Effect of ABO incompatibility on T-cell flow cytometry cross-match results prior to living donor kidney transplantation.

BACKGROUND: Due to its high sensitivity, the flow cytometry cross-match (FCXM) has been described as valuable tool for identifying an optimal donor. We here focused on the impact of ABO incompatibility on FCXM results. METHODS: We analyzed 29 ABO incompatible and 89 ABO compatible donor-recipient pairs (73 and 175 datasets, respectively) prior to living donor kidney transplantation. In all patients, lymphocytotoxic cross-matches for B and T cells were negative. RESULTS: Recipients with blood group O (A to O and B to O) displayed significantly (P < 0.05) higher T-FCXM results than those with blood group A and B (A to B, B to A and AB to A), respectively. Donor-specific T-FCXM responses (ΔMFI values) were significantly higher (P < 0.05) in ABO incompatible vs. compatible pairs (ABO incompatible recipients with blood group O: 32 ± 6; with blood group A: 19 ± 7; with blood group B: 7 ± 4; recipients with ABO compatibility: 3 ± 2, respectively, data represent mean ± SEM). Consistent with the T-FCXM results donor-specific isohemagglutinins (IgG titers) were significantly higher in recipients with blood group O vs. A, both prior to rituximab treatment and plasmapheresis/immune adsorption (P = 0.004) and immediately prior to transplantation, i.e., after rituximab and antibody-depleting therapies (P = 0.04). CONCLUSIONS: ABO incompatibility was associated with higher T-FCXM responses, especially in recipients with blood group O. This finding has major impact on the interpretation of flow cross-match results. Current cut-off values need to be reassessed in the ABO incompatible setting. © 2016 International Clinical Cytometry Society.

Donor-Recipient Matching Based on Predicted Indirectly Recognizable HLA Epitopes Independently Predicts the Incidence of De Novo Donor-Specific HLA Antibodies Following Renal Transplantation.

De novo donor-specific HLA antibodies (dnDSA) are recognized as a risk factor for premature allograft failure. Determinants of DSA specificity are generated via the indirect allorecognition pathway. Here, we present supportive data for the relevance of predicted indirectly recognizable HLA epitopes (PIRCHE) to predict dnDSA following kidney transplantation. A total of 2787 consecutive kidney transplants performed between 1995 and 2015 without preformed DSA have been analyzed. De novo DSA were detected by single antigen bead assay. HLA epitope mismatches were determined by the HLAMatchmaker and PIRCHE approach and correlated in uni- and multivariate analyses with 10-year allograft survival and incidence of dnDSA. The PIRCHE-II score moderately predicted allograft survival. However, the predictive value of elevated PIRCHE-II scores >9 for the incidence of dnDSA was statistically significant (p < 0.001). In a multivariate Cox regression analysis adjusted for antigen mismatch and HLAMatchmaker epitopes, the PIRCHE-II score could be identified as an independent risk factor for dnDSA. The PIRCHE-II score independently from the antigen mismatch and HLAMatchmaker epitopes could be revealed as being a strong predictor for dnDSA. PIRCHE may help to identify acceptable mismatches with decreased risk of dnDSA and thus improve long-term renal allograft survival.

Pertinence of electronic death certificates for real-time surveillance and alert, France, 2012-2014.

OBJECTIVES: In France, the early mortality monitoring, conducted by Santé publique France, the French National Public Health agency (SpFrance) (formerly French Institute for public health surveillance-InVS), is based on the administrative data provided by the National Institute for Statistic and Economic Studies (INSEE) and consequently does not allow analyses on medical causes of death. Since 2007, the physicians can certify deaths electronically. In this electronic system (Electronic Death Registration System; EDRS), the medical causes of death, in free-text format, are directly transmitted to SpFrance. In the future, these data could be used in a real-time surveillance system by medical causes of death. The objective of this study was to evaluate the pertinence of e-death certification using the following assessment criteria: timeliness, representativeness, and completeness of sociodemographic and medical information included in the e-death certificates. STUDY DESIGN: This study consisted of a descriptive analysis of the information collected by e-death certificates recorded between January 1, 2012 and July 31, 2014. METHODS: The study quantified the temporal and geographical evolution of the deployment of the EDRS between 2012 and 2014. The timeliness of the system was estimated by calculating the delay between the dates of death and of data availability for analysis. Sociodemographic and death-related characteristics were described. The frequency of missing data was measured for each variable. The number of completed fields per certificate and the number of words per field and per certificate were calculated for the medical causes of death. RESULTS: Between January 2012 and July 2014, 77,776 e-death certificates were collected. A slight increase in the use of the e-death certification was observed during the study period, reaching 6.1% of the total number of deaths in 2014. Good national coverage was noted. Nearly 79% of e-certificates were submitted to SpFrance on the day of the death. We observed a high completeness of the e-certificates. The rate of missing data did not exceed 2.7% for sociodemographic variables. On average, 10 words, distributed in three fields, were used to describe the medical causes of death. CONCLUSIONS: E-death certificates constitute a reactive source of information on medical causes of death. The deployment of EDRS is of major public health interest for the development of a real-time warning surveillance system of mortality by cause.

Identification of a novel HLA-B null allele, HLA-B*41:45N, by HLA typing of two related Caucasoid individuals.

The new HLA-B*41:45N allele differs from B*41:02 by insertion of 21 nucleotides in exon 2.

Determination of unacceptable HLA antigen mismatches in kidney transplant recipients: recommendations of the German Society for Immunogenetics.

One of the major tasks of histocompatibility and immunogenetics laboratories is the pretransplant determination of unacceptable antigen mismatches (UAM) in kidney transplant recipients. In this procedure, human leucocyte antigen (HLA) specificities are defined against which the patient has circulating alloantibodies that are expected to harm the transplanted organ. Using the information on UAM and the potential donor's complete HLA typing, prediction of the crossmatch result, the so called 'virtual crossmatch', is possible. Currently, the laboratories are using different algorithms for the determination of UAM, and depending on the algorithm, more or fewer organ offers are excluded for patients with a similar antibody profile. In order to bring homogeneity into the allocation of organs to immunized patients in Germany, the German Society for Immunogenetics established, on the basis of current knowledge, recommendations for the determination of UAM. The UAM recommendations, which are thought to serve as a common tool for responsible physicians at different transplant centers, contain technical issues that need to be considered and are individualized for sensitized patients with a high or intermediate risk of antibody-mediated rejection. The present review contains these recommendations and puts them into perspective to current international practice.

Identification of the novel HLA-A*11:192 allele by HLA typing of a Caucasian individual.

We report the new HLA-A*11:192 allele differing from A*11:01 by one nucleotide in exon 2.

Detection of a novel HLA-DQB1 allele, designated DQB1*06:49.

We report a novel allele HLA-DQB1*06:49 with a G→T transversion, most closely resembling HLA-DQB1*06:02:01.

Detection of a novel HLA-A allele, designated A*02:334.

We report a novel allele HLA-A*02:334 with the transition G→A at nucleotide position 282.

Donor-specific HLA antibodies in a cohort comparing everolimus with cyclosporine after kidney transplantation.

Donor-specific HLA antibodies (DSA) have a negative impact on kidney graft survival. Therefore, we analyzed the occurrence of DSA and antibody-mediated rejection (AMR) in patients from two prospective randomized trials in our center. At 3-4.5 months posttransplant 127 patients were randomized to continue cyclosporine or converted to everolimus therapy. The presence of DSA was prospectively assessed using Luminex assays. AMR was defined according to the Banff 2009 classification. Antibody screening was available in 126 patients with a median follow-up of 1059 days. Seven out of 65 (10.8%) patients on cyclosporine developed DSA after a median of 991 days. In comparison, 14/61 patients (23.0%) randomized to everolimus developed DSA after 551 days (log-rank: p = 0.048). Eight patients on everolimus compared to two patients on cyclosporine developed AMR (log-rank: p = 0.036). Four of 10 patients with AMR-all in the everolimus group-lost their graft. A multivariate regression model revealed everolimus, >3 mismatches and living donor as significant risk factors for DSA. Acute rejection within the first year, >3 mismatches, everolimus and living donor were independent risk factors for AMR. This single center analysis demonstrates for the first time that everolimus-based immunosuppression is associated with an increased risk for the development of DSA and AMR.

A new HLA-B*52 allele, B*52:23, detected in a patient before bone marrow transplantation.

The new allele HLA-B*52:23 differs from B*52:01:01 at position 208 in exon 2.

A new HLA-C*07 variant allele, C*07:108, identified by sequence-based typing.

The new HLA-C*07:108 differs from C*07:01:01 by two transversions in exon 3.

Allogeneic gene-modified tumor cells (RCC-26/IL-7/CD80) as a vaccine in patients with metastatic renal cell cancer: a clinical phase-I study.

Despite novel targeted agents, prognosis of metastatic renal cell cancer (RCC) remains poor, and experimental therapeutic strategies are warranted. Transfection of tumor cells with co-stimulatory molecules and/or cytokines is able to increase immunogenicity. Therefore, in our clinical study, 10 human leukocyte antigen (HLA)-A(*)0201(+) patients with histologically-confirmed progressive metastatic clear cell RCC were immunized repetitively over 22 weeks with 2.5-40 × 10(6) interleukin (IL)-7/CD80 cotransfected allogeneic HLA-A(*)0201(+) tumor cells (RCC26/IL-7/CD80). Endpoints of the study were feasibility, safety, immunological and clinical responses. Vaccination was feasible and safe. In all, 50% of the patients showed stable disease throughout the study; the median time to progression was 18 weeks. However, vaccination with allogeneic RCC26/IL-7/CD80 tumor cells was not able to induce TH1-polarized immune responses. A TH2 cytokine profile with increasing amounts of antigen-specific IL-10 secretion was observed in most of the responding patients. Interferon-γ secretion by patient lymphocytes upon antigen-specific and non-specific stimulation was substantially impaired, both before and during vaccination, as compared with healthy controls. This is possibly due to profound tumor-induced immunosuppression, which may prevent induction of antitumor immune responses by the gene-modified vaccine. Vaccination in minimal residual disease with concurrent depletion of regulatory cells might be one strategy to overcome this limitation.

Haplotype-specific sequencing reveals a novel HLA-B*37 allele, B*3714.

We report on a novel human leukocyte antigen (HLA)-B allele, HLA-B*3714. This allele differs from HLA-B*3711 by two nucleic acid substitutions at positions 317 and 319 in exon 2, both resulting in amino acid exchanges. The first one leads to the exchange from arginine to leucine at position 82, and the latter one from glycine to arginine at position 83.

Identification of the novel HLA-A*240215 allele by haplotype-specific sequencing.

Here, we report on a novel allele human leukocyte antigen (HLA)-A*240215. This allele differs from HLA-A*240201 by a synonymous nucleotide exchange at nucleotide 255 in exon 2.

Identification of a novel HLA-B allele, HLA-B*5529, by haplotype-specific sequencing.

We have identified a novel HLA-B allele, B*5529. The novel allele differs from HLA-B*5501 by a single nucleotide substitution at codon 479 in exon 3 resulting in an amino acid change from alanine to valine. This alteration neither affects the peptide binding site nor the T-cell receptor (TCR) contact residues. Thus, the newly found allele is estimated to have a low alloreactive potential in case of a mismatch to the most common HLA-B allele B*5501.

Identification of a novel HLA-DQB1 allele, HLA-DQB1*0632.

A novel human leukocyte antigen-DQ allele, DQB1*0632, was identified in a 68-year-old bone marrow transplantation candidate. DQB1*0632 differs from DQB1*0603 by one nucleotide change in exon 2 resulting in the amino acid exchange Gly --> Arg.

Application of the particle gel agglutination assay in the typing of single human leucocyte antigens.

We describe a simple and rapid particle gel agglutination assay (PaGIA) for typing of the human leucocyte antigens (HLA) HLA-A2, HLA-B7 and HLA-B27. Superparamagnetic streptavidin particles were coated with biotinylated monoclonal antibodies (MoAbs) to HLA-A2, HLA-B7 and HLA-B27. Anticoagulated whole blood samples from healthy blood donors (n = 118) with known HLA patterns were incubated with MoAb-coated particles, transferred into a standard ID-gel card, and subsequently centrifuged. Samples were evaluated macroscopically, with antigen-positive samples resulting in a visible agglutination reaction. A clear distinction could be made between all positive and negative samples tested. Fifty-seven samples were found to be positive for HLA-A2 (48%), 26 samples for HLA-B7 (22%) and 5 samples for HLA-B27 (4%).

Application of the particle gel agglutination system as a new check gel assay for PCR products.

In this study, we describe a simple and rapid agglutination test for the detection of PCR products prior to the application of specific hybridization by sequence-specific oligonucleotide typing. This test is based on the particle gel agglutination immunoassay, incorporating biotinylated primers and streptavidin particles. Visually detectable agglutination was only observed in samples which contained the specific amplification products. The results obtained by the new test were in accordance with those obtained by standard gel electrophoresis in all cases that have been tested to date.

14th International HLA and Immunogenetics Workshop: report on the Prospective Chronic Rejection Project.

An international collaborative study of 45 transplant centers was undertaken at the 14th International HLA (human leukocyte antigen) and Immunogenetics Workshop to see if HLA antibodies detected posttransplant are predictive of chronic graft failure. With the newly developed assay, MICA (major histocompatibility complex class I-related chain A) antibodies were also measured and their effect analyzed. Total of 5219 sera from patients who were more than 6 months posttransplant with functioning graft were tested for HLA antibodies by enzyme-linked immunosorbent assay, flow cytometry, or Luminex. HLA antibodies were found in 27.2% of kidney patients, 23.6% in the liver, 52.7% in the heart, and 21.7% in the lung. The method of antibody testing did not have a marked influence on the frequency of antibodies detected. MICA antibodies were detected in 15% of kidney patients, 30% of heart patients, and 31% of liver patients. Among 948 kidney patients who had HLA antibodies, 7.3% had rejected their graft within 1 year of testing, compared with 1.7% in 2615 patients without HLA antibodies (P= 0.8 x 10(-17)). Death occurred in 1.4% of total kidney patients and did not correlate to the presence of antibodies. We conclude that patients with posttransplant HLA antibodies indeed have a higher rate of chronic graft failure and that posttransplant antibodies are predictive of chronic rejection.