[Lung transplantation: current situation and developments]. / Lungentransplantation: aktueller Stand und Entwicklungen.

Lung transplantation is currently the gold standard treatment for end-stage lung diseases. Advances in the preservation of donor lungs, the surgical technique and immunosuppressive therapy have led to lung transplantation now being a routine procedure. Nevertheless, the shortage of donor organs, the acute and particularly chronic lung allograft dysfunction (CLAD) still represent major challenges even in experienced centers. Research in this area is still necessary to improve the long-term survival of lung recipients.

Persistence of de novo donor specific HLA-Antibodies after lung transplantation: a potential marker of decreased patient survival.

The impact of de novo donor-specific anti-HLA antibodies (DSA) on outcomes in lung transplantation is still a matter of debate. We hypothesize that differentiating DSA by persistent and transient appearance may offer an additional risk assessment. The clinical relevance of HLA-antibodies was investigated prospectively in 72 recipients with a median follow-up period of 21 months. The presence of HLA-antibodies was analysed by single antigen bead assay prior to and after (3 weeks, 3, 6, 12 and 18 months) transplantation. In 23 patients (32%) de novo DSA were detected. In 10 of these patients (44%) DSA persisted throughout the follow-up period whereas 13 of these patients (56%) had transient DSA. There was a trend towards lower one-year-survival in DSA positive compared to DSA negative patients (83% versus 94%; p=0.199). Remarkably, patients with persistent DSA had significantly reduced survival (one-year survival 60%) compared with both patients without DSA and those with transient DSA (p=0.005). Persistent DSA represented an independent prognostic factor for reduced overall survival in multivariate analysis (HR 8.3, 95% CI 1.8-37.0; p=0.006). Persistence of DSA during the first year after transplantation seems to be more harmful for lung allograft function than transiently detected DSA at an early stage. This article is protected by copyright. All rights reserved.

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.

Bronchiolitis obliterans syndrome due to donor-specific HLA-antibodies.

Chronic lung allograft dysfunction (CLAD) is a limiting factor for long-term survival in lung transplant recipients. Donor-specific human leukocyte antigen (HLA)-antibodies (DSA) have been suggested as potential risk factors for CLAD. However, their impact on clinical outcome following lung transplantation remains controversial. We performed a single-center study of 120 lung transplant recipients transplanted between 2006 and 2011. Patient sera were investigated before and after transplantation. The sera were screened by means of Luminex(®) technology (Luminex Inc., Austin, TX, USA) for IgG-HLA-class I and class II antibodies (ab). Using single antigen beads, DSA were identified and correlated retrospectively with clinical parameters. After transplantation 39 out of 120 patients (32.5%) were positive for HLA-ab. The incidence of de novo DSA formation was 27 of 120 patients (22.5%). Eleven of 27 (41%) of de novo DSA-positive patients developed BOS compared to 13 of 93 (14%) DSA-negative patients (p = 0.002). Furthermore, the generation of de novo DSA was independently associated with the development of BOS in multivariable analysis [hazard ration (HR) 2.5, 95% confidence interval (CI) 1.0-6.08; p = 0.046). Our results indicate that de novo DSA are associated with the development of BOS after lung transplantation. Monitoring of HLA-ab after transplantation is useful for identifying high-risk patients and offers an opportunity for early therapeutic intervention.

Spiegelmer Inhibition of MCP-1/CCR2--Potential as an Adjunct Immunosuppressive Therapy in Transplantation.

The rejection process remains the key unsolved issue after transplantation of disparate tissue. The CC chemokine monocyte chemoattractant protein-1 (MCP-1/CCL2) has been reported to be involved in the process of alloimmune interaction. Spiegelmers are l-oligonucleotides that can be designed to bind to pharmacologically relevant target molecules. Here, we tested a high-affinity Spiegelmer-based MCP-1 inhibitor (mNOX-E36) in an allogeneic heart transplant model. Fully vascularized allogeneic heterotopic heart transplantations from BALB/c to C57BL/6 mice were performed. Mice were either treated with the anti-MCP-1-Spiegelmer (mNOX-E36) in monotherapy or in combination with subtherapeutic doses of cyclosporine A (CsA) (10 mg/kgBW/day) for 10 days. Controls received equivalent doses of a non-functional Spiegelmer (revmNOX-E36). Graft survival of allogeneic heart transplants was slightly but significantly prolonged under mNOX-E36 monotherapy (median graft survival 10 day ± 0.7) compared to revmNOX-E36 (median graft survival 7 day ± 0.3; P = 0.001). A synergistic beneficial effect could be seen when mNOX-E36 was administered in combination with subtherapeutic doses of CsA (18 day ± 2.8 versus 7 day ± 0.3; P < 0.0001). Levels of inflammatory cytokines and 'alarmins' were significantly reduced, and the number of F4/80(+) cells was lower under combination therapy (1.8% ± 1.3%; versus 14.6% ± 4.4%; P = 0.0002). This novel inhibitor of the MCP-1/CCR2 axis (mNOX-E36), which has already proven efficacy and tolerability in early clinical trials, alleviates acute rejection processes in allogeneic transplantation especially when combined with subtherapeutic doses of CsA. Thus, mNOX-E36 may have potential as an adjunct immunomodulatory agent.

Group-specific amplification of HLA-DQA1 revealed a number of genomic full-length sequences including the novel HLA alleles DQA1*01:10 and DQA1*01:11.

In this article, we describe a subgroup-specific amplification assay for HLA-DQA1 that encompasses the whole coding region and allows us to sequence full-length HLA-DQA1 genes. We introduce the novel alleles HLA-DQA1*01:10 and HLA-DQA1*01:11. Moreover, we were able to confirm the full-length genomic sequence data of the alleles HLA-DQA1*01:07, HLA-DQA1*03:01:01, HLA-DQA1*03:02, HLA-DQA1*04:01:02, HLA-DQA1*04:02, HLA-DQA1*05:03, HLA-DQA1*05:05:01:02 and HLA-DQA1*06:01:01. A complete genomic overview of all six HLA-DQA1 allele groups is now available from the submission of our data to the IMGT/HLA database. Because our approach facilitates the analysis of all HLA-DQA1 allele sequences, HLA-DQA1 may become the first HLA locus from which all subgroup members will be known in detail in the near future.

Sequence-based typing confirmed a new HLA-A allele, A*31:53, in a liver recipient patient.

In this report, we present the full-length coding sequence of A*31:53, a novel allele with a single-nucleotide difference in exon 3 with respect to A*31:01:02.

A new polymorphic position in exon 2 shows the novel allele HLA-DPB1*123:01.

Introduction of a novel human leukocyte antigen-DPB1 allele, DPB1*123:01, which featured one nucleotide mismatch in comparison with DPB1*02:01:02.

Absence of donor-specific anti-HLA antibodies after ABO-incompatible heart transplantation in infancy: altered immunity or age?

Specific B-cell tolerance toward donor blood group antigens develops in infants after ABO-incompatible heart transplantation, whereas their immune response toward protein antigens such as HLA has not been investigated. We assessed de novo HLA-antibodies in 122 patients after pediatric thoracic transplantation (28 ABO-incompatible) and 36 controls. Median age at transplantation was 1.7 years (1 day to 17.8 year) and samples were collected at median 3.48 years after transplantation. Antibodies were detected against HLA-class I in 21 patients (17.2%), class II in 18 (14.8%) and against both classes in 10 (8.2%). Using single-antigen beads, donor-specific antibodies (DSAs) were identified in six patients (all class II, one additional class I). Patients with DSAs were significantly older at time of transplantation. In patients who had undergone pretransplant cardiac surgeries, class II antibodies were more frequent, although use of homografts or mechanical heart support had no influence. DSAs were absent in ABO-incompatible recipients and class II antibodies were significantly less frequent than in children with ABO-compatible transplants. This difference was present also when comparing only children transplanted below 2 years of age. Therefore, tolerance toward the donor blood group appears to be associated with an altered response to HLA beyond age-related effects.

In a study for acne vulgaris, sequence-based HLA typing showed a novel DPB1 allele, DPB1*2402.

In this paper, we characterize the novel human leucocyte antigen (HLA)-DPB1*2402 allele that we found in a patient suffering from acne vulgaris. In comparison to the closest related allele DPB1*0401, HLA-DPB1*2402 has a single nucleotide exchange at position 115 (202), T replaces G. In consequence, codon 39 (68) TAC encodes for tyrosine in the novel allele instead of aspartic acid 39 (68) GAC in DPB1*0401.

HLA-B*1832, a novel B allele was found through high-resolution HLA typing of a Spanish blood donor.

In this paper, we describe the novel human leukocyte antigen (HLA)-B*1832 allele that we found in a female Spanish volunteer blood donor for clinical investigation during her high-resolution HLA typing. The HLA-B typing is B*1801, 1832, and the DNA sequence is homozygous with the exception characterized by a nucleotide exchange 'C' to 'A' at position 505, which, in consequence, replaced arginine at codon 169 (CGC) by serine in the new allele B*1832.

Sequence-based HLA high-resolution retyping of a bone marrow donor/recipient pair reveals the novel HLA allele DQB1*0322.

In this paper, we characterize the novel human leukocyte antigen (HLA)-DQB1*0322. We found this novel allele in a hematopoietic stem cell donor. The donor and the recipient were high-resolution HLA retyped using sequence-based typing. Both, the female patient and her donor were previously typed HLA identical, which was confirmed with the exception of the novel DQB1 allele. The novel allele is characterized by a nucleotide exchange 'G' to 'A' at position 485 in exon 3. This affected codon 130-arginine (CGG), which is replaced by glutamine (CAG) in the new allele DQB1*0322. The transplant was performed because of an acute myeloid leukemia at first remission.

HLA-DQB1*0634, a novel DQB1 allele found by high-resolution HLA typing of a sibling pair for potential bone marrow transplantation.

In this paper, we characterize the novel human leukocyte antigen (HLA)-DQB1*0634 allele we found in a sibling pair during high-resolution HLA typing in forecast of upcoming bone marrow transplantation. Both siblings, the female patient and her brother, were HLA identical, and therefore, both figured out the novel DQB1 allele characterized by a nucleotide exchange 'C' to 'T' at position 565, which is the last nucleotide of DQB1 exon 3. DQB1 exon 4 sequencing confirmed the exchange of codon 189-arginine (CGG), which is replaced by tryptophan (TGG) in the new allele DQB1*0634.

A novel HLA-DRB1 allele, HLA-DRB1*0465, was identified in a Hodgkin's lymphoma cell line.

The new human leucocyte antigen-DRB1*0465 allele was identified in the Hodgkin's lymphoma cell line KM-H2. This novel allele differs from the DRB1*0406 allele by a single nucleotide exchange at position 288 (211) (A-->T), which results in an arginine to tryptophan amino acid replacement at codon 90 in the new allele.

Identification of a novel HLA-A*24 allele, HLA-A*2467.

In this report, we describe the identification of a novel human leukocyte antigen-A*24 (HLA-A*24) allele, designated HLA-A*2467. The new allele differs from the most closely related allele HLA-A*2408 at five nucleotide positions all located in exon 2. Four of the five nucleotide changes result in amino acid substitution.

HLA-DQB1*0319, a novel HLA-DQB1 allele, shows strong haplotype association to HLA-DRB1*1102.

The new human leukocyte antigen-DQB1*0319 allele was identified in a prospective bone marrow donor by sequence-based typing. This novel allele differs from the DQB1*0301 allele at nucleotide position 554 (C-->T), which results in a Thr to Ile amino acid exchange. The new allele shows a strong association to DRB1*1102, suggesting that the haplotype DRB1*1102-DQB1*0319 is quite common.

A novel HLA-DQB1*06 allele, DQB1*0628, found through routine sequence-based HLA typing and confirmation of DQB1*060302.

In this paper we report the identification of human leukocyte antigen (HLA)-DQB1*0628 and the confirmation of HLA-DQB1*060302.

A novel HLA-B*13 allele, B*1314, was found through routine HLA class I sequence-specific oligonucleotide typing and confirmed by sequence-based HLA typing.

In this study, we report the identification of HLA-B*1314 that differs from B*130201 at two single nucleotide positions.

A novel HLA-DRB1*11 allele, DRB1*1155, was found in a patient through routine DRB1 typing using sequence-specific primers (SSP) and confirmed by allele-specific sequence-based typing.

In comparison with DRB1*1155 allele, DRB1*1103 differs at position 220/221, 'GC' is changed to 'CT', or DRB1*1125 differs at position 210/211, 'AG' is substituted with 'GA'. This results in a single amino acid exchange depending on the closest related allele investigated, whether DRB*1103 codon 74 alanine (GCG) is changed to leucine (CTG) or DRB1*1125 codon 71 arginine (GAG) is replaced with glutamic acid.

Platelet-associated tissue factor contributes to the collagen-triggered activation of blood coagulation.

The extravascular localization of tissue factor (TF), the central initiator of coagulation, is thought to ensure that thrombus formation is prevented in the intact vessel. We observed that during a 5-min stimulation of human blood with collagen (type I), TF antigen appeared on the surface of platelets adhering to leukocytes. The rapidly presented intravascular TF was competent to start the coagulation cascade. The isolated platelets from healthy donors contained appreciable amounts of the TF protein, while no TF antigen was detected in the neutrophils and rapidly isolated monocytes. Direct interactions with the neutrophils and monocytes were apparently necessary to activate the platelet-associated TF. This was most likely mediated by inactivation of tissue factor pathway inhibitor through leukocyte elastase. In summary, the leukocyte-elicited activation of the platelet TF participates in the rapid initiation of coagulation by collagen.