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Introduction: Antibody mediated rejection (ABMR) is a major factor limiting outcome after organ transplantation. Anti-HLA donor-specific antibodies (DSA) of the IgG isotype are mainly responsible for ABMR. Recently DSA of the IgE isotype were demonstrated in murine models as well as in a small cohort of sensitized transplant recipients. In the present study, we aimed to determine the frequency of pre-existing and de novo anti-HLA IgE antibodies in a cohort of 105 solid organ transplant recipients. Methods: We prospectively measured anti-HLA IgE antibodies in a cohort of kidney (n=60), liver, heart and lung (n=15 each) transplant recipients before and within one-year after transplantation, employing a single-antigen bead assay for HLA class I and class II antigens. Functional activity of anti-HLA IgE antibodies was assessed by an in vitro mediator release assay. Antibodies of the IgG1-4 subclasses and Th1 and Th2 cytokines were measured in anti-HLA IgE positive patients. Results: Pre-existing anti-HLA IgE antibodies were detected in 10% of renal recipients (including 3.3% IgE-DSA) and in 4.4% of non-renal solid organ transplant recipients (heart, liver and lung cohort). Anti-HLA IgE occurred only in patients that were positive for anti-HLA IgG, and most IgE positive patients had had a previous transplant. Only a small fraction of patients developed de novo anti-HLA IgE antibodies (1.7% of kidney recipients and 4.4% of non-renal recipients), whereas no de novo IgE-DSA was detected. IgG subclass antibodies showed a distinct pattern in patients who were positive for anti-HLA IgE. Moreover, patients with anti-HLA IgE showed elevated Th2 and also Th1 cytokine levels. Serum from IgE positive recipients led to degranulation of basophils in vitro, demonstrating functionality of anti-HLA IgE. Discussion: These data demonstrate that anti-HLA IgE antibodies occur at low frequency in kidney, liver, heart and lung transplant recipients. Anti-HLA IgE development is associated with sensitization at the IgG level, in particular through previous transplants and distinct IgG subclasses. Taken together, HLA specific IgE sensitization is a new phenomenon in solid organ transplant recipients whose potential relevance for allograft injury requires further investigation. [ABSTRACT FROM AUTHOR]

Summary: Kidney paired donation (KPD) is a valuable tool to overcome immunological barriers in living donor transplantation. While small national registries encounter difficulties in finding compatible matches, multi‐national KPD may be a useful strategy to facilitate transplantation. The Czech (Prague) and Austrian (Vienna) KPD programs, both initiated in 2011, were merged in 2015. A bi‐national algorithm allowed for ABO‐ and low‐level HLA antibody‐incompatible exchanges, including the option of altruistic donor‐initiated domino chains. Between 2011 and 2019, 222 recipients and their incompatible donors were registered. Of those, 95.7% (Prague) and 67.9% (Vienna) entered into KPD registries, and 81 patients received a transplant (95% 3‐year graft survival). Inclusion of ABO‐incompatible pairs in the Czech program contributed to higher KPD transplant rates (42.6% vs. 23.6% in Austria). After 2015 (11 bi‐national match runs), the median pool size increased to 18 pairs, yielding 33 transplants (8 via cross‐border exchanges). While matching rates doubled in Austria (from 9.1% to 18.8%), rates decreased in the Czech program, partly due to implementation of more stringent HLA antibody thresholds. Our results demonstrate the feasibility of merging small national KPD programs to increase pool sizes and may encourage the implementation of multi‐national registries to expand the full potential of KPD. [ABSTRACT FROM AUTHOR]

Summary: We assessed whether standardized application of an absorbable polysaccharide hemostatic powder (HaemoCer™) has an effect on lymphocele rate after kidney transplantation. For this nonrandomized prospective trial, we first aimed to know our center‐specific lymphocele rate diagnosed by ultrasound imaging. We retrospectively assessed all patient records of the elapsed year resulting in a center‐specific rate of 20%, this was consistent with literature. The power analysis showed that 108 patients were required to detect a 50% reduction in lymphocele rate. During the prospective study period, 155 patients undergoing kidney transplantation were recruited to receive HaemoCer™ intraoperatively. In two patients, the product accidentally was not used. Six patients were excluded from analysis because of failure to complete follow‐up (one early death and five early graft failures). Of the remaining 147 patients, 15 developed lymphoceles, which represents a rate of 10.2%; (95% CI: 6.3–16.2%). Compared to the expected occurrence, this was significantly lower (P = 0.003). Lymphoceles appeared to be associated with preoperative donor‐specific antibody, retransplantation and immunoadsorption in HLA or ABO incompatible donors. At our institution, the frequency of lymphoceles after kidney transplantation appeared to be significantly reduced when HaemoCer™ was applied routinely. The magnitude of the effect warrants randomized evaluation. [ABSTRACT FROM AUTHOR]

Model for end-stage liver disease (MELD) score has emerged as a useful tool in predicting mortality in patients awaiting liver transplantation. There is still, however, discussion as to whether further parameters could improve the sensitivity and specificity of the MELD score. From 1997 to 2003, 621 adult patients with end-stage liver disease were listed for orthotopic liver transplantation (OLT). Patients suffering from hepatoma were excluded from analysis (113 patients). The MELD score was investigated at the time of listing (MELD ON) and of coming off the list (MELD OFF). Patients who died while on the waiting list showed a significant increase in their MELD score during the waiting time (MELD ON: 21 ± 7 vs. MELD OFF: 28 ± 9) as well as a significantly higher MELD ON compared with patients who were transplanted (MELD ON: 16 ± 5 vs. MELD OFF: 17 ± 7) or removed from the waiting list (MELD ON: 16 ± 6 vs. MELD OFF: 12 ± 3). Multivariate analysis identified MELD ON, ascites and recurrent infection as independent risk factors for death on the waiting list ( P < 0.01). MELD score was not identified as a predictor for the post-transplant survival rate. MELD score is a strong predictor for death on the waiting list, but refractory ascites and recurrent infection are independent risk factors, too. [ABSTRACT FROM AUTHOR]

Sufficient assessment of potential candidates for orthotopic liver transplantation (OLT) is the most important factor for a low alcohol relapse rate after transplantation in patients suffering from alcoholic cirrhosis. In the current study the efficiency of pretransplant screening with carbohydrate-deficient transferrin (CDT) was analysed in patients on the waiting list for OLT. A prospective study was performed in 44 patients who had undergone OLT for alcoholic cirrhosis. All patients had had pretransplant assessment by a specialist psychologist and were found to have no problems with alcohol. Pre- and post-transplant CDT monitoring was performed. Overall, 790 CDT values were measured in the study population. The median observation period was 2.1 months before and 41.2 months after transplantation, respectively. In 35 patients (80%) pretransplant CDT values were found to be above the reference value, but only one patient suffered an alcohol relapse after transplantation. Of the nine patients (20%) who demonstrated normal CDT before transplantation, two suffered an alcohol relapse after transplantation. CDT is a very useful marker for the monitoring of an alcohol relapse in patients following OLT for alcoholic cirrhosis, as has been previously indicated. However, CDT does not appear to be useful as a pretransplant screening marker for selection of potential transplant candidates suffering from alcoholic cirrhosis. [ABSTRACT FROM AUTHOR]

The article presents the authors' gratitude to guest editors of the periodical "Transplant International." It appreciates the significant contribution of the guest editors for their critical help in the editorial processing of the papers submitted at the 11th Congress of the European Society for Organ Transplantation in Venice, Italy in 2003. All of these papers underwent the full review process and were critically evaluated by the Guest Editors.