0000000000082194
AUTHOR
Daniel Fürst
P046 Deconstructing HLA-C mismatch in hematopoietic stem cell transplantation
Contrary to other HLA loci, allele vs antigen mismatches in HLA-C appear to differentially impact HSCT outcome. Aim of this study was to investigate the independent role of other factors characterizing a patient’s HLA-C non-shared allele, in HSCT outcome as well as their distribution in allele vs antigen mismatched cases. 288 9/10 HLA-C mismatched unrelated transplant pairs, were additionally genotyped by sequence based typing for rs9264942(C/T) and rs67384697(ins/del), which are considered surrogate markers of HLA-C expression levels. A proxy MFI model as previously described (Petersdorf et al., Blood 2014), was also implemented in the analysis. All patient non-shared alleles were characte…
Is HLA type a possible cancer risk modifier in Lynch syndrome?
Lynch syndrome (LS) is the most common inherited cancer syndrome. It is inherited via a monoallelic germline variant in one of the DNA mismatch repair (MMR) genes. LS carriers have a broad 30-80% risk of developing various malignancies, and more precise, individual risk estimations would be of high clinical value, allowing tailored cancer prevention and surveillance. Due to MMR deficiency, LS cancers are characterized by the accumulation of frameshift mutations leading to highly immunogenic frameshift peptides (FSPs). Thus, immune surveillance is proposed to inhibit the outgrowth of MMR-deficient cell clones. Recent studies have shown that immunoediting during the evolution of MMR-deficient…
High-resolution HLA matching in hematopoietic stem cell transplantation: a retrospective collaborative analysis.
To validate current donor selection strategies based on previous international studies, we retrospectively analyzed 2646 transplantations performed for hematologic malignancies in 28 German transplant centers. Donors and recipients were high resolution typed for HLA-A, -B, -C, -DRB1, and -DQB1. The highest mortality in overall survival analysis was seen for HLA-A, -B, and DRB1 mismatches. HLA-DQB1 mismatched cases showed a trend toward higher mortality, mostly due to HLA-DQB1 antigen disparities. HLA incompatibilities at >1 locus showed additive detrimental effects. HLA mismatching had no significant effect on relapse incidence and primary graft failure. Graft source had no impact on surviv…
OR26. Investigating the impact of patient’s non-shared HLA-C Allotype expression levels in A 9/10 Single HLA-C mismatched hematopoieticstem cell transplantationsetting using two different HLA-C Expression proxy models
Aim Petersdorf et al. reported in 2014 an association between patient high expressed HLA-C (C) allotypes and inferior HSCT outcome using an imputed C-expression model (Apps et al., 2013). This study aims at: a) examining the validity of Apps et al. model in Caucasians by using the same methodology in a sample of 400 healthy German blood donors. b) specifically investigating the effect of patient’s non-shared (PNS) C expression levels on outcome by applying C expression imputed data in a 9/10 HLA C-mismatched HSCT setting. Methods Buffy coats from 400 healthy German blood donors were tested by flow cytometry as previously described (Apps et al., 2013) in order to determine C expression on ly…
Impact of Donor Activating KIR Genes on HSCT Outcome in C1-Ligand Negative Myeloid Disease Patients Transplanted with Unrelated Donors-A Retrospective Study.
Natural Killer cells (NK) are lymphocytes with the potential to recognize and lyse cells which escaped T-cell mediated lysis due to their aberrant HLA expression profiles. Killer cell immunoglobulin-like receptors (KIR) influence NK-cell activity by mediation of activating or inhibitory signals upon interaction with HLA-C (C1, C2) ligands. Therefore, absence of ligands for donor inhibitory KIRs following hematopoietic stem cell transplantation (HSCT) may have an influence on its outcome. Previous studies showed that C1 negative patients have a decreased HSCT outcome. Our study, based on a cohort of 200 C1-negative patients, confirmed these findings for the endpoints: overall survival (OS: H…
Increased age-associated mortality risk in HLA-mismatched hematopoietic stem cell transplantation.
We investigated a possible interaction between age-associated risk and HLA-mismatch associated risk on prognosis in different age categories of recipients of unrelated hematopoietic stem cell transplants (HSCT) (n=3019). Patients over 55 years of age transplanted with 8/10 donors showed a mortality risk of 2.27 (CI 1.70–3.03, P<0.001) and 3.48 (CI 2.49–4.86, P<0.001) when compared to 10/10 matched patients in the same age group and to 10/10 matched patients aged 18–35 years, respectively. Compared to 10/10 matched transplantations within each age category, the Hazards Ratio for 8/10 matched transplantation was 1.14, 1.40 and 2.27 in patients aged 18–35 years, 36–55 and above 55 years. Model…
Donor Genetic Determinant of Thymopoiesis rs2204985 Impacts Clinical Outcome after Single HLA Mismatched HSCT
Abstract Introduction: A common genetic variant within the TCRA-TCRD locus has been recently identified as a predictive factor of thymic function and T cell repertoire diversity (Clave et al., 2018). Specifically it was shown in a mouse model that transplantation of rs2204985 AA human hematopoietic stem cells (HSC) into immunodeficient mice led to lower thymocyte counts and poorer TCR diversity. T cell mediated pathways are known to play a significant role in immunological processes affecting HSCT outcome like GvL, GvH and infection. Aim of this study was to investigate the potential impact of donor rs2204985 genotype on patient's outcome after unrelated HSCT. Methods: The study included 2,…
Human leukocyte antigen-E mismatch is associated with better hematopoietic stem cell transplantation outcome in acute leukemia patients
The immunomodulatory role of human leukocyte antigen (HLA)-E in hematopoietic stem cell transplantation (HSCT) has not been extensively investigated. To this end, we genotyped 509 10/10 HLA unrelated transplant pairs for HLA-E, in order to study the effect of HLA-E as a natural killer (NK)-alloreactivity mediator on HSCT outcome in an acute leukemia (AL) setting. Overall survival (OS), disease free survival (DFS), relapse incidence (RI) and non-relapse mortality (NRM) were set as endpoints. Analysis of our data revealed a significant correlation between HLA-E mismatch and improved HSCT outcome, as shown by both univariate (53% vs. 38%, P=0.002, 5-year OS) and multivariate (hazard ratio (HR)…