Home About us Contact
|
Home About us Contact | ||
|
|
||
HLA Matching (hla + matching)
Selected AbstractsPutting One Objection to HLA Matching on IceAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2002J. Michael Cecka No abstract is available for this article. [source] Adequate HLA Matching in KeratoplastyACTA OPHTHALMOLOGICA, Issue 3 2003Niels Ehlers No abstract is available for this article. [source] Role of adult living donor liver transplantation in patients with hepatitis CLIVER TRANSPLANTATION, Issue 10C 2003Gregory T. Everson Key points 1. Living donor liver transplantation (LDLT) is an option for patients with end-stage liver disease or hepatoma caused by chronic hepatitis C. 2. Reports from some, but not all, transplant centers indicate that hepatitis C may recur earlier, recurrence may be more severe, and graft loss caused by recurrent hepatitis C may be more frequent in LDLT compared with cadaveric transplantation. 3. Several unique characteristics of LDLT (versus cadaveric transplantation) may favor severe recurrence of hepatitis C. These include an increase in genetic similarity between donor and recipient, higher degree of HLA matching, greater systemic bioavailability of immunosuppressive agent, and hepatic regeneration. 4. Hepatic regeneration may promote the acceleration and severity of recurrent hepatitis C by enhancement of hepatitis C viral uptake by hepatocytes through stimulation of the low-density lipoprotein receptor and increase in activity of the internal ribosomal entry site. [source] Resolving a genetic paradox throughout preimplantation genetic diagnosis for autosomal dominant severe congenital neutropeniaPRENATAL DIAGNOSIS, Issue 3 2010Mira Malcov Abstract Objective Severe congenital neutropenia is an inherited disease characterized by low peripheral blood neutrophils, amenable to bone marrow transplantation. Genetic analysis in the family here described detected a ELA2 splice-site mutation in the affected child and also in his asymptomatic father. The parents requested preimplantation genetic diagnosis (PGD), coupled with HLA matching, to obtain a suitable bone marrow donor for the affected child. Methods A PGD protocol was developed, based on multiplex nested PCR for direct analysis of the ELA2 mutation, flanking polymorphic markers and HLA typing. Results The amplification efficiency of the mutation was > 90% in single leukocytes from the affected child but only 67% in the father. Analysis of single haploid sperm cells from the father demonstrated three different sperm-cell populations: (1) sperm cells harboring the ELA2 mutation on the ,affected' haplotype, (2) sperm cells without the ELA2 mutation on the ,normal' haplotype, and (3) sperm cells without the ELA2 mutation on the ,affected' haplotype. Conclusion These data demonstrate that the ELA2 mutation in the father occurred de novo during his embryonic development, resulting in somatic as well as germ-line mosaicism. This conclusion was also taken into consideration when PGD was performed. Copyright © 2010 John Wiley & Sons, Ltd. [source] Secondary Listing for Deceased-Donor Kidney Transplantation Does Not Increase Likelihood of Engraftment at a Large Transplant CenterAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009V. Kumar The supply of donor organs has not increased as fast as has the number of patients awaiting kidney transplantation. Few organs are shared outside the areas of recovery. This trend has caused some ESRD patients to seek listing at multiple centers. We examined UNOS registry data and transplant registry data at the University of Alabama at Birmingham (UAB) for the 576 patients listed at multiple centers over an 8-year span ending December 31, 2005. We identified 72 multilisted patients who received a deceased-donor renal allograft at UAB and reviewed their records for demographics, HLA matching and transfer of listing time. The only predictors for transplantation at UAB were initial listing at UAB or transfer of waiting time. Fifty-one of the 72 patients had listed at UAB first; the other 21 had transferred waiting time. None of the 176 patients who listed elsewhere first and did not transfer waiting time had been transplanted at UAB. Aggregate cost of listing and evaluation for the 176 patients listed elsewhere first who did not transfer waiting time was $1 254 528. Secondary listing at UAB, with a large cohort awaiting transplantation, without transfer of waiting time from another center was an expensive and futile process. [source] Current Kidney Allocation Rules and Their Impact on a Pediatric Transplant CenterAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2009E. C. Abraham In 2005, kidney allocation rules in the United States were updated to enhance access to kidneys from young adult deceased donors (DDs) for pediatric recipients. We studied how this rule change affected transplant activity at our pediatric center. We retrospectively compared kidney transplant activity at our center since the rule change (until December 31, 2007) to before the change (n = 36 each), focusing on those recipients directly affected by it, that is, younger than 18 years. There were no significant differences in recipients' age, gender or ethnicity before versus after the rule change. Percentages of preemptive transplants and retransplants were similar in both groups, as was the percentage of sensitized patients. There was a significant decrease in overall, but not DD, mean donor age. Mean wait time for DD kidneys decreased for pediatric recipients. Increases were found in percentage of DD transplants and in mean HLA mismatches after the rule change. Patient and short-term graft survival were not significantly different. These data suggest that the allocation rule change was not only followed by improvement in overall access to kidney transplantation for children, but also by decreases in living donor transplants and HLA matching. Larger studies are needed to evaluate the long-term impact of the change. [source] Long-Term Insulin-Independence After Allogeneic Islet Transplantation for Type 1 Diabetes: Over the 10-Year MarkAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2009T. Berney Results of islet of Langerhans transplantation have markedly improved in recent years, but most patients still lose insulin independence in the long-term. We report herein the longest (over 11 years) case of insulin independence after allogeneic islet transplantation. The subject had a 27-year history of type 1 diabetes and received a single islet-after-kidney graft of 8800 islet equivalents (IEQ)/kg, pooled from 2 donors. Insulin was discontinued by 3 months posttransplant and the patient has remained off insulin ever since. Yearly follow-up studies have revealed normal metabolic control, including normal oral glucose tolerance test (OGTT). Reasons for success may involve choice of immunosuppression, low metabolic demand and low immune responsiveness as suggested by an excellent HLA matching and a high count of circulating regulatory T cells. This observation is so far an exceptional case, but clearly demonstrates the validity of the concept that long-term insulin independence after allogeneic islet transplantation is an achievable target. [source] High Incidence of Donor-Reactive Delayed-Type Hypersensitivity Reactivity in Transplant PatientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2002Ronald P. Pelletier Evidence of transplant recipient cellular sensitization towards donor antigens has rarely been directly measured. Rather, sensitization has been generally inferred by the presence of detectable allo-reactive or donor-reactive antibodies. In this study a newly developed delayed-type hypersensitivity assay was used to directly determine the incidence of post-transplant donor-reactive T-cell sensitization in a large cohort of kidney and simultaneous kidney-pancreas recipients. These results were compared with the presence of detectable circulating alloantibodies and with patient clinical outcome. We found an unexpectedly high incidence (52%) of donor-reactive delayed-type hypersensitivity reactivity in our study patients. Donor-reactive delayed-type hypersensitivity reactivity occurred at a much higher frequency than detectable alloantibodies (20%). Further, we found no correlation between the presence of alloantibodies and donor-reactive delayed-type hypersensitivity reactivity. We also found no correlation between the development of donor-reactive delayed-type hypersensitivity reactivity and the degree of donor and recipient HLA matching. Finally, the presence of detectable donor-reactive delayed-type hypersensitivity reactivity did not correlate with a worse clinical outcome at the time of these analyses. We conclude that in transplant recipients, the presence of circulating alloantibodies is a poor indicator of previous T-cell sensitization to donor antigens. We also conclude that our current immunosuppression strategies are relatively ineffective at blocking T-cell allosensitization, but are very effective at blocking the biological consequences of that allosensitization. [source] Improving outcomes of cord blood transplantation: HLA matching, cell dose and other graft- and transplantation-related factorsBRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2009Vanderson Rocha Summary The use of unrelated umbilical cord blood (UCB) as an alternative source of haematopoietic stem cells transplantation (HSCT) has been widely used for patients lacking a human leucocyte antigen (HLA) matched donor. One of the disadvantages of using UCB is the limited number of haematopoietic stem cells and, consequently, delayed engraftment and increased risk of early mortality. Many approaches have been investigated in the attempt to improve engraftment and survival. Among those, studies analysing prognostic factors related to patients, disease, donor and transplantation have been performed. Variable factors have been identified, such as factors related to donor choice (HLA, cell dose and others) and transplantation (conditioning and graft- versus -host disease prophylaxis regimens). This review will focus on the interactions between HLA, cell dose and other modifiable factors related to the UCB unit selection and transplantation that may improve outcomes after UCB transplantation. [source] Factors affecting kidney-transplant outcome in recipients with lupus nephritisCLINICAL TRANSPLANTATION, Issue 3 2008Hongying Tang Abstract:, Background:, Factors associated with outcome in renal transplant recipients with lupus nephritis have not been studied. Methods:, Using the data from the United States Renal Data System of patients transplanted between January 1, 1995 through December 31, 2002 (and followed through December 31, 2003) (n = 2882), we performed a retrospective analysis of factors associated with long-term death-censored graft survival and recipient survival. Results:, The number of pretransplant pregnancies incrementally increased the risk of graft failure [hazard ratio (HR) 1.54, p < 0.05] in the entire subgroup of females and in the subgroup of recipients aged 25,35 yr. Recipient and donor age had an association with both the risk of graft failure (HR 0.96, p < 0.001; HR 1.01, p < 0.005) and recipient death (HR 1.04, p < 0.001; HR 1.01, p < 0.05). Greater graft-failure risk accompanied increased recipient weight (HR 1.01, p < 0.001); African Americans compared with whites (HR 1.55, p < 0.001); greater Charlson comorbidity index (HR 1.17, p < 0.05); and greater panel reactive antibody (PRA) levels (HR 1.06, p < 0.001). Pretransplant peritoneal dialysis as the predominant modality had an association with decreased risk of graft failure (HR 0.49, p < 0.001), while prior transplantation was associated with greater risk of graft failure and recipient death (HR 2.29, p < 0.001; HR 3.59, p < 0.001, respectively) compared with hemodialysis (HD). The number of matched human leukocyte antigens (HLA) antigens and living donors (HR 0.92, p < 0.05; HR 0.64, p < 0.001, respectively) was associated with decreased risk of graft failure. Increased risk of graft failure and recipient death was associated with nonuse of calcineurin inhibitors (HR 1.89, p < 0.005; HR 1.80, p < 0.005) and mycophenolic acid (MPA) (including mycophenolate mofetil and MPA) or azathioprine (HR 1.41, p < 0.05; HR 1.66, p < 0.01). Using both cyclosporine and tacrolimus was associated with increased risk of graft failure (HR 2.09, p < 0.05). Using MPA is associated with greater risk of recipient death compared with azathioprine (HR 1.47, p < 0.05). Conclusion:, In renal transplant recipients with lupus nephritis, multiple pregnancies, multiple blood transfusions, greater comorbidity index, higher body weight, age and African American race of the donor or recipient, prior history of transplantation, greater PRA levels, lower level of HLA matching, deceased donors, and HD in pretransplant period have an association with increased risk of graft failure. Similarly, higher recipient and donor age, prior transplantations, and higher rate of pretransplant transfusions are associated with greater risk of recipient mortality. Using neither cyclosporine nor tacrolimus or using both (compared with tacrolimus) and neither MPA nor azathioprine (compared with azathioprine) was associated with increased risk of graft failure and recipient death. Using MPA is associated with greater risk of recipient death compared with azathioprine. Testing these results in a prospective study might provide important information for clinical practice. [source] The impact of late acute rejection after cadaveric kidney transplantationCLINICAL TRANSPLANTATION, Issue 4 2001JT Joseph Background: Acute graft rejection (AR) following renal transplantation results in reduced graft survival. However, there is uncertainty regarding the definition, aetiology and long-term graft and patient outcome of AR occurring late in the post-transplant period. Aim: To determine if rejection episodes can be classified by time from transplantation by their impact on graft survival into early acute rejection (EAR) and late acute rejection (LAR). Materials and methods: 687 consecutive adult renal transplant recipients who received their first cadaveric renal transplant at a single centre. All received cyclosporine (CyA)-based immunosuppression, from 1984 to 1996, with a median follow-up of 6.9 yr. Details were abstracted from clinical records, with emphasis on age, sex, co-morbid conditions, HLA matching, rejection episodes, patient and graft survival. Analysis: Patients were classified by the presence and time to AR from the date of transplantation. Using those patients who had no AR (NAR) as a baseline, we determined the relative risk of graft failure by time to rejection. The characteristics of patients who had no rejection, EAR and LAR were compared. Results: Compared with NAR, the risk of graft failure was higher for those patients who suffered a rejection episode. A much higher risk of graft failure was seen when the first rejection episode occurred after 90 d. Thus, a period of 90 d was taken to separate EAR and LAR (relative risk of 3.06 and 5.27 compared with NAR as baseline, p<0.001). Seventy-eight patients (11.4%) had LAR, 271 (39.4%) had EAR and 338 (49.2%) had NAR. The mean age for each of these groups differed (LAR 39.6 yr, EAR 40.8 yr compared with NAR 44 yr, p<0.003). The 5-yr graft survival for those who had LAR was 45% and 10-yr survival was 28%. HLA mismatches were more frequent in those with EAR vs. NAR (zero mismatches in HLA-A: 36 vs. 24%, HLA-B: 35 vs. 23% and HLA-DR: 63 vs. 41%, p<0.003). There was no difference in mismatching frequency between NAR and LAR. Conclusions: AR had a deleterious impact on graft survival, particularly if occurring after 90 d. AR episodes should therefore be divided into early and late phases. In view of the very poor graft survival associated with LAR, it is important to gain further insight into the main aetiological factors. Those such as suboptimal CyA blood levels and non-compliance with medication should be further investigated with the aim of developing more effective immunosuppressive regimens in order to reduce the incidence of LAR. [source] | ||||||||||