Recipient Genotype Research Articles

Weight, CYP3A5 Genotype, and Voriconazole Co-administration Influence Tacrolimus Initial Dosage in Pediatric Lung Transplantation Recipients with Low Hematocrit based on a Simulation Model.

The method of administering the initial doses of tacrolimus in recipients of pediatric lung transplantation, especially in patients with low hematocrit, is not clear. The present study aims to explore whether weight, CYP3A5 genotype, and voriconazole co-administration influence tacrolimus initial dosage in recipients of pediatric lung transplantation with low hematocrit based on safety and efficacy using a simulation model. The present study utilized the tacrolimus population pharmacokinetic model, which was employed in lung transplantation recipients with low hematocrit. For pediatric lung transplantation recipients not carrying CYP3A5*1 and without voriconazole, the recommended tacrolimus doses for weights of 10-13, 13-19, 19-22, 22-35, 35-38, and 38-40 kg are 0.03, 0.04, 0.05, 0.06, 0.07, and 0.08 mg/kg/day, which are split into two doses, respectively. For pediatric lung transplantation recipients carrying CYP3A5*1 and without voriconazole, the recommended tacrolimus doses for weights of 10-18, 18-30, and 30-40 kg are 0.06, 0.08, 0.11 mg/kg/day, which are split into two doses, respectively. For pediatric lung transplantation recipients not carrying CYP3A5*1 and with voriconazole, the recommended tacrolimus doses for weights of 10-20 and 20-40 kg are 0.02 and 0.03 mg/kg/day, which are split into two doses, respectively. For pediatric lung transplantation recipients carrying CYP3A5*1 and with voriconazole, the recommended tacrolimus doses for weights of 10-20, 20-33, and 33-40 kg are 0.03, 0.04, and 0.05 mg/kg/day, which are split into two doses, respectively. The present study is the first to recommend the initial dosages of tacrolimus in recipients of pediatric lung transplantation with low hematocrit using a simulation model.

LIM Zinc Finger Domain Containing 1 Risk Genotype of Recipient Is Associated with Renal Tubular Inflammation in Kidney Transplantation.

Homozygosity for LIMS1 rs893403-GG genotype is linked to an increased risk of allograft rejection after kidney transplantation. Ischemia-reperfusion of the kidney allograft leads to long term infiltration of activated and effector-memory T lymphocytes and resulting in rejection and long-term fibrosis. However, the genotype, LIMS1 expression under ischemic conditions and the long-term histopathological relationships remain ill-defined. We examined the impact of the recipient's LIMS1-rs893403 genotype with transplant kidney histopathology. The association of the LIMS1-rs893403 genotype and LIMS1 and GCC2 mRNA expression in ischemic donor kidneys were also examined. Recipients who underwent transplant kidney biopsy were genotyped for the LIMS1-rs893403 variant and associated deletion. Histopathological findings were compared between recipients with LIMS1 risk and non-risk genotypes. Real-time PCR and immunofluorescence staining for LIMS1 and GCC2 expression were performed in non-utilized donor kidneys. Demographic, clinical, and treatment characteristics and the histopathological diagnosis were similar between recipients with rs893403 GG and AA/AG genotype. The Banff tubulitis score was higher in GG recipients (n = 24) compared to AA/AG (n = 86) recipients (1.42 ± 0.65 vs. 1.12 ± 0.66, p = 0.03). Ischemic kidneys with GG showed higher LIMS1 and GCC2 mRNA expression than kidneys with AG. Kidneys with rs893403-GG had higher tubular LIMS1 and GCC2 immunohistochemical staining compared to kidneys with rs893403-AG. Our data supports the role of the LIMS1 locus in kidney transplant rejection, particularly in lymphocyte infiltration into the internal aspect of the tubular basement membranes. Increased LIMS1 and GCC2 expression in ischemic donor kidneys with the GG genotype require further studies.

Multi-centre analytical performance verification of an IVD assay to quantify donor-derived cell-free DNA in solid organ transplant recipients.

Donor-derived cell-free DNA (dd-cfDNA) has been widely studied as biomarker for non-invasive allograft rejection monitoring. Earlier rejection detection enables more prompt diagnosis and intervention, ultimately improving patient treatment and outcomes. This multi-centre study aims to verify analytical performance of a next-generation sequencing-based dd-cfDNA assay at end-user environments. Three independent laboratories received the same experimental design and 16 blinded samples to perform cfDNA extraction and the dd-cfDNA assay workflow. dd-cfDNA results were compared between sites and against manufacturer validation to evaluate concordance, reproducibility, repeatability and verify analytical performance. A total of 247 sample libraries were generated across 18 runs, with completion time of <24 h. A 96.0% first pass rate highlighted minimal failures. Overall observed versus expected dd-cfDNA results demonstrated good concordance and a strong positive correlation with linear least squares regression r2 = 0.9989, and high repeatability and reproducibility within and between sites, respectively (p > 0.05). Manufacturer validation established limit of blank 0.18%, limit of detection 0.23% and limit of quantification 0.23%, and results from independent sites verified those limits. Parallel analyses illustrated no significant difference (p = 0.951) between dd-cfDNA results with or without recipient genotype. The dd-cfDNA assay evaluated here has been verified as a reliable method for efficient, reproducible dd-cfDNA quantification in plasma from solid organ transplant recipients without requiring genotyping. Implementation of onsite dd-cfDNA testing at clinical laboratories could facilitate earlier detection of allograft injury, bearing great potential for patient care.

Impact of KIR-HLA Genotype on Natural-Killer-Cell-Based Immunotherapy for Preventing Hepatocellular Carcinoma after Living-Donor Liver Transplantation

Natural killer (NK) cells have immunosurveillance potential in hepatocellular carcinoma (HCC). We performed adaptive immunotherapy using donor-liver-derived natural killer (NK) cells after living-donor liver transplantation (LDLT) to prevent HCC recurrence. Dominant inhibitory signals tightly regulate NK cell activity via human leukocyte antigen (HLA)-specific inhibitory receptors, such as killer immunoglobulin-like receptors (KIRs). The functional recognition of HLA through KIR raises the NK cell capacity, which is a process termed “licensing.” Here, we investigated the effect of polymorphic KIR-HLA genotypes on the efficacy of NK-cell-based immunotherapy after LDLT. Seventy-seven Japanese recipients with HCC who underwent LDLT and their corresponding donors between 1996 and 2016 were enrolled in this study. The median follow-up period was 8.3 years. The HCC recurrence risk was stratified using radiological and pathological assessments according to the Milan criteria. Of the 77 recipients, 38 received immunotherapy. Immunotherapy improves early post-transplantation survival and lowers the recurrence rate in the intermediate-risk recipients. We analyzed the genotypes of five inhibitory KIRs and HLA using sequence-specific polymorphism-based typing. The polymorphic KIR-HLA genotype revealed that genetically vulnerable liver transplant recipients with a poorly licensed NK genotype have an improved prognosis by immunotherapy with donor-liver-derived NK cells. Thus, the combination of recipient and donor KIR-HLA genotypes is worthy of attention for further investigation, especially considering the clinical application of NK-cell-based immunotherapy.

Interaction between tacrolimus and calcium channel blockers based on CYP3A5 genotype in Chinese renal transplant recipients.

To investigate the effect of calcium channel blockers (CCBs) on tacrolimus blood concentrations in renal transplant recipients with different CYP3A5 genotypes. This retrospective cohort study included renal transplant recipients receiving tacrolimus-based immunosuppressive therapy with or without CCBs in combination. Patients were divided into combination and control groups based on whether or not they were combined with CCBs, and then further analyzed according to the type of CCBs (nifedipine/amlodipine/felodipine). Propensity score matching was conducted for the combination and the control groups using SPSS 22.0 software to reduce the impact of confounding factors. The effect of different CCBs on tacrolimus blood concentrations was evaluated, and subgroup analysis was performed according to the patients' CYP3A5 genotypes to explore the role of CYP3A5 genotypes in drug-drug interactions between tacrolimus and CCBs. A total of 164 patients combined with CCBs were included in the combination groups. After propensity score matching, 83 patients with nifedipine were matched 1:1 with the control group, 63 patients with felodipine were matched 1:2 with 126 controls, and 18 patients with amlodipine were matched 1:3 with 54 controls. Compared with the controls, the three CCBs increased the dose-adjusted trough concentration (C0/D) levels of tacrolimus by 41.61%-45.57% (P < 0.001). For both CYP3A5 expressers (CYP3A5*1*1 or CYP3A5*1*3) and non-expressers (CYP3A5*3*3), there were significant differences in tacrolimus C0/D between patients using felodipine/nifedipine and those without CCBs (P < 0.001). However, among CYP3A5 non-expressers, C0/D values of tacrolimus were significantly higher in patients combined with amlodipine compared to the controls (P = 0.001), while for CYP3A5 expressers, the difference in tacrolimus C0/D values between patients with amlodipine and without was not statistically significant (P = 0.065). CCBs (felodipine/nifedipine/amlodipine) can affect tacrolimus blood concentration levels by inhibiting its metabolism. The CYP3A5 genotype may play a role in the drug interaction between tacrolimus and amlodipine. Therefore, genetic testing for tacrolimus and therapeutic drug monitoring are needed when renal transplant recipients are concurrently using CCBs.

The effects of human umbilical cord-derived multipotent mesenchymal stromal cells transplantation in mice of different strains with an experimental model of parkinsonism

One of the promising directions in cell therapy for Parkinson's disease or parkinsonism is the transplantation of multipotent mesenchymal stromal cells from various sources, including human umbilical cord (hUC-MMSCs), the effectiveness of which may depend on the recipient's genotype. Objective. To compare the impact of transplanted MMSC-P on behavior, T-lymphocytes, and macrophages in the brain and lymphoid organs of mice from different lines with a toxic model of parkinsonism. Materials and methods. Adult (6-7 months old) male mice of FVB/N (genotype H-2q) and 129/Sv (genotype H-2b) strains were administered the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) at a dose of 30 mg/kg (control group), and after 7 days, hUC-MMSCs (500,000 cells) were transplanted into the tail vein. Behavioral reactions were assessed in open field, rigidity, and rotarod tests. The relative content of T-lymphocytes and activated macrophages in the brain was measured by flow cytometry, and the mass of lymphoid organs was determined. Results. Under the influence of MPTP, the number of rearings, "sniffs into the nest," body length, and step length decreased, the number of boluses increased in FVB/N and 129/Sv mice, and the number of squares crossed in the open field test decreased in 129/Sv mice. In the brain of mice from both lines, the content of activated macrophages increased, and in FVB/N mice, the number of T-lymphocytes also increased. The thymus mass decreased in mice from both lines, while the spleen mass decreased only in 129/Sv mice. The transplantation of hUC-MMSCs improved predominantly motor activity in FVB/N mice, while in 129/Sv mice, emotional activity improved, and manifestations of rigidity decreased in mice from both lines. The content of T-lymphocytes and activated macrophages in the brain of mice from both lines, as well as the thymus mass, corresponded to the values of intact animals. MMSC transplantation promoted the survival of FVB/N and 129/Sv mice with the MPTP-induced parkinsonism model. Conclusions. The manifestations of behavioral disorders, changes in the content of T-lymphocytes and activated macrophages in the brain, and the mass of lymphoid organs in mice with the MPTP-induced parkinsonism model, as well as the positive effects of transplanted hUC-MMSCs in these animals, largely depend on their genotype according to the H-2 system (analogous to the HLA system in humans). The results may provide a basis for developing personalized cell therapy for this pathology using multipotent mesenchymal stromal cells.

Development of a predictive nomogram for switching immunosuppressive drugs in pediatric liver transplant recipients

BackgroundTacrolimus (TAC) is the preferred calcineurin inhibitor (CNI) for pediatric liver transplant recipients. However, some recipients may not achieve the desired therapeutic window concentration of TAC, leading to poor prognosis. This study aimed to develop a clinical model that can predict the effectiveness of TAC in pediatric liver transplant recipients and help clinicians quickly identify cyclosporin as an alternative.MethodsWe retrospectively analyzed data from 2,032 pediatric liver transplant recipients who underwent surgery at Renji Hospital, Shanghai Jiaotong University School of Medicine between 2006 and 2019. Demographic, comorbidity and pre-operative laboratory data were collected, and a nomogram was constructed using multivariate logistic regression analysis to estimate the risk of poor therapeutic outcomes for TAC-based immunosuppression.ResultsThe constructed nomogram included seven parameters, namely recipient CYP3A4 genotype, pre-transplant cholangitis, GRWR, spleen long diameter, serum albumin, graft volume reduction, and donor CYP genotype. The nomogram showed good discriminative ability with an area under the receiver operating characteristic curve (AUC) of 74.5% and good calibration. Decision curve analysis indicated a high potential clinical application of the model.ConclusionThis simple clinical model effectively predicts the risk of poor therapeutic outcomes in pediatric liver transplant recipients who receive TAC-based immunosuppression. Clinicians can use the model to identify cyclosporin as an alternative quickly, potentially improving patient prognosis.

Robust segregation of donor and recipient cells from single-cell RNA-sequencing of transplant samples.

Single-cell RNA-sequencing (scRNA-seq) technology has revealed novel cell populations in organs, uncovered regulatory relationships between genes, and allowed for tracking of cell lineage trajectory during development. It demonstrates promise as a method to better understand transplant biology; however, fundamental bioinformatic tools for its use in the context of transplantation have not been developed. One major need has been a robust method to identify cells as being either donor or recipient genotype origin, and ideally without the need to separately sequence the donor and recipient. We implemented a novel two-stage genotype discovery method (scTx) optimized for transplant samples by being robust to disparities in cell number and cell type. Using both in silico and real-world scRNA-seq transplant data, we benchmarked our method against existing demultiplexing methods to profile their limitations in terms of sequencing depth, donor and recipient cell imbalance, and single nucleotide variant input selection. Using in silico data, scTx could more accurately separate donor from recipient cells and at much lower genotype ratios than existing methods. This was further validated using solid-organ scRNA-seq data where scTx could more reliably identify when a second genotype was present and at lower numbers of cells from a second genotype. scTx introduces the capability to accurately segregate donor and recipient gene expression at the single-cell level from scRNA-seq data without the need to separately genotype the donor and recipient. This will facilitate the use of scRNA-seq in the context of transplantation.

Multidrug resistant 1 (MDR1) C3435T and G2677T gene polymorphism: impact on the risk of acute rejection in pediatric kidney transplant recipients

BackgroundTacrolimus is the backbone drug in kidney transplantation. Single nucleotide polymorphism of Multidrug resistant 1 gene can affect tacrolimus metabolism consequently it can affect tacrolimus trough level and incidence of acute rejection. The aim of this study is to investigate the impact of Multidrug resistant 1 gene, C3435T and G2677T Single nucleotide polymorphisms on tacrolimus pharmacokinetics and on the risk of acute rejection in pediatric kidney transplant recipients.MethodsTyping of Multidrug resistant 1 gene, C3435T and G2677T gene polymorphism was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for 83 pediatric kidney transplant recipients and 80 matched healthy controls.ResultsIn Multidrug resistant 1 gene (C3435T), CC, CT genotypes and C allele were significantly associated with risk of acute rejection when compared to none acute rejection group (P = 0.008, 0.001 and 0.01 respectively). The required tacrolimus doses to achieve trough level were significantly higher among CC than CT than TT genotypes through the 1st 6 months after kidney transplantation. While, in Multidrug resistant 1 gene (G2677T), GT, TT genotypes and T allele were associated with acute rejection when compared to none acute rejection (P = 0.023, 0.033 and 0.028 respectively). The required tacrolimus doses to achieve trough level were significantly higher among TT than GT than GG genotypes through the 1st 6 months after kidney transplantation.ConclusionThe C allele, CC and CT genotypes of Multidrug resistant 1 gene (C3435T) and the T allele, GT and TT genotypes of Multidrug resistant 1 gene (G2677T) gene polymorphism may be risk factors for acute rejection and this can be attributed to their effect on tacrolimus pharmacokinetics. Tacrolimus therapy may be tailored according to the recipient genotype for better outcome.

Intestinal Bacteremia After Liver Transplantation is a Risk Factor for Recurrence of Primary Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic progressive pathological process, related to inflammatory bowel disease and subsequent bacterial translocation. Liver transplantation (LT) is the only curative therapy, but outcomes are compromised by recurrence of PSC (rPSC). The aim of the study was to investigate a potential link between intestinal bacteremia, fucosyltransferase-2 (FUT2), and rPSC after LT. LT recipients with PSC (n = 81) or without PSC (n = 271) were analyzed for clinical outcomes and positive bacterial blood cultures. A link between bacteremia and the genetic variant of the FUT2 gene was investigated. The incidence of inflammatory bowel disease was significantly higher in PSC recipients but not associated with rPSC. Bacteremia occurred in 31% of PSC recipients. The incidence of rPSC was 37% and was significantly more common in patients with intestinal bacteremia versus no bacteremia (82% versus 30%; P = 0.003). The nonsecretor polymorphism of the FUT2 gene was identified as a genetic risk factor for both intestinal bacteremia and rPSC. Combined FUT2 genotype and intestinal bacteremia in recipients resulted in the highest risk for rPSC (hazard ratio, 15.3; P < 0.001). Thus, in this article, we showed that bacterial translocation is associated with rPSC after LT and related to the FUT2 nonsecretor status.

Evaluation of limited-sampling strategies to calculate AUC(0-24) and the role of CYP3A5 in Chilean pediatric kidney recipients using extended-release tacrolimus.

Background: Kidney transplantation (KTx) requires immunosuppressive drugs such as Tacrolimus (TAC) which is mainly metabolized by CYP3A5. TAC is routinely monitored by trough levels (C0) although it has not shown to be a reliable marker. The area-under-curve (AUC) is a more realistic measure of drug exposure, but sampling is challenging in pediatric patients. Limited-sampling strategies (LSS) have been developed to estimate AUC. Herein, we aimed to determine AUC(0-24) and CYP3A5 genotype in Chilean pediatric kidney recipients using extended-release TAC, to evaluate different LSS-AUC(0-24) formulas and dose requirements. Patients and methods: We analyzed pediatric kidney recipients using different extended-release TAC brands to determine their trapezoidal AUC(0-24) and CYP3A5 genotypes (SNP rs776746). Daily TAC dose (TAC-D mg/kg) and AUC(0-24) normalized by dose were compared between CYP3A5 expressors (*1/*1 and *1/*3) and non-expressors (*3/*3). We evaluated the single and combined time-points to identify the best LSS-AUC(0-24) model. We compared the performance of this model with two pediatric LSS-AUC(0-24) equations for clinical validation. Results: Fifty-one pharmacokinetic profiles were obtained from kidney recipients (age 13.1 ± 2.9years). When normalizing AUC(0-24) by TAC-D significant differences were found between CYP3A5 expressors and non-expressors (1701.9 vs. 2718.1ng*h/mL/mg/kg, p < 0.05). C0 had a poor fit with AUC(0-24) (r 2 = 0.5011). The model which included C0, C1 and C4, showed the best performance to predict LSS-AUC(0-24) (r 2 = 0.8765) and yielded the lowest precision error (7.1% ± 6.4%) with the lowest fraction (9.8%) of deviated AUC(0-24), in comparison to other LSS equations. Conclusion: Estimation of LSS-AUC(0-24) with 3 time-points is an advisable and clinically useful option for pediatric kidney recipients using extended-release TAC to provide better guidance of decisions if toxicity or drug inefficacy is suspected. The different CYP3A5 genotypes associated with variable dose requirements reinforce considering genotyping before KTx. Further multi-centric studies with admixed cohorts are needed to determine the short- and long-term clinical benefits.

An Optimized Search Prognosis Tool to Predict 8/8 HLA Allele-Matched Unrelated Donor Procurement

For patients in need of allogeneic transplantation who lack an HLA-identical sibling, an 8/8 HLA allele-matched unrelated donor (URD) is a standard alternative. However, delays in URD procurement can adversely impact patient care. Recipient genotype and search assessment (MSKv1.0)-based tools can predict search prognosis for many, but both tools have lower performance in non-European ancestry patients. Using the MSKv1.0 tool, we analyzed searches from 1530 potential allograft recipients (including 863 who underwent transplantation) with the aim of creating an optimized MSKv2.0 search prognosis tool that can classify a URD search as either Good or Poor with a high level of accuracy while also limiting an ambiguous Fair search prognosis regardless of patient ancestry. By MSKv2.0, the 8/8 URD search prognosis distribution was 57% Good, 21% Fair, and 22% Poor in Europeans and 15% Good, 21% Fair, and 63% Poor in non-Europeans. Importantly, compared to MSKv1.0, the likelihood of Fair categorization was reduced to <25% with comparable Fair rates (P=.847) in both European and non-European groups. Moreover, all patients with an MSKv2.0 Good prognosis had an 8/8 URD identified, and almost all of those who underwent transplantation had an 8/8 URD (Europeans, 99%; non-Europeans, 98%; P=.504). The MSKv2.0 tool also was highly accurate at classifying Poor searches, with <10% identifying an 8/8 URD, and almost all patients who underwent transplantation (Europeans, 95%; non-Europeans, 96%) receiving an alternative donor. Using preliminary search results, MSKv2.0 accurately classifies patients by likelihood of 8/8 URD procurement, greatly facilitating triage to 8/8 URD (Good prognosis) or alternative donor (Poor prognosis) transplantations.

Frailty and genetic risk predict fracture after lung transplantation.

Fractures negatively impact quality of life and survival. We hypothesized that recipient frailty score and genetic profile measured before transplant would predict risk of fracture after lung transplant. We conducted a retrospective cohort study of bone mineral density (BMD) and fracture among lung transplant recipients at a single center. The association between predictors and outcomes were assessed by multivariable time-dependent Cox models or regression analysis. Among the 284 participants, osteoporosis and fracture were highly prevalent. Approximately 59% of participants had posttransplant osteopenia, and 35% of participants developed at least 1 fracture. Low BMD was associated with a polygenic osteoporosis risk score, and the interaction between genetic score and BMD predicted fracture. Pretransplant frailty was associated with risk for spine and hip fracture, which were not associated with chronic lung allograft dysfunction or death. Chest fractures were the most frequent type of fracture and conferred a 2.2-fold increased risk of chronic lung allograft dysfunction or death (time-dependent P < .001). Pneumonia, pleural effusions, and acute rejection frequently occurred surrounding chest fracture. Pretransplant frailty and recipient genotype may aid clinical risk stratification for fracture after transplant. Fracture carries significant morbidity, underscoring the importance of surveillance and osteoporosis prevention.

Donor and recipient human leukocyte antigen-G polymorphisms modulate the risk of adverse immunologic events following lung transplantation

The long-term benefits of lung transplantation (LTx) are limited by pathogenic alloimmune responses that drive injury, inflammation, and chronic dysfunction. Human leukocyte antigen-G (HLA-G) plays a key role in the modulation of these pathways. This study assesses the impact of the HLA-G genotype on immunologic risk and survival following LTx.This retrospective cohort study included 289 bilateral LTx. Recipient and donor HLA-G genotypes were analyzed to identify associations with de novo donor-specific antibodies, acute rejection, chronic lung allograft dysfunction, and allograft survival. We further assessed these associations, both individually and in paired analysis, based on a grouped haplotype classification of HLA-G expression.Donor HLA-G single nucleotide polymorphisms were associated with allograft injury, the onset of chronic lung allograft dysfunction following injury, and allograft survival. Recipient HLA-G single nucleotide polymorphisms were associated with allograft injury, cellular rejection, and donor-specific antibody formation. “Low HLA-G expression” donor haplotypes were associated with impaired allograft survival, as were “low HLA-G expression” donor-recipient haplotype pairs.This study provides compelling evidence for the role of HLA-G in modulating immunologic risk after LTx. Our results highlight the importance of both donor and recipient HLA-G genotypes on the overall risk profile and underscore the lasting influence of donor genotype on lung transplant outcomes.

Genotype-guided model significantly improves accuracy of tacrolimus initial dosing after liver transplantation.

The initial dose of tacrolimus after liver transplantation (LT) is critical for rapidly achieving the steady state of the drug concentration, minimizing the potential adverse reactions and warranting long-term patient prognosis. We aimed to develop and validate a genotype-guided model for determining personalized initial dose of tacrolimus. By combining pharmacokinetic modeling, pharmacogenomic analysis and multiple statistical methods, we developed a genotype-guided model to predict individualized tacrolimus initial dose after LT in the discovery (n=150) and validation cohorts (n=97) respectively. This model was further validated in a prospective, randomized and single-blind clinical trial from August, 2021 to February, 2022 (n=40, ChiCTR2100050288). Our model included donor's and recipient's genotypes, recipient's weight and total bilirubin, which achieved an area under the curve of receiver operating characteristic curve (AUC of ROC) of 0.88 and 0.79 in the discovery and validation cohorts, respectively. We found that patients who were given tacrolimus within the recommended concentration range (RCR) (4-10ng/mL), the new-onset metabolic syndromes are lower, especially for new-onset diabetes (p=0.043). In the clinical trial, compared to those in experience-based (EB) group, patients in the model-based (MB) group were more likely to achieving the RCR (75% vs 40%, p=0.025) with a more variable individualized dose (0.023-0.096mg/kg/day vs 0.045-0.057mg/kg/day). Moreover, significantly fewer medication adjustments were required for the MB group than the EB group (2.75±2.01 vs 6.05±3.35, p=0.001). Our genotype-based model significantly improved the initial dosing accuracy of tacrolimus and reduced the number of medication adjustments, which are critical for improving the prognosis of LT patients. National Natural Science Foundation of China, Shanghai three-year action plan, National Science and Technology Major Project of China.

Selecting the Best Transplant Donor (HLA-Matched vs. Haploidentical) for Patients with Lymphoid Malignancy Based on Recipient HLA-B-Leader Genotype

Choosing the best donor type for allogeneic transplant (HLA-matched related (MRD) or unrelated (MUD) vs. haploidentical (HAPLO)) is typically based on the timely availability of an HLA-matched donor. There is currently no role for either patient or disease characteristics to facilitate this decision. In the context of HAPLO transplant, our group has previously demonstrated that an M+ recipient HLA-B-leader genotype (either M/T or M/M) is associated with reduced relapse risk and superior survival in patients with lymphoid, but not myeloid, malignancies (Solomon et al. TCT journal 2022). Based on this finding, we hypothesized that recipient HLA-B-leader genotype may be important in donor selection. To this end, we analyzed 352 patients with lymphoid malignancies (ALL[ 166], NHL [111], HL [39] and CLL [36]) receiving a first allogeneic transplant from an MRD [110], MUD [104] or HAPLO [138] donor. GVHD prophylaxis was PTCy-based in all HAPLO recipients, in contrast to MRD and MUD recipients who received conventional prophylaxis with calcineurin inhibitor + methotrexate. M+ or M- (T/T) genotype was seen in 165 (47%) and 187 (53%) respectively. Compared to MUD and MRD, HAPLO recipients tended to be younger (median 46 vs. 49 and 51 years respectively) and less likely to be non-Hispanic white (46% vs. 90% and 71% respectively). There were no differences in baseline characteristics between patients with M+ and M- B-leader genotype. Overall, MRD, MUD and HAPLO recipients had similar overall survival (OS, see figure). In HAPLO recipients, those with an M+ HLA-B-leader demonstrated improved 5-yr OS and DFS when compared to M- recipients (81% vs. 49%, p<0.001 and 70% vs. 42%, p=0.001, respectively), due to decreased relapse risk (18% vs. 48%, p=0.002). In multivariable analysis (MVA), controlling for other relevant variables (e.g. age, race, DRI, conditioning intensity, transplant year), M+ HAPLO transplant recipients had decreased relapsed risk (HR 0.27, p<0.001) leading to improved DFS (HR 0.34, p<0.001) and OS (HR 0.28, p<0.001). In contrast, relapse and DFS did not significantly differ according to recipient HLA-B-leader genotype in MRD or MUD recipients in either univariate or MVA. We then analyzed differences in transplant outcome according to donor type (HAPLO vs. MRD/MUD) and recipient HLA-B-leader genotype (M+ vs. M-). In univariate analysis, M+ HAPLO recipients had superior 5-yr OS and DFS when compared to M+ MRD/MUD recipients (81% vs. 52%, p=0.002 and 70% vs. 47%, p=0.008, respectively). In contrast, M- HAPLO recipients demonstrated inferior 5-yr OS and DFS when compared to M- MRD/MUD recipients (49% vs. 67%, p=0.005 and 42% vs. 57%, p=0.022, respectively) (see figure). This result was confirmed in MVA where M- HAPLO recipients demonstrated inferior OS and DFS compared to M- MRD/MUD recipients (HR 2.83, p<0.001 and HR 2.06, p=0.003 respectively). Conversely, M+ HAPLO recipients showed superior OS and DFS (HR 0.54, p=0.045 and HR 0.57, p=0.036 respectively). In summary, recipient HLA-B-leader genotype predicts relapse risk and survival following PTCy-based HAPLO transplant for lymphoid malignancy, but not MRD/MUD transplant utilizing conventional GVHD prophylaxis. As a result, recipient HLA-B-leader genotype can help guide optimal donor selection for patients with lymphoid malignancies with preference for MRD/MUD or HAPLO donor in the context of recipient M- or M+ HLA-B-leader genotype, respectively. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Recipient maternal genotypes improved the litter size components of a paternal line involved in a MOET programme in rabbits

An essential factor in the success of multiple ovulation and embryo transfer programmes (MOET) in any species is the selection of the recipient females. In rabbit there is a notable lack of studies on the effects of recipient genotype on postnatal growth. The aim of this study was to evaluate the effects of recipient maternal genotypes on litter size components within a MOET programme applied to a commercial paternal line that appears to have exhausted its selection programme after 37 generations. The experiment was designed using 13 nulliparous donors from the R line (paternal line) to produce 453 embryos, which were transferred to two recipient maternal genotypes (A and V lines) and the own donor paternal line (R line). Litter size components and pre-and postnatal body mass of kits were evaluated. The differences between the genetic groups of recipients were estimated using a general linear model applying Bayesian analysis. The results showed that maternal lines have a high capacity to implant the embryos, maintain the pregnancy and present a favourable environment for embryo development compared to the R line. Specifically, A line dams showed the highest prenatal survival, total born and number born alive without effects on growth traits. The present study demonstrated the applicability of a MOET programme based on maternal ability recipients to improve the number of kits per cycle. Therefore, to allow the genetic improvement programme of meat rabbits to continue using the R line, we recommended applying for a MOET programme as a routine procedure. HIGHLIGHTS MOET programme based on maternal ability recipients enhanced the number of kits per cycle. The MOET programme could be a routine procedure to favour the selection of paternal lines by increasing selection pressure.

Posttransplant Complications and Genetic Loci Involved in Telomere Maintenance in Heart Transplant Patients.

Reaching critically short telomeres induces cellular senescence and ultimately cell death. Cellular senescence contributes to the loss of tissue function. We aimed to determine the association between variants within genes involved in telomere length maintenance, posttransplant events, and aortic telomere length in heart transplant patients. DNA was isolated from paired aortic samples of 383 heart recipients (age 50.7 ± 11.9 years) and corresponding donors (age 38.7 ± 12.0 years). Variants within the TERC (rs12696304), TERF2IP (rs3784929 and rs8053257), and OBCF1 (rs4387287) genes were genotyped, and telomere length was measured using qPCR. We identified similar frequencies of genotypes in heart donors and recipients. Antibody-mediated rejection (AMR) was more common (p < 0.05) in carriers of at least one G allele within the TERF2IP locus (rs3784929). Chronic graft dysfunction (CGD) was associated with the TERC (rs12696304) GG donor genotype (p = 0.05). The genetic risk score did not determine posttransplant complication risk prediction. No associations between the analyzed polymorphisms and telomere length were detected in either donor or recipient DNA. In conclusion, possible associations between donor TERF2IP (rs3784929) and AMR and between TERC (rs12696304) and CGD were found. SNPs within the examined genes were not associated with telomere length in transplanted patients.

Donor-derived urologic cancers after renal transplantation: A retrospective non-randomized scientific analysis.

BackgroundMalignancies in the urinary tract and the kidney graft are quite common after kidney transplantation. In some selected cases tumours develop from donor-derived tissue.ObjectivesWe hypothesised that there is a clinical value to investigate donor/recipient origin in urologic malignancies in renal transplant recipients.MethodsIn this retrospective study, including patients transplanted between the years 1969 and 2014 at Uppsala University Hospital, Sweden, 11 patients with malignancies in urinary tract and 4 patients with malignancies in kidney transplants were investigated. Donor/recipient origin of tumour tissue was analysed by polymerase chain reaction (PCR) of human leucocyte antigen (HLA) genotypes or by fluorescence in situ hybridization (FISH analysis) of sex chromosomes. HLA genotype and sex chromosomes of the tumour were compared to the known HLA genotype and sex chromosomes of recipient and donor.ResultsThree of ten cancers in the urinary tract and three of four cancers in the kidney transplants were donor-derived.ConclusionsWe suggest that urologic malignancies in renal transplant recipients can be investigated for transplant origin. In addition to conventional therapy the allograft immune response against these tumours can be valuable to treat donor-derived cancers.

POS-075 ASSOCIATION OF CYP3A5 POLYMORPHISM WITH INFECTIONS IN KIDNEY TRANSPLANT RECIPIENTS

Kidney transplant recipients who are non-expressors (CYP3A5*3/*3 genotype) are known to have increased dose-adjusted trough concentrations of tacrolimus as compared with those who are CYP3A5 expressors (CYP3A5*1/*1 and CYP3A5*1/*3 genotypes), possibly delaying achievement of target concentrations. Also, tacrolimus increases the exposure of mycophenolate mofetil by 30%. Both these factors in patients who are non-expressors can increase the risk of infections. However, there is lack of data corelating CYP3A5 polymorphism with infections post-kidney transplant. We retrospectively evaluated 181 out of 260 kidney transplant recipients who were at regular follow up at the transplant clinic of a tertiary referral center in western India from 2018 to 2021. Recipients on tacrolimus for at least 3 months post-transplant were eligible for evaluation. They were categorized into non-expressors (CYP3A5*3/*3) and expressors (CYP3A5*1/*1 and CYP3A5*1/*3 genotype). The infectious burden was evaluated by the incidence of total infections and further classified according to etiologies such as bacterial, viral, parasitic, fungal and mycobacterial and specific system patterns such as diarrhea, urinary tract infections, tropical illnesses, infections of the skin, soft tissue and musculoskeletal system. The incidence of non-infectious diarrhea was evaluated as a measure of increased MMF exposure. Multivariate logistic regression was performed to evaluate the impact of genotype on the risk of infections. Out of 181 recipients, 103 (56.9%) were non-expressors and 78 (43%) were expressors. Mean (SD) age was 35±10 years with 128 (70.7%) being males. Their mean (SD) eGFR at enrollment was 57.72± 23.15 ml/min/1.73m2. Higher number of non-expressors received antibody induction at the time of transplant but this difference was not statistically significant (52.4% vs 42.3%, p= 0.177). New onset diabetes after transplant observed in the non-expressor group was higher, but did not reach statistical significance (37.2% vs 29.1%, p= 0.252). Overall incidence of infections was similar in both groups (85.4% vs 89.7%, p = 0.389), however tuberculosis was significantly more common in non-expressors (16.7 % vs 6.8%, p= 0.036). This association remained significant (p= 0.043) after controlling for factors such as history of tuberculosis before transplant, antibody induction, living vs deceased donor, triple or dual immunosuppression at time of transplant, and anti-rejection therapy. Infectious diarrhea, fungal infections, parasitic infections, were higher in non-expressors, but this difference was not statistically significant. Hospitalization for infectious diarrhea was significantly higher in non-expressors (20.5% vs 7.8%, p= 0.012). Non-infectious diarrhea attributed to MMF was significantly higher in non-expressors (32.1% vs 19.2%, p= 0.035). Viral infections were higher in non-expressors but were statistically insignificant (51.3% vs 40.8%, p= 0.160). Mortality due to infectious causes was higher in non-expressors but was not statistically significant (6.4% vs 3.9%, p= 0.439). Non-expressor CYP3A5 genotype in kidney transplant recipients is associated with a significant burden of infectious complications and a higher incidence of MMF induced diarrhea. A genotype-based approach may help individualizing dosing of tacrolimus in this population.