Cadaveric Donors Research Articles

From Bank Preparation to Clinical Use of Homologous Skin Allografts in Wound Healing: A Sustainable Approach.

Given progressive population ageing and the increase in the number of patients with comorbidities, the management of chronic and/or hard-to-heal wounds (HHWs) nowadays represents a common problem in many clinical settings. In these cases, standard strategies may not be sufficient. Autologous grafting represent the gold standard for permanent wound closure, but is almost never realized when the skin loss is extensive/the patient is young. The grafting of homologous skin/dermal tissue procured from cadaver donors (i.e., allografting) represents the best alternative, especially when the dermal component is lost. This request supports the activities of skin bank establishments (including donor screening, skin procurement, processing, storage, and distribution) that are regulated by specific guidelines and need to continuously meet quality standard requirements. The aim of this work is to both give specific insights of all the procedures implied in allograft preparation as well as an overview of their practical application in the treatment of different HHWs. The particular characteristics of each skin/dermal allograft released by Siena Skin Bank (cryopreserved/glycerol-preserved skin/de-epidermized dermis, acellular lyophilized de-epidermized dermis/reticular dermis) are also discussed. The exemplificative series of HHWs managed in the Dermatology Department of Siena were classified according their etiology into post-traumatic, vascular (arterial/venous/mixed/lymphatic), inflammatory, surgical, and heat/chemical burns. Globally, the clinical advantages obtained include: acceleration of healing process, pain sparing, resistance to bacterial contamination, dermal regeneration (instead of scarring), and better aesthetic-functional outcome.

Profiles, tissue and microbial integrity of cadavers used in medical faculties in South-western Uganda: implication in anatomical education.

Cadaveric dissection has remained an integral part of anatomical education globally; hence, the profiles of cadavers, their gross tissue and microbial integrity has great implication in anatomical education. This study determined the profiles, gross tissue and microbial integrity of cadavers used in South-western Uganda (SWU) medical schools. A cross-sectional study was carried out for three months in anatomy and microbiology laboratories of SWU medical teaching institutions. Ethical approval was obtained, cadavers were proportionately selected and examined grossly, and surface swabs taken for microbial analysis. Data collected was entered into Microsoft Excel, cleaned, and exported to Stata version 17 for analysis. Majority of cadavers were male (68%), adult (96%), blacks (100%), unknown cause of death (96%), obtained as unclaimed bodies (100%) and with no cadaver record tag (96%). Nearly a half (48%) cadavers had disrupted dentition, 68% had poor muscle integrity and 80% with abnormal fat. About 27% cadavers had poor surface microbial integrity among which 62.5% had a mixture of both bacteria and fungi, 25.0% had only fungi while 12.5% had only bacteria. A high number of cadavers had micro-organisms on their surfaces with majority having a mixture of bacteria and fungi. Majority of cadavers had poor gross tissue integrity. Better cadaver preservation methods should be adopted. To advocate for the establishment of cadaver donation policy and programs through which good quality cadavers can be obtained.

Stress fracture of bone under physiological multiaxial cyclic loading: Activity-based predictive models

While it is known that excessive accumulation of fatigue damage from daily activities contributes to fracture, a model of bone failure under physiologically relevant multiaxial cyclic loading needs to be developed in order to develop effective management strategies for stress or fatigue fractures. The role of strain-induced damage from repetitive loading is a strong candidate for such a model, as cycles of mechanical loading leading to failure can be measured directly. However, this approach has been limited by the restrictions of uniaxial loading models, which often overestimates the fatigue life of bone and suggests that bone will only break well beyond the realistic limits of exercise. To address this gap and develop a physiologically relevant model, our study leverages the power of four commonly used engineering failure criteria as a model for multiaxial loading using a cohort of human tibiae from cadaveric donors (age range 21–85 years old). Four failure criteria (Von Mises, Tsai-Wu, Findley critical plane, and maximum shear strain) were found to be effective in vitro models of tibial fracture when age groups of donors were combined (r2 > 0.84) and stratified (younger: 21–52-years-old versus older: 57–85-years-old) (r2 > 0.83) (p < 0.001). Each failure criterion displayed distinctly lower fatigue curves for the older age group. The maximum shear strain model was used to determine the efficacy of this approach to predict fatigue fractures in humans using published in vivo data from human volunteers. Consistent with in vivo observations in general population, the model demonstrated failure at 5000 to 200,000 loading cycles depending on activities such as jumping, sprinting, and walking, with a 3-fold reduction of fatigue life in older donors. These findings dramatically improve estimates of fatigue life under repetitive loading and demonstrate how age-related changes in bone significantly increase its propensity for fatigue-induced fractures.

Case Report of First Kidney Transplant in Mexico Using Horseshoe Kidney from a Cadaveric Donor in a Single Recipient

Case Report of First Kidney Transplant in Mexico Using Horseshoe Kidney from a Cadaveric Donor in a Single Recipient

Downregulation of PIEZO2 in the Detrusor of Men With Bladder Outlet Obstruction and Its Association With Urinary Retention and Decreased Bladder Compliance.

Recent research has highlighted the mechanotransducer PIEZO2 as a crucial factor in lower urinary tract function, demonstrating associations with bladder compliance (BC), bladder wall thickening, and elevated bladder pressure. We explored the hypothesis that PIEZO2 expression may be associated with lower urinary tract dysfunction in men with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH). The study included a consecutive series of patients undergoing open prostatectomy for BPH at our hospital between September 2014 and January 2016. All participants underwent comprehensive preoperative evaluations, including urodynamic assessments. During prostatectomy, a full-thickness fragment of the bladder wall was obtained for subsequent PIEZO2 gene expression analysis. Cadaveric organ donors served as the control group. PIEZO2 expression was downregulated in the detrusor muscle of men with BPH compared to the control group. Among patients with BPH, those experiencing urinary retention and requiring an indwelling catheter exhibited significantly lower PIEZO2 messenger RNA (mRNA) expression than patients capable of spontaneous voiding. PIEZO2 mRNA expression was similar in men with and without detrusor overactivity. Additionally, a positive correlation was found between PIEZO2 mRNA expression levels and BC. Our findings indicate that PIEZO2 is downregulated in the detrusor muscle of men with BPH, particularly in those experiencing urinary retention and those with reduced BC. These results suggest a potential role for PIEZO2 in BOOinduced bladder dysfunction. Further research is required to clarify the role of PIEZO mechanotransducers in the bladder and to explore their therapeutic implications.

A Retrospective View of Post Renal Transplant Urinary Tract Infections: An Experience of A UK Transplant Centre

Urinary tract infections (UTIs) are prevalent post renal transplant complication. These infections are most common in renal transplant recipient’s contrary to their incidence in general healthy population as shown by previous studies. Though the frequencies of occurrences are different in renal transplant patients. There is general lack of consensus on the risk factors associated with development of UTIs in renal transplant patients as well as effects posed by them and occurrence of mortality in patient group. This retrospective cohort study investigated and included adults’ patients who were operated for renal transplant in a single transplant center in UK from Jan 2014 to December 2023. The number of patients were 604 with two hundred and fifty-nine developed one or more UTIs in 42 months follow-up period. Significant risk factors for post-transplant UTIs were advanced age, female gender, reflux kidney disease, use of azathioprine and cadaveric donor. UTIs did not increase risk for renal graft loss, but were associated with increased mortality (3.5 odds ratio, 95% confidence interval 1.68–7.23). We conclude UTIs may be associated with an increased mortality risk in renal transplant recipients. Prevention of UTIs in high-risk renal transplant patients or those with recurrent UTIs may possibly decrease post-transplant mortality.

Midterm results after allogeneic simple limbal epithelial transplantation from deceased-donor eyes in patients with persistent corneal epithelial defects due to limbal stem cell deficiency.

This study aims to characterize the clinical outcomes after allogeneic simple limbal epithelial transplantation (alloSLET) utilizing tissue from cadaveric donor eyes to address persistent corneal epithelial defects caused by limbal stem cell deficiency. We conducted a retrospective analysis of medical records from 20 patients, encompassing 24 eyes, who underwent alloSLET at least 2 years prior. The primary endpoint was the achievement of complete epithelialization of the corneal surface by corneal epithelium. Secondary endpoints included corrected distance visual acuity (CDVA) and postoperative adverse events. The median postoperative follow-up period was 36 months (range, 24-74 months). At 1, 3 and 6 months post-surgery, 96% of eyes demonstrated epithelialized corneal surfaces, which declined to 71% at 12 months, to 54% at 24 and 36 months after surgery, and to 50% thereafter. There were no significant differences in graft survival between alloSLET performed alone versus in combination with penetrating keratoplasty. However, instances of graft failure were associated with postoperative elevated intraocular pressure (IOP) and a history of multiple amniotic membrane and corneal graft transplants. AlloSLET emerges as a viable mid-term intervention for limbal stem cell deficiency-associated non-healing corneal epithelial defects in the absence of autologous limbal tissue. Our findings underscore the increased risk of graft failure in patients with elevated IOP and a background of multiple previous amniotic membrane and corneal graft procedures.

Epidemiological Study and Seropositivity in Viral Panel Testing Among Corneal Tissue Donors.

Corneal tissue is a critical component for vision restoration through transplantation, yet the availability of suitable corneal tissue is limited. This limitation results in long waiting lists and high demand, especially in countries with lower donation rates compared to global benchmarks. In Mexico, the corneal donation rate remains significantly behind other Latin American countries and leading nations such as Spain. Understanding the characteristics of corneal tissue donors is essential for improving donation practices and addressing the shortage of available tissues. This descriptive retrospective study analyzed electronic medical records of cadaveric corneal donors at the General Regional Hospital 1 of the Mexican Social Security Institute of Querétaro from January 2022 to December 2023. Donors were included based on criteria such as age (2-85 years) and known cause of death. Exclusion criteria included age outside the specified range, neoplastic diseases, active systemic infections, and prior ocular surgeries. Serological testing for human immunodeficiency virus (HIV), Venereal Disease Research Laboratory (VDRL), coronavirus disease 2019 (COVID-19), hepatitis B virus (HBV), and hepatitis C virus (HCV was performed to assess viral reactivity. Statistical analyses were conducted usingIBM SPSS Statistics for Windows, Version 25 (Released 2017; IBM Corp., Armonk, New York, United States), summarizing data with descriptive statistics. The study included 185 corneal donors with a mean age of 56.34 years. The majority were male (109; 58.9%), and the leading causes of death were cardiogenic shock (34; 18.4%), hypovolemic shock (31; 16.8%), and acute respiratory failure (30; 16.2%). Exclusion due to positive serological tests included seven donors (3.8%) for HIV and seven (3.8%) for SARS-CoV-2. A total of 16 donors (8.6%) were excluded due to positive results in the viral serological panel. The most common comorbidities were chronic kidney disease (36; 19.5%), type 2 diabetes mellitus (28; 15.1%), and systemic hypertension (31; 16.8%). The study highlights a predominantly male donor profile with a mean age of 56.34 years and emphasizes cardiogenic shock as a leading cause of death. The notably higher seropositivity rate of 8.6% for various viral infections compared to international reports indicates a need for improved health interventions and screening processes. The focus on cardiovascular and respiratory causes of death underscores regional health issues affecting donation patterns. To address the organ and tissue donation shortfall, it is crucial to enhance coordination within donation teams and increase public awareness, given the significant gap in donation rates compared to leading countries.

Relationship between depth-wise refractive index and biomechanical properties of human articular cartilage.

Optical properties of biological tissues, such as refractive index (RI), are fundamental properties, intrinsically linked to the tissue's composition and structure. We hypothesize that, as the RI and the functional properties of articular cartilage (AC) are dependent on the tissue's structure and composition, the RI of AC is related to its biomechanical properties. This study aims to investigate the relationship between RI of human AC and its biomechanical properties. Human cartilage samples ( ) were extracted from the right knee joint of three cadaver donors (one female, aged 47 years, and two males, aged 64 and 68 years) obtained from a commercial biobank (Science Care, Phoenix, Arizona, United States). The samples were initially subjected to mechanical indentation testing to determine elastic [equilibrium modulus (EM) and instantaneous modulus (IM)] and dynamic [dynamic modulus (DM)] viscoelastic properties. An Abbemat 3200 automatic one-wavelength refractometer operating at 600 nm was used to measure the RI of the extracted sections. Similarly, Spearman's and Pearson's correlation coefficients were employed for non-normal and normal datasets, respectively, to determine the correlation between the depth-wise RI and biomechanical properties of the cartilage samples as a function of the collagen fibril orientation. A positive correlation with statistically significant relations ( ) was observed between the RI and the biomechanical properties (EM, IM, and DM) along the tissue depth for each zone, e.g., superficial, middle, and deep zones. Likewise, a lower positive correlation with statistically significant relations ( ) was also observed for collagen fibril orientation of all zones with the biomechanical properties. The results indicate that, although the RI exhibits different levels of correlation with different biomechanical properties, the relationship varies as a function of the tissue depth. This knowledge paves the way for optically monitoring changes in AC biomechanical properties nondestructively via changes in the RI. Thus, the RI could be a potential biomarker for assessing the mechanical competency of AC, particularly in degenerative diseases, such as osteoarthritis.

Abstract 35: The Dual Endothelin-1 Antagonist Aprocitentan Attenuates Mitochondrial Oxidative Stress in Human Cardiac Fibroblasts

Endothelin-1 (ET-1) is a peptide hormone primarily produced by endothelial cells that functions as a potent vasoconstrictor through two receptors, ETA and ETB. While most research on ET-1 has focused on endothelial dysfunction and hypertension, increasing evidence shows that ET-1 is also involved in other physiological processes such as cell proliferation, inflammation, and tissue remodeling. Dysregulation of ET-1 has been implicated in the pathogenesis of various diseases, including heart failure, atherosclerosis, fibrosis, systemic sclerosis, and cancer. Aprocitentan (also known as ACT-132577) is a relatively new dual ET-1 receptor antagonist that prevents ET-1 from binding to both endothelin receptors and has been shown to significantly reduce blood pressure in patients with resistant hypertension. Our hypothesis was that aprocitentan could reduce the proliferation rate and mitochondrial ROS production induced by TGF-β in human cardiac fibroblasts (HCFs). HCFs were isolated from hearts from fully de-identified cadaveric donors and cultured in cardiac fibroblast growth medium. HCFs were treated with aprocitentan (4 μM) and/or TGF-β1 (10 ng/ml) for 72 hours (doses and times identified in preliminary dose-response and time-course assays). Aprocitentan reduced the TGF-β1-induced proliferation rate in HCFs by approximately 23% ( Figure 1A ). Our study also aimed to determine if aprocitentan could mitigate mitochondrial dysfunction. Since the mitochondrion is a major source of reactive oxygen species (ROS), which can promote myofibroblast differentiation, mitochondrial properties in HCFs were assessed using MitoTracker Green and MitoSOX staining. TGF-β1 treatment increased mitochondrial ROS production, which was significantly reduced by aprocitentan ( Figure 1BC ); furthermore, aprocitentan reduced mitochondrial fragmentation induced by TGF-β1 treatment ( Figure 1D ). To the best of our knowledge, we are the first to demonstrate that aprocitentan can reduce the increased production of mitochondrial ROS, mitochondrial fragmentation, and cell proliferation rate induced by TGF-β1 in HCFs. This discovery could pave the way for new research and therapeutic strategies for treating fibrosis in cardiovascular disorders.

Kidney Transplantation and Cellular Immunity Dynamics: Immune Cell Alterations and Association with Clinical and Laboratory Parameters.

Background/Objectives: The purpose of this study was to evaluate numerical changes in immune cells after successful kidney transplantation and associate their recovery with clinical and laboratory factors. Methods: In 112 kidney transplant recipients, we performed flow cytometry to evaluate counts of CD4+, CD8+, and regulatory T cells (Tregs), as well as natural killer (NK) cells, before kidney transplantation (T0) and three (T3), six (T6), and twelve (T12) months later. The results were associated with the recipient's age, cold ischemia time (CIT), the type of donor, dialysis method and vintage, and graft function in one year. Results: Total and CD8+ T cell counts increased gradually one year post transplantation in comparison with pre-transplantation levels, whereas the number of CD4+ T cells and Tregs increased, and the number of NK cells decreased in the first three months and remained stable thereafter. The recipient's age was negatively correlated with total, CD4+, and Treg counts at T12, whereas CIT affected only total and CD4+ T cell count. Moreover, recipients receiving kidneys from living donors presented better recovery of all T cell subsets at T12 in comparison with recipients receiving kidneys from cadaveric donors. Patients on peritoneal dialysis had increased numbers of total and CD8+ T cells, as well as NK cells. Finally, estimated glomerular filtration rate was positively correlated with Treg level and potentially CD4+ T cells one-year post transplantation. Conclusions: Successful kidney transplantation results in the recovery of most T cell subsets. Lower recipient age and better graft function contribute to increased T cell counts, whereas donor type and dialysis modality are the most important modifiable factors for optimal immune recovery.

The impact of cadaveric donor transplant on the development of chronic rhinosinusitis and recalcitrant disease.

The study found a higher incidence of chronic rhinosinusitis (CRS) and recalcitrant CRS in cadaveric organ transplant recipients compared to those receiving living donor transplants. Recipients of cadaveric transplants were 1.32 times more likely to develop CRS and 1.68 times more likely to develop medically recalcitrant CRS. Living kidney transplants significantly reduced the risk of developing CRS (OR=0.12) and recalcitrant CRS (OR=0.11), highlighting a potentially protective effect against these conditions. In contrast, cadaveric liver transplants were associated with an increased risk of CRS and medically recalcitrant CRS. Kaplan-Meier survival analysis indicated a significant difference in time to CRS onset between cadaveric and living donor transplants. Median time to CRS onset was longer for living donor recipients (21.1 months) compared to cadaveric recipients (15.6 months). This study underscores the need for transplant teams and otolaryngologist to consider donor type during transplant follow-up due to differing risks of CRS development.

Sexual Dimorphism in the Architectural Design of Rat and Human Pelvic Floor Muscles.

Skeletal muscle architecture is a strong predictor of in vivo functional capacity and is evaluated in fixed tissues, accommodating the study of human muscles from cadaveric donors. Previous studies evaluating the pelvic floor muscles (PFMs) demonstrated that the rat is the most appropriate small animal model for the study of female PFM architecture, but the rat's suitability for the study of male PFMs is undetermined. We aimed to determine (1) whether PFM architecture exhibits sexual dimorphism in rats or humans, and (2) if the rat is also a suitable animal model for the study of male human PFMs. PFMs were fixed in situ and harvested en bloc from male and female cadaveric donors and 3-month-old male and female Sprague-Dawley rats. Three architectural parameters influenced by species size were used to compare male versus female PFMs within species, while four size-independent measures compared species within sex. All comparisons were made with two-way analysis of variances and Tukey's multiple comparisons tests post hoc. Sarcomere length (rats and humans, p = 0.016 and = 0.002) and normalized fiber length (rats, p < 0.001) were significantly larger in male PFMs. Three of the size-independent measures exhibited similar species trends in both sexes, while the size-independent sarcomere length measure (Ls/Lso) differed between male rats and humans (p < 0.001). Thus, sexual dimorphism is present in rat and human PFM architecture, and the male rat is suitable for studies of human male PFMs.

Predicting graft survival in paediatric kidney transplant recipients using machine learning.

Identification of factors that affect graft survival in kidney transplantation can increase graft survival and reduce mortality. Artificial intelligence modelling enables impartial evaluation of clinician bias. This study aimed to examine factors that affect the survival of grafts in paediatric kidney transplantation through the use of machine learning. A retrospective review was conducted on records of paediatric patients who underwent kidney transplantation between 1994 and 2021 and had post-transplant follow-up > 12months. The nearest neighbour method was used to impute missing fields from a total of 48 variables in the dataset. Models including Naive Bayes, logistic regression, support vector machine (SVM), multi-layer perceptron, and XGBoost were trained to predict graft survival. The study used 80% of the patients for training and the remaining 20% for testing. Modelling success was evaluated based on accuracy and F1 score metrics. The study analysed 465 kidney transplant recipients. Of these, 56.7% were male. The mean age at transplantation was 12.08 ± 5.01years. Of the kidney transplants, 73.1% (n = 339) were from living donors, 34.5% (n = 160) were pre-emptive transplants, and 2.2% (n = 10) were second-time transplants. The machine learning model identified several features associated with graft survival, including antibody-mediated rejection (+ 0.7), acute cellular rejection (+ 0.66), eGFR at 3years (+ 0.43), eGFR at 5years (+ 0.34), pre-transplant peritoneal dialysis (+ 0.2), and cadaveric donor (+ 0.2). The successes of the logistic regression and SVM models were similar. The F1 score was 91.9%, and accuracy was 96.5%. Machine learning can be used to identify factors that affect graft survival in kidney transplant recipients. By expanding similar studies, risk maps can be created prior to transplantation.

Mass Spectrometry Imaging of the Subchondral Bone in Osteoarthritis Reveals Tissue Remodeling of Extracellular Matrix Proteins that Precede Cartilage Loss.

Osteoarthritis (OA) of the knee is a degenerative condition of the skeletal extracellular matrix (ECM) marked by the loss of articular cartilage and subchondral bone homeostasis. Treatments for OA in the knee beyond full joint replacement are lacking primarily due to gaps in molecular knowledge of the biological drivers of disease. Here, Mass Spectrometry Imaging (MSI) enabled molecular spatial mapping of the proteomic landscape of human knee tissues. Histologic sections of human tibial plateaus from OA patients and cadaveric controls were treated with collagenase III to target ECM proteins prior to imaging using a timsTOF fleX mass spectrometer (Bruker) for matrix-assisted laser desorption ionization (MALDI)-MSI of bone and cartilage proteins in human knees. Spatial MSI data of the knee, using sections of the tibial plateau from non-arthritic, cadaveric donors or from knee replacement patients with medial OA were processed and automatically segmented identifying distinct areas of joint damage. ECM peptide markers compared either OA to cadaveric tissues or OA medial to OA lateral. Not only did candidate peptides distinguish OA relative to intact cartilage, but also emphasized a significant spatial difference between OA and intact subchondral bone (AUROC >0.85). Overall, 31 peptide candidates from ECM proteins, including COL1A1, COL3A1, and unanticipated detection of collagens COL6A1 and COL6A3 in adult bone, exhibited significantly elevated abundance in diseased tissue. Highly specific hydroxyproline-containing collagens dominated OA subchondral bone directly under regions of lost cartilage revealing dramatic tissue remodeling providing molecular details on the progression of joint degeneration in OA. The identification of specific spatial markers for the progression of subchondral bone degeneration in OA advances our molecular understanding of coupled deterioration of joint tissues.

COMPARAISON DES RESULTATS A LONG TERME DE LA TRANSPLANTATION RENALE ENTRE CONJOINTS ET DONNEURS VIVANTS APPARENTES: EXPERIENCE MONOCENTRIQUE AU MAROC

Objective: End-stage kidney disease is a serious medical condition that often requires a kidney transplant. This single-center study, conducted in Morocco, examines the long-term outcomes of kidney transplants from spouses and related living donors. The goal is to enhance access to organ transplantation by assessing the success of transplants using spouses as donors. Patients and methods:A total of 117 patients were eligible for a kidney transplant from their spouses kidneys. Out of these, 36 received a transplant and were compared to 56 patients who received a kidney from a related donor. Demographic, clinical, and immunological data, as well as long-term outcomes, including graft survival, were analyzed. Results: Recipientswerepredominantly male in both groups (69.6% versus 83.3%). Recipients in the related group wereyoungerthanthose in the unrelated group (39.80 versus 56.56 years). Relatedgraftsshowed more HLA matchingthanunrelatedgrafts (4.45 versus 1.64). The occurrence of DSA after transplantation wasslightlylower in the relatedgraft (16.1% versus 19.4%). Graftsurvival at 1, 3, 5, and 10 yearswassimilar in both groups, with a slight favorable trend for the related group. Conclusion: Kidney transplant survival rates are broadlysimilarbetweenspouses and related living donors. This suggeststhatspousal donation can compensate for the scarcity of cadaveric donation, particularly in Morocco.

Safe immunosuppression. New tool for personalized immunosuppressant treatment in renal transplantation. A case report

Background: The adjustment of immunosuppressive therapy after kidney transplantation (KT) to avoid graft rejection remains an important challenge for clinicians. It is difficult to achieve a good balance between under-immunosuppression (with an increased risk of graft rejection) and over-immunosuppression (with an increased risk of side effects) by only relying on the available information about immunosuppressive drugs (IMS). Immunobiogram® (IMBG) is a novel in vitro diagnostic test that provides clinicians with information about the patient’s sensitivity to individual IMS. Objective: To present a case report of a patient with renal transplant in the maintenance phase who presented several complications probably related to the immunosuppression during the follow-up, where the use of IMBG as complementary information helped clinicians to guide the therapeutical decision. Methods: IMBG is a first-in-class in vitro immunoassay that involves the culture of the patient peripheral blood mononuclear cells (PBMCs) in a semi-solid 3D matrix, then submitted to immune stimulation. It reveals the capacity of an IMS over a gradient to inhibit the activation of immune cells. The read-out allows the building of a dose-response curve per IMS tested, which is mathematically analyzed by a software using the key curve parameters and finally to be translated into a sensitivity map to IMS. Findings: We present a case report of a 72-year-old patient with a cadaveric donor kidney transplant receiving standard immunosuppressive treatment with mycophenolate, tacrolimus, and corticosteroids. The patient presented several episodes of infections during the follow-up (SARS-CoV2, Cytomegalovirus, spondylodisquitis by Staphylococcus aureus, and emphysematous cystitis) which were managed with different treatment adjustments such as de-escalation of mycophenolate and switching to mTOR. The information provided by the IMBG showed a lack of sensitivity to mTOR which allowed to confirm the final adjustment to a treatment with tacrolimus and corticosteroids, remaining the patient stable since then. Discussion: Despite various adjustments to the immunosuppressive therapy during the follow-up, the patient continued experiencing adverse effects that could be related to an over-immunosuppression state. The IMBG provided pharmacodynamic information that complemented the clinical and pharmacokinetic data available, facilitating the individualization of the treatment. Conclusion: The case highlights the potential of the IMBG as a complementary clinical tool for personalized treatment of kidney transplant patient management.

Pharmaceutical targeting of the cannabinoid type 1 receptor impacts the crosstalk between immune cells and islets to reduce insulitis in humans

Aims/hypothesisInsulitis, a hallmark of inflammation preceding autoimmune type 1 diabetes, leads to the eventual loss of functional beta cells. However, functional beta cells can persist even in the face of continuous insulitis. Despite advances in immunosuppressive treatments, maintaining functional beta cells to prevent insulitis progression and hyperglycaemia remains a challenge. The cannabinoid type 1 receptor (CB1R), present in immune cells and beta cells, regulates inflammation and beta cell function. Here, we pioneer an ex vivo model mirroring human insulitis to investigate the role of CB1R in this process.MethodsCD4+ T lymphocytes were isolated from peripheral blood mononuclear cells (PBMCs) from male and female individuals at the onset of type 1 diabetes and from non-diabetic individuals, RNA was extracted and mRNA expression was analysed by real-time PCR. Single beta cell expression from donors with type 1 diabetes was obtained from data mining. Patient-derived human islets from male and female cadaveric donors were 3D-cultured in solubilised extracellular matrix gel in co-culture with the same donor PBMCs, and incubated with cytokines (IL-1β, TNF-α, IFN-γ) for 24–48 h in the presence of vehicle or increasing concentrations of the CB1R blocker JD-5037. Expression of CNR1 (encoding for CB1R) was ablated using CRISPR/Cas9 technology. Viability, intracellular stress and signalling were assayed by live-cell probing and real-time PCR. The islet function measured as glucose-stimulated insulin secretion was determined in a perifusion system. Infiltration of immune cells into the islets was monitored by microscopy. Non-obese diabetic mice aged 7 weeks were treated for 1 week with JD-5037, then euthanised. Profiling of immune cells infiltrated in the islets was performed by flow cytometry.ResultsCNR1 expression was upregulated in circulating CD4+ T cells from individuals at type 1 diabetes onset (6.9-fold higher vs healthy individuals) and in sorted islet beta cells from donors with type 1 diabetes (3.6-fold higher vs healthy counterparts). The peripherally restricted CB1R inverse agonist JD-5037 arrested the initiation of insulitis in humans and mice. Mechanistically, CB1R blockade prevented islet NO production and ameliorated the ATF6 arm of the unfolded protein response. Consequently, cyto/chemokine expression decreased in human islets, leading to sustained islet cell viability and function.Conclusions/interpretationThese results suggest that CB1R could be an interesting target for type 1 diabetes while highlighting the regulatory mechanisms of insulitis. Moreover, these findings may apply to type 2 diabetes where islet inflammation is also a pathophysiological factor.Data availabilityTranscriptomic analysis of sorted human beta cells are from Gene Expression Omnibus database, accession no. GSE121863, available at https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSM3448161.Graphical

Minimally Invasive Anterior Closing–wedge Osteotomy for Posterior Tibial Slope Correction: A Pilot Study

Introduction: The purpose of this study was to investigate the feasibility of performing a new minimally invasive technique for anterior closing–wedge high tibial osteotomy. Our hypothesis was that we would be able to successfully perform the minimally invasive osteotomy with consistent correction of the posterior tibial slope. Materials and Methods: Five lower limbs from cadaveric unidentified donors were obtained. Fluoroscopic imaging of the knee was obtained to determine the baseline tibial slope. A standard anterior closing–wedge osteotomy was planned to obtain the desired correction. The anterior bony segment was resected from the proximal tibia utilizing the Shannon burr under fluoroscopic guidance through a 2 cm medial incision. Fixation was completed with 2 staples positioned medial and lateral to the tibial tubercle. Results: The average posterior tibial slope of the 5 specimens was 8 degrees (SD: 2.3, range: 6 to 12). The average final posterior tibial was 1.8 degrees (SD: 2.1, range: −1 to 5). The average slope correction was 6.2 degrees (SD: 0.7, range: 5 to 7). Posterior tibial cortical fracture did not occur in any of the cases. Conclusions: Our novel minimally invasive anterior closing–wedge high tibial osteotomy technique resulted in a reproducible correction of posterior tibial slope in a cadaveric model. This is the first study to describe a minimally invasive technique for anterior closing–wedge high tibial osteotomy. Larger cadaveric studies including multiple surgeons across institutions are warranted to validate the described technique between providers. Level of Evidence: Level IV—Controlled laboratory study

Gastrointestinal Cytomegalovirus Infection in a Transplantation Recipient With a Negative Serum Viral Load: Case Report

Kidney transplant recipients are vulnerable to infections, especially cytomegalovirus (CMV) disease. It is recommended that clinicians plan their prophylaxis and therapeutic regimens based on viral load testing. CMV viral load monitoring testing provides useful information for identifying virologic response and possible antiviral resistance. Due to the paucity of medical literature on guiding viral therapy in cases of CMV tissue disease with nondetectable serum viral load, we intend to provide physicians with evidence on how to guide medical therapy in these cases. A 49-year-old Hispanic male recipient of a kidney transplant from a cadaver donor presented to the emergency department with anorexia, asthenia, diarrhea, weight loss, and supraclavicular and mediastinal adenomegalies at 2 months post-transplantation. Both patients were serum IgG- and IgM-positive for CMV, which classified them as intermediate risk for developing CMV disease or tissue-invasive disease (donor-positive/recipient-positive [D+/R+]). The patient was induced with basiliximab and methylprednisolone and received maintenance therapy with tacrolimus, mycophenolic acid, and prednisone. Real-time polymerase chain reaction analyses were performed due to suspicion for BK virus, B19 parvovirus, Epstein-Barr virus, and CMV, with an undetectable viral load for all. A biopsy specimen taken from the gastrointestinal tract confirmed CMV infection, which was corroborated through immunocytochemistry. Histopathologic testing is a possible option for patients with CMV tissue disease symptoms but no detectable serum viral load. Clinical observation is fundamental when viral monitoring is difficult.