Mihai Oltean

Multiplex cytokine profiling in patients with sepsis.

Mera S, Tatulescu D, Cismaru C, Bondor C, Slavcovici A, Zanc V, Carstina D, Oltean M. Multiplex cytokine profiling in patients with sepsis. APMIS 2010; 119: 155–63.

Improved intestinal preservation using an intraluminal macromolecular solution: evidence from a rat model.

Background. Intestinal preservation injury consists of progressive submucosal edema, with fluid originating both from the lumen and the interstitium. Although vascular flushing aims to control electrolyte shifts in the tissue, the lumen is not addressed, and luminal water and electrolytes enter the tissue during ischemia. Because macromolecular solutions may retain water and electrolytes intraluminally, we investigated whether these solutions administered intraluminally may alleviate preservation injury. Methods. Sprague-Dawley rat intestines were perfused with University of Wisconsin solution. After excision of the intestines, we intraluminally introduced solutions containing polyethylene glycol 3350 with high (125 mEq) or low (65 mEq) sodium before cold preservation. Controls underwent only vascular flush. After 8, 14, or 20 hr of cold storage, the intestines were analyzed for extent of tissue injury, water retention, brush-border maltase, and tight junction proteins zonula occludens-1 and claudin-3. Results. Intraluminal composition changed over time, indicating sodium absorption and potassium secretion. After 8 and 14 hr of cold storage, intestines from the low-sodium group had the best morphology and least edema, followed by the controls. Maltase activity slightly decreased in all groups over time and was not affected by the intraluminal polyethylene glycol solutions. Various degrees of delocalization and degradation of zonula occludens-1 and claudin-3 were recorded within the tight junctions, with the most significant effects in intestines from the high-sodium group. Conclusions. Intraluminal macromolecular solutions may modulate the preservation injury in University of Wisconsin- perfused intestines. Low-sodium solutions administered immediately before preservation may improve preservation injury, but high-sodium solutions may be detrimental.

Esophageal barrier function and tight junction expression in healthy subjects and patients with gastroesophageal reflux disease: functionality of esophageal mucosa exposed to bile salt and trypsin in vitro.

Abstract Background and aims. Gastroesophageal reflux disease (GERD) is associated with impaired epithelial barrier function. However, the influence of acid and/or bile acids on human esophageal epithelial barrier function and the tight junction (TJ) proteins has not been fully elucidated. The aim of the study is to investigate the esophageal barrier function and TJ expression in healthy subjects and patients with GERD. The functionality of esophageal mucosa exposed to bile salt deoxycholic acid (DCA) and trypsin has been studied in vitro. Material and methods. Endoscopic biopsies from healthy controls and patients with GERD-related symptom with endoscopic erosive signs, as well as esophageal mucosa taken from patients undergoing esophagectomy were evaluated in Ussing chambers and by western blot and immunohistochemistry. Results. The esophageal epithelium from GERD patients had lower electrical resistance and higher epithelial currents than controls. Claudin-1 and -4 were significantly decreased in GERD patients. The bile salt DCA in the low concentration of 1.5 mM and trypsin increased the resistance and claudin-1 expression, while the higher concentration of 2.5 mM DCA and trypsin decreased the resistance and the claudin-3, -4 and E-cadherin expressions. Conclusion. In addition to acidic reflux, duodenal reflux components, such as bile salts and trypsin, have the potential to disrupt the esophageal barrier function, partly by modulating the TJ proteins. However, the expression of TJ is dependent on both the refluxed material as well as the concentration of the bile salt.

Charlson's weighted index of comorbidities is useful in assessing the risk of death in septic patients

PURPOSE We investigated the efficiency of the Charlsons weighted index of comorbidities (WIC) in predicting the risk of death in septic patients. MATERIALS AND METHODS A single-center, 3-year analysis of all septic patients was conducted; WIC and organ failure assessed using the Sepsis-related Organ Failure Assessment (SOFA) score were calculated retrospectively. RESULTS Of 250 septic patients, 60 patients (34%) had WIC above 2. Fifty-five patients (22%) died during the hospitalization. Increasing WIC was associated with increased mortality. Mean WIC differed significantly between survivors and nonsurvivors (P < .0001), and the univariate logistic regression revealed that risk of death depends significantly of WIC with odds ratio of 1.59 (95% confidence interval, 1.31-1.93; P < .001). The accuracy of prediction for the risk of death was 79.2%. Receiver operating characteristics curve indicated a WIC of 2 as a cutoff value, the association between WIC greater than 2, and the risk of death being described by an odds ratio of 1.87 (95% confidence interval, 1.017-3.457; P = .042); the area under the receiver operating characteristics curve in predicting mortality was 0.81 for the SOFA score and 0.68 for WIC; WIC correlated positively with SOFA (r = 0.27; P < .0001). CONCLUSION In septic patients, WIC is predictive for hospital mortality, and the risk of death significantly depends on WIC.

Intraluminal Polyethylene Glycol Stabilizes Tight Junctions and Improves Intestinal Preservation in the Rat

Rapidly progressing mucosal breakdown limits the intestinal preservation time below 10 h. Recent studies indicate that intraluminal solutions containing polyethylene glycol (PEG) alleviate preservation injury of intestines stored in UW‐Viaspan. We investigated whether a low‐sodium PEG solution is beneficial for intestines stored in histidine‐tryptophane‐ketoglutarate (HTK) preservation solution. Rat intestines used as control tissue (group 1) were perfused with HTK, groups 2 and 3 received either a customized PEG‐3350 (group 2) or an electrolyte solution (group 3) intraluminally before cold storage. Tissue injury, brush‐border maltase activity, zonula occludens‐1 (ZO‐1) and claudin‐3 expression in the tight junctions (TJ) were analyzed after 8, 14 and 20 h. We measured epithelial resistance and permeability (Ussing chamber) after 8 and 14 h. Group 2 had superior morphology while maltase activity was similar in all groups. TJ proteins rapidly decreased and decolocalized in groups 1 3; these negative events were delayed in group 2, where colocalization persisted for about 14 h. Intestines in group 2 had higher epithelial resistance and lower permeability than the other groups. These results suggest that a customized PEG solution intraluminally reduces the intestinal preservation injury by improving several major epithelial characteristics without negatively affecting the brush‐border enzymes or promoting edema.

Is Indoleamine 2,3-Dioxygenase Important for Graft Acceptance in Highly Sensitized Patients After Combined Auxiliary Liver-Kidney Transplantation?

Background. In the clinical setting, transplanted liver seems to protect other grafts from the same donor from rejection. Our previous findings suggest that an auxiliary liver transplantation a few hours before a renal transplantation not only inhibits hyperacute antibody-mediated rejection but also improves long-term kidney graft survival in sensitized recipients. Here, we investigated indoleamine 2,3-dioxygenase (IDO) activity, as one potential mechanism for liver-induced long-term acceptance of kidney grafts. Methods. Tryptophan degradation was measured to estimate IDO activity in patient sera and cell culture supernatants with high performance liquid chromatography. Gene expression in the grafted organs and cell lysates was studied using real time polymerase chain reaction analysis. Results. Tryptophan degradation increased in peripheral blood from patients undergoing combined auxiliary liver-kidney transplantation, whereas it decreased in patients after regular renal transplantation. A 100-fold increase in IDO mRNA, preceded by upregulation of the IDO-inducing cytokines tumor necrosis factor-α, interleukin-1β, and interferon-&ggr;, was observed in the transplanted organs after graft reperfusion in patients undergoing combined graft transplantation. Subsequent studies in vitro revealed that immature dendritic cells, but not hepatocytes, strongly activated IDO on maturation with tumor necrosis factor-α, interleukin-1β, and interferon-&ggr;. Finally, serum from liver-transplanted patients elicited an even stronger IDO-activity in such cytokine-stimulated dendritic cells. Conclusions. Taken together these findings suggest that the liver-induced long-term acceptance seen in human combined auxiliary liver and kidney transplantation is at least partly mediated by IDO activity.

Fifteen years’ experience of intestinal and multivisceral transplantation in the Nordic countries

Abstract Objective. Intestinal and multivisceral transplantation have gained acceptance as treatment modalities for patients with: intestinal failure and life-threatening complications of parenteral nutrition (PN), rare cases of vascular abdominal catastrophes and selected cases of low-grade neoplastic tumors such as neuroendocrine pancreatic tumors and desmoids involving the mesenteric root. The aim was to describe the survival and nutritional outcome in the transplanted Nordic patients and the complications attributed to this procedure. Method. The authors included all Nordic patients transplanted between January 1998 and December 2013. Information on patients transplanted outside the Nordic region was collected through questionnaires. Results. A total of 34 patients received different types of intestinal allografts. Currently, there are two Nordic transplant centers (n = 29) performing these procedures (Gothenburg, Sweden n = 24, Helsinki, Finland n = 5). The remaining five patients were transplanted in the USA (n = 3) and the UK (n = 2). Most patients were transplanted for life-threatening failure of PN (70%) caused primarily by intestinal motility diseases (59%). Allograft rejection was the most common complication and occurred in 79% of the patients followed by post-transplantation lymphoproliferative disorders (21%) and graft-versus-host disease (18%). The 1- and 5-year survival was 79% and 65% respectively for the whole cohort and nutritional autonomy was achieved in 73% of the adults and 57% of the children at 1 year after transplantation. Conclusion. This collective Nordic experience confirms that intestinal transplantation is a complex procedure with many complications, yet with the possibility to provide long-term survival in selected conditions previously considered untreatable.

Reduced liver injury and cytokine release after transplantation of preconditioned intestines.

BACKGROUND The postischemic intestine liberates pro-inflammatory mediators (cytokines, lipopolysaccharide [LPS], free radicals) proportional with the local injury that may trigger a systemic inflammatory response and multi-system organ failure. Previously, intestines from donors receiving Tacrolimus revealed improved morphology and abrogated nuclear factor kappa B (NF-kappaB) activation. Because of its pivotal role in inflammation, we investigated if NF-kappaB intragraft inhibition influences the posttransplant inflammatory response and remote organ injury. MATERIALS AND METHODS Donor Sprague Dawley rats received tacrolimus (0.3 mg/kg) or saline i.v. 6 h before graft harvest. The intestines were preserved for 3 h and then transplanted heterotopically. Hepatic microcirculation was assessed at 20 min, 6 h, 12 h, or 24 h post-reperfusion (postR) using laser-Doppler flowmetry (n = 10/group). Blood pressure measurements and liver sampling were performed at 6, 12, or 24 h postR. Blood samples were obtained at 1, 3, 6, 12, and 24 h postR. Hepatic intercellular adhesion molecule 1 (ICAM-1) expression, caspase-3 and -9 activity, and circulating tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and LPS were studied. RESULTS Pretreated graft (PG) recipients had superior cardiovascular parameters at 6 and 12 h postR, while liver perfusion was similar between groups at all time points. Recipients of PG had lower transaminase levels and ICAM-1 liver expression. Liver caspase 3 and 9 activity were similar at 6 and 12 h but increased at 24 h in both groups. At every time point, circulating tumor necrosis factor alph, IL-1beta, and IL-6 were lower in animals receiving PG. LPS was found increased only at the last time point. CONCLUSIONS Transplantation of tacrolimus-pretreated intestines triggered a milder inflammatory response and decreased liver injury early posttransplantation compared with untreated grafts. Cytokines, but not neutrophils, hypoperfusion, or LPS may underlie the dysfunction.

Chronic kidney disease--a common and serious complication after intestinal transplantation.

Background. Chronic kidney disease after organ transplantation is a serious complication that negatively impacts on long-term patient survival. We describe long-term renal function after intestinal transplantation by serial measurements of glomerular filtration rates (GFR) with 51Chromium EDTA clearance. Materials and Methods. Ten patients with at least 6 months survival form the basis of this report. Glomerular filtration rate measurements were performed at baseline, 3 months posttransplantation, and yearly thereafter. Median follow-up time for the cohort was 1.5 years (0.5–7.8 years). Tacrolimus (Prograf) was discontinued in four patients because of impaired renal function. These four patients were switched to sirolimus (Rapamune) at 11, 18, 24, and 40 months posttransplantation. Results. Median baseline GFR was 67 (22–114) mL/min/1.73 m2. In the adult patients, GFR 3 months posttransplantation had decreased to 50% of the baseline. At 1 year, median GFR in the adult patients was reduced by 72% (n=5). Two patients developed renal failure within the first year and required hemodialysis. One of the pediatric patients fully recovered her renal function, the second pediatric patient lost 20% of her baseline GFR at 6 months posttransplantation. Glomerular filtration rate calculated with the modified diet in renal disease formula consistently overestimated GFR by approximately 30% compared with measured GFR. Conclusion. Chronic kidney disease and renal failure are common after intestinal transplantation. These two factors significantly contribute to poor long-term survival rates. Measurements of GFR may help to identify those individuals at risk for developing chronic kidney disease to implement renal sparing strategies.

Organ-Specific Solutions and Strategies for the Intestinal Preservation

Among the intraabdominal organs, the intestine is the most susceptible to storage injury and as a consequence its safe cold ischemic time in the clinic is restricted to below 10 hours. The current practice for the intestinal preservation (IP) consists of an in-situ vascular flush with iced University of Wisconsin or Histidine-Tryptophan-Ketoglutarate solution followed by cold storage at 4°C. Mucosal injury is initiated within 1 hour and rapidly progresses to mucosal breakdown; tissue injury worsens upon reperfusion and further impairs the mucosal barrier, favoring bacterial translocation and sepsis. In addition of releasing danger signals, an advanced ischemia-reperfusion injury (IRI) may increase graft immunogenicity and promote rejection. Several alternative approaches have been tested as alternatives to the static storage. The aim of this review is to summarize and discuss the various intraluminal interventions as additional strategies aiming to reduce the IP/reperfusion injury and highlight the underlying pathophysiological mechanisms.