Recipient Genotype Research Articles

245.9: Influence of Tacrolimus CYP3A5 Polymorphisms on the Doselevel Response After Pediatric Kidney Transplantation

Background: Tacrolimus exhibits wide inter and intra-patient variability. CYP3A5 tacrolimus polymorphisms predict its metabolization. We aim to identify the influence of polymorphisms on the pharmacological parameters. The present report is part of the exploratory data analysis of a pediatric trial that used the initial tacrolimus dose according to the CYP3A5 genotype in kidney transplant recipients. Methods: We performed an exploratory data analysis of pharmacological parameters from a single-center, non-randomized, open-label clinical trial in children from 0-to 18 years of age who received a kidney transplant at the Hospital Infantil de México, Federico Gómez from January 2013 to December 2018. All children were genotyped before transplantation and assigned to one of two groups: the Genotype-guided group, which initial dose was according to the CYP3A5 polymorphisms and the Conventional-dose group (see abstract AID-1780), with further dose adjustments on the decision of the clinicians. We followed them for six weeks and recorded tacrolimus dose received, trough level achieved, deltas of dose and trough levels between time points (weekly). Results: We included 81 subjects; 40 received the genotype-guided dose, the mean age at transplantation was 13.3 y/o, 51.8% were female. After six weeks of transplantation, linear regressions showed no linear associations between tacrolimus dose and levels in the genotype-guided dose group (r2=0.0003, p=0.78) or the conventional-dose group (r2=0.0008, p=67). However, there were linear associations between the delta-dose and delta-levels in the genotype-guided dose group (r2=0.138, p=<0.0001) and conventional-dose group (r2=0.081, p=<0.0001). The subgroup analysis by genotype showed that AG1*3 polymorphism had a linear association between the tacrolimus delta-dose and delta-level (r2=0.168, p=<0.001). Furthermore, It reached statistical significance in the tacrolimus dose vs level analysis (r2=0.0308, p= 0.02). The GG3*3 polymorphism showed an association only in the delta-dose vs delta-level analysis (r2=0.057, p=<0.001), while the AA1*1 genotype did not show any linear associations between tacrolimus dose vs trough level or deltas (r2=0.006, p=0.64 and r2=0.108, p=0.08 respectively) (Figure). Conclusion: The tacrolimus delta-dose and delta-level across the different polymorphisms translate the clinician’s decisions. The trough levels’ response to dose adjustments might be guided by the CYP3A5 genotypes, specifically the AG1*3. Further studies are needed to estimate more accurate associations.

Development of powdery mildew resistant derivatives of wheat variety Fielder for use in genetic transformation

Genetic transformation is widely used to improve target traits and to study gene function in wheat. However, transformation efficiency depends on the physiological status of the recipient genotype and that is affected by several factors including powdery mildew (PM) infection. The widely used recipient variety Fielder is very susceptible to PM. Therefore, it would be beneficial to develop PM resistant derivatives with high regeneration ability for use in genetic transformation. In the present study PM resistant lines CB037 and Pm97033 carrying genes Pm21 and PmV, respectively, were backcrossed to Fielder with selection for PM resistance. Five lines, NT89, NT90, NT154, and WT48 with Pm21 and line FL347 with PmV were developed, identified by molecular markers and genomic in situ hybridization (GISH) or fluorescent in situ hybridization (FISH), and further subjected to detailed assessment of agronomic traits and regeneration ability following genetic transformation capacity. Lines FL347, WT48, NT89 and NT154 assessed as being equal to, or superior, to Fielder in regeneration and transformation ability are recommended as suitable materials for the replacement of Fielder for wheat gene transfer and genome editing study.

Donor CYP3A5 Expression Decreases Renal Transplantation Outcomes in White Renal Transplant Recipients.

BackgroundAfter renal transplantation, immunosuppressants should be administered to prevent organ rejection and prolong graft survival. One of them is tacrolimus, which is metabolized by the CYP3A enzyme family. The variability of the CYP3A5 gene in renal transplant recipients has been previously studied for its correlation with acute rejection and allogeneic kidney function. CYP3A5 enzyme is also present in the renal tissue, and its relevance has not yet been extensively investigated. This study aimed to evaluate the effect of donor and recipient CYP3A5 expression status on early and long-term transplant outcomes.Material/MethodsSingle-nucleotide polymorphism in CYP3A5 (rs776746) was analyzed in 95 kidney transplant recipients and their grafts. The effect of donor and recipient genotypes on the primary endpoint, which was the loss of the renal graft over 5-year follow-up, was assessed. The secondary endpoints were biopsy-proven acute rejection, proteinuria, delayed graft function, and renal function.ResultsPatients who received a CYP3A5*1 allele-carrying kidney (n=16) were at greater risk of graft loss (adjusted hazard ratio, 95% CI: 10.61, 2.28–49.42, P=.003) than those with the CYP3A5*3/*3 genotype (n=79). Renal CYP3A5 expression was also a predictor of acute rejection between the 2nd and 12th post-transplant months (adjusted odds ratio, 95% CI: 4.36; 1.08–17.6, P=.038) and proteinuria at different time intervals. No effect of the recipient CYP3A5 genotype was observed.ConclusionsThe donor CYP3A5 genotype is associated with inferior transplantation outcomes. Local renal tacrolimus metabolism is a potential target for improving long-term transplantation outcomes.

Molecular Detection and Glycoprotein B (UL55) Genotyping of Cytomegalovirus among Sudanese Renal Transplant Recipients.

Background Cytomegalovirus (CMV) is the most common opportunistic pathogen among renal transplants with significant morbidity and mortality. This study was designed to detect CMV DNA and to determine the frequency of different glycoprotein B (UL55) genotypes among Sudanese renal transplant recipients. Methods One hundred and four renal transplant recipients were included in this study. A blood specimen was collected from each recipient. DNA was extracted from plasma using the QIAamp DNA mini kit. CMV amplification and quantification were performed using CMV Real-RT Quant kits. Genotyping of human CMV gB was carried out by nested PCR and sequencing of the highly diverse region of gB. Results CMV DNA was detected in 40/104 (38.5%) of renal transplant recipients. The average of the CMV DNA viral load was 358 × 104 copies/ml (6.5 log10) ranging from 62 copies/ml (1.8 log10) to 1.43 × 108 copies/ml (9 log10). CMV viremia was detected in 60% of recipients of less than 1–12 months, 17% of 13–24, 10% of 25–36, 5% of 37–48, and 8% in more than 48 months posttransplantation with no association (p = 0.296) between CMV viremia and postrenal transplantation time. The association between the type of immunosuppressive drugs and high viral loads (>1000 copies/ml) showed a significant difference (p = 0.05). The association between CMV loads of >1000 copies/ml and symptoms of CMV disease was highly significant (p ≤ 0.001). Fever 7 (41%), fever and leucopenia 6 (35%), and gastrointestinal disease 4 (24%) were the most common symptoms of CMV disease. CMV genotyping revealed 8 cases (80%) for gB3 and 2 cases (20%) for gB4 genotypes. The most frequent genotype among Sudanese renal transplant recipients was gB3. Conclusions The frequency of CMV DNA is high among Sudanese renal transplant recipients. CMV gB3 is the most predominant glycoprotein B genotype in Sudanese renal transplant recipients.

Utilizing modern tissue typing technologies to promote precision kidney transplantation

Improving quality is the primary goal of the kidney transplantation community in China. Promoting new technologies for tissue typing, including adopting high-resolution human leucocyte antigen (HLA) typing methods to ensure the integrity and uniqueness of the donor and recipient HLA genotype, combining modified cytological method and purified single antigen technology to improve the accuracy of HLA antibody detection, etc., can assess the donor-recipient's mismatch load and the immune risk of recipients more precisely, so as to guide the scientific allocation of organs and individualized immunosuppressive regime, which can contribute to the long-term survival of recipients. This is the embodiment of the core essence of"precision medicine"in the field of kidney transplantation.

Expanding the genetic variation of Brassica juncea by introgression of the Brassica rapa Genome.

Brassica juncea is an important vegetable and oil crop cultivated worldwide. To increase its genetic variation, we introgressed the A genome of Brassica rapa into B. juncea. We used three each of heading and semi-heading B. juncea accessions as recipient parents and a B. rapa line, B9008, as the donor parent. We obtained 101 BC1S1 lines in total with expanded phenotypic variations such as leafy head shapes. We developed 132 single-nucleotide polymorphism (SNP) markers that could distinguish the A genome of B. juncea from the B. rapa genome, and tracked the introgression of B. rapa segments in the new B. juncea germplasm. On average, 59.2% of the B. juncea A genome in the B. juncea introgression lines was covered by the donor segments. We also identified three markers whose donor genotype frequencies were significantly lower than the theoretical value, suggesting strong selection of the recipient genotype during the introgression process. We provide an effective strategy to evaluate the diversity of the new germplasm based on the combination of parental resequencing data and marker genotyping results. Further genetic analysis of 1642 SNPs showed that the genetic diversity of the new B. juncea germplasm with the introgressed B. rapa genome was significantly increased. This study illustrates the potential for expanding the genetic diversity of B. juncea through the introgression of the B. rapa genome.

Similar cost of Hamiltonella defensa in experimental and natural aphid-endosymbiont associations.

Endosymbiont‐conferred resistance to parasitoids is common in aphids, but comes at a cost to the host in the absence of parasitoids. In black bean aphids (Aphis fabae), costs in terms of reduced lifespan and lifetime reproduction were demonstrated by introducing 11 isolates of the protective symbiont Hamiltonella defensa into previously uninfected aphid clones. Transfection of H. defensa isolates into a common genetic background allows to compare the costs of different endosymbiont isolates unconfounded by host genetic variation, but has been suggested to overestimate the realized costs of the endosymbiont in natural populations, because transfection creates new and potentially maladapted host–symbiont combinations that would be eliminated by natural selection in the field. In this experiment, we show that removing H. defensa isolates from their natural host clones with antibiotics results in a fitness gain that is comparable to the fitness loss from their introduction into two new clones. This suggests that estimating cost by transfecting endosymbiont isolates into a shared host genotype does not lead to gross overestimates of their realized costs, at least not in the two recipient genotypes used here. By comparing our data with data reported in previous publications using the same lines, we show that symbiont‐induced costs may fluctuate over time. Thus, costs estimated after extended culture in the laboratory may not always be representative of the costs at the time of collection in the field. Finally, we report the accidental observation that two isolates from a distinct haplotype of H. defensa could not be removed by cefotaxime treatment, while all isolates from two other haplotypes were readily eliminated, which is suggestive of variation in susceptibility to this antibiotic in H. defensa.

CYP3A7, CYP3A4, and CYP3A5 genetic polymorphisms in recipients rather than donors influence tacrolimus concentrations in the early stages after liver transplantation.

The purpose of this study was to investigate the effect of CYP3A7, CYP3A4, and CYP3A5 genetic polymorphisms in liver transplant recipients and donors on tacrolimus concentrations in the early stages after liver transplantation. One hundred and thirty-eight liver transplant recipients and matched donors were genotyped for CYP3A7 (rs10211 and rs2257401), CYP3A4 (rs4646437 and rs2242480), and CYP3A5*3 (rs776746) polymorphisms. The relationships between dose-adjusted trough concentrations (C0/D) of tacrolimus and corresponding genotypes were investigated. Recipient CYP3A polymorphisms were associated with tacrolimus concentrations. The CYP3A7 rs10211 AA carriers (186.2 vs 90.5, p<0.001), CYP3A4 rs4646437 CC carriers (184.0 vs 88.8, p<0.001), CYP3A4*1G rs2242480 CC carriers (189.8 vs 99.7, p<0.001), and CYP3A5*3 rs776746 GG carriers (197.3 vs 86.0, p<0.001) had an almost twofold increase in the tacrolimus C0/D compared to that of the non-carriers. We further investigated the effect of the combination of recipient (intestinal) and donor (hepatic) genotypes on tacrolimus concentrations. Regardless of the genotype of the matched donor, CYP3A7 rs10211, CYP3A4*1G (rs2242480), and CYP3A5*3 (rs776746) polymorphisms of recipients could affect tacrolimus concentrations. For the CYP3A4 rs4646437 polymorphisms, when the donor carried CYP3A4 rs4646437 CC, the recipient CYP3A4 rs4646437 polymorphism was associated with the C0/D of tacrolimus, and when the donor carried CYP3A4 rs4646437 CT/TT genotype, the recipient CYP3A4 rs4646437 polymorphism also affected on tacrolimus C0/D, although the effect was not significant. The large inter-individual variation in tacrolimus concentrations in the early stages after liver transplantation is influenced by genetic polymorphisms of CYP3A7, CYP3A4, and CYP3A5. Recipient (intestinal) CYP3A7, CYP3A4, and CYP3A5 polymorphisms seem to contribute more to such variation than donors. Therefore, the detection of CYP3A polymorphisms in recipients could help to predict the tacrolimus starting dose in the early stages after liver transplantation.

Impact of PNPLA3 (rs738409-G) Polymorphism on Post-Transplant Outcomes after Liver Transplantation for Alcohol-Related Liver Disease

Background and Aims: We aimed to evaluate the association between PNPLA3 polymorphism and post-liver transplantation (LT) outcomes related to alcohol relapse (AR). Methods: We retrospectively analyzed data from patients receiving LT for alcoholic liver disease (ALD) from 04/2014 to 12/2017. Liver-related clinical outcomes were assessed by the gamma-glutamyltransferase (GGT) level and alcohol-related liver failure (ARLF). Genotyping was performed using prospectively collected DNA samples in both donors and recipients. Results: A total of 83 recipients were enrolled. Post-LT AR occurred in 31 patients (37.3%). Thirty-one patients (14 AR, 9 abstainers) showed elevated GGT levels, and 3 AR patients experienced ARLF. In the multivariate analysis, rs738409 G allele carrier and heavy drinking (HRAR score≥4) were independent risk factors for elevated GGT levels (odds ratio [OR]=8.69, p<0.01; OR=13.07, p=0.01) and ARLF (OR=4.52, p=0.04; OR=19.62, p=0.03). Among 15 heavy AR patients, being an rs738409 G allele carrier was related to GGT elevation (p=0.03) and ARLF (p=0.04), but it was not to GGT elevation in mild drinkers (n=16) or abstainers (n=52). Conclusions: PNPLA3 polymorphism of the recipient genotype can independently affect the post-LT prognosis of LT patients for ALD, especially in heavy AR patients. Therefore, strong abstinence education is recommended in patients with this single nucleotide polymorphism.

216. Bacterial Genotype and Clinical Outcomes in Solid Organ Transplant Recipients with Staphylococcus aureus Bacteremia

BackgroundSolid organ transplant (SOT) recipients are characterized by extensive healthcare exposure and have high rates of Staphylococcus aureus bacteremia (SAB). The clinical characteristics and outcome determinants of SAB in this population are poorly understood. We undertook a prospective cohort study compared the bacterial genotype and clinical outcomes of SAB among SOT and non-solid organ transplant (non-SOT) recipients. MethodsConsecutive patients presenting to our institution with SAB between January 1, 2016 and December 31, 2019 were eligible for study inclusion. Each subject’s initial S. aureus bloodstream isolate was genotyped using spa typing and assigned to clonal complexes using Ridom StaphType software. ResultsA total of 32 SOT and 634 non-SOT recipients with SAB were included. Bacterial genotype did not differ significantly between SOT and non-SOT recipients (p=0.4855), including the proportion of SAB caused by USA300 (12.5% vs 16.7%, p=0.6339). Ninety-day mortality and incidence of metastatic complications did not significantly differ between SOT and non-SOT recipients (18.8% vs 30.1%, p=0.2329, and 37.5% vs 48.6%, p=0.2769, respectively). Transplant status was significantly associated with septic shock (50.0% vs 21.8%, adjusted OR 2.63, 95% CI: 1.22 to 5.66). Infection with USA300 was not associated with 90-day mortality or septic shock among SOT recipients (p=1.0000 for both). Staphylococcus aureus Genotype by Transplant Status ConclusionIn conclusion, SOT recipients with SAB do not experience greater mortality than non-SOT recipients. Differences in genotype of the infecting bacteria do not appear to be a significant determinant of outcome in SOT recipients with SAB. Disclosures Vance G. Fowler, Jr., MD, MHS, Achaogen (Consultant)Advanced Liquid Logics (Grant/Research Support)Affinergy (Consultant, Grant/Research Support)Affinium (Consultant)Akagera (Consultant)Allergan (Grant/Research Support)Amphliphi Biosciences (Consultant)Aridis (Consultant)Armata (Consultant)Basilea (Consultant, Grant/Research Support)Bayer (Consultant)C3J (Consultant)Cerexa (Consultant, Other Financial or Material Support, Educational fees)Contrafect (Consultant, Grant/Research Support)Debiopharm (Consultant, Other Financial or Material Support, Educational fees)Destiny (Consultant)Durata (Consultant, Other Financial or Material Support, educational fees)Genentech (Consultant, Grant/Research Support)Green Cross (Other Financial or Material Support, Educational fees)Integrated Biotherapeutics (Consultant)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Locus (Grant/Research Support)Medical Biosurfaces (Grant/Research Support)Medicines Co. (Consultant)MedImmune (Consultant, Grant/Research Support)Merck (Grant/Research Support)NIH (Grant/Research Support)Novadigm (Consultant)Novartis (Consultant, Grant/Research Support)Pfizer (Grant/Research Support)Regeneron (Consultant, Grant/Research Support)sepsis diagnostics (Other Financial or Material Support, Pending patent for host gene expression signature diagnostic for sepsis.)Tetraphase (Consultant)Theravance (Consultant, Grant/Research Support, Other Financial or Material Support, Educational fees)Trius (Consultant)UpToDate (Other Financial or Material Support, Royalties)Valanbio (Consultant, Other Financial or Material Support, Stock options)xBiotech (Consultant)

Bacterial genotype and clinical outcomes in solid organ transplant recipients with Staphylococcus aureus bacteremia.

Outcomes from Staphylococcus aureus bacteremia (SAB) in solid organ transplant (SOT) recipients are poorly understood. This is a prospective cohort study comparing the bacterial genotype and clinical outcomes of SAB among SOT and non-transplant (non-SOT) recipients from 2005 to 2019. Each subject's initial S. aureus bloodstream isolate was genotyped using spa typing and assigned to a clonal complex. A total of 103 SOT and 1783 non-SOT recipients with SAB were included. Bacterial genotype did not differ significantly between SOT and non-SOT recipients (p=.4673), including the proportion of SAB caused by USA300 (13.2%vs. 16.0%, p=.2680). Transplant status was not significantly associated with 90-day mortality (18.4%vs. 29.5%; adjusted odds ratio [aOR] 0.74; 95% confidence interval [CI]: 0.44, 1.25), but was associated with increased risk for septic shock (50.0%vs. 21.8%; aOR 2.31; 95% CI: 1.48, 3.61) and acute respiratory distress syndrome (21.4%vs. 13.7%; aOR 2.03; 95% CI: 1.22, 3.37), and a significantly lower risk of metastatic complications (33.0%vs. 45.5%; aOR 0.49; 95% CI: 0.32, 0.76). No association was found between bacterial genotype and 90-day mortality (p=.6222) or septic shock (p=.5080) in SOT recipients with SAB. SOT recipients with SAB do not experience greater mortality than non-SOT recipients. The genotype of S. aureus bloodstream isolates in SOT recipients is similar to that of non-SOT recipients, and does not appear to be an important determinant of outcome in SOT recipients with SAB.

Single nucleotide polymorphisms within HLA region are associated with the outcomes of unrelated cord blood transplantation

Cord blood transplantation (CBT) provides a treatment scheme for hematologic diseases and leukemia in both children and adults. However, adverse reactions and transplantation-related death may still occur in patients receiving CBT even when donor and recipient have fully matched HLA in high-resolution HLA typing analysis. Single nucleotide polymorphisms (SNPs) of HLA-related and unrelated genes are known to associate with disease status of patients with unrelated stem cell transplantation. In this study, the genomic regions ranging from 500 base pairs upstream to 500 base pairs downstream of the eight SNPs that were reported as transplantation determinants by Petersdorf et al. were analyzed to evaluate whether genetic variants were associated with the survival status of patients, and the risk for severe (grades 3–4) graft-versus-host disease (GVHD) or cytomegalovirus (CMV) infection/reactivation. The analyses were performed in the mode of recipient genotype, donor genotype, and recipient-donor mismatching, respectively. By analysis of sixty-five patients and their HLA-matched unrelated donors, we found that five SNPs were associated with patient survival which included the recipient genotype with SNPs of rs107822 in the RING1 gene, and rs2070120, rs17220087 and rs17213693 in the HLA-DOB gene; and the recipient-donor mismatching with SNPs of rs9282369 in HLA-DOA gene, and rs2070120, rs17220087 and rs17213693 in the HLA-DOB gene. Five SNPs were associated with the risk for severe GVHD which included the donor genotype with SNPs of rs213210 and rs2523675; the recipient genotype with SNPs of rs9281491 in the HCP5 gene; and the recipient-donor mismatching with SNPs of rs209130 in the TRIM27 gene, and rs986522 in the COL11A2 gene. Six SNPs were related to the risk for CMV infection/reactivation which included the donor genotype with SNPs of rs435766, rs380924, and rs2523957; and the recipient-donor mismatching with SNPs of rs2070120, rs17220087, and rs17213693 in the HLA-DOB gene; and rs435766 and rs380924 in the MICD gene. This study provides the basis for larger analyses and if the results are confirmed, a way of selecting better unrelated CBT candidate donors.

Recipient HLA-B Leader Genotype, and Its Relationship to Total KIR Missing Ligand, Informs Relapse and Survival Following Haploidentical Transplantation Using Post-Transplant Cyclophosphamide

▪In addition to donor T cells, natural killer (NK) cells are proposed to play a significant role in the graft-versus-leukemia (GVL) effect following haploidentical donor transplantation (HIDT). Following HIDT, donor NK cells express activating (NKG2C) receptors (Ciurea, Leukemia 2021), whose ligand is the non-classical human leukocyte antigen, HLA-E. For surface expression, HLA-E requires binding of leader peptides derived from class I HLA molecules. The rs1050458C/T dimorphism at position -21 of exon 1 of HLA-B gives rise to leader peptides with either methionine (M) or threonine (T) at the second residue of the processed leader peptide. M-containing HLA-B leader peptides promote higher HLA-E expression than T-leaders, potentially favoring more robust natural NK cell recognition of HLA-E-expressing tumor cells. Alternatively, donor NK cells can be activated through inhibitory killer cell immunoglobulin-like receptors (iKIR: 2DL1, 2DL23, 3DL1, 3DL2), if they fail to engage a corresponding class I HLA ligand on recipient leukemia cells (missing ligand (ML) paradigm). We hypothesized that M-containing B-leaders (either MM or MT genotype), and potentially its association with KIR ML, may inform relapse and survival after HIDT using post-transplant cyclophosphamide (PTCy). A total of 322 patients with acute leukemia, MDS, lymphoma, CLL or CML, receiving a HIDT-PTCy from a single institution were evaluated with a median follow-up time of 45 months [range 6, 184]. Baseline characteristics included a median age of 50 years [19, 80], 47% non-white, HCT-CI ≥3 in 50%, PBSC graft in 80%, and myeloablative conditioning in 49%. M-containing B-leader genotype (either MM or MT) was seen in 42% and 44% of recipients and donors, respectively. The B-leader on the unshared donor-recipient haplotypes was matched (either T or M) in 61% of transplants. ML for iKIR 2DL1, 2DL23, 3DL1, and 3DL2 was noted in 29%, 20%, 24% and 72% respectively. Total ML was 0, 1, 2 and 3 in 10%, 43%, 40% and 7% respectively. In univariate analysis, an M-containing recipient B-leader genotype [R(M+)] improved OS and DFS compared to a recipient TT genotype [R(M-)] (75 vs. 53%, p<0.001; 66 vs. 47%, p<0.001), which was primarily due to a lower risk of relapse/progression (24% vs. 38%, p=0.012). In regard to total iKIR ML, the presence of 2-3 ML was associated with better overall (OS) and disease-free (DFS) survival compared with 0-1 (67% vs. 57%, p=0.08; 62% vs. 48%, p=0.019), which was due to lower relapse/progression (25% vs. 38%, p=0.015). There was no association of either recipient B-leader or total iKIR ML with the incidence of NRM, acute or chronic GVHD. When recipient B-leader and ML were combined, the detrimental effect of a R(M-) genotype was seen exclusively in patients with ML 0-1 (see figure). DFS for R(M-)/ML(0-1), R(M+)/ML(0-1), R(M-)/ML(2-3), R(M+)/ML(2-3) was 36%, 68%, 65% and 60%, respectively (p<0.001). Corresponding relapse/progression rates were 49%, 22%, 26% and 25%, respectively (P<0.001). In multivariate analysis, controlling for patient age/sex/race, disease risk index, donor age, HLA-DR mm, HLA-DP npmm and year of transplantation, both recipient B leader and total iKIR ML were independently associated with DFS (HR 0.57, p=0.002 and HR 0.67, p=0.026) and relapse/progression (HR 0.55, p=0.006 and HR 0.55, p=0.007). In summary, a recipient M-containing B-leader genotype (MM or MT) reduces relapse and improves survival following HIDT-PTCy, presumably through HLA-E-mediated effector cell engagement. Furthermore, the negative consequences of low total ML for iKIR, in terms of increased relapse risk and lower DFS, can be mitigated when a R(M+) B-leader is present. In addition to the clinical importance of this novel finding for optimizing HIDT-PTCy, it further supports the role of alloreactive donor NK cells for optimal GVL in this context. [Display omitted] DisclosuresSolh: Partner Therapeutics: Research Funding; Jazz Pharmaceuticals: Consultancy; ADCT Therapeutics: Consultancy, Research Funding; BMS: Consultancy.

Metabolic dissimilarity determines the establishment of cross-feeding interactions in bacteria

The exchange of metabolites among different bacterial genotypes profoundly impacts the structure and function of microbial communities. However, the factors governing the establishment of these cross-feeding interactions remain poorly understood. While shared physiological features may facilitate interactions among more closely related individuals, a lower relatedness should reduce competition and thus increase the potential for synergistic interactions. Here, we investigate how the relationship between a metabolite donor and recipient affects the propensity of strains to engage in unidirectional cross-feeding interactions. For this, we performed pairwise cocultivation experiments between four auxotrophic recipients and 25 species of potential amino acid donors. Auxotrophic recipients grew in the vast majority of pairs tested (63%), suggesting metabolic cross-feeding interactions are readily established. Strikingly, both the phylogenetic distance between donor and recipient and the dissimilarity of their metabolic networks were positively associated with the growth of auxotrophic recipients. Analyzing the co-growth of species from a gut microbial community in silico also revealed that recipient genotypes benefitted more from interacting with metabolically dissimilar partners, thus corroborating the empirical results. Together, our work identifies the metabolic dissimilarity between bacterial genotypes as a key factor determining the establishment of metabolic cross-feeding interactions in microbial communities.

A Multi-Marker Test for Analyzing Paired Genetic Data in Transplantation.

Emerging evidence suggests that donor/recipient matching in non-HLA (human leukocyte antigen) regions of the genome may impact transplant outcomes and recognizing these matching effects may increase the power of transplant genetics studies. Most available matching scores account for either single-nucleotide polymorphism (SNP) matching only or sum these SNP matching scores across multiple gene-coding regions, which makes it challenging to interpret the association findings. We propose a multi-marker Joint Score Test (JST) to jointly test for association between recipient genotype SNP effects and a gene-based matching score with transplant outcomes. This method utilizes Eigen decomposition as a dimension reduction technique to potentially increase statistical power by decreasing the degrees of freedom for the test. In addition, JST allows for the matching effect and the recipient genotype effect to follow different biological mechanisms, which is not the case for other multi-marker methods. Extensive simulation studies show that JST is competitive when compared with existing methods, such as the sequence kernel association test (SKAT), especially under scenarios where associated SNPs are in low linkage disequilibrium with non-associated SNPs or in gene regions containing a large number of SNPs. Applying the method to paired donor/recipient genetic data from kidney transplant studies yields various gene regions that are potentially associated with incidence of acute rejection after transplant.

Direct modification of multiple gene homoeologs in Brassica oleracea and Brassica napus using doubled haploid inducer-mediated genome-editing system.

Thediploid Brassica oleracea and allopolyploidy Brassica napus are predominant members of commonly consumed vegetables and plant oil, respectively. B. oleracea vegetables mainly include Broccoli, Cauliflower, Cabbage, Brussels sprouts and Kohlrabi. The complex genome structure and gene function redundancy are the main obstacles for gene stacking through traditional cross breeding approach. To solve this problem, high-efficiency CRISPR/Cas9 genome editing technologies have been established (Lawrenson et al., 2015; Li et al., 2018). However, an open question is that most of these established approaches employed Agrobacterium-mediated T-DNA transformation to deliver CRISRP/Cas9 components into plant cells, which would unavoidably introduce exogenous large DNA fragments. Moreover, Agrobacterium-based strategy deeply relies on transformation efficiency of the recipient genotype, which extremely restricts rapid application of CRISRP/Cas9 in the majority of elite commercial verities.

Donor genetic variants in interleukin-6 and interleukin-6 receptor associate with biopsy-proven rejection following kidney transplantation

Rejection after kidney transplantation remains an important cause of allograft failure that markedly impacts morbidity. Cytokines are a major player in rejection, and we, therefore, explored the impact of interleukin-6 (IL6) and IL-6 receptor (IL6R) gene polymorphisms on the occurrence of rejection after renal transplantation. We performed an observational cohort study analyzing both donor and recipient DNA in 1271 renal transplant‐pairs from the University Medical Center Groningen in The Netherlands and associated single nucleotide polymorphisms (SNPs) with biopsy-proven rejection after kidney transplantation. The C-allele of the IL6R SNP (Asp358Ala; rs2228145 A > C, formerly rs8192284) in donor kidneys conferred a reduced risk of rejection following renal transplantation (HR 0.78 per C-allele; 95%-CI 0.67–0.90; P = 0.001). On the other hand, the C-allele of the IL6 SNP (at position-174 in the promoter; rs1800795 G > C) in donor kidneys was associated with an increased risk of rejection for male organ donors (HR per C-allele 1.31; 95%-CI 1.08–1.58; P = 0.0006), but not female organ donors (P = 0.33). In contrast, neither the IL6 nor IL6R SNP in the recipient showed an association with renal transplant rejection. In conclusion, donor IL6 and IL6R genotypes but not recipient genotypes represent an independent prognostic marker for biopsy-proven renal allograft rejection.

The study of the effects of reducing the negative influence of 1BL-1RS translocation on the bread making quality in spring bread wheat lines

The effects of the combinations 7DS-7DL-7Ae#1L (Lr19 gene) and 1BL-1RS (Lr26 gene) translocations, substitution of 6D(6Agi) (Lr6Agi gene) and 1BL-1RS translocation, as well as translocations of 7DS-7DL-7Ae#1L, 1BL-1RS and Lr39 gene on the bread making quality were evaluated in spring bread wheat introgressive lines. It was found that the genotype of recipient, the 1BL-1RS translocation donor, and the vegetation conditions have a great influence on the parameters quality of flour and bread. The role of selection within a single crosses combination for production of lines with good quality indicators is revealed. The high compensatory ability of the cultivar L505 and the synthetic hexaploid line with the pedigree Croc/Ae.squarosa(205)//Weaver (1BL-1RS translocation + Lr39 gene) for reducing the negative effect of the 1BL-1RS translocation on bread making quality was noted.

Impact of patatin-like phospholipase domain-containing protein 3 (rs738409-G) polymorphism on post-transplant outcomes after liver transplantation for alcohol-related liver disease

We aimed to evaluate the association between patatin-like phospholipase domain-containing protein 3 (PNPLA3) polymorphism and post-liver transplantation (LT) outcomes related to alcohol relapse (AR). We retrospectively analyzed data from patients receiving LT for alcoholic liver disease (ALD) from 04/2014 to 12/2017. Liver-related clinical outcomes were assessed by the gamma-glutamyltransferase (GGT) level and alcohol-related liver failure (ARLF). Genotyping was performed using prospectively collected DNA samples in both donors and recipients. A total of 83 recipients were enrolled. Post-LT AR occurred in 31 patients (37.3%). Thirty-one patients (14 AR, 9 abstainers) showed elevated GGT levels, and 3 AR patients experienced ARLF. In the multivariate analysis, rs738409-G allele carrier and heavy drinking (HRAR score ≥4) were independent risk factors for elevated GGT levels (odds ratio [OR] = 8.69, p < 0.01; OR = 13.07, p = 0.01) and ARLF (OR = 4.52, p = 0.04; OR = 19.62, p = 0.03). Among 15 heavy AR patients, being an rs738409-G allele carrier was related to GGT elevation (p = 0.03) and ARLF (p = 0.04), but it was not to GGT elevation in mild drinkers (n = 16) or abstainers (n = 52). PNPLA3 polymorphism of the recipient genotype can independently affect the post-LT prognosis of LT patients for ALD, especially in heavy AR patients. Therefore, strong abstinence education is recommended in patients with this single nucleotide polymorphism.

CCR6, IL7R, FAS and Madcam-1 Single Nucleotide Polymorphisms Are Associated with Higher Incidence of Infections in Allogeneic Stem-Cell Transplant from a Related Donor after a Reduced Intensity Conditioning Regimen: A Multicenter Experience

INTRODUCTION: Infection complications are important cause of morbidity and non-relapse mortality after allogeneic hematopoietic stem cell transplantation (allo-SCT), even in HLA-identical sibling donors. Although there are many studies associating single nucleotide polymorphisms (SNPs) and allo-SCT evolution, these are mainly related with graft versus host disease (GVHD) and/or transplant related mortality (TRM), with few focused on post-allo-SCT infections. This multicentric study analyzes the potential implication of SNPs with cytomegalovirus (CMV) reactivation and fungal infection (FI) development in allo-SCT with reduced intensity conditioning (RIC).MATERIALS AND METHODS: We included paired recipient-donor samples from 247 RIC allo-SCT for patients diagnosed of AML (35%), NHL (21%), MDS (16%), MM (10%), CLL (7%), HL (6%), or others (5%) in four centers in Spain. Flu-Bu conditioning was used in 55% of the transplants while Flu-Mel in 42%. A total of 52 SNP were analyzed from 44 different gene loci and genotyping was carried out by Sequenom Mass ARRAY platform. Allele frequencies were estimated by direct counting and compared between groups using Fisher's test. P-value <0.05 was considered to be statistically significant. Log-rank analysis was used to compare differences between survival curves.RESULTS: Patient's characteristics are shown in Table 1. The median follow up for patients was 28 months (1-175), overall survival at 5 years was 45%, while the event-free survival at 5 years was 57%. Cumulative incidence of CMV reactivation at 3 years was 34% and of FI 11%. Transplant related mortality was 17%, and infection related mortality 14%.In univariate analysis, patients with genotype A/A in rs3093023 (CCR6) showed a lower incidence of CMV reactivation (table 2), along with acute GVHD were the variables associated in multivariate analysis.Regarding to FI, recipient genotype A/A in rs1494555 (IL7R), donor C/C in rs1800795 (FAS), and donor G/G in rs2302217 (MAdCAM-1) were associated with higher FI incidence (table 2), being the only variables related in multivariate analysis.CONCLUSION: This data suggest an association between rs3093023 (CCR6), rs1494555 (IL7R), rs1800795 (FAS) and rs2302217 (MAdCAM-1) polymorphisms with higher incidence of post-allo-SCT opportunist infection. Confirmation in larger series is required.FUNDING: RD12/0036/0069, CB16/12/00233 and 00480, PI12/02361 and ERDF, Innocampus; CEI-2010- 1-0010 [Display omitted] DisclosuresNo relevant conflicts of interest to declare.