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1.
Pediatr Nephrol ; 39(5): 1347-1353, 2024 May.
Article En | MEDLINE | ID: mdl-37658874

Paediatric kidney failure is a global problem responsible for significant childhood morbidity and mortality. The gold-standard treatment is kidney transplantation. However, the availability of kidney transplantation remains limited in some low- and middle-income countries (LMICs). Transplant Links Community (TLC) is a UK-based charity that mentors units in LMICs wishing to start kidney transplantation; the ultimate goal is for these units to become self-sufficient. TLC provides this support through in-person training visits and skill transfer, plus direct mentorship from the UK that is maintained over many years. From such mentoring programmes, it is evident that there are numerous challenges in the initial establishment and long-term maintenance of kidney transplant services, with specific and unique barriers applying to setting up paediatric transplant programmes compared to their adult counterparts. This review summarises TLC's first-hand experience of developing paediatric kidney transplantation services in LMICs over the past 15 years, the challenges encountered, and the major ongoing barriers that must be addressed to facilitate further progress in delivering transplantation services to children globally.


Kidney Transplantation , Mentoring , Adult , Humans , Child , Developing Countries , Mentors
2.
J Clin Med ; 10(5)2021 Feb 26.
Article En | MEDLINE | ID: mdl-33652905

The coronavirus disease, COVID-19, has caused widespread and sustained disruption to healthcare, not only in the delivery of emergency care, but knock-on consequences have resulted in major delays to the delivery of elective care, including surgery. COVID-19 has accelerated novel pathways for delivering clinical services, many of which have an increased reliance on technology. COVID-19 has impacted care for patients with both hypoparathyroidism and hyperparathyroidism. The role of vitamin D in the prevention of severe COVID-19 infection has also been widely debated. Severe hypocalcemia can be precipitated by infection in patients with hypoparathyroidism. With this in mind, compliance with medical management, including calcium and vitamin D supplementation, is crucial. Technology in the form of text message reminders and smartphone apps may have a key role in ensuring this. Furthermore, clinicians should ensure that patients are educated on the symptoms of hypocalcemia and the steps needing to be taken should these symptoms be experienced. Patients with primary hyperparathyroidism (PHPT) should be educated on the symptoms of hypercalcemia, as well as the importance of remaining adequately hydrated. In addition, patients should be reassured that the postponement of parathyroidectomy is likely to have negligible impact on their condition; for those with symptomatic hypercalcemia, cinacalcet can be considered as an interim measure.

3.
PLoS Pathog ; 17(2): e1009260, 2021 02.
Article En | MEDLINE | ID: mdl-33524040

Epidemiological studies have identified a correlation between maternal helminth infections and reduced immunity to some early childhood vaccinations, but the cellular basis for this is poorly understood. Here, we investigated the effects of maternal Schistosoma mansoni infection on steady-state offspring immunity, as well as immunity induced by a commercial tetanus/diphtheria vaccine using a dual IL-4 reporter mouse model of maternal schistosomiasis. We demonstrate that offspring born to S. mansoni infected mothers have reduced circulating plasma cells and peripheral lymph node follicular dendritic cells at steady state. These reductions correlate with reduced production of IL-4 by iNKT cells, the cellular source of IL-4 in the peripheral lymph node during early life. These defects in follicular dendritic cells and IL-4 production were maintained long-term with reduced secretion of IL-4 in the germinal center and reduced generation of TFH, memory B, and memory T cells in response to immunization with tetanus/diphtheria. Using single-cell RNASeq following tetanus/diphtheria immunization of offspring, we identified a defect in cell-cycle and cell-proliferation pathways in addition to a reduction in Ebf-1, a key B-cell transcription factor, in the majority of follicular B cells. These reductions are dependent on the presence of egg antigens in the mother, as offspring born to single-sex infected mothers do not have these transcriptional defects. These data indicate that maternal schistosomiasis leads to long-term defects in antigen-induced cellular immunity, and for the first time provide key mechanistic insight into the factors regulating reduced immunity in offspring born to S. mansoni infected mothers.


B-Lymphocytes/immunology , Interleukin-4/immunology , Pregnancy Complications, Parasitic/immunology , Schistosomiasis mansoni/immunology , Animals , Animals, Newborn/immunology , Diphtheria-Tetanus Vaccine/immunology , Female , Immunologic Memory , Lymph Nodes/immunology , Male , Mice , Natural Killer T-Cells/immunology , Pregnancy , Prenatal Exposure Delayed Effects/immunology , Prenatal Exposure Delayed Effects/parasitology , RNA-Seq , Stromal Cells/immunology
4.
Transplantation ; 103(2): 314-322, 2019 02.
Article En | MEDLINE | ID: mdl-30461718

BACKGROUND: Supplemental oxygenation of the standard hypothermic machine perfusion (HMP) circuit has the potential to invoke favorable changes in metabolism, optimizing cadaveric organs before transplantation. METHODS: Eight pairs of porcine kidneys underwent 18 hours of either oxygenated (HMP/O2) or aerated (HMP/Air) HMP in a paired donation after circulatory death model of transplantation. Circulating perfusion fluid was supplemented with the metabolic tracer universally labeled glucose.Perfusate, end-point renal cortex, and medulla samples underwent metabolomic analysis using 1-dimension and 2-dimension nuclear magnetic resonance experiments in addition to gas chromatography-mass spectrometry. Analysis of C-labeled metabolic products was combined with adenosine nucleotide levels and differences in tissue architecture. RESULTS: Metabolomic analysis revealed significantly higher concentrations of universally labeled lactate in the cortex of HMP/Air versus HMP/O2 kidneys (0.056 mM vs 0.026 mM, P < 0.05). Conversely, newly synthesized [4,5-C] glutamate concentrations were higher in the cortex of HMP/O2 kidneys inferring relative increases in tricarboxylic acid cycle activity versus HMP/Air kidneys (0.013 mmol/L vs 0.003 mmol/L, P < 0.05). This was associated with greater amounts of adenoside triphosphate in the cortex HMP/O2 versus HMP/Air kidneys (19.8 mmol/mg protein vs 2.8 mmol/mg protein, P < 0.05). Improved flow dynamics and favorable ultrastructural features were also observed in HMP/O2 kidneys. There were no differences in thiobarbituric acid reactive substances and reduced glutathione levels, tissue markers of oxidative stress, between groups. CONCLUSIONS: The supplementation of perfusion fluid with high-concentration oxygen (95%) results in a greater degree of aerobic metabolism versus aeration (21%) in the nonphysiological environment of HMP, with reciprocal changes in adenoside triphosphate levels.


Kidney/blood supply , Oxygen/metabolism , Perfusion , Adenosine Triphosphate/analysis , Animals , Citric Acid Cycle , Gas Chromatography-Mass Spectrometry , Hypothermia, Induced , Kidney/metabolism , Magnetic Resonance Spectroscopy , Male , Swine
5.
Eur J Immunol ; 49(3): 428-442, 2019 03.
Article En | MEDLINE | ID: mdl-30575951

IL-4 is critical for differentiation of Th2 cells and antibody isotype switching, but our work demonstrated that it is produced in the peripheral LN under both Type 2, and Type 1 conditions, raising the possibility of other functions. We found that IL-4 is vital for proper positioning of hematopoietic and stromal cells in steady state, and the lack of IL-4 or IL-4Rα correlates with disarrangement of both follicular dendritic cells and CD31+ endothelial cells. We observed a marked disorganization of B cells in these mice, suggesting that the lymphocyte-stromal cell axis is maintained by the IL-4 signaling pathway. This study showed that absence of IL-4 correlates with significant downregulation of Lymphotoxin alpha (LTα) and Lymphotoxin beta (LTß), critical lymphokines for the development and maintenance of lymphoid organs. Moreover, immunization of IL-4 deficient mice with Type 2 antigens failed to induce lymphotoxin production, LN reorganization, or germinal center formation, while this process is IL-4 independent following Type 1 immunization. Additionally, we found that Type 1 antigen mediated LN reorganization is dependent on IFN-γ in the absence of IL-4. Our findings reveal a role of IL-4 in the maintenance of peripheral lymphoid organ microenvironments during homeostasis and antigenic challenge.


Cell Proliferation , Interleukin-4/immunology , Receptors, Cell Surface/immunology , Stromal Cells/immunology , Animals , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Dendritic Cells, Follicular/immunology , Dendritic Cells, Follicular/metabolism , Endothelial Cells/immunology , Endothelial Cells/metabolism , Germinal Center/immunology , Germinal Center/metabolism , Interferon-gamma/immunology , Interferon-gamma/metabolism , Interleukin-4/genetics , Interleukin-4/metabolism , Lymph Nodes/immunology , Lymph Nodes/metabolism , Lymphotoxin-alpha/immunology , Lymphotoxin-alpha/metabolism , Lymphotoxin-beta/immunology , Lymphotoxin-beta/metabolism , Mice, Inbred C57BL , Mice, Knockout , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Stromal Cells/cytology , Stromal Cells/metabolism
6.
Transplant Direct ; 4(12): e406, 2018 Dec.
Article En | MEDLINE | ID: mdl-30584587

BACKGROUND: Increasing numbers of patients with end-stage renal failure are receiving kidneys from nondirected kidney donors (NKDs), also known as altruistic donors. Transplant outcomes for recipients of such kidneys are largely inferred from studies on specified kidney donors (SKDs), which may be inaccurate due to differences in donor, recipient and transplant specific factors. We report the outcomes for recipients of NKD in the United Kingdom. METHODS: Outcomes for 6861 patients receiving a living donor kidney transplant between January 2007 and December 2014 were analyzed using both the National Health Service Blood and Transplant and the UK Renal Registry datasets. Graft and patient outcomes were compared for patients receiving NKD and SKD organs using univariable and multivariable analyses. RESULTS: There was significant discordance between the NKD and SKD donors and recipients. These included increased donor age (median, 58 years vs 47 years; P < 0.001) and higher rates of hemodialysis and previous transplants in the NKD group (both P < 0.001). Despite such markers of increased risk among both donors and recipients of NKD kidneys, there was no difference in graft survival on univariable (hazard ratio, 1.20; 95% confidence interval, 0.77-1.86; P = 0.419) or multivariable analysis (hazard ratio, 1.13; 95% confidence interval, 0.65-1.95; P = 0.665). CONCLUSIONS: Despite some markers of transplant complexity, nondirected kidney donor organs are an excellent source of organs for transplantation.

7.
Front Immunol ; 9: 2580, 2018.
Article En | MEDLINE | ID: mdl-30483256

Hepatic macrophages play an essential role in the granulomatous response to infection with the parasitic helminth Schistosoma mansoni, but the transcriptional changes that underlie this effect are poorly understood. To explore this, we sorted the two previously recognized hepatic macrophage populations (perivascular and Kupffer cells) from naïve and S. mansoni-infected male mice and performed microarray analysis as part of the Immunological Genome Project. The two hepatic macrophage populations exhibited remarkably different genomic profiles. However, this diversity was substantially reduced following infection with S. mansoni, and in fact, both populations demonstrated increases in transcripts of the monocyte lineage, suggesting that both populations may be replenished by monocytes following infection. Pathway analysis showed a profound alteration in global metabolic pathways, including changes to phospholipid and cholesterol metabolism, as well as amino acid biosynthesis and glucagon signaling. These changes suggest a possible mechanism for the previously reported athero-protective effects of S. mansoni infection. Indeed, we find that male ApoE null mice fed a high-fat diet in combination with S. mansoni infection have reduced plaque area and increased glucose tolerance as compared to control mice. Transcript analysis of infected and control high-fat diet fed ApoE-/- mice confirm that ApoC1, Psat1, and Gys1 are all altered by infection, suggesting that altered hepatic macrophage metabolism is associated with S. mansoni- induced protection from hyperlipidemia, atherosclerosis, and glucose intolerance. These results suggest a previously unknown and unreported role of hepatic macrophages in the modulation of whole body lipid and glucose metabolism during infection and provide a template for examining the role of immunomodulation on the long-term metabolism of the host.


Atherosclerosis/immunology , Kupffer Cells/physiology , Liver/pathology , Macrophages/metabolism , Schistosoma mansoni/physiology , Schistosomiasis mansoni/immunology , Animals , Atherosclerosis/genetics , Cells, Cultured , Cytoprotection , Diet, High-Fat , Disease Models, Animal , Glucagon/metabolism , Humans , Lipid Metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout, ApoE , Microarray Analysis , Phenotype , Schistosomiasis mansoni/genetics , Signal Transduction , Transcriptional Activation
8.
Transpl Int ; 31(10): 1099-1109, 2018 10.
Article En | MEDLINE | ID: mdl-29665191

The aim of this study was to determine the effect of donor body mass index (BMI) on deceased donor kidney transplant outcomes. Data were collected from the UK Transplant Registry for all deceased donor kidney transplant recipients between January 2003 and January 2015. Univariable and multivariable analyses were undertaken to assess the impact of donor BMI on a range of outcomes. Donor BMI (kg/m2 ) was stratified as <18.5 (n = 380), 18.5-25.0 (n = 6890), 25.1-30.0 (n = 6669), 30.1-35.0 (n = 2503) and >35.0 (n = 1148). The prevalence of delayed graft function increased significantly with donor BMI (P < 0.001), with an adjusted odds ratio of 1.38 (95% CI: 1.16-1.63) for the >35.0 vs. 18.5-25.0 groups. However, there was no significant association between donor BMI and 12-month creatinine (P = 0.550), or patient (P = 0.109) or graft (P = 0.590) survival. In overweight patients, increasing donor BMI was associated with a significant increase in warm ischaemia time and functional warm ischaemia time, by an average of 4.6% (P = 0.043) and 5.2% (P = 0.013) per 10.0 kg/m2 . However, rising warm ischaemic time and functional warm ischaemic time was not significantly associated with delayed graft function, 12-month creatinine levels, graft loss or patient death. In this population cohort study, we identified no significant association between donor BMI and long-term clinical outcomes in deceased donor kidney transplantation.


Body Mass Index , Kidney Transplantation , Renal Insufficiency/surgery , Tissue Donors , Adult , Cohort Studies , Creatinine/blood , Death , Delayed Graft Function , Female , Graft Survival , Humans , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Perfusion , Prognosis , Registries , United Kingdom , Warm Ischemia
10.
Am J Transplant ; 18(6): 1408-1414, 2018 06.
Article En | MEDLINE | ID: mdl-29136348

Evidence is currently lacking regarding the outcomes of kidneys undergoing hypothermic machine perfusion (HMP) in patients in the United Kingdom. Using the National Health Service Blood and Transplant database, the authors compared outcomes for recipients of single-organ donation after circulatory death (DCD) kidneys preserved with HMP with those preserved using only static cold storage (SCS). Between 2007 and 2015, HMP was used in 19.1% (864/4,529) of kidneys. Rates of delayed graft function (DGF) were significantly lower in organs preserved with HMP than for organs preserved with SCS (34.2% vs 42.0%, P < .001), despite a slightly longer cold ischemic time (median: 14.8 vs 14.1 hours, P < .001). Multivariable analysis found the effect of preservation modality to remain significant, with HMP organs having a significantly lower rate of DGF (odds ratio 0.65, 95% confidence interval 0.53-0.80, P < .001) and significantly shorter times to DGF resolution (average: 6.1 vs 7.4 days, P = .003) than SCS organs. The patient (P = .313) and graft (P = .263) survival rates were similar in the 2 preservation groups. HMP was associated with a marginal functional benefit in 1-year creatinine values (P = .044), with adjusted averages of 1.36 mg/dL (HMP) versus 1.40 mg/dL (SCS). This study supports the use of HMP and aids decision-making over its instigation, which may improve short-term patient outcomes.


Cold Ischemia , Organ Preservation/methods , Tissue and Organ Procurement , Adult , Creatinine/blood , Delayed Graft Function , Graft Survival , Humans , Middle Aged , Survival Analysis , United Kingdom
11.
Cryobiology ; 74: 115-120, 2017 02.
Article En | MEDLINE | ID: mdl-27919740

Hypothermic machine perfusion (HMP) and static cold storage (SCS) are the two methods used to preserve deceased donor kidneys prior to transplant. This study seeks to characterise the metabolic profile of HMP and SCS porcine kidneys in a cardiac death donor model. Twenty kidneys were cold flushed and stored for two hours following retrieval. Paired kidneys then underwent 24 h of HMP or SCS or served as time zero controls. Metabolite quantification in both storage fluid and kidney tissue was performed using one dimensional 1H NMR spectroscopy. For each metabolite, the net gain for each storage modality was determined by comparing the total amount in each closed system (i.e. total amount in storage fluid and kidney combined) compared with controls. 26 metabolites were included for analysis. Total system metabolite quantities following HMP or SCS were greater for 14 compared with controls (all p < 0.05). In addition to metabolic differences with control kidneys, the net metabolic gain during HMP was greater than SCS for 8 metabolites (all p < 0.05). These included metabolites related to central metabolism (lactate, glutamate, aspartate, fumarate and acetate). The metabolic environments of both perfusion fluid and the kidney tissue are strikingly different between SCS and HMP systems in this animal model. The total amount of central metabolites such as lactate and glutamate observed in the HMP kidney system suggests a greater degree of de novo metabolic activity than in the SCS system. Maintenance of central metabolic pathways may contribute to the clinical benefits of HMP.


Cryopreservation/methods , Energy Metabolism/physiology , Kidney/physiology , Organ Preservation/veterinary , Perfusion/methods , Acetic Acid/metabolism , Animals , Aspartic Acid/metabolism , Cryopreservation/veterinary , Fumarates/metabolism , Glutamic Acid/metabolism , Hypothermia, Induced/methods , Lactic Acid/metabolism , Magnetic Resonance Imaging/methods , Male , Models, Animal , Organ Preservation/methods , Renal Dialysis/methods , Swine
13.
Transplant Res ; 5: 7, 2016.
Article En | MEDLINE | ID: mdl-27499851

BACKGROUND: The aim of this study is to determine the feasibility of using nuclear magnetic resonance (NMR) tracer studies ((13)C-enriched glucose) to detect ex vivo de novo metabolism in the perfusion fluid and cortical tissue of porcine kidneys during hypothermic machine perfusion (HMP). METHODS: Porcine kidneys (n = 6) were subjected to 24 h of HMP using the Organ Recovery Systems LifePort Kidney perfusion device. Glucose, uniformly enriched with the stable isotope (13)C ([U-(13)C] glucose), was incorporated into KPS-1-like perfusion fluid at a concentration of 10 mM. Analysis of perfusate was performed using both 1D (1)H and 2D (1)H,(13)C heteronuclear single quantum coherence (HSQC) NMR spectroscopy. The metabolic activity was then studied by quantifying the proportion of key metabolites containing (13)C in both perfusate and tissue samples. RESULTS: There was significant enrichment of (13)C in a number of central metabolites present in both the perfusate and tissue extracts and was most pronounced for lactate and alanine. The total amount of enriched lactate (per sample) in perfusion fluid increased during HMP (31.1 ± 12.2 nmol at 6 h vs 93.4 ± 25.6 nmol at 24 h p < 0.01). The total amount of enriched alanine increased in a similar fashion (1.73 ± 0.89 nmol at 6 h vs 6.80 ± 2.56 nmol at 24 h p < 0.05). In addition, small amounts of enriched acetate and glutamic acid were evident in some samples. CONCLUSIONS: This study conclusively demonstrates that de novo metabolism occurs during HMP and highlights active metabolic pathways in this hypothermic, hypoxic environment. Whilst the majority of the (13)C-enriched glucose is metabolised into glycolytic endpoint metabolites such as lactate, the presence of non-glycolytic pathway derivatives suggests that metabolism during HMP is more complex than previously thought. Isotopic labelled ex vivo organ perfusion studies using 2D NMR are feasible and informative.

14.
Transplantation ; 100(8): 1667-74, 2016 Aug.
Article En | MEDLINE | ID: mdl-27222932

BACKGROUND: Current transplant immunosuppression regimens have numerous limitations. Recent evidence suggests histone deacetylase inhibitors (HDACis) may represent a class of drug with immunosuppressive properties. This study compares cyclosporin A (CyA) with the pan-HDACi suberoylanilide hydroxamic acid (SAHA) and a novel HDAC6-specific inhibitor (KA1010) in models of alloreactivity. METHODS: Proliferation and mixed lymphocyte reaction (MLR)-based assays were used to determine the immunosuppressive effect of compounds, and a murine model of allogeneic skin transplantation was adopted to assess the in vivo effects of HDAC6 inhibition. RESULTS: KA1010 displayed superior inhibitory effects on the activation of peripheral mononuclear cells using in vitro models of transplantation. In a 1-way MLR, KA1010 (5 µΜ) reduced parent cell proliferation from 92% to 64% (P = 0.001). A 2-way MLR, adopting IFN-γ production as a marker of alloresponse, resulting in up to 91% reduction. Dose-response curves revealed dose-dependent profiles with greater potency of HDACis over CyA (IC50 values of 82.0 nM and 13.4 nM for KA1010 and SAHA).Mice treated with KA1010 displayed no significant features of skin allograft rejection upon histological analysis at 70 days and graft survival of 80% in subjects treated with 160 mg/kg. Immunological assessment, revealed a significant increase in CD4CD25forkhead box P3 regulatory T cells (from 18% to 25%, P = 0.0002) and a corresponding reduction in CD4 T cells (from 58% to 42%, P = 0.0009). CONCLUSIONS: HDAC6 may represent an optimal target for future immunosuppressant therapeutics with a particular role in transplantation. In this article, we have demonstrated a superior immunosuppressive effect of KA1010 over both CyA and SAHA, in the models of allotransplantation adopted.


Aminopyridines/pharmacology , Graft Rejection/prevention & control , Graft Survival/drug effects , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , Hydroxamic Acids/pharmacology , Immunosuppressive Agents/pharmacology , Leukocytes, Mononuclear/drug effects , Skin Transplantation/adverse effects , Skin/drug effects , Animals , Cell Proliferation/drug effects , Cells, Cultured , Cyclosporine/pharmacology , Disease Models, Animal , Dose-Response Relationship, Drug , Graft Rejection/enzymology , Graft Rejection/immunology , Graft Rejection/pathology , Histone Deacetylase 6 , Humans , Interferon-gamma/metabolism , Leukocytes, Mononuclear/enzymology , Leukocytes, Mononuclear/immunology , Lymphocyte Activation/drug effects , Lymphocyte Culture Test, Mixed , Male , Mice, Inbred BALB C , Mice, Inbred C57BL , Molecular Targeted Therapy , Signal Transduction/drug effects , Skin/enzymology , Skin/immunology , Skin/pathology , T-Lymphocytes, Regulatory/drug effects , T-Lymphocytes, Regulatory/enzymology , T-Lymphocytes, Regulatory/immunology , Time Factors , Transplantation, Homologous , Vorinostat
15.
Transpl Int ; 29(6): 727-39, 2016 Jun.
Article En | MEDLINE | ID: mdl-27062063

South Asians have increased risk for type 2 diabetes mellitus compared with Caucasians in the general population, but data for the development of post-transplantation diabetes mellitus (PTDM) is scarce. In this retrospective analysis, data was extracted from electronic patient records at a single centre (2004-2014). Caucasians were more likely to be male, with higher age and BMI than South Asians. Case-control matching was therefore undertaken to remove this bias, resulting in 102 recipient pairs. Median follow-up was 50 months (range 4-127 months). Matched groups had similar baseline characteristics, although South Asians compared with Caucasians received more deceased-donor kidneys (74% vs. 43%, respectively, P < 0.001) and were more likely to be CMV positive (77% vs. 43%, respectively, P < 0.001). PTDM incidence was significantly higher in South Asians versus Caucasians (35% vs. 10%, respectively, subhazard ratio 4.2 [95% CI: 2.1-8.5, P < 0.001]). Donor type had significant interaction with ethnicity, with the observed difference in PTDM rates between ethnicities most visible with receipt of deceased-donor kidneys. No significant difference was detected in allograft function, rejection episodes, adverse cardiovascular events or patient/graft survival. South Asians have increased risk of PTDM, especially recipients of deceased kidneys, and recognition of this allows appropriate patient counselling and development of targeted strategies.


Diabetes Mellitus/etiology , Kidney Transplantation/methods , Renal Insufficiency/surgery , Adult , Aged , Allografts , Asian People , Body Mass Index , Diabetes Complications/surgery , Female , Graft Rejection/epidemiology , Graft Survival , Humans , Immunosuppressive Agents , Incidence , Male , Middle Aged , Postoperative Complications , Renal Insufficiency/ethnology , Retrospective Studies , Risk , Risk Factors , Transplantation, Homologous , White People
16.
Exp Clin Transplant ; 13(2): 130-7, 2015 Apr.
Article En | MEDLINE | ID: mdl-25871364

OBJECTIVES: The logistics of deceased-donor renal transplants are largely affected by cold ischemia time. However, to attain successful outcomes, other issues must be considered. Extending cold ischemia time to accommodate these issues would be valuable. We investigated the role of hypothermic machine perfusion to extend cold ischaemia time. MATERIALS AND METHODS: Deceased-donor kidneys were allocated to a storage method, depending on predicted time to operation. Kidneys to be transplanted from 8:00 AM to 8:00 PM in the transplant room remained in static cold storage. If predicted operating time was out of hours, the kidney was transferred to hypothermic machine perfusion and transplanted at the earliest opportunity on the dedicated transplant list. RESULTS: There were 74 kidneys transplanted from hypothermic machine perfusion and 101 kidneys from static cold storage. Median cold ischemia time was 23.85 hours in the hypothermic machine perfusion group, compared with 13 hours in the static cold storage group (P ≤ .0001). There were 20 kidneys (27%) from hypothermic machine perfusion that had delayed graft function, compared with 47 kidneys (47%) in the static cold storage group (P = .012). There were no other significant differences in graft or postoperative complications. CONCLUSIONS: This study demonstrated that improved early graft outcomes can be achieved following longer cold ischemia time by using hypothermic machine perfusion rather than static cold storage. This effect is likely multifactorial including the inherent effects of hypothermic machine perfusion, improved recipient preparation, and possibly better perioperative conditions.


Cold Ischemia/methods , Kidney Transplantation/methods , Kidney/physiology , Adult , Creatinine/blood , Female , Humans , Length of Stay , Male , Middle Aged , Postoperative Complications , Postoperative Period , Time Factors
17.
PLoS One ; 10(1): e0116662, 2015.
Article En | MEDLINE | ID: mdl-25581165

Visualizing the three-dimensional morphology and spatial patterning of cells embedded deep within dense connective tissues of the musculoskeletal system has been possible only by utilizing destructive techniques. Here we utilize fructose-based clearing solutions to image cell connectivity and deep tissue-scale patterning in situ by standard confocal microscopy. Optical clearing takes advantage of refractive index matching of tissue and the embedding medium to visualize light transmission through a broad range of bovine and whole mount murine tissues, including cartilage, bone, and ligament, of the head and hindlimb. Using non-destructive methods, we show for the first time intercellular chondrocyte connections throughout the bulk of cartilage, and we reveal in situ patterns of osteocyte processes and the lacunar-canalicular system deep within mineralized cortical bone. Optical clearing of connective tissues is expected to find broad application for the study of cell responses in normal physiology and disease pathology.


Bone and Bones/cytology , Cartilage/cytology , Ligaments/cytology , Animals , Cattle , Chondrocytes/cytology , Head/physiology , Hindlimb/cytology , Histological Techniques/methods , Mice , Microscopy, Confocal/methods , Osteocytes/cytology , Solutions/chemistry
18.
Transplantation ; 99(4): 754-9, 2015 Apr.
Article En | MEDLINE | ID: mdl-25222017

BACKGROUND: The metabolic processes occurring within the preserved kidney during hypothermic machine perfusion (HMP) are not well characterized. The aim of this study was to use nuclear magnetic resonance (NMR) spectroscopy to examine the metabolomic profile of HMP perfusate from human cadaveric kidneys awaiting transplantation and to identify possible discriminators between the profiles of kidneys with delayed graft function (DGF) and immediate graft function (IGF). METHODS: Perfusates from HMP kidneys were sampled at 45 min and 4 hr of preservation with the LifePort Kidney Transporter 1.0 (Organ Recovery Systems, Chicago, IL) using KPS-1. Prepared samples underwent 1-D Proton-NMR spectroscopy, and resultant spectra were analyzed. Clinical parameters were collected prospectively. RESULTS: Perfusate of 26 transplanted cadaveric kidneys was analyzed; 19(73%) with IGF and 7(27%) with DGF. Glucose concentrations were significantly lower in DGF kidneys compared to those with IGF at both 45 min (7.772 vs. 9.459 mM, P = 0.006) and 4 hr (8.202 vs. 10.235 mM, P = 0.003). Concentrations of inosine and leucine were significantly different between DGF and IGF kidneys at 45 min (0.002 vs. 0.013 mM, P = 0.009 and 0.011 vs. 0.006 mM, P = 0.036), and gluconate levels were also significantly different between DGF and IGF kidneys at 4 hr (49.099 vs. 59.513 mM, P = 0.009). CONCLUSION: Significant metabolic activity may be occurring in kidneys during HMP. The NMR spectroscopy of the perfusate can identify differences in the metabolomic profiles of DGF and IGF kidneys that might have a predictive role in viability assessment. Modification of harmful metabolic processes may improve outcomes for HMP kidneys.


Cold Ischemia , Hypothermia, Induced , Kidney Transplantation/methods , Kidney/blood supply , Kidney/metabolism , Metabolomics , Organ Preservation Solutions/metabolism , Organ Preservation/methods , Perfusion/methods , Tissue Donors , Area Under Curve , Cadaver , Cold Ischemia/adverse effects , Cold Ischemia/instrumentation , Delayed Graft Function/etiology , Delayed Graft Function/metabolism , Equipment Design , Humans , Hypothermia, Induced/adverse effects , Hypothermia, Induced/instrumentation , Kidney/surgery , Kidney Transplantation/adverse effects , Magnetic Resonance Spectroscopy , Metabolomics/methods , Organ Preservation/adverse effects , Organ Preservation/instrumentation , Perfusion/adverse effects , Perfusion/instrumentation , Predictive Value of Tests , Prospective Studies , ROC Curve , Risk Factors , Time Factors , Treatment Outcome
19.
PLoS One ; 9(12): e114818, 2014.
Article En | MEDLINE | ID: mdl-25502759

INTRODUCTION: Hypothermic machine perfusion offers great promise in kidney transplantation and experimental studies are needed to establish the optimal conditions for this to occur. Pig kidneys are considered to be a good model for this purpose and share many properties with human organs. However it is not established whether the metabolism of pig kidneys in such hypothermic hypoxic conditions is comparable to human organs. METHODS: Standard criteria human (n = 12) and porcine (n = 10) kidneys underwent HMP using the LifePort Kidney Transporter 1.0 (Organ Recovery Systems) using KPS-1 solution. Perfusate was sampled at 45 minutes and 4 hours of perfusion and metabolomic analysis performed using 1-D 1H-NMR spectroscopy. RESULTS: There was no inter-species difference in the number of metabolites identified. Of the 30 metabolites analysed, 16 (53.3%) were present in comparable concentrations in the pig and human kidney perfusates. The rate of change of concentration for 3-Hydroxybutyrate was greater for human kidneys (p<0.001). For the other 29 metabolites (96.7%), there was no difference in the rate of change of concentration between pig and human samples. CONCLUSIONS: Whilst there are some differences between pig and human kidneys during HMP they appear to be metabolically similar and the pig seems to be a valid model for human studies.


Hypothermia, Induced/methods , Metabolome/genetics , Metabolomics/methods , Models, Animal , Perfusion/methods , Swine , Analysis of Variance , Animals , Humans , Magnetic Resonance Spectroscopy
20.
Clin Transplant ; 28(7): 808-15, 2014 Jul.
Article En | MEDLINE | ID: mdl-24801162

BACKGROUND: Deceased kidney donors are increasingly "marginal," and many have risk factors for acute kidney injury (AKI) that may impact on subsequent renal transplant outcome. Despite this, determining the presence of AKI at the time of deceased organ donation remains difficult. METHODS: Urine samples from 182 brainstem dead multi-organ donors (all of whom donated hearts that were transplanted) were analyzed for a Luminex(™) panel of biomarkers linked with AKI. This included KIM-1, NGAL, IFN-γ, TNF-α, cystatin C, Fractalkine and vascular endothelial growth factor. Levels were correlated to early renal transplant outcomes, most specifically delayed graft function. RESULTS: Donor urinary KIM-1 levels were significantly higher in donors whose kidneys displayed aberrant early function (p = 0.011). Fractalkine levels showed a trend toward elevation in such donors but uncorrected this did not attain significance. No correlation occurred with the remaining biomarkers. CONCLUSIONS: KIM-1 appears to show promise as a marker for AKI in deceased cardiac organ donors. The availability of a lateral flow device (Renastick(™) ) for KIM-1 that also demonstrates higher urinary KIM-1 levels in donors whose kidneys show aberrant initial function (p = 0.03), makes KIM-1 a potential indicator of AKI that may merit further evaluation for its application at the donor bedside.


Acute Kidney Injury/urine , Biomarkers/urine , Kidney Transplantation , Membrane Glycoproteins/urine , Tissue Donors , Adolescent , Adult , Aged , Cadaver , Case-Control Studies , Child , Child, Preschool , Female , Follow-Up Studies , Hepatitis A Virus Cellular Receptor 1 , Humans , Infant , Male , Middle Aged , Prognosis , Receptors, Virus , Young Adult
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