In this case report, we describe an 85-year-old female patient who presented with a rare but important problem of anticoagulant rebound complicating dabigatran use. Despite multiple attempts to correct the bleeding, it continued and the coagulation times remained prolonged. Important risk factors for high dabigatran concentrations and prolonged coagulation are renal insufficiency, drug-drug interactions and older age. Treatment of dabigatran-related bleeding with idarucizumab may be complicated by a rebound effect presenting as the reappearance of dabigatran after an initial response. The risk of anticoagulation rebound is higher with higher initial dabigatran levels and is associated with the severity of renal insufficiency. The rebound is best monitored by the diluted thrombin time and may be treated with repeated doses of idarucizumab. In case of persisting bleeding and high dabigatran levels, renal replacement therapy is an acceptable therapeutic option.

Previously, we and others showed that dietary restriction protects against renal ischemia-reperfusion injury in animals.However, clinical translation of preoperative diets is scarce, and in the setting of kidney transplantation these data are lacking.In this pilot study, we investigated the effects of five days of a preoperative protein and caloric dietary restriction (PCR) diet in living kidney donors on the perioperative effects in donors, recipients and transplanted kidneys.Thirty-five kidney donors were randomized into either the PCR, 30% calorie and 80% protein reduction, or control group without restrictions.Adherence to the diet and kidney function in donors and their kidney recipients were analyzed.Perioperative kidney biopsies were taken in a selected group of transplanted kidneys for gene expression analysis.All donors adhered to the diet.From postoperative day 2 up until month 1, kidney function of donors was significantly better in the PCR-group.PCR-donor kidney recipients showed significantly improved kidney function and lower incidence of slow graft function and acute rejection.PCR inhibited cellular immune response pathways and activated stress-resistance signaling.These observations are the first to show that preoperative dietary restriction induces postoperative recovery benefits in humans and may be beneficial in clinical settings involving ischemia-reperfusion injury.

BACKGROUND:Irinotecan use is limited due to severe toxicity. Preconditioning by fasting (PBF) protects against side effects of irinotecan while preserving its antitumor activity. The mechanisms underlying the effects of PBF still need to be elucidated. Here, we investigated the transcriptional responses of PBF on irinotecan in both tumor and healthy liver tissue.EXPERIMENTAL APPROACH:Male BALB/c mice were subcutaneously injected with C26 colon carcinoma cells. Twelve days after tumor inoculation, two groups were fasted for three days and two groups were allowed food ad libitum (AL). Subsequently, both groups received one dose of irinotecan. Twelve hours after administration mice were sacrificed and blood, tumor and liver tissue were harvested. Blood samples were analyzed to determine liver, kidney and bone marrow function, tissues were used for transcriptome analyses.KEY RESULTS:The AL irinotecan group showed worsened organ function and decreased leukocyte numbers. These effects were abated in PBF animals. PBF led to an altered transcriptional response in the liver of irinotecan-treated mice, including decreased cellular injury and increased stress resistance. Hepatic metabolism of irinotecan was also significantly changed due to PBF. The transcriptional response of tumor tissue observed after PBF was hardly affected compared to AL fed animals.CONCLUSIONS:Transcriptional changes after PBF to irinotecan treatment showed an improved protective stress response in healthy liver but not in tumor tissue, including changes in irinotecan metabolism. These data help to unravel the mechanisms underlying the effects of fasting on irinotecan and help to improve outcome of chemotherapeutic treatment in cancer patients.

INTRODUCTION:Surgery-induced oxidative stress increases the risk of perioperative complications and delay in postoperative recovery. In mice, short-term preoperative dietary and protein restriction protect against oxidative stress. We investigated the feasibility of a calorie- and protein-restricted diet in two patient populations.METHODS:In this pilot study, 30 live kidney donors and 38 morbidly obese patients awaiting surgery were randomized into three groups: a restricted diet group, who received a synthetic liquid diet with 30% fewer calories and 80% less protein for five consecutive days; a group who received a synthetic diet containing the daily energy requirements (DER); and a control group. Feasibility was assessed using self-reported discomfort, body weight changes, and metabolic parameters in blood samples.RESULTS:Twenty patients (71%) complied with the restricted and 13 (65%) with the DER-diet. In total, 68% of the patients reported minor discomfort that resolved after normal eating resumed. The mean weight loss on the restricted diet was significantly greater (2.4 kg) than in the control group (0 kg, p = 0.002), but not in the DER-diet (1.5 kg). The restricted diet significantly reduced levels of serum urea and plasma prealbumin (PAB) and retinol binding protein (RBP).CONCLUSIONS:A short-term preoperative calorie- and protein-restricted diet is feasible in kidney donors and morbidly obese patients. Compliance is high and can be objectively measured via changes in urea, PAB, and RBP levels. These results demonstrate that this diet can be used to study the effects of dietary restriction on surgery-induced oxidative stress in a clinical setting.

Ischemia-reperfusion injury (IRI) is inevitable during kidney transplantation leading to oxidative stress and inflammation. We previously reported that preoperative fasting in young-lean male mice protects against IRI. Since patients are generally of older age with morbidities possibly leading to a different response to fasting, we investigated the effects of preoperative fasting on renal IRI in aged-overweight male and female mice. Male and female F1-FVB/C57BL6-hybrid mice, average age 73 weeks weighing 47.2 grams, were randomized to preoperative ad libitum feeding or 3 days fasting, followed by renal IRI. Body weight, kidney function and survival of the animals were monitored until day 28 postoperatively. Kidney histopathology was scored for all animals and gene expression profiles after fasting were analyzed in kidneys of young and aged male mice. Preoperative fasting significantly improved survival after renal IRI in both sexes compared with normal fed mice. Fasted groups had a better kidney function shown by lower serum urea levels after renal IRI. Histopathology showed less acute tubular necrosis and more regeneration in kidneys from fasted mice. A mRNA analysis indicated the involvement of metabolic processes including fatty acid oxidation and retinol metabolism, and the NRF2-mediated stress response. Similar to young-lean, healthy male mice, preoperative fasting protects against renal IRI in aged-overweight mice of both genders. These findings suggest a general protective response of fasting against renal IRI regardless of age, gender, body weight and genetic background. Therefore, fasting could be a non-invasive intervention inducing increased oxidative stress resistance in older and overweight patients as well.

C1683 Preoperative Fasting Protects Aged Obese Mice Against Renal Ischemia-Reperfusion Injury. F. Jongbloed,1,2 R. de Bruin,1 S. van den Engel,1 L. van der Laan,1 H. van Steeg,2 J. Ijzermans,1 M. Dollé.2 1Department of Surgery, Laboratory for Experimental Transplantation and Intestinal Surgery (LETIS), Erasmus Medical Center, Rotterdam, Netherlands; 2Laboratory of Health Protection Research, National Institute of Public Health and the Environment (RIVM), Bilthoven, Netherlands. Introduction. Ischemia-reperfusion injury (IRI) is inevitable during kidney transplantation and leads to oxidative stress and infl ammation. We previously reported that preoperative fasting in young-lean male mice protects against IRI. Since patients are generally of older age and overweight, factors that may lead to a different response to fasting, we investigated the effects of preoperative fasting on renal IRI in aged overweight male and female mice. Methods. Male and female F1-FVB/C57BL6-hybrid mice, average age 73 weeks weighing 47.2 grams, were randomized to preoperative ad libitum feeding or 3 days fasting, followed by renal IRI. Body weight, kidney function and survival of the animals were monitored until day 28 postoperatively. Histopathology was examined for all animals and scored for acute tubular necrosis and tubular regeneration. All experiments had the approval of the local Animal Experiments Committee of the National Institute of Public Health and the Environment, the Netherlands. Results. Preoperative fasting signifi cantly improved survival after renal IRI in both sexes compared with normal fed mice. Fasted groups had a better kidney function shown by lower serum urea levels after IRI. Histopathology showed less acute tubular necrosis and more regeneration in kidneys from fasted mice. Fasting resulted in a body weight loss of 14-17% in male and female mice. In the fi rst week after IRI, body weight declined followed by recovery in the weeks thereafter. The normal fed mice showed a larger and faster weight loss after IRI. Conclusions. Similar to young-lean, healthy male mice, preoperative fasting protects against renal IRI in aged overweight mice of both genders. These fi ndings suggest a general protective response of fasting against renal IRI regardless of age, gender, body weight and genetic background. Therefore, fasting could be a non-invasive intervention inducing increased oxidative stress resistance in older and overweight patients as well. Abstract# C1684 Microarray Analysis After Preoperative Dietary Restriction Reveals Potential Mechanisms Involved in the Protection Against Ischemia-Reperfusion Injury. F. Jongbloed,1,2 T. Saat,1 M. Dollé,2 H. van Steeg,2 J. Hoeijmakers,3 C. Payan Gomez,3 L. van der Laan,1 J. Ijzermans,1 R. de Bruin.1 1Department of Surgery, Laboratory for Experimental Transplantation and Intestinal Surgery (LETIS), Erasmus University Medical Center, Rotterdam, Netherlands; 2Laboratory of Health Protection Research, National Institute of Public Health and the Environment, Bilthoven, Netherlands; 3Department of Genetics, Erasmus University Medical Center, Rotterdam, Netherlands. Background. Ischemia-reperfusion injury (IRI) is inevitable during kidney transplantation and leads to oxidative stress and infl ammation. We previously reported that short-term preoperative dietary restriction (DR), 3-day fasting and protein-free diets protect against renal IRI while a fat-free or carbohydrate-free (CHO-free) diet do not. To understand underlying mechanisms, we performed microarrays and compared gene expression profi les of (non)-protective diets in search for pathways involved in the effect. Methods. Male C57BL/6 mice were randomized to preoperative normal food or: 2 weeks 30%DR, 3-day fasting, 3-day protein-free, 3-day CHO-free or 3-day fat-free diet. Kidneys were harvested after each diet. Gene expressions were analysed by Affymetrix array and pathway analysis was done with Ingenuity. Cut-off for signifi cance was set on fold change ≥1.5 and p-value <0.05. Results. Compared to ad libitum fed, 2 weeks 30%DR resulted in 492 differentially expressed genes (DEG). Similarly, 3-day fasting led to 2604 DEG and a protein-free diet to 391 DEG. The fat-free diet resulted in zero DEG and a CHO-free diet in 1717 DEG. Seventy DEG overlapped in all 3 protective diets, with an overlap of 30 with CHO-free. Ingenuity analysis revealed the involvement of metabolic processes like retinol biosynthesis as well as stress responses like Nrf2-pathway. Preliminary in depth analysis shows differences in these pathways between the protective diets and CHO-free, in which genes like txnip and mrp1 may play a central role. Conclusions. This unique microarray dataset of different dietary interventions points to the involvement of pathways related to oxidative stress resistance and retinol metabolism in the benefi cial effects against renal IRI. Since the non-protective CHO-free diet also induced activation of these pathways, further exploration is needed. Collectively, these data suggest that a combined action of both metabolic and stress resistance pathways results in protection against IRI given by preoperative dietary interventions. Abstract# C1685 STAT3/CCR5 Signal Regulation Mitigates Renal IschemiaReperfusion Injury. K. Yoo,1 J. Park,1 S. Han,1 J. An,1 H. Lee,1 Y. Kim,1,2 S. Yang.2 1Internal Medicine, Seoul National University College of Medicine, Seoul, Korea, Republic of; 2Kidney Research Institute, Seoul, Korea, Republic of. Signal transducer and activator of transcription3 (STAT3) is unique transcription factor and known for a key member of the JAK-STAT signaling pathway. STAT3 was recently revealed to play roles in chemokine receptor 5 (CCR5) expression in human monocytes. CCR5 promoter regions contain STAT3 binding sites. In kidney disease, its role is unclarifi ed. Therefore, we studied the interaction of STAT3 and CCR5 signals on renal ischemia-reperfusion injury (IRI). B6 wild type and CCR5 KO mice were performed in bilateral renal artery pedicles clamping for 30 min followed by reperfusion. After then, we quantifi ed intrarenal cytokine expression using real-time PCR. Moreover, we cultured human tubular epithelial cells (TEC) in hypoxic condition and evaluated the effect of caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE, JAK2/STAT3 inhibitor) treatment. IRI produced more severe tubular damage in B6 wild type mice than in CCR5 KO mice (BUN, 191.0 ± 2.7 vs. 176.3 ± 2.3 mg/dL; creatinine, 2.37 ± 0.04 vs. 1.75 ± 1.16 mg/dL, p < 0.05). Although infl ammatory cytokines/chemokines, such as monocyte chemotactic protein-1, IL-1β, CCR5, CCL4, and CCL5 were increased by IRI in wild type mice compared to sham mice, they were signifi cantly attenuated in CCR5 KO mice. The expression of STAT3α as well as total STAT3 was more reduced in CCR5 KO mice than in wild type mice, whereas STAT3β level was not different between the two groups. These fi ndings were supported by in vitro study with human TEC. The level of CCR5 and pSTAT3 were elevated in the hypoxia-conditioned TECs, however, decreased in CADPE treated cells. We demonstrated that the activation of CCR5 via STAT3 (dominantly STAT3α) may be associated with progression of ischemia-reperfusion injury. These mechanisms of STAT3/CCR5 signaling suggest a novel strategy for management of acute kidney injury with STAT3 inhibitor. C1685 STAT3/CCR5 Signal Regulation Mitigates Renal IschemiaReperfusion Injury. K. Yoo,1 J. Park,1 S. Han,1 J. An,1 H. Lee,1 Y. Kim,1,2 S. Yang.2 1Internal Medicine, Seoul National University College of Medicine, Seoul, Korea, Republic of; 2Kidney Research Institute, Seoul, Korea, Republic of. Signal transducer and activator of transcription3 (STAT3) is unique transcription factor and known for a key member of the JAK-STAT signaling pathway. STAT3 was recently revealed to play roles in chemokine receptor 5 (CCR5) expression in human monocytes. CCR5 promoter regions contain STAT3 binding sites. In kidney disease, its role is unclarifi ed. Therefore, we studied the interaction of STAT3 and CCR5 signals on renal ischemia-reperfusion injury (IRI). B6 wild type and CCR5 KO mice were performed in bilateral renal artery pedicles clamping for 30 min followed by reperfusion. After then, we quantifi ed intrarenal cytokine expression using real-time PCR. Moreover, we cultured human tubular epithelial cells (TEC) in hypoxic condition and evaluated the effect of caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE, JAK2/STAT3 inhibitor) treatment. IRI produced more severe tubular damage in B6 wild type mice than in CCR5 KO mice (BUN, 191.0 ± 2.7 vs. 176.3 ± 2.3 mg/dL; creatinine, 2.37 ± 0.04 vs. 1.75 ± 1.16 mg/dL, p < 0.05). Although infl ammatory cytokines/chemokines, such as monocyte chemotactic protein-1, IL-1β, CCR5, CCL4, and CCL5 were increased by IRI in wild type mice compared to sham mice, they were signifi cantly attenuated in CCR5 KO mice. The expression of STAT3α as well as total STAT3 was more reduced in CCR5 KO mice than in wild type mice, whereas STAT3β level was not different between the two groups. These fi ndings were supported by in vitro study with human TEC. The level of CCR5 and pSTAT3 were elevated in the hypoxia-conditioned TECs, however, decreased in CADPE treated cells. We demonstrated that the activation of CCR5 via STAT3 (dominantly STAT3α) may be associated with progression of ischemia-reperfusion injury. These mechanisms of STAT3/CCR5 signaling suggest a novel strategy for management of acute kidney injury with STAT3 inhibitor. © The Authors. Compilation © The American Society of Transplant Surgeons, The Transplantation Society and the American Society of Transplantation