a longitudinal study of mortality in 228,552 patients who were receiving long-term dialysis for end-stage renal disease. Of these patients, 46,164 were placed on a waiting list for transplantation, 23,275 of whom received a first cadaveric transplant between 1991 and 1997. The relative risk of death and survival were assessed with time-dependent nonproportional-hazards analysis, with adjustment for age, race, sex, cause of end-stage renal disease, geographic region, time from first treatment for end-stage renal disease to placement on the waiting list, and year of initial placement on the list. Results Among the various subgroups...

Prognosis of hepatocellular carcinoma : the bclc staging classification

Abstract: The classifications of hepatocellular carcinoma (HCC) currently used are based on prognostic factors obtained from studies performed years ago when most tumors were diagnosed at advanced stages and the survival rates were substantially poor. Recent investigations have reviewed the survival of early tumors properly selected to receive radical therapies and the natural outcome of nonsurgical HCC patients. These data enable a new staging system to be proposed, the Barcelona Clinic Liver Cancer (BCLC) staging classification, that comprises four stages that select the best candidates for the best therapies currently available. Early stage (A) includes patients with asymptomatic early tumors suitable for radical therapies--resection, transplantation or percutaneous treatments. Intermediate stage (B) comprises patients with asymptomatic multinodular HCC. Advanced stage (C) includes patients with symptomatic tumors and/or an invasive tumoral pattern (vascular invasion/extrahepatic spread). Stage B and C patients may receive palliative treatments/new agents in the setting of phase II investigations or randomized controlled trials. End-stage disease (D) contain patients with extremely grim prognosis (Okuda stage III or PST 3-4) that should merely receive symptomatic treatment.

Dystrophin expression in the mdx mouse restored by stem cell transplantation

Abstract: The development of cell or gene therapies for diseases involving cells that are widely distributed throughout the body has been severely hampered by the inability to achieve the disseminated delivery of cells or genes to the affected tissues or organ. Here we report the results of bone marrow transplantation studies in the mdx mouse, an animal model of Duchenne's muscular dystrophy, which indicate that the intravenous injection of either normal haematopoietic stem cells or a novel population of muscle-derived stem cells into irradiated animals results in the reconstitution of the haematopoietic compartment of the transplanted recipients, the incorporation of donor-derived nuclei into muscle, and the partial restoration of dystrophin expression in the affected muscle. These results suggest that the transplantation of different stem cell populations, using the procedures of bone marrow transplantation, might provide an unanticipated avenue for treating muscular dystrophy as well as other diseases where the systemic delivery of therapeutic cells to sites throughout the body is critical. Our studies also suggest that the inherent developmental potential of stem cells isolated from diverse tissues or organs may be more similar than previously anticipated.

Treatment of High-Risk Neuroblastoma with Intensive Chemotherapy, Radiotherapy, Autologous Bone Marrow Transplantation, and 13-cis-Retinoic Acid

Abstract: Background Children with high-risk neuroblastoma have a poor outcome. In this study, we assessed whether myeloablative therapy in conjunction with transplantation of autologous bone marrow improved event-free survival as compared with chemotherapy alone, and whether subsequent treatment with 13-cis-retinoic acid (isotretinoin) further improves event-free survival. Methods All patients were treated with the same initial regimen of chemotherapy, and those without disease progression were then randomly assigned to receive continued treatment with myeloablative chemotherapy, total-body irradiation, and transplantation of autologous bone marrow purged of neuroblastoma cells or to receive three cycles of intensive chemotherapy alone. All patients who completed cytotoxic therapy without disease progression were then randomly assigned to receive no further therapy or treatment with 13-cis-retinoic acid for six months. Results The mean (±SE) event-free survival rate three years after the first randomization was si...

Autologous Transplantation of Bone Marrow Cells Improves Damaged Heart Function

Abstract: Background—Autologous bone marrow cells (BMCs) transplanted into ventricular scar tissue may differentiate into cardiomyocytes and restore myocardial function. This study evaluated cardiomyogenic differentiation of BMCs, their survival in myocardial scar tissue, and the effect of the implanted cells on heart function. Methods and Results—In vitro studies: BMCs from adult rats were cultured in cell culture medium (control) and medium with 5-azacytidine (5-aza, 10 μmol/L), TGFβ1 (10ng/mL), or insulin (1 nmol/L) (n=6, each group). Only BMCs cultured with 5-aza formed myotubules which stained positively for troponin I and myosin heavy chain. In vivo studies: a cryoinjury-derived scar was formed in the left ventricular free wall. At 3 weeks after injury, fresh BMCs (n=9), cultured BMCs (n=9), 5-aza–induced BMCs (n=12), and medium (control, n=12) were autologously transplanted into the scar. Heart function was measured at 8 weeks after myocardial injury. Cardiac-like muscle cells which stained positively for my...

Embryonic Stem Cell-Derived Glial Precursors: A Source of Myelinating Transplants

Abstract: Self-renewing, totipotent embryonic stem (ES) cells may provide a virtually unlimited donor source for transplantation. A protocol that permits the in vitro generation of precursors for oligodendrocytes and astrocytes from ES cells was devised. Transplantation in a rat model of a human myelin disease shows that these ES cell-derived precursors interact with host neurons and efficiently myelinate axons in brain and spinal cord. Thus, ES cells can serve as a valuable source of cell type-specific somatic precursors for neural transplantation.

Impact of graft size mismatching on graft prognosis in liver transplantation from living donors.

Abstract: Background. Although living donor liver transplantation for small pediatric patients is increasingly accepted, its expansion to older/larger patients is still in question because of the lack of sufficient information on the impact of graft size mismatching. Methods. A total of 276 cases of living donor liver transplantation, excluding ABO-incompatible, auxiliary, or secondary transplants, were reviewed from graft size matching. Forty-three cases were highly urgent cases receiving intensive care preoperatively. Cases were categorized into five groups by graft-to-recipient weight ratio (GRWR): extra-small-for-size (XS; GRWR<0.8%, 17 elective and 4 urgent cases), small (S; 0.8

Sirolimus (rapamycin)-based therapy in human renal transplantation: similar efficacy and different toxicity compared with cyclosporine. Sirolimus European Renal Transplant Study Group.

Abstract: Background. Sirolimus (rapamycin) is a potent immunosuppressant with a mechanism of action different from cyclosporine (CsA) or tacrolimus. Methods. In 11 European centers, first cadaveric renal allograft recipients were randomized to CsA (n=42) or sirolimus (n=41). Dosing of these agents was concentration-controlled and open-labeled. All patients received corticosteroids and azathioprine. Results. At 12 months, graft survival (98% sirolimus vs. 90% CsA), patient survival (100% vs. 98%), and incidence of biopsy-confirmed acute rejection (41% vs. 38%) were similar. Serum creatinine was lower with sirolimus, significantly (P<0.05) so at 3 and 4 months, and serum uric acid and magnesium were normal. Laboratory abnormalities reported significantly more often with sirolimus included hypertriglyceridemia (51% vs. 12%), hypercholesterolemia (44% vs. 14%), thrombocytopenia (37% vs. 0%), leukopenia (39% vs. 14%), and, of lesser importance, increased liver enzymes and hypokalemia. These abnormalities improved 2 months after transplantation when the sirolimus target trough level was lowered from 30 to 15 ng/ml. Occurrence of cytomegalovirus was comparable (14% vs. 12%); incidences of herpes simplex (24% vs. 10%, P=0.08) and pneumonia (17% vs. 2%, P=0.03) were higher with sirolimus. No gingival hyperplasia was seen with sirolimus, tremor was rare, and hypertension was less frequent (17% vs. 33%). Two malignancies were observed with CsA and none with sirolimus. Conclusions. Results at 12 months suggest that sirolimus can be used as base therapy in the prophylaxis of acute renal transplant rejection, and has a safety profile that differs from CsA.

An analysis of 412 cases of hepatocellular carcinoma at a Western center.

Abstract: Objective Using a large single-institution experience at a Western referral center, the authors examine partial hepatectomy as treatment of hepatocellular carcinoma and relate treatment outcomes to clinical parameters, including the etiology of underlying cirrhosis. Methods Four hundred and twelve patients seen between December 1991 and January 1998 were identified in a prospective database. Data about the surgical procedure, perioperative complications, and long-term outcome were examined. Results One hundred twenty-six patients did not have underlying cirrhosis. Of the 286 patients with cirrhosis, 119 were the result of hepatitis B, 39 hepatitis C, 36 both B and C, 43 ethanol abuse, and the remainder other causes. Two hundred forty-three patients underwent surgical exploration, and 154 patients underwent hepatic resection. Seven (4.5%) died from the surgery. One hundred forty-three patients were treated by ablative methods. Patients with cirrhosis had smaller tumors but nevertheless had a lower resectability rate. Neither the presence of cirrhosis nor the etiology of the cirrhosis altered the perioperative morbidity or mortality rate. The greatest determinant of long-term outcome was resectability. The size of the lesion, an alpha-fetoprotein level >2000 ng/ml, and vascular invasion were also determinants of poor outcome. The presence of cirrhosis was a detrimental factor when analysis was stratified for size of tumor. The cause of cirrhosis did not influence the long-term outcome. The 5-year survival rate was 57% for patients with resected lesions 10 cm. Conclusion Partial hepatectomy is safe, effective, and potentially curative therapy for hepatocellular carcinoma. The presence of cirrhosis did not affect the surgical mortality rate but did affect the long-term survival rate. The cause of cirrhosis did not influence outcome. As treatment for small hepatocellular carcinomas, partial hepatectomy produces results similar to those of transplantation. For patients with large tumors who are poor candidates for transplantation, resection results in long-term survival in one third of patients.

Blocking both signal 1 and signal 2 of T-cell activation prevents apoptosis of alloreactive T cells and induction of peripheral allograft tolerance

Abstract: The alloimmune response against fully MHC-mismatched allografts, compared with immune responses to nominal antigens, entails an unusually large clonal size of alloreactive T cells. Thus, induction of peripheral allograft tolerance established in the absence of immune system ablation and reconstitution is a challenging task in transplantation. Here, we determined whether a reduction in the mass of alloreactive T cells due to apoptosis is an essential initial step for induction of stable allograft tolerance with non-lymphoablative therapy. Blocking both CD28-B7 and CD40-CD40 ligand interactions (co-stimulation blockade) inhibited proliferation of alloreactive T cells in vivo while allowing cell cycle-dependent T-cell apoptosis of proliferating T cells, with permanent engraftment of cardiac allografts but not skin allografts. Treatment with rapamycin plus co-stimulation blockade resulted in massive apoptosis of alloreactive T cells and produced stable skin allograft tolerance, a very stringent test of allograft tolerance. In contrast, treatment with cyclosporine A and co-stimulation blockade abolished T-cell proliferation and apoptosis, as well as the induction of stable allograft tolerance. Our data indicate that induction of T-cell apoptosis and peripheral allograft tolerance is prevented by blocking both signal 1 and signal 2 of T-cell activation.

Core assessment program for surgical interventional therapies in Parkinson's disease (CAPSIT-PD).

Abstract: In 1992 the Core Assessment Program for Intracerebral Transplantations (CAPIT) was published providing the minimal requirements for a common patient evaluation protocol. Despite the intent, the program was thought to be too laborious to carry out in large scale trials, and it also lacked evaluations of cognitive functions and quality of life. Moreover, the CAPIT was designed for neural transplantation only and has not been revised since. Since then, pallidotomy and deep brain stimulation have emerged as additional treatment modalities but there exists no common tool for evaluation of, and between, the techniques. In 1996, within the framework of NECTAR (Network for European CNS Transplantation and Restoration), a dedicated program entitled "Neurosurgical Interventions in Parkinson's Disease" (NIPD) was funded by the European Union Biomed 2 program to develop a new Core Assessment Program for Surgical Interventional Therapies in PD (CAPSIT-PD) and to establish an European registry for patients with PD subjected to functional neurosurgery. This article presents the recommendations of this new program.

Search for Cross-Species Transmission of Porcine Endogenous Retrovirus in Patients Treated with Living Pig Tissue

Abstract: Pig organs may offer a solution to the shortage of human donor organs for transplantation, but concerns remain about possible cross-species transmission of porcine endogenous retrovirus (PERV). Samples were collected from 160 patients who had been treated with various living pig tissues up to 12 years earlier. Reverse transcription–polymerase chain reaction (RT-PCR) and protein immunoblot analyses were performed on serum from all 160 patients. No viremia was detected in any patient. Peripheral blood mononuclear cells from 159 of the patients were analyzed by PCR using PERV-specific primers. No PERV infection was detected in any of the patients from whom sufficient DNA was extracted to allow complete PCR analysis (97 percent of the patients). Persistent microchimerism (presence of donor cells in the recipient) was observed in 23 patients for up to 8.5 years.

Hematopoietic stem-cell transplantation for the treatment of severe combined immunodeficiency.

Abstract: Background Since 1968 it has been known that bone marrow transplantation can ameliorate severe combined immunodeficiency, but data on the long-term efficacy of this treatment are limited. We prospectively studied immunologic function in 89 consecutive infants with severe combined immunodeficiency who received hematopoietic stem-cell transplants at Duke University Medical Center between May 1982 and September 1998. Methods Serum immunoglobulin levels and lymphocyte phenotypes and function were assessed and genetic analyses performed according to standard methods. Bone marrow was depleted of T cells by agglutination with soybean lectin and by sheep-erythrocyte rosetting before transplantation. Results Seventy-seven of the infants received T-cell–depleted, HLA-haploidentical parental marrow, and 12 received HLA-identical marrow from a related donor; 3 of the recipients of haploidentical marrow also received placental-blood transplants from unrelated donors. Except for two patients who received placental bloo...

Long-term survival and late deaths after allogeneic bone marrow transplantation. Late Effects Working Committee of the International Bone Marrow Transplant Registry.

Abstract: Background and Methods It is uncertain whether mortality rates among patients who have undergone bone marrow transplantation return to the level of the mortality rates of the general population. We analyzed the characteristics of 6691 patients listed in the International Bone Marrow Transplant Registry. All the patients were free of their original disease two years after allogeneic bone marrow transplantation. Mortality rates in this cohort were compared with those of an age-, sex-, and nationality-matched general population. Cox proportional-hazards regression was used to identify risk factors for death more than two years after transplantation (late death). Results Among patients who were free of disease two years after transplantation, the probability of living for five more years was 89 percent (95 percent confidence interval, 88 to 90 percent). Among patients who underwent transplantation for aplastic anemia, the risk of death by the sixth year after transplantation did not differ significantly from ...

Valacyclovir for the Prevention of Cytomegalovirus Disease after Renal Transplantation

Abstract: Background Cytomegalovirus (CMV) disease is a major complication of organ transplantation. We hypothesized that prophylactic treatment with valacyclovir would reduce the risk of CMV disease. Methods A total of 208 CMV-negative recipients of a kidney from a seropositive donor and 408 CMV-positive recipients were randomly assigned to receive either 2 g of valacyclovir or placebo orally four times daily for 90 days after transplantation, with the dose adjusted according to renal function. The primary end point was laboratory-confirmed CMV disease in the first six months after transplantation. Results Treatment with valacyclovir reduced the incidence or delayed the onset of CMV disease in both the seronegative patients (P<0.001) and the seropositive patients (P=0.03). Among the seronegative patients, the incidence of CMV disease 90 days after transplantation was 45 percent among placebo recipients and 3 percent among valacyclovir recipients. Among the seropositive patients, the respective values were 6 percent and 0 percent. At six months, the incidence of CMV disease was 45 percent among seronegative recipients of placebo and 16 percent among seronegative recipients of valacyclovir; it was 6 percent among seropositive placebo recipients and 1 percent among seropositive valacyclovir recipients. At six months, the rate of biopsy-confirmed acute graft rejection in the seronegative group was 52 percent among placebo recipients and 26 percent among valacyclovir recipients (P=0.001). Treatment with valacyclovir also decreased the rates of CMV viremia and viruria, herpes simplex virus disease, and the use of inpatient medical resources. Hallucinations and confusion were more common with valacyclovir treatment, but these events were not severe or treatment limiting. The rates of other adverse events were similar among the groups. Conclusions Prophylactic treatment with valacyclovir is a safe and effective way to prevent CMV disease after renal transplantation. (N Engl J Med 1999; 340:1462-70.) (C) 1999, Massachusetts Medical Society.

Transduction of Human CD34+ Cells That Mediate Long-Term Engraftment of NOD/SCID Mice by HIV Vectors

Abstract: Efficient gene transfer into human hematopoietic stem cells (HSCs) is an important goal in the study of the hematopoietic system as well as for gene therapy of hematopoietic disorders. A lentiviral vector based on the human immunodeficiency virus (HIV) was able to transduce human CD34+ cells capable of stable, long-term reconstitution of nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. High-efficiency transduction occurred in the absence of cytokine stimulation and resulted in transgene expression in multiple lineages of human hematopoietic cells for up to 22 weeks after transplantation.

Requirement for T-cell apoptosis in the induction of peripheral transplantation tolerance.

Abstract: The mechanisms of allograft tolerance have been classified as deletion, anergy, ignorance and suppression/regulation. Deletion has been implicated in central tolerance1, whereas peripheral tolerance has generally been ascribed to clonal anergy and/or active immunoregulatory states2. Here, we used two distinct systems to assess the requirement for T-cell deletion in peripheral tolerance induction. In mice transgenic for Bcl-xL, T cells were resistant to passive cell death through cytokine withdrawal, whereas T cells from interleukin-2-deficient mice did not undergo activation-induced cell death. Using either agents that block co-stimulatory pathways or the immunosuppressive drug rapamycin, which we have shown here blocks the proliferative component of interleukin-2 signaling but does not inhibit priming for activation-induced cell death, we found that mice with defective passive or active T-cell apoptotic pathways were resistant to induction of transplantation tolerance. Thus, deletion of activated T cells through activation-induced cell death or growth factor withdrawal seems necessary to achieve peripheral tolerance across major histocompatibility complex barriers.

The role of anti-glomerular basement membrane antibody in the pathogenesis of human glomerulonephritis.

Abstract: These observations established the presence of anti-GBM antibodies in the sera and/or kidneys of six humans with glomerulonephritis. Further, it seems clear that these antibodies do combine with the host's glomeruli in vivo and with GBM antigen of several species in vitro. Transfer of acute glomerulonephritis to normal recipient monkeys was possible with serum or renal eluate IGG from the three patients with anti-GBM antibodies in whom sufficient material was available. Based on this transfer of nephritis and on the presence of these antibodies at the site of injury in the nephritic kidneys of both the patients and the recipient monkeys, it seems likely that they are at least a contributing, if not primary, cause of the glomerular injury. The frequency of anti-GBM antibodies in human nephritis is not certain, but on the basis of preliminary observations it would appear that they are present in all cases of Goodpasture's nephritis and somewhat less than half of the cases of subacute and chronic glomerulonephritis of adults. The nature and source of immunogen stimulating the production of anti-GBM antibodies is not known, but the presence of potentially nephritogenic GBM antigens in normal urine raises the question of possible autoimmunization. From a practical point of view, it appears that patients forming anti-GBM antibodies may not be good candidates for renal transplantation since they are likely to produce in the transplants the nephritic changes already suffered by their own kidneys.

Robust regeneration of adult sensory axons in degenerating white matter of the adult rat spinal cord

Abstract: We have recently reported that minimally disturbed adult CNS white matter can support regeneration of adult axons by using a novel microtransplantation technique to inject minute volumes of dissociated adult rat dorsal root ganglion neurons directly into adult rat CNS pathways (Davies et al., 1997). This atraumatic injection procedure minimized scarring and allowed considerable numbers of regenerating adult axons immediate access to the adult CNS glial terrain where they rapidly extended for long distances. A critical question remained as to whether degenerating white matter at acute and chronic stages (up to 3 months) after injury could still support regeneration. To investigate this, we have microtransplanted adult sensory neurons into degenerating white matter of the adult rat spinal cord several millimeters rostral to a severe lesion of the dorsal columns. Regeneration of donor sensory axons in both directions away from the site of transplantation was robust even within white matter undergoing fulminant Wallerian degeneration despite intimate contact with myelin. Along their route, the regrowing axons extended large numbers of collaterals into the adjacent dorsal horn. However, after entering the lesion, the rapidly extending growth cones stopped and became dystrophic within high concentrations of reactive glial matrix. Our results offer compelling evidence that the major environmental impediment to regeneration in the adult CNS is the molecular barrier that forms directly at the lesion site, and that degenerating white matter beyond the glial scar has a far greater intrinsic ability to support axon regeneration than previously thought possible.

Apoptosis in heart failure: Release of cytochrome c from mitochondria and activation of caspase-3 in human cardiomyopathy

Abstract: Apoptosis has been shown to contribute to loss of cardiomyocytes in cardiomyopathy, progressive decline in left ventricular function, and congestive heart failure. Because the molecular mechanisms involved in apoptosis of cardiocytes are not completely understood, we studied the biochemical and ultrastructural characteristics of upstream regulators of apoptosis in hearts explanted from patients undergoing transplantation. Sixteen explanted hearts from patients undergoing heart transplantation were studied by electron microscopy or immunoblotting to detect release of mitochondrial cytochrome c and activation of caspase-3. The hearts explanted from five victims of motor vehicle accidents or myocardial ventricular tissues from three donor hearts were used as controls. Evidence of apoptosis was observed only in endstage cardiomyopathy. There was significant accumulation of cytochrome c in the cytosol, over myofibrils, and near intercalated discs of cardiomyocytes in failing hearts. The release of mitochondrial cytochrome c was associated with activation of caspase-3 and cleavage of its substrate protein kinase C δ but not poly(ADP-ribose) polymerase. By contrast, there was no apparent accumulation of cytosolic cytochrome c or caspase-3 activation in the hearts used as controls. The present study provides in vivo evidence of cytochrome c-dependent activation of cysteine proteases in human cardiomyopathy. Activation of proteases supports the phenomenon of apoptosis in myopathic process. Because loss of myocytes contributes to myocardial dysfunction and is a predictor of adverse outcomes in the patients with congestive heart failure, the present demonstration of an activated apoptotic cascade in cardiomyopathy could provide the basis for novel interventional strategies.

The Effect of Patients' Preferences on Racial Differences in Access to Renal Transplantation

Abstract: Background In the United States, black patients undergo renal transplantation less often than white patients, but few studies have directly assessed the association between race and patients' preferences with respect to transplantation. Methods To assess preferences with respect to transplantation and experiences with medical care, we interviewed 1392 (82.9 percent) of 1679 eligible patients with end-stage renal disease (age range, 18 to 54 years) approximately 10 months after they had begun maintenance treatment with dialysis. Participants were selected from a stratified random sample of patients undergoing dialysis in four regions of the United States (Alabama, southern California, Michigan, and the mid-Atlantic region of Maryland, Virginia, and the District of Columbia) in 1996 and 1997. Patients were followed until March 1999. Results The interviews were conducted with 384 black women, 354 white women, 337 black men, and 317 white men. Black patients were less likely than white patients to want a tran...