Annika Mutanen

Persistent abnormal liver fibrosis after weaning off parenteral nutrition in pediatric intestinal failure.

The aim of this study was to evaluate the long‐term effects of pediatric intestinal failure (IF) on liver histology. Altogether, 38 IF patients (median age: 7.2 years; range, 0.2‐27) underwent liver biopsy, gastroscopy, abdominal ultrasound, and laboratory tests. Sixteen patients were on parenteral nutrition (PN) after 74 PN months (range, 2.5‐204). Twenty‐two had weaned off PN 8.8 years (range, 0.3‐27) earlier, after 35 PN months (range, 0.7‐250). Fifteen transplant donor livers served as controls. Abnormal liver histology was found in 94% of patients on PN and 77% of patients weaned off PN (P = 0.370). During PN, liver histology weighted with cholestasis (38% of patients on PN versus 0% of patients weaned off PN; P = 0.003) and portal inflammation (38% versus 9%; P = 0.050) were found. Fibrosis (88% versus 64%; P = 0.143; Metavir stage: 1.6 [range, 0‐4] versus 1.1 [range, 0‐2]; P = 0.089) and steatosis (50% versus 45%; P = 1.000) were equally common during and after weaning off PN. Plasma alanine aminotransferase (78 U/L [range, 19‐204] versus 34 [range, 9‐129]; P = 0.009) and conjugated bilirubin (43 μmol/L [range, 1‐215] versus 4 [range, 1‐23]; P = 0.037) were significantly higher during than after weaning off PN. Esophageal varices were encountered in 1 patient after weaning off PN. Metavir stage was associated with small bowel length (r = −0.486; P = 0.002) and number of septic episodes (r = 0.480; P = 0.002). In a multivariate analysis, age‐adjusted small bowel length (ß = −0.533; P = 0.001), portal inflammation (ß = 0.291; P = 0.030), and absence of an ileocecal valve (ß = 0.267; P = 0.048) were predictive for fibrosis stage. Conclusion: Despite resolution of cholestasis and portal inflammation, significant liver fibrosis and steatosis persist after weaning off PN. Extensive small intestinal resection was the major predictor for liver fibrosis stage. (Hepatology 2013;58:729–738)

Serum FGF21 increases with hepatic fat accumulation in pediatric onset intestinal failure

BACKGROUND & AIMS Previously, FGF21 has been related to glucose and lipid metabolism and liver steatosis. Our aim was to evaluate serum FGF21 levels in pediatric onset intestinal failure (IF). METHODS Serum FGF21 was measured in 35 IF patients at median age of 7.8 years (range 0.2-27) and 59 matched healthy controls. Thirty patients underwent liver biopsy. RESULTS Serum FGF21 levels were increased in patients compared to controls [229 pg/ml (21-20,345) vs. 133 pg/ml (7-1607), p=0.018]. Frequency of liver steatosis (60% vs. 50%, p=0.709) was similar during (6/10) and after (10/20) weaning off parenteral nutrition (PN). Patients with steatosis had markedly higher serum FGF21 concentration [626 pg/ml (21-20,345) vs. 108 pg/ml (32-568), p=0.002] and more advanced liver fibrosis [Metavir stage 1.6 (0-4) vs. 0.7 (0-3), p=0.020] without associated inflammation or Mallory body formation. Serum FGF21 levels reflected the degree of steatosis [FGF21 in grade 3 vs. grades 0-2, p<0.001; grade 1 vs. controls, p=0.002], and correlated with steatosis grade (r=0.589, p=0.001). Hepatic steatosis and serum FGF21 showed similar associations with duration of PN and remaining small bowel length (p<0.05 for all). In a multivariate regression model, liver steatosis grade (β=0.630, p=0.001) predicted serum FGF21 concentration. CONCLUSIONS In pediatric IF increased serum FGF21 levels reflect liver steatosis, while both are exclusively associated with duration of PN and extent of small intestinal resection. Liver steatosis is coupled with progression of fibrosis without accompanying inflammation. Serum FGF21 assay may be useful for diagnosing liver steatosis in IF patients.

Intestinal Microbiota Signatures Associated With Histological Liver Steatosis in Pediatric-Onset Intestinal Failure

Background: Intestinal failure (IF)–associated liver disease (IFALD) is the major cause of mortality in IF. The link between intestinal microbiota and IFALD is unclear. Methods: We compared intestinal microbiota of patients with IF (n = 23) with healthy controls (n = 58) using culture-independent phylogenetic microarray analysis. The microbiota was related to histological liver injury, fecal markers of intestinal inflammation, matrix metalloproteinase 9 and calprotectin, and disease characteristics. Results: Overabundance of Lactobacilli, Proteobacteria, and Actinobacteria was observed in IF, whereas bacteria related to Clostridium clusters III, IV, and XIVa along with overall diversity and richness were reduced. Patients were segregated into 3 subgroups based on dominating bacteria: Clostridium cluster XIVa, Proteobacteria, and bacteria related to Lactobacillus plantarum. In addition to liver steatosis and fibrosis, Proteobacteria were associated with prolonged current parenteral nutrition (PN) as well as liver and intestinal inflammation. Lactobacilli were related to advanced steatosis and fibrosis mostly after weaning off PN without associated inflammation. In multivariate permutational analysis of variance, liver steatosis, bowel length, PN calories, and antibiotic treatment best explained the microbiota variation among patients with IF. Conclusions: Intestinal microbiota composition was associated with liver steatosis in IF and better predicted steatosis than duration of PN or length of the remaining intestine. Our results may be explained by a model in which steatosis is initiated during PN in response to proinflammatory lipopolysaccharides produced by Proteobacteria and progresses after weaning off PN, as the L plantarum group Lactobacilli becomes dominant and affects lipid metabolism by altering bile acid signaling.

Serum plant sterols, cholestanol, and cholesterol precursors associate with histological liver injury in pediatric onset intestinal failure

BACKGROUND Increased serum concentrations of plant sterols, including stigmasterol, during parenteral nutrition (PN) have been linked with serum biochemical signs of intestinal failure-associated liver disease (IFALD), whereas clinical data on their correlation to histologic liver injury have been limited. OBJECTIVE We studied interrelations between serum noncholesterol sterols and histologic liver injury in pediatric-onset intestinal failure (IF). DESIGN Serum plant sterols (stigmasterol, avenasterol, sitosterol, and campesterol), cholestanol, and cholesterol precursors (cholestenol, lathosterol, and desmosterol) were measured in 50 IF patients at a median age 7.3 y and in 86 matched controls. Forty patients underwent liver biopsies. Sixteen patients had been receiving PN for 45 mo, and 34 patients had received PN for 9.1 mo but had not received PN for 5.4 y. RESULTS Serum plant sterols were higher in patients who were currently receiving PN than in controls and were related to conjugated bilirubin (r = 0.799-0.541, P < 0.05). During PN, the ratio of serum stigmasterol to cholesterol was 3.3-fold higher in patients with portal inflammation, and the ratio of avenasterol to cholesterol was 3.9-fold higher in patients with cholestasis (P < 0.05 for both). Ratios of stigmasterol and avenasterol to cholesterol were correlated with portal inflammation (r = 0.549-0.510, P < 0.05), cholestasis (r = 0.501-0.491, P = 0.048-0.053), and serum bile acids (r = 0.591-0.608, P < 0.05). The median (IQR) ratio of serum cholestanol to cholesterol was higher during (269 100× μg/mg cholesterol; 203-402 100× μg/mg cholesterol) than after (175 100× μg/mg cholesterol; 156-206 100× μg/mg cholesterol; P < 0.001) weaning off PN and was correlated with cholestasis (r = 0.428), portal inflammation (r = 0.511), and fibrosis (r = 0.323, P < 0.05 for all). After weaning off PN, ratios of cholestenol and lathosterol to cholesterol were >2-fold higher in patients with persistent liver steatosis than in those without steatosis or controls (P < 0.01 for all), whereas lathosterol was correlated with the steatosis grade (r = 0.320, P < 0.050). CONCLUSIONS Increased serum stigmasterol and avenasterol concentrations parallel the portal inflammation and cholestasis during PN, thereby reinforcing their contribution to IFALD. A bile acid malabsorption-driven increase in cholesterol synthesis underpins persistent liver steatosis after weaning off PN. Serum cholestanol reflects liver injury in IF patients.

Risk of Metabolic Bone Disease is Increased Both during and after Weaning off Parenteral Nutrition in Pediatric Intestinal Failure

Aim: To assess bone health in pediatric intestinal failure (IF). Methods: A population-based cohort of 41 IF patients (age 9.9 years) underwent evaluation of bone mineral density (BMD), bone biochemistry, nutritional status and growth. Eleven patients remained on parenteral nutrition (PN) after 69 months. Thirty had weaned off PN 9.0 years earlier (mean), i.e. after 30 months on PN. Results: The majority of patients had lumbar spine or femoral BMD Z-score ≤-1.0 (70%), vitamin D deficiency (serum 25-hydroxyvitamin-D, S-25-OHD, <50 nmol/l, 41%) or secondary hyperparathyroidism (plasma parathyroid hormone >47 ng/l, 44%), equally during and after weaning off PN. Hyperparathyroidism was absent when S-25-OHD was >80 nmol/l. Until puberty, height (-1.4 to -0.8, age 1-12) and weight Z-scores (-1.3 to -0.5, age 1-16) were below the normal mean (p < 0.05). Small bowel length associated with S-25-OHD levels (r = 0.489, p = 0.013). In a multivariate model, time after weaning off PN (β = -0.597, p = 0.001), duration of PN (β = -0.466, p = 0.006) and calcium intake (β = -0.331, p = 0.035) predicted decreased lumbar spine BMD. Conclusions: In pediatric IF, vitamin D insufficiency, secondary hyperparathyroidism and decreased BMD are common. BMD, vitamin D, calcium and nutritional status should be closely monitored during and after weaning off PN to ensure sufficient vitamin D and mineral substitution for normal growth and bone mass attainment.

Long-term health-related quality of life of patients with pediatric onset intestinal failure

BACKGROUND Despite improved survival rates of patients with pediatric intestinal failure (IF), data on health-related quality of life (HRQoL) of IF patients are still scarce. We hypothesized that I) continued parenteral nutrition, underlying intestinal motility disorder, abdominal pain and problematic bowel function would be associated with poorer HRQoL and higher parental stress levels, and II) the time intervals since the latest bowel operation, the latest episode of sepsis, and the latest inpatient care episode would be associated with better HRQoL and lower parental stress. METHODS Patients with pediatric onset IF and their parents answered questionnaires on HRQoL, parental stress, and bowel-related symptoms. Clinical data were gathered by chart review. Controls matched for age and sex were randomly chosen by the Population Register Centre of Finland. RESULTS Thirty-six (73%) IF patients participated at a median age of 9years. Overall HRQoL was similar to healthy peers, and frequent abdominal pain was the only factor associated with poorer HRQoL. Abdominal pain and stool frequency >3 times per day were associated with higher levels of parental stress, whereas longer time intervals since the latest bowel operation or hospitalization were associated with lower parental stress levels. CONCLUSION Long-term HRQoL of pediatric IF patients is comparable to that of healthy peers. Time often eases parental stress, but frequent abdominal pain presents a challenge to the well-being of some patients and requires medical attention.

Liver Inflammation Relates to Decreased Canalicular Bile Transporter Expression in Pediatric Onset Intestinal Failure.

Objective: Although liver disease is a major complication of parenteral nutrition (PN) for intestinal failure (IF), its pathogenesis remains unclear. We investigated potential molecular mechanisms of liver injury in pediatric onset IF. Methods: Liver expression of canalicular phospholipid (ABCB4), bile acid (ABCB11), and sterol (ABCG5/8) transporters, their upstream regulators LXR and FXR as well as pro-inflammatory cytokines interleukin-6 (IL6) and tumor necrosis factor (TNF) were investigated among patients with IF [age median 3.8 (IQR 1.2 to 11)] in relation to biochemical and histologic liver injury, PN, serum plant sterols, fibroblast growth factor 19, and &agr;-tocopherol. Results: Patients receiving PN currently (n = 18) showed more advanced liver injury than patients after weaning off PN (n = 30). Histologic portal inflammation strongly segregated PN-dependent (44%) from weaned off patients (3%, P = 0.001) and coupled with progression of cholestasis and liver fibrosis. Patients with portal inflammation demonstrated markedly induced liver RNA expression of IL6 and TNF, repression of FXR and its canalicular bile transporter target gene RNA expression, including ABCB4 and ABCB11 as well as decreased protein expression of ABCB11 and ABCB4. Furthermore, upregulation of LXR and ABCG5/8 RNA expression was suppressed in patients with portal inflammation. Current PN, increased serum levels of plant sterols stigmasterol, avenasterol, and sitosterol along with serum citrulline, a marker of enterocyte mass, predicted portal inflammation. Conclusions: In pediatric onset IF, current PN delivery synergistically with intestinal compromise promote liver inflammation, which associates with progression of biochemical and histologic liver injury, while reducing expression of canalicular bile transporters.

Perioperative Complications Following Surgery for Necrotizing Enterocolitis

&NA; Necrotizing enterocolitis (NEC) is a devastating condition that mainly affects premature infants. Advanced cases of NEC require surgical treatment, which in up to 70% of infants is associated with significant perioperative morbidity including anastomosis‐ or enterostomy‐related complications, sepsis, peritonitis, and wound infections. Moreover, the perioperative complications may compromise the long‐term gastrointestinal and neurodevelopmental outcome of patients requiring surgery for NEC.

Duodenal Disaccharidase Activities During and After Weaning Off Parenteral Nutrition in Pediatric Intestinal Failure.

Objectives: Data on factors affecting absorptive function in children with intestinal failure (IF) are sparse. We evaluated duodenal disaccharidase activities and inflammation in relation to parenteral nutrition (PN) and intestinal resection in pediatric onset IF. Methods: Disaccharidase (maltase, sucrase, and lactase) activities and histologic inflammation were evaluated from duodenal biopsies in 58 patients during PN (n = 23) or full enteral nutrition (n = 40) and in 43 matched controls. The first and the last postresection biopsies were analyzed separately after 4.3 (1.2–9.7) years and 6.5 (2.3–12.4) years, respectively. Results: During PN, maltase and sucrase activities were 1.6-fold lower and mucosal inflammation more frequent (22% vs 3%) when compared to matched controls (P < 0.05 for both). In patients on full enteral nutrition, activities of maltase and sucrase were significantly higher than that in patients receiving PN and comparable to those of matched controls. Postresection time correlated positively (r = 0.448 and r = 0.369) and percentage length of the remaining small intestine inversely (r = –0.337 and r = –0.407) with maltase and sucrase activity in patients on full enteral nutrition (P < 0.05 for all), whereas proportional length of remaining colon correlated positively with maltase and lactase activity (r = 0.424–0.544, P < 0.05) in patients receiving PN. Conclusions: In children with IF, PN dependency associated with decreased duodenal maltase and sucrase activities and mucosal inflammation, which may disturb intestinal absorptive function. Localization and extent of intestinal resection and post-resection time correlated with duodenal disaccharidase activities.

Serum non-cholesterol sterols and cholesterol metabolism in childhood and adolescence

BACKGROUND AND AIMS The profile of cholesterol metabolism, i.e., high absorption vs. high synthesis, may have a role in the development of atherosclerosis, the early lesions of which can be present already in childhood. Since there is no information on cholesterol metabolism in children from birth to adolescence, we evaluated cholesterol metabolism in 0-15 year-old children and adolescents without dyslipidemia. METHODS The study population consisted of 96 children (39 girls, 57 boys) divided into age groups <1 (n = 14), 1-5 (n = 37), 6-10 (n = 24), and 11-15 (n = 21) years. Cholesterol metabolism was assessed by analysing serum non-cholesterol sterols, biomarkers of cholesterol synthesis and absorption, with gas-liquid chromatography. RESULTS Serum non-cholesterol sterol ratios to cholesterol did not differ between gender. Cholesterol precursors squalene, cholestenol, and desmosterol were higher in the <1 year than in the older age groups, whereas lathosterol was highest in the 11-15 year old. Plant sterols were low in the age group <1 year, after which they did not differ between the groups. Cholestanol was not age-dependent. From the age of 1 year, cholesterol homeostasis was intact. Cholesterol absorption prevailed cholesterol synthesis from 1 to 10 years of age (e.g., lathosterol/cholestanol ratio 0.35 ± 0.03 and 0.45 ± 0.05 in 1-5 and 6-10 vs. 0.66 ± 0.08 in 11-15 year-old (mean ± SE, p < 0.001). CONCLUSIONS Serum non-cholesterol sterols had different individual profiles by age in childhood and adolescence. From 1 to 10 years of age, cholesterol absorption prevailed cholesterol synthesis. This novel finding emphasizes the importance of dietary aspects related to cardiovascular risk even from early childhood.