Project description:Targeted metabolomics performed by GC-MS (for SCFAs by PFBBr derivatization) and LC-MS (for bile acids) on fecal samples from liver transplant patients.
Project description:Sapovirus are important agents of acute gastroenteritis (AGE) and they are associated with outbreaks and sporadic cases worldwide. They infect people of all ages, but mainly children, the elderly and immunocompromised individuals are affected. The aim of this study was investigate sapovirus and to determine viral loads in fecal samples from patient undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Fecal samples were submitted to extraction of the genetic material using a commercial kit, and RT-qPCR TaqMan was used for sapovirus screening and determination of viral loads, using a standard curve with serial dilutions of a recombinant plasmid. Positive samples were sequence by Sanger method. Sapovirus was detected in one patient, 5.3% (1/19). Viral excretion lasted for 16 days. Viral load varied from 1.73 × 106 to 8.97 × 106 GC/g. One of the positive samples was characterized as GI.1 genotype. This is the first study to determine sapovirus loads in samples from allo-HSCT and to identify GI.1 genotype in immunocompromised patients.
Project description:Noninvasive biomarkers of kidney allograft status can help minimize the need for standard of care kidney allograft biopsies. Metabolites that are measured in the urine may inform about kidney function and health status, and potentially identify rejection events. To test these hypotheses, we conducted a metabolomics study of biopsy-matched urine cell-free supernatants from kidney allograft recipients who were diagnosed with two major types of acute rejections and no-rejection controls. Non-targeted metabolomics data for 674 metabolites and 577 unidentified molecules, for 192 biopsy-matched urine samples, were analyzed. Univariate and multivariate analyses identified metabolite signatures for kidney allograft rejection. The replicability of a previously developed urine metabolite signature was examined. Our study showed that metabolite profiles can serve as biomarkers for discriminating rejection biopsies from biopsies without rejection features, but also revealed a role of estimated Glomerular Filtration Rate (eGFR) as a major confounder of the metabolite signal.
Project description:BackgroundWe performed a study to identify differences in the urinary microbiome associated with chronic allograft dysfunction (CAD) and compared the urinary microbiome of male and female transplant recipients with CAD.MethodsThis case-control study enrolled 67 patients within the Deterioration of Kidney Allograft Function (DeKAF) Genomics cohort at two transplant centers. CAD was defined as a greater than 25% rise in serum creatinine relative to a 3 month post-transplant baseline. Urine samples from patients with and without CAD were analyzed using 16S V4 bacterial ribosomal DNA sequences.ResultsCorynebacterium was more prevalent in female and male patients with CAD compared to non-CAD female patients (P = 0.0005). A total 21 distinct Operational Taxonomic Unit (OTUs) were identified as significantly different when comparing CAD and non-CAD patients using Kruskal-Wallis (P < 0.01). A subset analysis of female patients with CAD compared to non-CAD females identified similar differentially abundant OTUs, including the genera Corynebacterium and Staphylococcus (Kruskal-Wallis; P = 0.01; P = 0.004, respectively). Male CAD vs female CAD analysis showed greater abundance of phylum Proteobacteria in males.ConclusionThere were differences in the urinary microbiome when comparing female and male CAD patients with their female non-CAD counterparts and these differences persisted in the subset analysis limited to female patients only.
Project description:Early prediction of kidney graft function may assist clinical management, and for this, reliable non-invasive biomarkers are needed. We evaluated endotrophin (ETP), a novel non-invasive biomarker of collagen type VI formation, as a prognostic marker in kidney transplant recipients. ETP levels were measured with the PRO-C6 ELISA in the plasma (P-ETP) of 218 and urine (U-ETP/Cr) of 172 kidney transplant recipients, one (D1) and five (D5) days, as well as three (M3) and twelve (M12) months, after transplantation. P-ETP and U-ETP/Cr at D1 (P-ETP AUC = 0.86, p < 0.0001; U-ETP/Cr AUC = 0.70, p = 0.0002) were independent markers of delayed graft function (DGF) and P-ETP at D1 had an odds ratio of 6.3 (p < 0.0001) for DGF when adjusted for plasma creatinine. The results for P-ETP at D1 were confirmed in a validation cohort of 146 transplant recipients (AUC = 0.92, p < 0.0001). U-ETP/Cr at M3 was negatively associated with kidney graft function at M12 (p = 0.007). This study suggests that ETP at D1 can identify patients at risk of delayed graft function and that U-ETP/Cr at M3 can predict the future status of the allograft. Thus, measuring collagen type VI formation could aid in predicting graft function in kidney transplant recipients.
Project description:Background: Micro-RNA-21 (miR-21) is a post-translational regulator involved in epithelial-to-mesenchymal transition (EMT). Since EMT is thought to contribute to chronic lung allograft dysfunction (CLAD), we aimed to characterize miR-21 expression and distinct EMT markers in CLAD. Methods: Expression of miR-21, vimentin, Notch intracellular domain (NICD) and SMAD 2/3 was investigated in explanted CLAD lungs of patients who underwent retransplantation. Circulating miR-21 was determined in collected serum samples of CLAD and matched stable recipients. Results: The frequency of miR-21 expression was higher in restrictive allograft syndrome (RAS) than in bronchiolitis obliterans syndrome (BOS) specimens (86 vs 30%, p = 0.01); Vimentin, NICD and p-SMAD 2/3 were positive in 17 (100%), 12 (71%), and 7 (42%) BOS patients and in 7 (100%), 4 (57%) and 4 (57%) RAS cases, respectively. All four markers were negative in control tissue from donor lungs. RAS patients showed a significant increase in serum concentration of miR-21 over time as compared to stable recipients (p = 0.040). Conclusion: To the best of our knowledge this is the first study highlighting the role miR-21 in CLAD. Further studies are necessary to investigate the involvement of miR-21 in the pathogenesis of CLAD and its potential as a therapeutic target.
Project description:The presence of interstitial pneumonitis (IP) on surveillance lung biopsy specimens in lung transplant recipients is poorly described, and its impact on posttransplant outcomes is not established. The following study assessed the association of posttransplant IP with the development of bronchiolitis obliterans syndrome (BOS).We examined all recipients of primary cadaveric lung transplants at our institution between January 1, 2000, and December 31, 2007 (N = 145). Patients had bronchoscopies with BAL, and transbronchial biopsies performed for surveillance during posttransplant months 1, 3, 6, and 12 as well as when clinically indicated. Patients were given a diagnosis of IP if, in the absence of active infection and organizing pneumonia, they showed evidence of interstitial inflammation and fibrosis on two or more biopsy specimens.IP was a significant predictor of BOS (OR, 7.84; 95% CI, 2.84-21.67; P < .0001) and was significantly associated with time to development of BOS (hazard ratio, 3.8; 95% CI, 1.93-7.39; P = .0001) within the first 6 years posttransplant. The presence of IP did not correlate with a significantly higher risk of mortality or time to death. There was no association between the presence of IP and the development of or time to acute rejection.The presence of IP on lung transplant biopsy specimens suggests an increased risk for BOS, which is independent of the presence of acute cellular rejection.
Project description:High dose intravenous immunoglobulin (IVIG) are widely used after kidney transplantation and its biological effect on T and B cell phenotype in the context of maintenance immunosuppression was not documented yet. We designed a monocentric prospective cohort study of kidney allograft recipients with anti-HLA donor specific antibodies (DSA) without acute rejection on screening biopsies treated with prophylactic high-dose IVIG (2 g/kg) monthly for 2 months. Any previous treatment with Rituximab was an exclusion criterion. We performed an extensive analysis of phenotypic and transcriptomic T and B lymphocytes changes and serum cytokines after treatment (day 60). Twelve kidney transplant recipients who completed at least two courses of high-dose IVIG (2 g/kg) were included in a median time of 45 (12-132) months after transplant. Anti-HLA DSA characteristics were similar before and after treatment. At D60, PBMC population distribution was similar to the day before the first infusion. CD8+ CD45RA+ T cells and naïve B-cells (Bm2+) decreased (P = 0.03 and P = 0.012, respectively) whereas Bm1 (mature B-cells) increased (P = 0.004). RORγt serum mRNA transcription factor and CD3 serum mRNA increased 60 days after IVIG (P = 0.02 for both). Among the 25 cytokines tested, only IL-18 serum concentration significantly decreased at D60 (P = 0.03). In conclusion, high dose IVIG induced limited B cell and T cell phenotype modifications that could lead to anti-HLA DSA decrease. However, no clinical effect has been isolated and the real benefit of prophylactic use of IVIG after kidney transplantation merits to be questioned.
Project description:BackgroundCalcineurin inhibitors, including tacrolimus, remain a cornerstone of immunosuppressive therapy after kidney transplantation. However, the therapeutic window is narrow, and nephrotoxic side effects occur with overdose, while the risk of alloimmunization and graft rejection increases with underdose. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allows quantification of tacrolimus in biological samples from patients. This study investigates the feasibility of quantifying tacrolimus in scalp hair from kidney transplant (KT) recipients and correlates hair tacrolimus concentrations with tacrolimus dosage and blood trough levels. The aim was to provide proof-of-principle for hair tacrolimus drug monitoring in KT recipients.MethodSingle-center prospective study between September 9, 2021 and December 4, 2021, including KT recipients under tacrolimus. Minors, patients with active skin or hair diseases, and patients with scalp hair shorter than 4 cm were excluded from participation. Scalp hair was collected from the posterior vertex of patients, cut into segments, and analyzed for tacrolimus by LC-MS/MS. Patients filled out a questionnaire on hair treatments and washing habits. In parallel, tacrolimus trough levels were measured in whole blood and correlated with hair tacrolimus concentrations.ResultsIn total, 39 consenting KT recipients were included, and hair samples were collected at 53 visits. Tacrolimus was detected in 98% of hair samples from patients exposed to the drug. Tacrolimus hair levels and whole blood trough levels were correlated with a beta coefficient of 0.42 (95% CI: -0.22-1.1, p = n.s.). Age and dark hair affected hair tacrolimus measurements, while different tacrolimus formulations (immediate release vs. extended release), hair washes, and permanent coloring did not. Longitudinal measurements in a subgroup of patients indicate that long-term measurement of hair tacrolimus levels is feasible.ConclusionMeasuring tacrolimus in hair is a potentially reliable method to monitor drug exposure in KT patients. Rapid wash-in effects and consistent concentrations over time indicate that tacrolimus is incorporated into the hair matrix, allowing temporal resolution in the analysis of recent exposure and exposure history. This method provides a simple and low-risk alternative to regular blood sampling, sparing patients from frequent hospital visits through the self-collection of hair samples.