Mesenchymal stromal cell treatment of donor kidneys during ex vivo normothermic machine perfusion: A porcine renal autotransplantation study

Normothermic machine perfusion (NMP) of injured kidneys offers the opportunity for interventions to metabolically active organs prior to transplantation. Mesenchymal stromal cells (MSCs) can exert regenerative and anti-inflammatory effects in ischemia-reperfusion injury. The aims of this study were to evaluate the safety and feasibility of MSC treatment of kidneys during NMP using a porcine autotransplantation model, and examine potential MSC treatment-associated kidney improvements up to 14 days posttransplant. After 75 min of kidney warm ischemia, four experimental groups of n = 7 underwent 14 h of oxygenated hypothermic machine perfusion. In three groups this was followed by 240 min of NMP with infusion of vehicle, 10 million porcine, or 10 million human adipose-derived MSCs. All kidneys were autotransplanted after contralateral nephrectomy. MSC treatment did not affect perfusion hemodynamics during NMP or cause adverse effects at reperfusion, with 100% animal survival. MSCs did not affect plasma creatinine, glomerular filtration rate, neutrophil gelatinase-associated lipocalin concentrations or kidney damage assessed by histology during the 14 days, and MSCs retention was demonstrated in renal cortex. Infusing MSCs during ex vivo NMP of porcine kidneys was safe and feasible. Within the short posttransplant follow-up period, no beneficial effects of ex vivo MSC therapy could be demonstrated.

Ex Vivo Administration of Mesenchymal Stromal Cells in Kidney Grafts Against Ischemia-reperfusion Injury-Effective Delivery Without Kidney Function Improvement Posttransplant

BACKGROUND

Mesenchymal stromal cell (MSC) therapy may improve renal function after ischemia-reperfusion injury in transplantation. Ex vivo renal intraarterial administration is a targeted delivery method, avoiding the lung vasculature, a known barrier for cellular therapies. In a randomized and blinded study, we tested the feasibility and effectiveness of MSC therapy in a donation after circulatory death autotransplantation model to improve posttransplant kidney function, using an ex vivo MSC delivery method similar to the clinical standard procedure of pretransplant cold graft flush.

METHODS

Kidneys exposed to 75 minutes of warm ischemia and 16 hours of static cold storage were intraarterially infused ex vivo with 10 million male porcine MSCs (Tx-MSC, n = 8) or vehicle (Tx-control, n = 8). Afterwards, the kidneys were autotransplanted after contralateral nephrectomy. Biopsies an hour after reperfusion confirmed the presence of MSCs in the renal cortex. Animals were observed for 14 days.

RESULTS

Postoperatively, peak plasma creatinine was 1230 and 1274 µmol/L (Tx-controls versus Tx-MSC, P = 0.69). During follow-up, no significant differences over time were detected between groups regarding plasma creatinine, plasma neutrophil gelatinase-associated lipocalin, or urine neutrophil gelatinase-associated lipocalin/creatinine ratio. At day 14, measured glomerular filtration rates were 40 and 44 mL/min, P = 0.66. Renal collagen content and fibrosis-related mRNA expression were increased in both groups but without significant differences between the groups.

CONCLUSIONS

We demonstrated intraarterial MSC infusion to transplant kidneys as a safe and effective method to deliver MSCs to the graft. However, we could not detect any positive effects of this cell treatment within 14 days of observation.

Reversibility of oxalate nephropathy in a kidney transplant recipient with prior gastric bypass surgery

Bariatric surgery is an acknowledged treatment for obesity and related comorbidities with beneficial effects on kidney function. However, bariatric surgery can also lead to secondary hyperoxaluria and oxalate nephropathy, resulting in end-stage kidney disease in both native and transplanted kidneys. We present a 66-year-old man who was in need of dialysis 3 months after kidney transplantation due to recurrent oxalate nephropathy. Intensified haemodialysis together with increased liquid intake, dietary restrictions of oxalate and fat and supplementation with calcium citrate and a bile acid binder were applied. Graft function improved and the patient did not require dialysis during the following 8 months.

Subclinical effects of remote ischaemic conditioning in human kidney transplants revealed by quantitative proteomics

Background

Remote ischaemic conditioning (RIC) is currently being explored as a non-invasive method to attenuate ischaemia/reperfusion injuries in organs. A randomised clinical study (CONTEXT) evaluated the effects of RIC compared to non-RIC controls in human kidney transplants.

Methods

RIC was induced prior to kidney reperfusion by episodes of obstruction to arterial flow in the leg opposite the transplant using a tourniquet (4 × 5 min). Although RIC did not lead to clinical improvement of transplant outcomes, we explored whether RIC induced molecular changes through precision analysis of CONTEXT recipient plasma and kidney tissue samples by high-resolution tandem mass spectrometry (MS/MS).

Results

We observed an accumulation of muscle derived proteins and altered amino acid metabolism in kidney tissue proteomes, likely provoked by RIC, which was not reflected in plasma. In addition, MS/MS analysis demonstrated transient upregulation of several acute phase response proteins (SAA1, SAA2, CRP) in plasma, 1 and 5 days post-transplant in RIC and non-RIC conditions with a variable effect on the magnitude of acute inflammation.

Conclusions

Together, our results indicate sub-clinical systemic and organ-localised effects of RIC.

Treating Ischemically Damaged Porcine Kidneys with Human Bone Marrow- and Adipose Tissue-Derived Mesenchymal Stromal Cells During Ex Vivo Normothermic Machine Perfusion

Pretransplant normothermic machine perfusion (NMP) of donor kidneys offers the unique opportunity to perform active interventions to an isolated renal graft before transplantation. There is increasing evidence that mesenchymal stromal cells (MSCs) could have a paracrine/endocrine regenerative effect on ischemia-reperfusion injury. The purpose of this study was to determine which cytokines are secreted by MSCs during NMP of a porcine kidney. Viable porcine kidneys and autologous whole blood were obtained from a slaughterhouse. Warm ischemia time was standardized at 20 min and subsequent hypothermic machine perfusion was performed during 2-3 h. Thereafter, kidneys were machine perfused at 37°C during 7 h. After 1 h of NMP, 0, 10⁷ cultured human adipose tissue-derived MSCs, or 10⁷ cultured bone marrow-derived MSCs were added (n = 5 per group). In a fourth experimental group, 7-h NMP was performed with 10⁷ adipose tissue-derived MSCs, without a kidney in the circuit. Kidneys perfused with MSCs showed lower lactate dehydrogenase and neutrophil gelatinase-associated lipocalin levels in comparison with the control group. Also, elevated levels of human hepatocyte growth factor, interleukin (IL)-6, and IL-8 were found in the perfusate of the groups perfused with MSCs compared to the control groups. This study suggests that MSCs, in contact with an injured kidney during NMP, could lead to lower levels of injury markers and induce the release of immunomodulatory cytokines.

Organ-specific metabolic profiles of the liver and kidney during brain death and afterwards during normothermic machine perfusion of the kidney

We investigated metabolic changes during brain death (BD) using hyperpolarized magnetic resonance (MR) spectroscopy and ex vivo graft glucose metabolism during normothermic isolated perfused kidney (IPK) machine perfusion. BD was induced in mechanically ventilated rats by inflation of an epidurally placed catheter; sham-operated rats served as controls. Hyperpolarized [1-¹³ C]pyruvate MR spectroscopy was performed to quantify pyruvate metabolism in the liver and kidneys at 3 time points during BD, preceded by injecting hyperpolarized[1-¹³ C]pyruvate. Following BD, glucose oxidation was measured using tritium-labeled glucose (d-6-3H-glucose) during IPK reperfusion. Quantitative polymerase chain reaction and biochemistry were performed on tissue/plasma. Immediately following BD induction, lactate increased in both organs (liver: eµ_d 0.21, 95% confidence interval [CI] [-0.27, -0.15]; kidney: eµ_d 0.26, 95% CI [-0.40, -0.12]. After 4 hours of BD, alanine production decreased in the kidney (eµ_d 0.14, 95% CI [0.03, 0.25], P < .05). Hepatic lactate and alanine profiles were significantly different throughout the experiment between groups (P < .01). During IPK perfusion, renal glucose oxidation was reduced following BD vs sham animals (eµ_d 0.012, 95% CI [0.004, 0.03], P < .001). No differences in enzyme activities were found. Renal gene expression of lactate-transporter MCT4 increased following BD (P < .01). In conclusion, metabolic processes during BD can be visualized in vivo using hyperpolarized magnetic resonance imaging and with glucose oxidation during ex vivo renal machine perfusion. These techniques can detect differences in the metabolic profiles of the liver and kidney following BD.

Reparative effect of mesenchymal stromal cells on endothelial cells after hypoxic and inflammatory injury

Background

The renal endothelium is a prime target for ischemia-reperfusion injury (IRI) during donation and transplantation procedures. Mesenchymal stromal cells (MSC) have been shown to ameliorate kidney function after IRI. However, whether this involves repair of the endothelium is not clear. Therefore, our objective is to study potential regenerative effects of MSC on injured endothelial cells and to identify the molecular mechanisms involved.

Methods

Human umbilical vein endothelial cells (HUVEC) were submitted to hypoxia and reoxygenation and TNF-α treatment. To determine whether physical interaction or soluble factors released by MSC were responsible for the potential regenerative effects of MSC on endothelial cells, dose-response experiments were performed in co-culture and transwell conditions and with secretome-deficient MSC.

Results

MSC showed increased migration and adhesion to injured HUVEC, mediated by CD29 and CD44 on the MSC membrane. MSC decreased membrane injury marker expression, oxidative stress levels, and monolayer permeability of injured HUVEC, which was observed only when allowing both physical and paracrine interaction between MSC and HUVEC. Furthermore, viable MSC in direct contact with injured HUVEC improved wound healing capacity by 45% and completely restored their angiogenic capacity. In addition, MSC exhibited an increased ability to migrate through an injured HUVEC monolayer compared to non-injured HUVEC in vitro.

Conclusions

These results show that MSC have regenerative effects on injured HUVEC via a mechanism which requires both physical and paracrine interaction. The identification of specific effector molecules involved in MSC-HUVEC interaction will allow targeted modification of MSC to apply and enhance the therapeutic effects of MSC in IRI.

Prognostic impact of elevated lactate levels on mortality in critically ill patients with and without preadmission metformin treatment: a Danish registry-based cohort study

BACKGROUND

Lactate is a robust prognostic marker for the outcome of critically ill patients. Several small studies reported that metformin users have higher lactate levels at ICU admission without a concomitant increase in mortality. However, this has not been investigated in a larger cohort. We aimed to determine whether the association between lactate levels around ICU admission and mortality is different in metformin users compared to metformin nonusers.

METHODS

This cohort study included patients admitted to ICUs in northern Denmark between January 2010 and August 2017 with any circulating lactate measured around ICU admission, which was defined as 12 h before until 6 h after admission. The association between the mean of the lactate levels measured during this period and 30-day mortality was determined for metformin users and nonusers by modelling restricted cubic splines obtained from a Cox regression model.

RESULTS

Of 37,293 included patients, 3183 (9%) used metformin. The median (interquartile range) lactate level was 1.8 (1.2-3.2) in metformin users and 1.6 (1.0-2.7) mmol/L in metformin nonusers. Lactate levels were strongly associated with mortality for both metformin users and nonusers. However, the association of lactate with mortality was different for metformin users, with a lower mortality rate in metformin users than in nonusers when admitted with similar lactate levels. This was observed over the whole range of lactate levels, and consequently, the relation of lactate with mortality was shifted rightwards for metformin users.

CONCLUSION

In this large observational cohort of critically ill patients, early lactate levels were strongly associated with mortality. Irrespective of the degree of hyperlactataemia, similar lactate levels were associated with a lower mortality rate in metformin users compared with metformin nonusers. Therefore, lactate levels around ICU admission should be interpreted according to metformin use.

Hyperpolarised 13C-MRI metabolic and functional imaging: an emerging renal MR diagnostic modality

Magnetic resonance imaging (MRI) is a well-established modality for assessing renal morphology and function, as well as changes that occur during disease. However, the significant metabolic changes associated with renal disease are more challenging to assess with MRI. Hyperpolarized carbon-13 MRI is an emerging technique which provides an opportunity to probe metabolic alterations at high sensitivity by providing an increase in the signal-to-noise ratio of 20,000-fold or more. This review will highlight the current status of hyperpolarised 13C-MRI and its translation into the clinic and how it compares to metabolic measurements provided by competing technologies such as positron emission tomography (PET).

Remote ischaemic conditioning and early changes in plasma creatinine as markers of one year kidney graft function-A follow-up of the CONTEXT study

BACKGROUND

Ischaemia-reperfusion injury in kidney transplantation leads to delayed graft function (DGF), which is associated with reduced long term graft function. Remote ischaemic conditioning (RIC) improved early kidney graft function in a porcine model of donation after brain death and was associated with improved long-term cardiac outcome after myocardial ischaemia. This randomised, double-blinded trial evaluated the effect of RIC on kidney graft outcome in the first year, and examined the predictive value of a new measure of initial kidney graft function, i.e. the estimated time to a 50% reduction in plasma creatinine post-transplantation (tCr50).

METHODS

A total of 225 patients undergoing deceased donor kidney transplantation were randomised to RIC or a sham procedure performed prior to kidney reperfusion. Up to four repetitive cycles of five minutes of leg ischaemia and five minutes of reperfusion were given. GFR, plasma creatinine, cystatin C and neutrophil gelatinase associated lipocalin (NGAL) were measured at three and twelve months and estimated GFR was calculated using four different equations. Other secondary outcomes were identified from patient files.

RESULTS

RIC did not affect GFR or other outcomes when compared to the sham procedure at three or twelve months. tCr50 correlated with one year graft function (p<0.0001 for both mGFR and eGFR estimates). In contrast, DGF i.e. "need of dialysis the first week" did not correlate significantly with one year GFR.

CONCLUSION

RIC during deceased donor kidney transplantation did not improve one year outcome. However, tCr50 may be a relevant marker for studies aiming to improve graft onset.

TRIAL REGISTRATION

www.ClinicalTrials.gov Identifier: NCT01395719.

Goal-Directed Fluid Therapy Does Not Improve Early Glomerular Filtration Rate in a Porcine Renal Transplantation Model

BACKGROUND:

Insufficient fluid administration intra- and postoperatively may lead to delayed renal graft function (DGF), while fluid overload increases the risk of heart failure, infection, and obstipation. Several different fluid protocols have been suggested to ensure optimal fluid state. However, there is a lack of evidence of the clinical impact of these regimens. This study aimed to determine whether individualized goal-directed fluid therapy (IGDT) positively affects the initial renal function compared to a high-volume fluid therapy (HVFT) and to examine the effects on renal endothelial glycocalyx, inflammatory and oxidative stress markers, and medullary tissue oxygenation. The hypothesis was that IGDT improves early glomerular filtration rate (GFR) in pigs subjected to renal transplantation.

METHODS:

This was an experimental randomized study. Using a porcine renal transplantation model, animals were randomly assigned to receive IGDT or HVFT during and until 1 hour after transplantation from brain-dead donors. The kidneys were exposed to 18 hours of cold ischemia. The recipients were observed until 10 hours after reperfusion, which included GFR measured as clearance of chrom-51-ethylendiamintetraacetat (⁵¹Cr-EDTA), animal weight, and renal tissue oxygenation by fiber optic probes. The renal expression of inflammatory and oxidative stress markers as well as glomerular endothelial glycocalyx were analyzed in the graft using polymerase chain reaction (PCR) technique and immunofluorescence.

RESULTS:

Twenty-eight recipient pigs were included for analysis. We found no evidence that IGDT improved early GFR compared to HVFT (P = .45), while animal weight increased more in the HVFT group (a mean difference of 3.4 kg [1.96–4.90]; P < .0001). A better, however nonsignificant, preservation of glomerular glycocalyx (P = .098) and significantly lower levels of the inflammatory marker cyclooxygenase 2 (COX-2) was observed in the IGDT group when compared to HVFT. COX-2 was 1.94 (1.50–2.39; P = .012) times greater in the HVFT group when compared to the IGDT group. No differences were observed in outer medullary tissue oxygenation or oxidative stress markers.

CONCLUSIONS:

IGDT did not improve early GFR; however, it may reduce tissue inflammation and could possibly lead to preservation of the glycocalyx compared to HVFT.

Mesenchymal Stromal Cells Are Retained in the Porcine Renal Cortex Independently of Their Metabolic State After Renal Intra-Arterial Infusion

The regenerative capacities of mesenchymal stromal cells (MSCs) make them suitable for renal regenerative therapy. The most common delivery route of MSC is through intravenous infusion, which is associated with off-target distribution. Renal intra-arterial delivery offers a targeted therapy, but limited knowledge is available regarding the fate of MSCs delivered through this route. Therefore, we studied the efficiency and tissue distribution of MSCs after renal intra-arterial delivery to a porcine renal ischemia-reperfusion model. MSCs were isolated from adipose tissue of healthy male pigs, fluorescently labeled and infused into the renal artery of female pigs. Flow cytometry allowed MSC detection and quantification in tissue and blood. In addition, quantitative polymerase chain reaction was used to trace MSCs by their Y-chromosome. During infusion, a minor number of MSCs left the kidney through the renal vein, and no MSCs were identified in arterial blood. Ischemic and healthy renal tissues were analyzed 30 min and 8 h after infusion, and 1-4 × 10⁴ MSCs per gram of tissue were detected, predominantly, in the renal cortex, with a viability >70%. Confocal microscopy demonstrated mainly glomerular localization of MSCs, but they were also observed in the capillary network around tubuli. The infusion of heat-inactivated (HI) MSCs, which are metabolically inactive, through the renal artery showed that HI-MSCs were distributed in the kidney in a similar manner to regular MSCs, suggesting a passive retention mechanism. Long-term MSC survival was analyzed by Y-chromosome tracing, and demonstrated that a low percentage of the infused MSCs were present in the kidney 14 days after administration, while HI-MSCs were completely undetectable. In conclusion, renal intra-arterial MSC infusion limited off-target engraftment, leading to efficient MSC delivery to the kidney, most of them being cleared within 14 days. MSC retention was independent of the metabolic state of MSC, indicating a passive mechanism.

Infusing Mesenchymal Stromal Cells into Porcine Kidneys during Normothermic Machine Perfusion: Intact MSCs Can Be Traced and Localised to Glomeruli

Normothermic machine perfusion (NMP) of kidneys offers the opportunity to perform active interventions, such as the addition of mesenchymal stromal cells (MSCs), to an isolated organ prior to transplantation. The purpose of this study was to determine whether administering MSCs to kidneys during NMP is feasible, what the effect of NMP is on MSCs and whether intact MSCs are retained in the kidney and to which structures they home. Viable porcine kidneys were obtained from a slaughterhouse. Kidneys were machine perfused during 7 h at 37 °C. After 1 h of perfusion either 0, 10⁵, 10⁶ or 10⁷ human adipose tissue derived MSCs were added. Additional ex vivo perfusions were conducted with fluorescent pre-labelled bone-marrow derived MSCs to assess localisation and survival of MSCs during NMP. After NMP, intact MSCs were detected by immunohistochemistry in the lumen of glomerular capillaries, but only in the 10⁷ MSC group. The experiments with fluorescent pre-labelled MSCs showed that only a minority of glomeruli were positive for infused MSCs and most of these glomeruli contained multiple MSCs. Flow cytometry showed that the number of infused MSCs in the perfusion circuit steeply declined during NMP to approximately 10%. In conclusion, the number of circulating MSCs in the perfusate decreases rapidly in time and after NMP only a small portion of the MSCs are intact and these appear to be clustered in a minority of glomeruli.

Effects of Normothermic Machine Perfusion Conditions on Mesenchymal Stromal Cells

Ex-situ normothermic machine perfusion (NMP) of transplant kidneys allows assessment of kidney quality and targeted intervention to initiate repair processes prior to transplantation. Mesenchymal stromal cells (MSC) have been shown to possess the capacity to stimulate kidney repair. Therefore, the combination of NMP and MSC therapy offers potential to repair transplant kidneys. It is however unknown how NMP conditions affect MSC. In this study the effect of NMP perfusion fluid on survival, metabolism and function of thawed cryopreserved human (h)MSC and porcine (p)MSC in suspension conditions was studied. Suspension conditions reduced the viability of pMSC by 40% in both perfusion fluid and culture medium. Viability of hMSC was reduced by suspension conditions by 15% in perfusion fluid, whilst no differences were found in survival in culture medium. Under adherent conditions, survival of the cells was not affected by perfusion fluid. The perfusion fluid did not affect survival of fresh MSC in suspension compared to the control culture medium. The freeze-thawing process impaired the survival of hMSC; 95% survival of fresh hMSC compared to 70% survival of thawed hMSC. Moreover, thawed MSC showed increased levels of reactive oxygen species, which indicates elevated levels of oxidative stress, and reduced mitochondrial activity, which implies reduced metabolism. The adherence of pMSC and hMSC to endothelial cells was reduced after the thawing process, effect which was particularly profound in in the perfusion fluid. To summarize, we observed that conditions required for machine perfusion are influencing the behavior of MSC. The freeze-thawing process reduces survival and metabolism and increases oxidative stress, and diminishes their ability to adhere to endothelial cells. In addition, we found that hMSC and pMSC behaved differently, which has to be taken into consideration when translating results from animal experiments to clinical studies.

P-NGAL Day 1 predicts early but not one year graft function following deceased donor kidney transplantation - The CONTEXT study

BACKGROUND

Early markers to predict delayed kidney graft function (DGF) may support clinical management. We studied the ability of four biomarkers (neutrophil gelatinase associated lipocalin (NGAL), liver-type fatty acid-binding protein (L-FABP), cystatin C, and YKL-40) to predict DGF after deceased donor transplantation, and their association with early graft function and GFR at three and twelve months.

METHODS

225 deceased donor kidney transplant recipients were included. Biomarkers were measured using automated assays or ELISA. We calculated their ability to predict the need for dialysis post-transplant and correlated with the estimated time to a 50% reduction in plasma creatinine (tCr50), measured glomerular filtration rate (mGFR) and estimated GFR (eGFR).

RESULTS

All biomarkers measured at Day 1, except urinary L-FABP, significantly correlated with tCr50 and mGFR at Day 5. Plasma NGAL at Day 1 and a timed urine output predicted DGF (AUC = 0.91 and AUC 0.98). Nil or only weak correlations were identified between early biomarker levels and mGFR or eGFR at three or twelve months.

CONCLUSION

High plasma NGAL at Day 1 predicts DGF and is associated with initial graft function, but may not prove better than P-creatinine or a timed urine output. Early biomarker levels do not correlate with one-year graft function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01395719.

A triangulated evaluation of a youth clinic for patients with kidney disease

BACKGROUND

With inspiration from Oxford, UK, a youth clinic outside the hospital for young people with kidney disease was established at a Danish university hospital in Autumn 2014. Four clinics have been held annually.

OBJECTIVES

To qualitatively evaluate a new established youth clinic and to gain knowledge of the experiences of young people and their parents with this clinic.

METHODS

Three data sets were collected (observation, interviews and focus groups). Data were analysed using Malterud's systematic text condensation.

FINDINGS

Eight themes were identified: (1) A meeting place; (2) a mutual understanding; (3) the young people have established a social community between themselves; (4) I feel less directed by my kidney disease; (5) I accept my life with the disease to a larger extent; (6) I am the safety net; (7) they have their life with the disease under control and they handle it and (8) the youth clinic is a gift from heaven.

CONCLUSION

The youth clinic had a positive impact on the young peoples' daily life with kidney disease and has helped most of the young people to have more faith in themselves and their own abilities to handle life with kidney disease. Meeting with peers and the youth clinic being located outside the hospital were of utmost importance.

Identification of differential gene expression patterns in human arteries from patients with chronic kidney disease

Uremia accelerates atherosclerosis, but little is known about affected pathways in human vasculature. This study aimed to identify differentially expressed arterial transcripts in patients with chronic kidney disease (CKD). Global mRNA expression was estimated by microarray hybridization in iliac arteries ( n = 14) from renal transplant recipients and compared with renal arteries from healthy living kidney donors ( n = 19) in study 1. Study 2 compared nonatherosclerotic internal mammary arteries (IMA) from five patients with elevated plasma creatinine levels and age- and sex-matched controls with normal creatinine levels. Western blotting and immunohistochemistry for selected proteins were performed on a subset of study 1 samples. Fifteen gene transcripts were significantly different between the two groups in study 1 [fold changes (FC) > 1.05 and false discovery rates (FDR) < 0.005]. Most upregulated mRNAs associated with cellular signaling, apoptosis, TNFα/NF-κB signaling, smooth muscle contraction, and 10 other pathways were significantly affected. To focus attention on genes from genuine vascular cells, which dominate in IMA, concordant deregulated genes in studies 1 and 2 were examined and included 23 downregulated and eight upregulated transcripts (settings in study 1: FC > 1.05 and FDR < 0.05; study 2: FC > 1.2 and P < 0.2). Selected deregulated gene products were investigated at the protein level, and whereas HIF3α confirmed mRNA upregulation, vimentin showed upregulation in contrast to the mRNA results. We conclude that arteries from CKD patients display change in relatively few sets of genes. Many were related to differentiated vascular smooth muscle cell phenotype. These identified genes may contribute to understanding the development of arterial injury among patients with CKD.

Efficacy of the Danish epilepsy surgery programme

OBJECTIVE

Despite optimal medical treatment, approximately one-third of patients with epilepsy continue to have seizures. Epilepsy surgery is widely accepted as a therapeutic option in the selected subset of patients with drug-resistant focal epilepsy. Here, we report the results of the Danish epilepsy surgery programme from 2009 to 2014.

MATERIAL AND METHODS

A total of 169 consecutive patients, operated at Rigshospitalet, were included. Information was gathered from digital patient records. Before 1-year follow-up, two patients were lost to follow-up and three were referred to new surgery.

RESULTS

The median years of drug resistance before operation were 11 years. At 1-year follow-up (n = 164), seizure outcomes were as follows: 65% Engel I (free from disabling seizures), 51% Engel IA (completely seizure free) and 9% Engel IV (no worthwhile improvement), and for patients operated in the medial temporal lobe (n = 114): 70% Engel I, 56% Engel IA, 5% Engel IV. The outcomes of the 53 patients needing intracranial EEG recording (ICR) were not significantly different from the patients only evaluated with surface EEG. None of the eight MRI-negative patients operated outside the medial temporal lobe after ICR were free of disabling seizures. 12% of MTLE patients developed de novo depression after epilepsy surgery despite good surgical outcome. Three patients required rehabilitation due to post-operative hemiplegia.

CONCLUSION

The outcomes of the Danish epilepsy surgery programme align with international results found in recent meta-analyses. Serious complications to epilepsy surgery are seldom. In accordance with international recommendations, Danish drug-resistant patients should be referred to epilepsy surgery evaluation at an earlier stage of the disease.

Unilateral nephrectomy diminishes ischemic acute kidney injury through enhanced perfusion and reduced pro-inflammatory and pro-fibrotic responses

While unilateral nephrectomy (UNx) is suggested to protect against ischemia-reperfusion injury (IRI) in the remaining kidney, the mechanisms underlying this protection remain to be elucidated. In this study, functional MRI was employed in a renal IRI rat model to reveal global and regional changes in renal filtration, perfusion, oxygenation and sodium handling, and microarray and pathway analyses were conducted to identify protective molecular mechanisms. Wistar rats were randomized to either UNx or sham UNx immediately prior to 37 minutes of unilateral renal artery clamping or sham operation under sevoflurane anesthesia. MRI was performed 24 hours after reperfusion. Blood and renal tissue were harvested. RNA was isolated for microarray analysis and QPCR validation of gene expression results. The perfusion (T1 value) was significantly enhanced in the medulla of the post-ischemic kidney following UNx. UNx decreased the expression of fibrogenic genes, i.a. Col1a1, Fn1 and Tgfb1 in the post-ischemic kidney. This was associated with a marked decrease in markers of activated myofibroblasts (Acta2/α-Sma and Cdh11) and macrophages (Ccr2). This was most likely facilitated by down-regulation of Pdgfra, thus inhibiting pericyte-myofibroblast differentiation, chemokine production (Ccl2/Mcp1) and macrophage infiltration. UNx reduced ischemic histopathologic injury. UNx may exert renoprotective effects against IRI through increased perfusion in the renal medulla and alleviation of the acute pro-inflammatory and pro-fibrotic responses possibly through decreased myofibroblast activation. The identified pathways involved may serve as potential therapeutic targets and should be taken into account in experimental models of IRI.