Donor Genetic Determinant of Thymopoiesis rs2204985 Impacts Clinical Outcome after Single HLA Mismatched HSCT

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 2,016 adult patients with hematologic malignancies who received their first unrelated (10/10 or 9/10 HLA matched) graft between 2000 and 2013 in a German transplant center. Patients with refractory disease at time of transplantation were excluded from the analysis. Both donors and patients were retrospectively genotyped for the TCRA-TCRD rs2204985 polymorphism by next generation sequencing using a validated protocol on an Illumina Miseq platform. Overall survival (OS), disease free survival (DFS), relapse (RI), non-relapse mortality (NRM), acute GvHD (aGvHD) and chronic GvHD (cGvHD) were evaluated; p<0.05 was considered significant and donor rs2204985 GG/AG genotype was set as reference vs the AA genotype. Stratification for diagnosis was performed and a backward stepwise model finding approach was used to select variables related to a given outcome with a threshold of 0.10 for retention in the model. Results: The rs2204985 genotype frequencies found in both patients and donors were in line with those previously reported for Caucasian populations indicating a codominance of the two alleles (i.e. A and G). Regarding the impact of this genetic variation on outcome, multivariate analysis of the combined cohort indicated different risk estimates in 10/10 and 9/10 HLA matched transplantations, therefore subanalysis on account of HLA incompatibility was performed. Analysis in the subgroup of single HLA mismatched cases (n=624) revealed that donor AA genotype associated with markedly inferior OS (55.1% vs 70.6%, p=0.004, Fig. 1) and DFS (47.6% vs 63.4%, p=0.002, Fig. 2) one year after HSCT as compared to the donor AG/GG genotypes. These results were confirmed in the corresponding multivariate models (OS HR: 1.48, p=0.003; DFS HR: 1.50, p=0.001) which are visually displayed as forest plots in Fig. 3 and Fig 4, respectively. The adverse effect of donor AA genotype on survival appears to be driven by a combined higher risk of RI (1Y after HSCT: 29.3% vs 18.3%, p=0.048; HR: 1.38, p=0.035) and NRM (1Y after HSCT: 28.6% vs 19.9%, p=0.043; HR: 1.38, p=0.042) as shown by both the univariate and multivariate analyses for the two respective endpoints. No association was found between donor rs2204985 genotype and risk of acute or chronic GvHD. The donor rs2204985 genotype had also no significant impact on any outcome endpoint in the 10/10 HLA matched subgroup. Last, no significant interactions were observed between this variable and the other adjusted covariates in the multivariate models. Conclusion: To our knowledge this is the first study to date investigating the potential effect of donor's genotype regarding a common genetic variant within the TCRA-TCRD locus on the outcome of patients receiving unrelated HSC grafts. Our data suggest that donor rs2204985 AA genotype in combination with single HLA mismatches may adversely affect the outcome of HSC transplanted patients and should therefore be avoided. It is of note that one in four unrelated donors of Caucasian origin is expected to carry the AA genotype. A weaker relapse and -presumably- infection control, especially in the early post-transplantation period, due to compromised T cell reconstitution as a result of the unfavorable donor AA genotype may account for these findings. Confirmatory studies in larger independent cohorts are warranted before final conclusions are drawn. Figure 1 Figure 1. Disclosures Platzbecker: Geron: Honoraria; Janssen: Honoraria; Takeda: Honoraria; AbbVie: Honoraria; Novartis: Honoraria; Celgene/BMS: Honoraria. Sala: Celgene/BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Jazz: Consultancy, Honoraria. Wulf: Gilead: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Clinigen: Consultancy, Honoraria. Kroeger: Celgene: Honoraria, Research Funding; Riemser: Honoraria, Research Funding; Gilead/Kite: Honoraria; AOP Pharma: Honoraria; Novartis: Honoraria; Jazz: Honoraria, Research Funding; Sanofi: Honoraria; Neovii: Honoraria, Research Funding. Einsele: Janssen, Celgene/BMS, Amgen, GSK, Sanofi: Consultancy, Honoraria, Research Funding. Hertenstein: Novartis: Honoraria; Sanofi: Honoraria; Celgene: Honoraria; BMS: Honoraria. Schrezenmeier: Alexion, AstraZeneca Rare Disease: Honoraria, Other: Travel support, Research Funding; Roche: Honoraria; Novartis: Honoraria; Apellis: Honoraria; Sanofi: Honoraria.

Effect of Temperature on the Corrosion Inhibition of 4-ethyl-1-(4-oxo-4-phenylbutanoyl)thiosemicarbazide on Mild Steel in HCl Solution

Brugada syndrome is a syndrome causing abnormal electrolyte and electrocardophysiology. In an attack of Brugada syndrome, a patient might sleep and die without any other clear causes. Genetic underlying Brugada syndrome is widely studied. SCN5A p.R965C is a common genetic variant seen in an endemic area of Burgarda syndrome such as Southeast Asia. An assessment of the impact of SCN5A p.$965C was performed using standard nanomolecular quantum calculation. According to the assessment, a decreased molecular weight due to mutation is observed, implying an increased SCN5A expression. The nanomolecular charge well explains the clinical problem of Brugada syndrome.

Human genetic variant E756del in the ion channel PIEZO1 not associated with protection from severe malaria in a large Ghanaian study

Recently, a common genetic variant E756del in the human gene PIEZO1 was associated with protection from severe malaria. Here, we performed a genetic association study of this gain-of-function variant in a large case-control study including 4149 children from the Ashanti Region in Ghana, West Africa. The statistical analysis did not indicate an association with protection from severe malaria and, thus, providing evidence against a strong protective effect of the PIEZO1 E756del variant on severe malaria susceptibility.

Association of a Common Genetic Variant with Parkinson’s Disease is Propagated through Microglia

Studies of the genetic basis of Parkinson’s disease (PD) have identified many disease-associated genetic variants, but the mechanisms linking variants to pathogenicity are largely unknown. PD risk is attributed to both coding mutations in the Leucine-rich repeat kinase 2 (LRRK2) gene and to common non-coding variation upstream of the LRRK2 locus. Here we show that the influence of genotype at non-coding variant rs76904798 on LRRK2 expression is propagated specifically through microglia, in contrast to evaluations based on general rather than genotype-dependent expression. We find evidence of microglia-specific regulatory regions that may modulate LRRK2 expression using single nuclei sequencing analyses of human frontal cortex and confirm these results in a human induced pluripotent stem cell-derived microglia model. Our study demonstrates that cell type is an important consideration in interrogation of the role of non-coding variation in disease pathogenesis.