Stable Graft Research Articles

Kidney transplant artery and vein stenting: 15-year follow-up

BackgroundWe would like to present an unusual case of simultaneous stenosis of renal graft artery and vein diagnosed four months after transplantation. both treated by stent placement. Our aim is to point at the fact that renal graft venous stenosis is very rarely reported in the literature and – as it is not easy to diagnose by routine US - it could be overlooked. If early detected it can be treated by stent placement.Case presentationWe present a case of 36-old-male with renal failure who received a kidney graft from deceased donor. The patient experienced delayed graft function. No rejection was found in the biopsy. Four months after transplantation the kidney function deteriorated to sCr 280 µmol/l. Graft artery stenosis together with graft vein stenosis was revealed. Both lesions were dilated with stent placement, the graft function returned to 230 µmol/l and became stable for 10 years. Ten years after stent placement graft function deteriorated to 300 µmol/l. An in stent restenosis of arterial stent was detected. It was successfully dilated by the balloon, the graft function returned to 230 µmol/l and stays stable for another 5 years.ConclusionsAn unusual simultaneous transplanted kidney artery and vein stenosis treated by stent placement is presented. The patient had stable graft function for 15 years after the procedure with one re-intervention on arterial stent.

Effects of switching from twice-daily tacrolimus to once-daily extended-release meltdose tacrolimus on cellular immune response.

LCP-Tacro [LCPT], a novel once-daily, extended-release formulation of tacrolimus, has a reduced Cmax with comparable AUC exposure, requiring a ∼30% dose reduction in contrast to immediate-release tacrolimus (IR-Tac). Once-daily LCPT in de novo kidney transplantation has a comparable efficacy and safety profile to that of IR-Tac with advantages in bioavailability and absorption. The present investigation intends to analyze the effects of conversion from IR-Tac to LCPT on phenotype and function of T-cells and B-cells. 16 kidney transplant patients treated by triple standard immunosuppression with a stable graft function undergoing a switch from IR-Tac to LCPT were included in this observational prospective study. We measured the main immune cell types and performed an in-depth characterization of B cell, dendritic cells and T cells including regulatory T cells of the patients before, 4 and 8 weeks after IR-Tac to LCPT conversion using multi-parameter fl ow cytometry. Additionally, we analyzed T cells by assessing third-party antigens (Tetanus Diphtheria, TD)-reactive T cells, which could be analyzed by restimulation with tetanus vaccine. Overall, we found no significant alterations following LCPT conversion for the most immune cell populations with a few cell populations showing transient quantitative increase. Thus, 4 weeks after conversion, more regulatory T cells could be measured in the patients with a significant shift from memory to naïve Tregs. Furthermore, we found a transient B cell expansion 4 weeks after conversion from IR-Tac to LCPT. There were no changes in the percentage of other basic immune cell types and the antigen-reactive T cells were also not altered after changing the medication to LCP-tacrolimus. Here, we demonstrate first insights into the immune system changes occurred under IR-Tac to LCPT conversion therapy in kidney transplant patients. While phenotypic and functional characteristics of the most immune cell populations did not change, we could observe an a transient expansion of regulatory T cells in peripheral blood following IR-Tac to LCTP conversion, which might additionally contribute to the overall immunosuppressive effect.

447.9: Porcine islet-after-kidney transplantation in with cure of diabetes and six months of stable graft function in life-supporting pig-to-baboon model.

447.9: Porcine islet-after-kidney transplantation in with cure of diabetes and six months of stable graft function in life-supporting pig-to-baboon model.

Arthroscopic Autologous Iliac Crest Grafting with an Adjustable Loop Suspensory Device Yields Favorable Outcomes for Anterior Shoulder Instability with Glenoid Defects.

This study aims to evaluate the clinical and radiological outcomes of the arthroscopic autologous iliac crest grafting (AICG) procedure with an adjustable-loop suspensory fixation device in the treatment of anterior shoulder instability (ASI) with glenoid bone defects. A retrospective review was conducted on the patients who underwent arthroscopic AICG with an adjustable-loop suspensory fixation device from January 2017 to December 2020. Patients with traumatic ASI, significant glenoid bone defects, and a minimum follow-up of 24 months were included. Patient-reported outcomes (PROs), including the Oxford Shoulder Instability Score (OSIS), the Rowe score, the Walch-Duplay score, the Constant score, and the Visual Analogue Score (VAS), were compared preoperatively and postoperatively. Radiological assessments using computed tomography (CT) were performed before and after the procedure. Additional data on active range of motion, recurrence events, and complications were recorded. A total of 42 patients were included in the study, with a mean follow-up time of 35.2 months ranging from 25.1 to 55.9 months. Mean preoperative OSIS, Rowe score, Walch-Duplay score, and Constant score significantly improved from 24.4±7.2, 25.0±9.0, 25.2±9.8, 87.5±7.1 to 42.4±4.9, 92.4±8.1, 87.9±8.3, 93.6±4.5 at the last follow-up, respectively. All patients exceeded the minimal clinically important difference (MCID) for OSIS, Rowe, and Walch-Duplay scores. The graft union rate was 100%, and the glenoid area increased significantly from 82.5% preoperatively to 100.1% at the final follow-up. No patient experienced a recurrence of instability. Two recorded complications included one case of dysesthesia around the donor site and one case of postoperative shoulder stiffness. The outcomes of the arthroscopic AICG procedure, which utilizes an adjustable-loop suspensory fixation device, demonstrated stable bone graft fixation, high rates of graft integration, favorable clinical results, and a low incidence of complications. Moreover, the remodeling of the graft during the follow-up period significantly restored the width and concavity of the inferior glenoid, contributing to the overall recovery. Level IV, retrospective case series.

Regulatory B Cells Expressing Granzyme B from Tolerant Renal Transplant Patients: Highly Differentiated B Cells with a Unique Pathway with a Specific Regulatory Profile and Strong Interactions with Immune System Cells.

The aim of our study was to determine whether granzyme B-expressing regulatory B cells (GZMB+ B cells) are enriched in the blood of transplant patients with renal graft tolerance. To achieve this goal, we analysed two single-cell RNA sequencing (scRNAseq) datasets: (1) peripheral blood mononuclear cells (PBMCs), including GZMB+ B cells from renal transplant patients, i.e., patients with stable graft function on conventional immunosuppressive treatment (STA, n = 3), drug-free tolerant patients (TOL, n = 3), and patients with antibody-mediated rejection (ABMR, n = 3), and (2) ex-vivo-induced GZMB+ B cells from these groups. In the patient PBMCs, we first showed that natural GZMB+ B cells were enriched in genes specific to Natural Killer (NK) cells (such as NKG7 and KLRD1) and regulatory B cells (such as GZMB, IL10, and CCL4). We performed a pseudotemporal trajectory analysis of natural GZMB+ B cells and showed that they were highly differentiated B cells with a trajectory that is very different from that of conventional memory B cells and linked to the transcription factor KLF13. By specifically analysing GZMB+ natural B cells in TOLs, we found that these cells had a very specific transcriptomic profile associated with a reduction in the expression of HLA molecules, apoptosis, and the inflammatory response (in general) in the blood and that this signature was conserved after ex vivo induction, with the induction of genes associated with migration processes, such as CCR7, CCL3, or CCL4. An analysis of receptor/ligand interactions between these GZMB+/- natural B cells and all of the immune cells present in PBMCs also demonstrated that GZMB+ B cells were the B cells that carried the most ligands and had the most interactions with other immune cells, particularly in tolerant patients. Finally, we showed that these GZMB+ B cells were able to infiltrate the graft under inflammatory conditions, thus suggesting that they can act in locations where immune events occur.

Orchestrating the Impact of KIR/HLA Interactions on Kidney Transplant.

This study examines the interplay between human leukocyte antigen (HLA) compatibility and killer-cell immunoglobulin-like receptor (KIR) genotypes in influencing kidney transplantation outcomes. Understanding these interactions is crucial for improving graft survival and minimizing rejection risks. We evaluated 84 kidney transplant recipients, dividing them into two groups based on post-transplant outcomes: there were 68 with stable graft function (SGF) and 16 who experienced chronic rejection (CR). Patients were selected based on specific inclusion criteria. HLA mismatches (Class I: HLA-A, -B; Class II: HLA-DR) and KIR genotypes were determined using standard genotyping techniques. Statistical analyses, including logistic regression, were performed to correlate these factors with transplant outcomes. Significant age differences were observed, with younger patients more likely to experience graft rejection, while no significant gender-based differences were noted. A significant correlation was found between Class II mismatches and increased rejection rates, highlighting the importance of HLA-DR compatibility. Further analysis revealed that certain inhibitory KIRs, such as KIR3DL1, were associated with favorable outcomes, suggesting a protective role against graft rejection. These findings were corroborated by evaluating serum creatinine levels over multiple years, serving as a biomarker for renal function post transplant. This study underscores the critical need for meticulous HLA matching and the consideration of KIR genotypes in pre-transplant evaluations to enhance graft survival and minimize rejection risks. Integrating these genetic factors into routine clinical assessments could significantly improve personalized transplant medicine strategies, ultimately enhancing patient outcomes. Further research is needed to explore the underlying mechanisms and validate these findings in larger, diverse populations.

Relevance of Proteinuria in Kidney Transplant Recipients and Allograft Outcomes

BackgroundThe onset of proteinuria in renal allograft recipients is frequently associated with an increased risk for both graft failure and mortality. We investigated the risk associated with post-transplant proteinuria and its time-dynamics in a select group treated for biopsy proven antibody-mediated rejection (ABMR). MethodsEighty-five patients who underwent transplantation were enrolled in our study and followed up from transplantation until October 31, 2020, death, or the date of the return to dialysis. We created two main groups: the ABMR group (n = 19) and an ABMR-negative control group with stable kidney function (n = 52) without donor-specific antibodies (DSA) and a subgroup with DSAs but stable graft function (n = 14) without ABMR. Differences in patient, donor, and transplant graft characteristics between the groups were assessed by Fisher's exact test for categorical variables. Death-censored graft loss was evaluated with the help of Kaplan-Meier analysis using log risk statistics. ResultsProteinuria decreased after treatment in the ABMR group (P < .0009). Pre-treatment every 10 mg/mmol increase in proteinuria was associated with a 7% increase in the risk for graft failure in the ABMR group. The estimated 3-year graft survival was 87.5% in the ABMR group, compared to 93% in the group without ABMR but with pre-formed DSA, and 100% in the DSA negative subgroup (log-rank probe P < .0666). ConclusionProteinuria is an independent predictor for graft failure, can be lowered by treatment for ABMR but ABMR is associated with lower graft survival in our study population.

Volumetric assessment of volume stable collagen matrix in maxillary single implant site development: A randomized controlled clinical trial.

The stability of soft tissue volume around dental implants is an important factor for the final esthetic outcome. The main objective of this study was to compare volume stable collagen matrix (VCMX) versus connective tissue graft (CTG) in the augmentation of soft tissue profiles in single implant sites with a class I Siebert ridge defect. Twenty patients (14 females and 6 males) were enrolled in the present study. After implant placement and augmentation of the buccal defect by VCMX or CTG, post-operative evaluation of the volumetric changes at the augmented implant site was carried out at 3, 6, and 9 months as primary outcome, clinical and radiographic soft tissue thickness were carried out at baseline and 9-month intervals, visual analog scale (VAS) and oral health impact profile-14 (OHIP14) were recorded 2 weeks after the surgery. A statistically significant difference in soft tissue volume was found between baseline and 3, 6, and 9 months postoperatively in both groups with the highest value at 9 months (136.33 ± 86.80) (mm3) in VCMX and (186.38 ± 57.52) (mm3) in CTG. Soft tissue thickness was significantly increased in both groups at 9 months in comparison to baseline. However, there was a significantly higher increase in soft tissue thickness at 9 months in CTG (3.87 ± 0.91) than in VCMX (2.94 ± 0.31). Regarding the radiographic soft tissue thickness, there was a statistically significant increase in both groups at 9 months in comparison to baseline. However, there was a statistically higher increase in the radiographic soft tissue thickness at 9 months in CTG (3.08 ± 0.97) than in VCMX (2.37 ± 0.29). VAS showed a statistically lower value in VCMX (0.4 ± 0.7) than CTG (2.8 ± 1.48). The OHIP recorded lower values in the VCMX group than the CTG group with no statistical significance. In addition, there was no difference in the PES between the two groups. The present study showed that CTG and VCMX were both effective in soft tissue augmentation around implants in the esthetic zone. However, CTG proved more efficient in increasing peri-implant soft tissue volume and mucosal thickness around single implants at a 9-month follow-up period. VCMX was associated with less pain or discomfort and reduced patient morbidity, as reflected by the significantly reduced VAS value in the VCMX group.

Decoding the hallmarks of allograft dysfunction with a comprehensive pan-organ transcriptomic atlas.

The pathogenesis of allograft (dys)function has been increasingly studied using 'omics'-based technologies, but the focus on individual organs has created knowledge gaps that neither unify nor distinguish pathological mechanisms across allografts. Here we present a comprehensive study of human pan-organ allograft dysfunction, analyzing 150 datasets with more than 12,000 samples across four commonly transplanted solid organs (heart, lung, liver and kidney, n = 1,160, 1,241, 1,216 and 8,853 samples, respectively) that we leveraged to explore transcriptomic differences among allograft dysfunction (delayed graft function, acute rejection and fibrosis), tolerance and stable graft function. We identified genes that correlated robustly with allograft dysfunction across heart, lung, liver and kidney transplantation. Furthermore, we developed a transfer learning omics prediction framework that, by borrowing information across organs, demonstrated superior classifications compared to models trained on single organs. These findings were validated using a single-center prospective kidney transplant cohort study (a collective 329 samples across two timepoints), providing insights supporting the potential clinical utility of our approach. Our study establishes the capacity for machine learning models to learn across organs and presents a transcriptomic transplant resource that can be employed to develop pan-organ biomarkers of allograft dysfunction.

Plasma immune signatures can predict rejection-free survival in the first year after pediatric liver transplantation

After pediatric liver transplantation (pLT), children undergo life-long immunosuppression since reliable biomarkers for the assessment of rejection probability are scarce. In the multicenter (n= 7) prospective clinical cohort "ChilSFree" study, we aimed to characterize longitudinal dynamics of soluble and cellular immune mediators during the first year after pLT and identify early biomarkers associated with outcome. Using a Luminex-based multiplex technique paired with flow cytometry, we characterized longitudinal dynamics of soluble immune mediators (SIMs, n= 50) and immune cells in the blood of 244 patients at eight visits over 1 year: before, and 7/14/21/28 days and 3/6/12 months after pLT. The unsupervised clustering of patients based on SIM profiles revealed six unique SIM signatures associated with clinical outcome. From three signatures linked to improved outcome, one was associated with 1-year-long rejection-free survival and stable graft function and was characterized by low levels of pro-inflammatory SIMs (CXCL8/9/10/12, CCL7, SCGF-β, sICAM-1), and high levels of regenerative (SCF, TNF-β) and pro-apoptotic (TRAIL) SIMs (all, p <0.001, fold change >100). Of note, this SIM signature appeared 2 weeks after pLT and remained stable over the entire year, pointing towards its potential as a novel early biomarker for minimizing or weaning immunosuppression. In the blood of these patients, a higher frequency of CD56bright natural killer cells (p <0.01), a known hallmark also associated with operationally tolerant pLT patients, was detected. The concordance of the model for prediction of rejection based on identified SIM signatures was 0.715, and 0.795, in combination with living-related transplantation as a covariate, respectively. SIM blood signatures may enable the non-invasive and early assessment of rejection risks in the first year after pLT, paving the way for improved clinical management. ChilSFree represents the largest pediatric liver transplant (pLT) cohort with paired longitudinal data on soluble immune mediators (SIMs) and immune phenotyping in the first year after pLT. SIM signatures allow for the selection of rejection-free patients 2 weeks after pLT independently of patient diagnosis, sex, or age. The SIM signatures may enable the non-invasive and early assessment of rejection risks, paving the way for minimization or withdrawal of immunosuppression after pLT.

Immune monitoring in pediatric kidney transplant.

Long-term outcomes in pediatric kidney transplantation remain suboptimal, largely related to chronic rejection. Creatinine is a late marker of renal injury, and more sensitive, early markers of allograft injury are an active area of current research. This is an educational review summarizing existing strategies for monitoring for rejection in kidney transplant recipients. We summarize supporting currently available clinical tests, including surveillance biopsy, donor specific antibodies, and donor-derived cell free DNA, as well as the potential limitations of these studies. In addition, we review the current avenues of active research, including transcriptomics, proteomics, metabolomics, and torque tenovirus levels. Advancing the use of noninvasive immune monitoring will depend on well-designed multicenter trials that include patients with stable graft function, include biopsy results on all patients, and can demonstrate both association with a patient-relevant clinical endpoint such as graft survival or change in glomerular filtration rate and a potential timepoint for intervention.

Immunophenotypic profiling reveals novel T cell subset associated with “tolerance” in pediatric transplant recipients

Abstract Achieving allograft health remains a challenge in pediatric organ transplantation. Recently. we performed multilineage, single-cell analysis of the immune cell composition in pediatric solid-organ transplant recipients who received a heart, liver, or kidney allograft (n=52); 24 children had stable graft function while 28 children had a rejection episode. Hierarchical clustering of the mean cell type proportion across allograft types and health states demonstrated a distinct subpopulation of CD4 T cells (CD45RA-,CD25+,CD5+,CD38-) was significantly (p&amp;lt;0.05) associated with stable graft function and were termed TOT cells. The cosine similarity analysis of proteomics data showed that TOT cells are phenotypically most like Tregs and least like CD4+ TEMRA. To characterize the TOT cells, we developed an 8-marker flow cytometry panel to specifically sort Treg and TOT populations and performed 10x single-cell RNA-seq and TCR-seq with subsequent analysis in R and Loupe Browser. Differentially expressed genes that were specifically associated with TOT cells included ANXA1, IL7R, TCF7, THEMIS, NELL2, KLRB1 and CD40LG while Treg expressed FOXP3, IKZF2, CTLA4, IL2RA, and RTKN2, consistent with their known function in immune suppression. TCR analysis indicates unique expansions of T cell clonotypes in TOT cells not seen in Treg. Further investigation into the immunoregulatory capacity of TOT cells could be instrumental in developing new strategies to prolong graft survival.

Transplantation and Pregnancy

Transplantation is becoming increasingly widespread worldwide as a life-saving treatment for patients with end-stage organ failure. While the woman's quality of life improves rapidly after transplantation, the improvement of the endocrine system helps to regain fertility. The success of conception and successful pregnancy rates are quite low compared to the general population. Particular attention should be paid to obstetric complications such as hypertension, preeclampsia, fetal growth restriction, and preterm delivery during pregnancy. Ideally, preconception counseling should begin in the period before transplantation. Initiating contraception immediately after transplantation is ideal and long-acting reversible methods such as intrauterine devices and subcutaneous implants may be preferable. Factors that influence pregnancy outcomes in women undergoing organ transplantation include good general health within two years of transplantation, no evidence of organ rejection in the last year, stable graft conditions, absence of acute infections affecting the fetus, and adequate doses of immunosuppression drugs. However, factors that may adversely affect pregnancy include the etiology of the disease requiring transplantation, chronic allograft dysfunction, renal failure, cardiopulmonary diseases, hypertension, diabetes, obesity, and infections such as hepatitis B, hepatitis C, and Cytomegalovirus (CMV). Postponing pregnancy for at least 1 year after transplantation is very important to optimize pregnancy outcomes. Pregnancy in the early post-transplant period increases the risk of acute rejection, infection risk, and graft-related problems. In general, transplanted women can have successful pregnancies and live birth rates are above 70% on average. Although perinatal morbidity and mortality rates are high, most newborns are healthy and develop normally. Specific criteria such as pre-pregnancy serum creatinine levels and blood pressure control, as well as adherence to immunosuppressive therapy, significantly influence pregnancy success in transplant patients. In this review, optimizing pregnancy outcomes often involves addressing maternal and fetal risks, regular graft monitoring to detect potential complications such as organ rejection, and regulation of transplant medications to ensure safety and efficacy during pregnancy. Successful management relies on a multidisciplinary approach with contributions from obstetricians, neonatologists, nephrologists, hepatologists, and transplant surgeons.

Maxillary Sinus Augmentation with Anorganic Bovine Bone Mineral of Different Particle Sizes: A Split-Mouth Study with Histomorphometric, Radiographic, and Clinical Analyses.

The aim of the present study was to compare the histomorphometrically evaluated new bone formation (NB), the radiographically measured graft stability, and the clinical implant outcome for maxillary sinus augmentation grafted with deproteinized bovine bone mineral (DBBM) with either small (Bio-Oss-S, Geistlich) or large (Bio-Oss-L, Geistlich) particles. Using a split-mouth study design, bilateral maxillary sinus augmentation was performed in 13 patients either with Bio-Oss-S particles (0.25 to 1 mm) or Bio-Oss-L particles (1 to 2 mm). After a healing period of 6 months, bone biopsies were axially retrieved in the molar region for histologic/histomorphometric analysis of NB, including subsequent staged implant placement. To determine graft stability, the maxillary sinus augmentation vertical graft heights were radiographically measured immediately after sinus augmentation, at implant placement, and at the 2- and 4-year post-augmentation follow-ups. In addition, the clinical implant-prosthodontic outcome (survival/ success/marginal bone loss) was assessed at 1 and 3 years post-loading. A total of 22 sinuses from 11 patients with split-mouth evaluation were ultimately available for data and statistical analysis. Histomorphometric analysis of the axially retrieved bone biopsies revealed the presence of NB (S: 25.5% ± 7.0% vs L: 23.6% ± 11.9%; P = .640), residual graft particles (S: 19.6% ± 9.2% vs L: 17.5% ± 6.3%; P = .365) as well as connective tissue (S: 54.9% ± 9.2% vs L: 58.9% ± 12.5%; P = .283), without significant differences between the use of small (Bio-Oss-S) and large (Bio-Oss-L) particles. However, there was significantly (P = .021) higher bone-to-graft contact (BGC) for the small-particle graft sites (27.9% ± 14.8%) compared to the large-particle graft sites (19.9% ± 12.9%), representing a significantly higher osteoconductivity. Both particle sizes showed significant (P < .01) vertical graft height reduction over time (4 years) of about 10%, with predominant graft reduction in the time period between sinus augmentation and implant placement compared to any follow-up periods after implant placement. At the 3-year post-loading implant evaluation, all implants and prostheses survived (100%), and the peri-implant marginal bone loss (S: 0.52 ± 0.19 mm; L: 0.48 ± 0.15 mm) as well as the peri-implant health conditions (S: 87.5%, L:81.2%) did not differ between implants inserted with the two different xenograft particles used. The use of small and large bovine xenograft particles for maxillary sinus augmentation provides for comparable bone formation, ensuring stable graft dimensions combined with high implant success and healthy peri-implant conditions. However, small particle size resulted in a higher BGC, providing for higher osteoconductivity than with the larger particle size.

Festivity: The Effects of Traditional Holidays on the Graft Function Among Stable Kidney Recipients

PurposeWe observed transient elevations in creatinine levels among kidney recipients after three traditional holidays in Taiwan. This retrospective cohort study aimed to compare the changes in eGFR levels after Chinese New Year, Dragon Boat Festival, and Mid-Autumn Festival, all of which are associated with high-calorie and high-fat diets. Materials and MethodsWe conducted a retrospective analysis of 364 kidney recipients with stable graft function who were following at Chang Gung Memorial Hospital Linkou from 2018 to 2020. The graft function before and after the festival was determined by calculating the eGFR level using the serum creatinine measured during clinic visits prior to and following the festival. The patients were then categorized into subgroups based on their sex, BMI, and co-morbidities. The eGFR levels before and after the festival were evaluated and compared within these subgroups. ResultsA total of 301 kidney recipients have been finally included in this retrospective cohort study. The analysis showed a significant decrease in overall eGFR levels after Chinese New Year (from 56.92 ± 29.70 to 55.14 ± 24.79, P = .006), Mid-Autumn Festival (from 54.03 ± 24.61 to 53.35 ± 24.33, P = .008), and Dragon Boat Festival only in 2020 (from 50.98 ± 24.35 to 49.99 ± 23.45, P = .018). The analysis of subgroups suggested a tendency of renal function decline after all 3 traditional holidays in patient groups with DM or hypertension or nonoverweight status. ConclusionIn this study, we observed a significant decline in renal function among kidney recipients following traditional holidays in Taiwan, particularly among recipients with hypertension or diabetes mellitus or those who were not overweight.

Renal graft function in transplanted patients correlates with CD45RC T cell phenotypic signature.

Biomarkers that could predict the evolution of the graft in transplanted patients and that could allow to adapt the care of the patients would be an invaluable tool. Additionally, certain biomarkers can be target of treatments and help to stratify patients. Potential effective biomarkers have been identified but still need to be confirmed. CD45RC, one of the splicing variants of the CD45 molecule, a tyrosine phosphatase that is critical in negatively or positively regulating the TCR and the BCR signaling, is one marker already described. The frequency of CD8+ T cells expressing high levels of CD45RC before transplantation is increased in patients with an increased risk of acute rejection. However, single biomarkers have limited predictive reliability and the correlation of the expression levels of CD45RC with other cell markers was not reported. In this study, we performed a fluorescent-based high dimensional immunophenotyping of T cells on a cohort of 69 kidney transplant patients either with stable graft function or having experienced acute transplant rejection during the first year after transplantation or at the time of rejection. We identified combinations of markers and cell subsets associated with activation/inflammation or Tregs/tolerance (HLA-DR, PD-1, IFNγ, CD28) as significant biomarkers associated to transplant outcome, and showed the importance of cell segregation based on the CD45RC marker to identify the signature of a stable graft function. Our study highlights potential reliable biomarkers in transplantation to predict and/or monitor easily graft-directed immune responses and adapt immunosuppression treatments to mitigate adverse effects.

Durable plasma-mediated zwitterionic grafting on polymeric surfaces for implantable medical devices

Adverse body reactions to blood-contacting medical devices endanger patient safety and impair device functionality, with events invariably linked to nonspecific protein adsorption due to suboptimal material biocompatibility. To improve the safety and durability of such devices, herein we propose a strategy for introducing stable zwitterionic grafts onto polymeric surfaces via plasma functionalization. The resulting zwitterion-grafted substrates exhibit long-lasting superhydrophilicity, enabling antifouling and anti-thrombogenic properties. We demonstrate the successful modification of the surface elemental composition, morphology, and hydrophilicity, while retaining the underlying mechanical properties of the polymeric substrate. Furthermore, we optimise the fabrication process to ensure long-lasting modifications at least three months after fabrication. This strategy decreases fibrinogen adsorption by approximately 9-fold, and thrombosis by almost 75% when applied to a commercial polyurethane. Moreover, this process is universally applicable to a wide range of polymeric materials, even those with stable chemistry such as polytetrafluoroethylene.

Clinicopathologic Spectrum and Outcomes of Infections Diagnosed on Graft Biopsies and Nephrectomy in Live Renal Allograft Recipients: An Institutional Experience.

Modern immunosuppressive regimens have reduced rejection episodes in renal allograft recipients but have increased the risk of opportunistic infections. Infections are considered to be the second leading cause of death after cardiovascular complications in renal allograft recipients. Data on opportunistic infections affecting the allograft itself are scarce. The present study describes the spectrum of renal opportunistic infections and their outcomes diagnosed on renal allograft biopsies and nephrectomy specimens. Our retrospective observational study was conducted from December 2011 to December 2021. We analyzed infectious episodes diagnosed on renal allograft biopsies or graft nephrectomy specimens. We obtained clinical, epidemiological, and laboratory details for analyses from hospital records. BK virus nephropathy was the most common opportunistic infection affecting the allograft, accounting for 47% of cases, followed by bacterial graft pyelonephritis (25%). Mucormycosis was the most common fungal infection. The diagnosis of infection from day of transplant ranged from 14 days to 39 months. Follow-up periods ranged from 1 to 10 years. Mortality was highest among patients with opportunistic fungal infection (62%), followed by viral infections, and graft failure rate was highest in patients with graft pyelonephritis (50%). Among patients with BK polyomavirus nephropathy, 45% had stable graft function compared with just 33% of patients with bacterial graft pyelonephritis. BK polyoma virus infection was the most common infection affecting the renal allograft in our study. Although fungal infections caused the highest mortality among our patients, bacterial graft pyelonephritis was responsible for maximum graft failure. Correctly identifying infections on histology is important so that graft and patient life can be prolonged.

Treatment of Sinus Graft Infection After Sinus Floor Elevation: A Series of Four Case Reports.

This report of cases aims to share our treatment experiences in 4 sinus graft infection cases after sinus floor elevation and simultaneous implant placement. The preoperative and postoperative intraoral and radiographic photographs were collected and used to assess the treatment outcomes. The sinus cavity status, bone augmentation results, and implant stability were used as measurements to determine the treatment effectiveness. Four patients received partial graft removal as their surgical treatment for sinus graft infection combined with antibiotic therapy, with or without immediate secondary grafting. After early intervention, antibiotic therapy, and partial debridement of the infected sinus grafts, radiographic and clinical outcomes indicate successful resolution of the graft infection and stable bone graft levels around the implants. The keys to the successful management of the sinus graft infection were: early detection of the infection; early intervention, including partial debridement of the infected graft particles; and antibiotic therapy.

A multi-center interventional study to assess pharmacokinetics, effectiveness, and tolerability of prolonged-release tacrolimus after pediatric kidney transplantation: study protocol for a prospective, open-label, randomized, two-phase, two-sequence, single dose, crossover, phase III b trial.

Tacrolimus, a calcineurin inhibitor (CNI), is currently the first-line immunosuppressive agent in kidney transplantation. The therapeutic index of tacrolimus is narrow due to due to the substantial impact of minor variations in drug concentration or exposure on clinical outcomes (i.e., nephrotoxicity), and it has a highly variable intra- and inter-individual bioavailability. Non-adherence to immunosuppressants is associated with rejection after kidney transplantation, which is the main cause of long-term graft loss. Once-daily formulations have been shown to significantly improve adherence compared to twice-daily dosing. Envarsus®, the once-daily prolonged-release formulation of tacrolimus, offers the same therapeutic efficacy as the conventional twice-daily immediate-release tacrolimus formulation (Prograf®) with improved bioavailability, a more consistent pharmacokinetic profile, and a reduced peak to trough, which may reduce CNI-related toxicity. Envarsus® has been approved as an immunosuppressive therapy in adults following kidney or liver transplantation but has not yet been approved in children. The objective of this study is to evaluate the pharmacokinetic profile, efficacy, and tolerability of Envarsus® in children and adolescents aged ≥ 8 and ≤ 18 years to assess its potential role as an additional option for immunosuppressive therapy in children after kidney transplantation. The study is designed as a randomized, prospective crossover trial. Each patient undergoes two treatment sequences: sequence 1 includes 4 weeks of Envarsus® and sequence 2 includes 4 weeks of Prograf®. Patients are randomized to either group A (sequence 1, followed by sequence 2) or group B (sequence 2, followed by sequence 1). The primary objective is to assess equivalency between total exposure (of tacrolimus area under the curve concentration (AUC0-24)), immediate-release tacrolimus (Prograf®) therapy, and prolonged-release tacrolimus (Envarsus®) using a daily dose conversion factor of 0.7 for prolonged- versus immediate-release tacrolimus. Secondary objectives are the assessment of pharmacodynamics, pharmacogenetics, adherence, gut microbiome analyses, adverse events (including tacrolimus toxicity and biopsy-proven rejections), biopsy-proven rejections, difference in estimated glomerular filtration rate (eGFR), and occurrence of donor-specific antibodies (DSAs). This study will test the hypothesis that once-daily prolonged-release tacrolimus (Envarsus®) is bioequivalent to twice-daily intermediate-release tacrolimus after pediatric kidney transplantation and may reduce toxicity and facilitate medication adherence. This novel concept may optimize immunosuppressive therapy for more stable graft function and increased graft survival by avoiding T-cell mediated and/or antibody-mediated rejection due to improved adherence. In addition, the study will provide data on the pharmacodynamics and pharmacogenetics of prolonged-release tacrolimus in children and adolescents. EUDRA-CT 2019-003710-13 and ClinicalTrial.gov, identifier NCT06057545.