Metabolic improvement in obese patients after duodenal-jejunal exclusion is associated with intestinal microbiota composition changes.

BACKGROUND: Intestinal microbiota have been suggested to play an important role in the pathogenesis of obesity and type 2 diabetes. Bariatric surgery improves both conditions and has been associated with changes in intestinal microbiota composition. We investigated the effect of a nonsurgical bariatric technique on intestinal microbiota composition in relation to metabolic improvement. METHODS: Seventeen patients with obesity and type 2 diabetes were treated with the nonsurgical duodenal-jejunal bypass liner, which excludes the proximal 60 cm small intestine from food. Fecal samples as well as metabolic parameters reflecting obesity and type 2 diabetes were obtained from the patients at baseline, after 6 months with the device in situ, and 6 months after explantation. RESULTS: After 6 months of treatment, both obesity and type 2 diabetes had improved with a decrease in weight from 106.1 [99.4-123.5] to 97.4 [89.4-114.0] kg and a decrease in HbA1c from 8.5% [7.6-9.2] to 7.2% [6.3-8.1] (both p < 0.05). This was paralleled by an increased abundance of typical small intestinal bacteria such as Proteobacteria, Veillonella, and Lactobacillus spp. in feces. After removal of the duodenal-jejunal bypass liner, fecal microbiota composition was similar to that observed at baseline, despite persistent weight loss. CONCLUSION: Improvement of obesity and type 2 diabetes after exclusion of the proximal 60 cm small intestine by treatment with a nonsurgical duodenal-jejunal bypass liner may be promoted by changes in fecal microbiota composition.

TUB gene expression in hypothalamus and adipose tissue and its association with obesity in humans.

BACKGROUND/OBJECTIVES: Mutations in the Tubby gene (TUB) cause late-onset obesity and insulin resistance in mice and syndromic obesity in humans. Although TUB gene function has not yet been fully elucidated, studies in rodents indicate that TUB is involved in the hypothalamic pathways regulating food intake and adiposity. Aside from the function in central nervous system, TUB has also been implicated in energy metabolism in adipose tissue in rodents. We aimed to determine the expression and distribution patterns of TUB in man as well as its potential association with obesity. SUBJECTS/METHODS: In situ hybridization was used to localize the hypothalamic regions and cells expressing TUB mRNA. Using RT-PCR, we determined the mRNA expression level of the two TUB gene alternative splicing isoforms, the short and the long transcript variants, in the hypothalami of 12 obese and 12 normal-weight subjects, and in biopsies from visceral (VAT) and subcutaneous (SAT) adipose tissues from 53 severely obese and 24 non-obese control subjects, and correlated TUB expression with parameters of obesity and metabolic health. RESULTS: Expression of both TUB transcripts was detected in the hypothalamus, whereas only the short TUB isoform was found in both VAT and SAT. TUB mRNA was detected in several hypothalamic regions involved in body weight regulation, including the nucleus basalis of Meynert and the paraventricular, supraoptic and tuberomammillary nuclei. We found no difference in the hypothalamic TUB expression between obese and control groups, whereas the level of TUB mRNA was significantly lower in adipose tissue of obese subjects as compared to controls. Also, TUB expression was negatively correlated with indices of body weight and obesity in a fat-depot-specific manner. CONCLUSIONS: Our results indicate high expression of TUB in the hypothalamus, especially in areas involved in body weight regulation, and the correlation between TUB expression in adipose tissue and obesity. These findings suggest a role for TUB in human obesity.

Doppler-guided goal-directed fluid therapy does not affect intestinal cell damage but increases global gastrointestinal perfusion in colorectal surgery: a randomized controlled trial.

AIM: Individualized, goal-directed fluid therapy (GDFT), based on Doppler measurements of stroke volume, has been proposed as a treatment strategy in terms of reducing complications, mortality and length of hospital stay in major bowel surgery. We studied the effect of Doppler-guided GDFT on intestinal damage as compared with standard postoperative fluid replacement. METHOD: Patients undergoing elective colorectal resection for malignancy were randomized either to standard intra- and postoperative fluid therapy or to standard fluid therapy with additional Doppler-guided GDFT. The primary outcome was intestinal epithelial cell damage measured by plasma levels of intestinal fatty acid-binding protein (I-FABP). Global gastrointestinal perfusion was measured by gastric tonometry, expressed as regional (gastric) minus arterial CO2 -gap (Pr-a CO2 -gap). RESULTS: I-FABP levels were not significantly different between the intervention group and the control group (respectively, 440.8 (251.6) pg/ml and 522.4 (759.9) pg/ml, P = 0.67). Mean areas under the curve (AUCs) of intra-operative Pr-a CO2 -gaps were significantly lower in the intervention group than in the control group (P = 0.01), indicating better global gastrointestinal perfusion in the intervention group. Moreover, the mean intra-operative Pr-a CO2 -gap peak in the intervention group was 0.5 (1.0) kPa, which was significantly lower than the mean peak in the control group, of 1.4 (1.4) kPa (P = 0.03). CONCLUSION: Doppler-guided GDFT during and in the first hours after elective colorectal surgery for malignancy increases global gastrointestinal perfusion, as measured by Pr-a CO2 -gap.

Progress towards non-invasive diagnosis and follow-up of celiac disease in children; a prospective multicentre study to the usefulness of plasma I-FABP.

This prospective study investigates whether measurement of plasma intestinal-fatty acid binding protein (I-FABP), a sensitive marker for small intestinal epithelial damage, improves non-invasive diagnosing of celiac disease (CD), and whether I-FABP levels are useful to evaluate mucosal healing in patients on a gluten-free diet (GFD). Ninety children with elevated tTG-IgA titres and HLA-DQ2/DQ8 positivity were included (study group). Duodenal biopsies were taken, except in those fulfilling the ESPGHAN criteria. Plasma I-FABP levels and tTG-IgA titres were assessed sequentially during six months of follow-up. Eighty children with normal tTG-IgA titres served as control group. In 61/90 (67.8%) of the children in the study group an increased I-FABP level was found; in all these children CD diagnosis was confirmed. Interestingly, in 14/30 (46.7%) children with slightly elevated tTG-IgA titres (<10x upper limit of normal), an increased I-FABP level was found. In all these children the diagnosis of CD was confirmed histologically. After gluten elimination for six weeks I-FABP levels had decreased towards levels in the control group. Measurement of plasma I-FABP, in addition to tTG-IgA, EMA-IgA and HLAtyping, enables non-invasive diagnosing of CD in a substantial number of children, and might therefore be of value in the diagnostic approach of CD.

Tumor Necrosis Factor: Function, Release and Clearance.

Tumor Necrosis Factor (TNF) is a multifunctional cytokine. It plays an important role in the pathophysiology of several diseases. Recently, it has been discovered that TNF is circulating in two different forms, a bioactive form and an immunologically detectable form. These two forms of TNF show different clearance kinetics. The immunological form is supposed to be an inactivated TNF protein. For this inactivation, proteolytic degradation or TNF binding by inactivating proteins is necessary. In this review we have focused on TNF inactivation by TNF binding proteins. Recent data show that there are soluble TNF receptors circulating which can bind and inactivate TNF. These receptors are membrane-bound TNF receptors which have been proteolytically cleaved from the cell membrane. Two TNF receptors are circulating, the soluble TNF receptor of 55 kDa (P55) and the receptor of 75 kDa (P75). The receptors are held responsible not only for inactivation of the TNF, but also for the clearance of TNF. Recent data show that the kidney is the most important organ for TNF clearance, followed by the liver. All other organs are of less importance. In this review, function, release, and clearance of TNF are discussed.

Relation between postoperative ileus and anastomotic leakage after colorectal resection: a post hoc analysis of a prospective randomized controlled trial.

AIM: Anastomotic leakage (AL) following abdominal surgery is a critical determinant of postoperative recovery, of which the aetiology is largely unknown. Interestingly, interventions aimed at reducing the inflammatory response and postoperative ileus (POI) have an unexpected effect on AL. The aim of this study was to investigate the relation of POI with inflammation and AL after colorectal resection. METHOD: A post hoc analysis of a prospective randomized controlled trial in which patients underwent a colorectal resection was performed. Patients undergoing a colorectal resection were stratified into having or not having POI. The incidence of AL and other clinical parameters was registered prospectively. Intestinal fatty acid binding protein (I-FABP, a marker for tissue damage) and the inflammatory response in plasma and colon tissue were determined. RESULTS: AL was present in nine of 43 patients in the POI group, and in one of 65 in the group without POI (P < 0.001). There was a significant association between POI and AL (OR 12.57, 95% CI: 2.73-120.65; P = 0.0005). Patients with POI had significantly higher plasma levels of soluble tumour necrosis factor receptor 1 (TNFRSF1A) at 4 h postoperatively (0.89 ng/l, interquartile range 0.56) than patients without POI (0.80 ng/l, interquartile range 0.37; P = 0.04) and higher plasma levels of C-reactive protein on the second day postoperatively (234 ± 77 vs 163 ± 86 mg/l; P = 0.001). Patients who developed AL had significantly higher plasma levels of I-FABP compared with patients without AL at 24 h after onset of surgery. CONCLUSION: POI is associated with a higher prevalence of AL and an increased inflammatory response.

Children With Morbid Obesity Benefit Equally as Children With Overweight and Obesity From an Ongoing Care Program.

CONTEXT: Despite stabilization of childhood overweight and obesity prevalence, there is a shift toward more severe degrees of obesity, which results in an increasing prevalence of children with morbid obesity. Prior studies demonstrated that lifestyle modification without ongoing treatment has only a modest and not sustainable effect in children with morbid obesity. This suggests that a chronic care model is necessary for long-term effects on weight management and health. OBJECTIVE: This study aimed to evaluate the effect of an ongoing lifestyle intervention in children with morbid obesity in comparison with children with overweight and obesity. DESIGN AND SETTING: This was a nonrandomized prospective intervention study with 12- and 24-month followup at the Centre for Overweight Adolescent and Children's Healthcare. PATIENTS AND INTERVENTION: Children and adolescents (n = 100 females and 72 males) with overweight, obesity, or morbid obesity were given long-term, outpatient, tailored lifestyle intervention. MAIN OUTCOME MEASURE: Body mass index (BMI) z score was measured. RESULTS: In children with morbid obesity, 12- and 24-month interventions resulted in a decrease of BMI z score of -0.13 ± 0.25 (P = .001) and -0.23 ± 0.32 (P = .01) respectively, whereas weight status category improved to obese in 21% and 25% of the children. Cardiovascular risk parameters including serum total cholesterol, low-density lipoprotein cholesterol, glycosylated hemoglobin (HbA1c), and diastolic blood pressure significantly improved after 1-year intervention in the complete group. Most important, BMI z score as well as cardiovascular risk parameters improved to a similar degree in children with overweight, obesity, and morbid obesity. CONCLUSIONS: Children with overweight, obesity, and morbid obesity benefit equally from an ongoing, outpatient, tailored lifestyle intervention, and demonstrate significant weight loss and improvement of cardiovascular risk parameters.

Visceral hypersensitivity in irritable bowel syndrome: evidence for involvement of serotonin metabolism--a preliminary study.

BACKGROUND: Altered serotonergic (5-HT) metabolism and visceral perception have been associated with the pathogenesis of irritable bowel syndrome (IBS). Aim of this preliminary study was to assess the effect of the direct precursor of 5-HT, 5-hydroxytryptophan (5-HTP), on systemic 5-HT metabolites and visceral perception and to assess potential differential responses between IBS and controls. METHODS: 15 IBS patients and 15 healthy volunteers participated in this randomized double-blind placebo controlled study. Visceroperception was measured by rectal barostat. The 100 mg 5-HTP or placebo was ingested orally. Serotonergic metabolites were assessed in platelet poor plasma. KEY RESULTS: 5-HTP induces rectal allodynia in a significant number of healthy controls; IBS patients exhibit lowered pain thresholds in both placebo and 5-HTP conditions. 5-HTP induces rectal hyperalgesia in hypersensitive but not in non-hypersensitive IBS patients. Administration of 5-HTP significantly increased plasma 5-HTP levels (p < 0.001), did not affect 5-HT levels (p > 0.05), while levels of the main metabolite of 5-HT, 5-hydroxyindoleacetic acid, increased significantly (p < 0.05) in both groups. The magnitude of these changes observed in 5-HT metabolites was significantly greater in IBS patients. CONCLUSIONS & INFERENCES: Oral administration of 5-HTP induced significant alterations in systemic 5-HT metabolites that were accompanied by increased visceroperception of pain in controls and hypersensitive IBS patients. Changes in 5-HT metabolism appear to be important factors involved in visceral hypersensitivity as the 5-HTP-induced pro-nociceptive response was observed in all hypersensitive IBS patients and to a lesser magnitude in a significant number of healthy controls but in none of the non-hypersensitive IBS patients.

Determining the association between adipokine expression in multiple tissues and phenotypic features of non-alcoholic fatty liver disease in obesity.

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is an obesity-associated disease, and in obesity adipokines are believed to be involved in the development of NAFLD. However, it is still not clear whether adipokines in the liver and/or adipose tissues can be related to the development of specific characteristics of NAFLD, such as steatosis and inflammation. We aimed to address this question by simultaneously examining the adipokine expression in three tissue types in obese individuals. METHODS: We enrolled 93 severely obese individuals with NAFLD, varying from simple steatosis to severe non-alcoholic steatohepatitis. Their expression of 48 adipokines in the liver, visceral and subcutaneous adipose tissue (SAT) was correlated to their phenotypic features of NAFLD. We further determined whether the correlations were tissue specific and/or independent of covariates, including age, sex, obesity, insulin resistance and type 2 diabetes (T2D). RESULTS: The expression of adipokines showed a liver- and adipose tissue-specific pattern. We identified that the expression of leptin, angiopoietin 2 (ANGPT2) and chemerin in visceral adipose tissue (VAT) was associated with different NAFLD features, including steatosis, ballooning, portal and lobular inflammation. In addition, the expression of tumor necrosis factor (TNF), plasminogen activator inhibitor type 1 (PAI-1), insulin-like growth factor 1 (somatomedin C) (IGF1) and chemokine (C-X-C motif) ligand 10 (CXCL10) in the liver tissue and the expression of interleukin 1 receptor antagonist (IL1RN) in both the liver and SAT were associated with NAFLD features. The correlations between ANGPT2 and CXCL10, and NAFLD features were dependent on insulin resistance and T2D, but for the other genes the correlation with at least one NAFLD feature remained significant after correcting for the covariates. CONCLUSIONS: Our results suggest that in obese individuals, VAT-derived leptin and chemerin, and hepatic expression of TNF, IGF1, IL1RN and PAI-1 are involved in the development of NAFLD features. Further, functional studies are warranted to establish a causal relationship.

Randomized clinical trial of the effect of gum chewing on postoperative ileus and inflammation in colorectal surgery.

BACKGROUND: Postoperative ileus (POI) is a common complication following colorectal surgery that delays recovery and increases length of hospital stay. Gum chewing may reduce POI and therefore enhance recovery after surgery. The aim of the study was to evaluate the effect of gum chewing on POI, length of hospital stay and inflammatory parameters. METHODS: Patients undergoing elective colorectal surgery in one of two centres were randomized to either chewing gum or a dermal patch (control). Chewing gum was started before surgery and stopped when oral intake was resumed. Primary endpoints were POI and length of stay. Secondary endpoints were systemic and local inflammation, and surgical complications. Gastric emptying was measured by ultrasonography. Soluble tumour necrosis factor receptor 1 (TNFRSF1A) and interleukin (IL) 8 levels were measured by enzyme-linked immunosorbent assay. RESULTS: Between May 2009 and September 2012, 120 patients were randomized to chewing gum (58) or dermal patch (control group; 62). Mean(s.d.) length of hospital stay was shorter in the chewing gum group than in controls, but this difference was not significant: 9·5(4·9) versus 14·0(14·5) days respectively. Some 14 (27 per cent) of 52 analysed patients allocated to chewing gum developed POI compared with 29 (48 per cent) of 60 patients in the control group (P = 0·020). More patients in the chewing gum group first defaecated within 4 days of surgery (85 versus 57 per cent; P = 0·006) and passed first flatus within 48 h (65 versus 50 per cent; P = 0·044). The decrease in antral area measured by ultrasonography following a standard meal was significantly greater among patients who chewed gum: median 25 (range -36 to 54) per cent compared with 10 (range -152 to 54) per cent in controls (P = 0·004). Levels of IL-8 (133 versus 288 pg/ml; P = 0·045) and TNFRSF1A (0·74 versus 0·92 ng/ml; P = 0·043) were lower among patients in the chewing gum group. Fewer patients in this group developed a grade IIIb complication (2 of 58 versus 10 of 62; P = 0·031). CONCLUSION: Gum chewing is a safe and simple treatment to reduce POI, and is associated with a reduction in systemic inflammatory markers and complications. REGISTRATION NUMBER: NTR2867 (http://www.trialregister.nl).

Serotonergic reinforcement of intestinal barrier function is impaired in irritable bowel syndrome.

BACKGROUND: Alterations in serotonergic (5-HT) metabolism and/or intestinal integrity have been associated with irritable bowel syndrome (IBS). AIMS: To assess the effects of the precursor of 5-HT, 5-hydroxytryptophan (5-HTP), on mucosal 5-HT availability and intestinal integrity, and to assess potential differences between healthy controls and IBS patients. METHODS: Fifteen IBS patients and 15 healthy volunteers participated in this randomised double-blind placebo-controlled study. Intestinal integrity was assessed by dual-sugar test and by determining the mucosal expression of tight junction proteins after ingestion of an oral bolus of 100 mg 5-HTP or placebo. Mucosal serotonergic metabolism was assessed in duodenal biopsy samples. RESULTS: 5-HTP administration significantly increased mucosal levels of 5-HIAA, the main metabolite of 5-HT, in both healthy controls (7.1 ± 1.7 vs. 2.5 ± 0.7 pmol/mg, 5-HTP vs. placebo, P = 0.02) and IBS patients (20.0 ± 4.8 vs. 8.1 ± 1.3 pmol/mg, 5-HTP vs. placebo, P = 0.02), with the latter group showing a significantly larger increase. Lactulose/L-rhamnose ratios were significantly lower after administration of 5-HTP (P < 0.05) in healthy controls and were accompanied by redistribution of zonula occludens-1 (ZO-1), pointing to reinforcement of the barrier. In IBS, expression of the tight junction proteins was significantly lower compared to healthy controls, and 5-HTP resulted in a further decrease in occludin expression. CONCLUSIONS: Oral 5-HTP induced alterations in mucosal 5-HT metabolism. In healthy controls, a reinforcement of the intestinal barrier was seen whereas such reaction was absent in IBS patients. This could indicate the presence of a serotonin-mediated mechanism aimed to reinforce intestinal barrier function, which seems to dysfunction in IBS patients.

Serum I-FABP as marker for enterocyte damage in coeliac disease and its relation to villous atrophy and circulating autoantibodies.

BACKGROUND: Enterocyte damage is the hallmark of coeliac disease (CD) resulting in malabsorption. Little is known about the recovery of enterocyte damage and its clinical consequences. Serum intestinal fatty acid binding protein (I-FABP) is a sensitive marker to study enterocyte damage. AIMS: To evaluate the severity of enterocyte damage in adult-onset CD and its course upon a gluten-free diet (GFD). Furthermore, the correlation among enterocyte damage, CD autoantibodies and histological abnormalities during the course of disease is studied. METHODS: Serum I-FABP levels were determined in 96 biopsy-proven adult CD patients and in 69 patients repeatedly upon a GFD. A total of 141 individuals with normal antitissue transglutaminase antibody (IgA-tTG) levels served as controls. I-FABP levels were related to the degree of villous atrophy (Marsh grade) and IgA-tTG. RESULTS: I-FABP levels were elevated in untreated CD (median 691 pg/mL) compared with controls (median 178 pg/mL, P < 0.001) and correlated with Marsh grade (r = 0.265, P < 0.05) and IgA-tTG (r = 0.403, P < 0.01). Upon a GFD serum levels decreased significantly, however, not within the range observed in controls, despite the common observed normalisation of IgA-tTG levels and Marsh grade. CD patients with elevated I-FABP levels nonresponding to GFD showed persistent histological abnormalities. CONCLUSIONS: Enterocyte damage assessed by serum I-FABP correlates with the severity of villous atrophy in coeliac disease at the time of diagnosis. Although enterocyte damage improves upon treatment, substantial enterocyte damage persists despite absence of villous atrophy and low IgA-tTG levels in the majority of cases. Elevated I-FABP levels nonresponding to gluten-free diet are indicative of histological abnormalities and warrant further evaluation.

Tumor angiogenesis is enforced by autocrine regulation of high-mobility group box 1.

The endothelium plays a pivotal role in the progression of solid tumors and is considered a highly relevant target for therapy. However, it emerges that current clinical angiogenesis inhibitors that act through inhibition of tumor-derived growth factors are prone to inducing drug resistance. Therefore, markers of tumor endothelial cells (ECs) themselves provide attractive novel therapeutic targets. In a screen for markers of tumor angiogenesis, we recently identified high-mobility group box 1 (HMGB1), known to act as proinflammatory cytokine and chromatin-binding molecule. Here we report on the role of HMGB1 in angiogenesis by showing that its overexpression is associated with an increased angiogenic potential of ECs. HMGB1 stimulates the expression of players in vascular endothelial growth factor and platelet-derived growth factor signaling, both in vitro and in vivo. Importantly, we show that HMGB1 triggers and helps to sustain this proangiogenic gene expression program in ECs, additionally characterized by increased activity of matrix metalloproteinases, integrins and nuclear factor-κB. Moreover, we found that HMGB1 is involved in several autocrine and/or paracrine feedback mechanisms resulting in positive enforcement of HMGB1 expression, and that of its receptors, RAGE (receptor for advanced glycation end products) and Toll-like receptor 4 (TLR4). Interference in HMGB1 expression and/or function using knockdown approaches and antibody-mediated targeting to break this vicious circle resulted in inhibited migration and sprouting of ECs. Using different in vivo models, therapeutic efficacy of HMGB1 targeting was confirmed. First, we demonstrated induction of HMGB1 expression in the chicken embryo chorioallantoic membrane (CAM) neovasculature following both photodynamic therapy and tumor challenge. We subsequently showed that anti-HMGB1 antibodies inhibited vessel density in both models, accompanied by a reduced vascular expression of angiogenic growth factor receptors. Collectively, these data identify HMGB1 as an important modulator of tumor angiogenesis and suggest the feasibility of targeting HMGB1 for multi-level cancer treatment.

Chenodeoxycholic acid reduces intestinal permeability in newly weaned piglets.

Piglets are highly susceptible to gut health-related problems. Intravenously administered chenodeoxycholic acid (CDCA) affects gut health mediated through glucagon-like peptide 2 (GLP-2). To test whether CDCA is a suitable feed additive for improving gut health, a trial was performed with newly weaned (21 d) piglets offered a diet with or without 60 mg CDCA/kg feed (n = 24/treatment). Upon weaning, piglets were fasted for 16 h and then intragastrically dosed with 20 g test feed in 40 g water. Subsequently, a jugular blood sample was taken on 45, 90, 135, or 180 min for analysis of GLP-2, peptide YY (PYY), and glucose. Afterwards, piglets were offered the experimental diets ad libitum. On days 3.5, 7.5, and 10.5 after weaning, serum responses to an intragastric dose of lactulose and Co-EDTA were tested at 2 h after dosing in 8 piglets per treatment. Immediately thereafter, piglets were euthanized, intestines were harvested, and permeability was measured ex vivo using the everted gut sac technique with 4 kDa fluorescein isothiocyanato (FITC)-dextran as marker at 25, 50, and 75% of the length of the small intestine. Dietary CDCA did not affect (P > 0.05) ADFI, ADG, G:F, blood glucose, and plasma GLP-2 and PYY. Serum cobalt and lactulose at day 10.5 tended to be lower in CDCA pigs compared with control pigs. Serum cobalt and lactulose concentrations were positively correlated (r = 0.67; P < 0.01). In conclusion, CDCA tended to reduce intestinal permeability at 10.5 d after weaning when fed to newly weaned piglets, implying that CDCA deserves further study as a means for improving intestinal health. The positive correlation found between Co-EDTA and lactulose indicates that both marker molecules measure similar change in permeability.

Mannose-binding lectin null alleles are associated with preserved epithelial cell integrity following intestinal ischemia reperfusion in man.

Mannose-binding lectin (MBL) deficiency is associated with reduced intestinal ischemia-reperfusion (IR) damage in rodents. We set out to investigate an association between frequently observed MBL deficiency and IR associated intestinal cell damage in man. Using a newly developed IR model of the human small intestine 29 patients were consecutively included. Part of the jejunum was subjected to 30 min of ischemia and reperfusion. The MBL genotype was assessed by means of quantitative-PCR analysis. Enterocyte loss was explored by measuring plasma intestinal-fatty acid binding protein (I-FABP) levels. Arterial and venous MBL plasma levels were measured to assess MBL consumption, MBL deposition was analyzed by immunofluorescence. Ethical approval and informed consent were obtained. The amount of epithelial cell damage varied significantly between the carriers of different mbl2 genotypes (ANOVA, p=0.02). I-FABP release, representing disintegration of differentiated enterocytes, observed in homozygous wildtype individuals was twice (p=0.03) that measured in heterozygous and ten times (p=0.04) that observed in homozygous variant individuals. No MBL deposition was observed over the course of reperfusion. The data indicate that MBL influences intestinal epithelial cell integrity in an immediate and non-complement dependent manner during ischemia and reperfusion.

Loss of enterocyte mass is accompanied by diminished turnover of enterocytes after myeloablative therapy in haematopoietic stem-cell transplant recipients.

BACKGROUND: Intestinal mucosal barrier injury (MBI), resulting from myeloablative conditioning for haematopoietic stem-cell transplantation (HSCT), is an important cause of morbidity. Despite its frequency, recognition presents a challenge, while the aetiology needs still to be unravelled. The relationship between enterocyte mass and enterocyte loss was explored by examining citrulline serum levels and by assessing circulating intestinal fatty acid-binding protein (I-FABP) and ileal bile acid-binding protein (I-BABP), proteins released by dying mature enterocytes. PATIENTS AND METHODS: Thirty-four adult patients with haematological malignancy received allogeneic HSCT (HSCT day 0) 12 days after being given idarubicin, cyclophosphamide and total body irradiation as myeloablative conditioning, a regimen known to induce oral and intestinal MBI. Serum levels of citrulline, I-FABP and I-BABP were measured on HSCT days -12, -6, 0, +7, +14 and +21. RESULTS: Myeloablative conditioning resulted in a significant decrease in serum citrulline with the nadir on HSCT day +7; thereafter, levels rose gradually. Simultaneously, a significant decrease in I-FABP and I-BABP levels occurred from the day of transplant until day +14. CONCLUSIONS: Simultaneous reduction and subsequent increase of citrulline and I-FABP and I-BABP levels following cytotoxic treatment show that enterocyte mass corresponds to lower rate of dying enterocytes, indicating reduced turnover of enterocytes. Assessment of enterocyte turnover and mass offers opportunities for evaluation of new MBI therapies.

Histological assessment of preimplantation biopsies may improve selection of kidneys from old donors after cardiac death.

Kidneys from old donors after cardiac death (DCD) may increase the donor pool but the prognosis of these kidneys is unsatisfactory. To improve these results, we retrospectively evaluated the diagnostic utility of published selection algorithms for old donor kidneys. We studied all DCD kidney transplantations between January 1, 1994 and July 1, 2005 at our institution (n = 199). Selection algorithms were evaluated in the subset of kidney transplantations from donors aged 60 years or older (n = 52). For histological assessment of kidney biopsies, glomerulosclerosis, tubular atrophy, interstitial fibrosis and vascular narrowing were blindly scored. Functional kidney weight was calculated as renal mass multiplied by the fraction of nonsclerosed glomeruli. Graft function and survival of kidneys from DCD aged 60 years or older were inferior to those from younger DCD. Histological scores were associated with kidney function and graft survival of old DCD kidney transplantations. Functional kidney weight was associated with kidney function but not graft survival, while donor glomerular filtration rate (GFR), donor age and machine perfusion characteristics were associated with neither of the clinical outcomes of interest. We conclude that histological assessment of preimplantation biopsies may improve the selection of kidneys from old DCD and may therefore contribute to expansion of the donor pool.