Hyperadiponectinemia During Infliximab Induction Therapy in Pediatric Crohn Disease.

OBJECTIVES: The inflammatory process in Crohn disease (CD) involves the visceral fat, characterized by adipocyte hyperplasia and altered adipose tissue and serum concentrations of tumor necrosis factor (TNF), leptin, adiponectin and resistin. We investigated the effect of anti-TNF therapy with infliximab (IFX) on serum adipokine levels in pediatric CD. METHODS: Serum concentrations of resistin (ng/mL), leptin (ng/mL), and total adiponectin (µg/mL) were assessed by enzyme-linked immunosorbent assays (ELISA) in 18 pediatric CD patients (mean age 15.0 ±â€Š1.5 years) before first, second, and fourth IFX infusion (weeks 0, 2, and 14) and compared with baseline values from sex- and BMI-matched healthy controls (HC, mean age 13.4 ±â€Š1.6 years). RESULTS: At baseline, CD patients (mean age 15.0 ±â€Š1.5 years, 10 of 18 boys) compared with HC (13.4 ±â€Š1.6 years, 7 of 15 boys) had higher resistin levels (median 14.7 ng/mL, range 5.1-50.5 vs 7.3 ng/mL, 0.5-14.5); P = 0.0002). At weeks 2 and 14, resistin decreased to 6.9 ng/mL (2.9-16.8) (P < 0.0001) and 9.2 ng/mL (4.1-20.6; P = 0.0011), respectively. Leptin and adiponectin were comparable between patients and HC at baseline. Leptin increased in girls from 9.5 ng/mL (4.0-30.1) to 16.0 ng/mL (7.9-35.2; P = 0.0156) and 17.2 ng/mL (10.8- 26.8; P = 0.1953) at weeks 0, 2, and 14 respectively; with a trend in boys from 2 (0.6-12.9) to 2.8 (1.7-8.6; P = 0.0840) and 3.3 (1.3-4.6; P = 0.1309). Adiponectin peaked initially from 7.8 µg/mL (4.6-11.9) at week 0 to 9.2 µg/mL (4.1-20.7; P = 0.0005) at week 2 and thereafter fell to 6.5 µg/mL (3.0-12.7; P = 0.0182) at week 14. CONCLUSIONS: TNF blockade is associated with changes in circulating adipokines. The marked early increase of the potent anti-inflammatory adiponectin may contribute to the rapid response to IFX in CD.

Response to cyclosporine in steroid-resistant nephrotic syndrome: discontinuation is possible.

BACKGROUND: Steroid-resistant nephrotic syndrome (SRNS) is still regarded as a serious disease although treatment with cyclosporine (CSA) has improved outcome. However, the duration of treatment in responders is unclear, and treatment of patients with genetic causes is a matter of debate. METHODS: Thirty-six patients with SRNS were studied retrospectively. Median age at presentation was 3.2 (range, 0.06-15.0) and median follow-up 15.5 years (range, 1.8-27.7), respectively; 23 (64%) had focal segmental glomerulosclerosis (FSGS) on biopsy. In 33/36 patients (92%), genetic testing was performed for at least three most common genes known to be mutated in SRNS. RESULTS: Nineteen patients (53%), especially those with minimal change nephrotic syndrome (MCNS) at initial biopsy (p < 0.002), entered complete remission with CSA monotherapy, including one patient with compound heterozygous NPHS1 and dominant ACTN4 mutation, respectively. Ten patients entered partial remission (28%, all FSGS), including two with NPHS2 mutations. Seven patients (six FSGS, one MCNS) did not respond to treatment. In 15 of 19 responders to CSA, treatment was stopped after a median of 3.1 years (range, 0.5-14) and no further relapses occurred in 11/15 (73%) patients with median follow-up of 9.7 years. CONCLUSIONS: CSA monotherapy is effective in SRNS. Discontinuation of CSA is possible in many patients with complete remission.

Comparison of three tests for faecal calprotectin in children and young adults: a retrospective monocentric study.

OBJECTIVE: Faecal calprotectin is used as a sensitive marker for gastrointestinal mucosal inflammation. We compared the performance of three different assays in a large cohort of symptomatic paediatric patients. DESIGN: Retrospective monocentric study. SETTING: Inpatients and outpatients of a tertiary referral centre for paediatric gastroenterology. PARTICIPANTS: 304 symptomatic patients (163 males, aged 2-20 years) with active inflammatory bowel disease (IBD/A, n=130), IBD in clinical remission (IBD/R, n=62), other intestinal diseases (n=45) and controls without identified intestinal disease (n=67). INTERVENTIONS: Calprotectin was measured in homogenised faecal samples with three tests (A: EliA Calprotectin, Phadia AB, Sweden; B: PhiCal, Calpro AS, Norway; C: EK-Cal, Bühlmann Laboratories, Switzerland). OUTCOMES: Concordance between tests was calculated using Kendall's τ coefficient. RESULTS: IBD/A and controls were correctly classified as 97.7%/82.1% (A), 97.7%/85.1% (B) and 98.4%/62.7% (C; not significant). Test C tended to have higher calprotectin values with a lower specificity compared to tests A and B. The concordance between two tests was 0.835 for tests A and B, 0.782 for tests A and C and 0.765 for tests B and C. CONCLUSIONS: All three tests are very sensitive for detecting mucosal inflammation, but major differences exist between specificity and absolute values. It is highly advisable to use the test of the same manufacturer for follow-up and to monitor for disease activity.

Serum 7-alpha-hydroxy-4-cholesten-3-one as a marker for bile acid loss in children.

OBJECTIVE: To establish age-related reference values for 7-alpha-hydroxy-4-cholesten-3-one (C4) in a pediatric population and to investigate bile acid malabsorption in children with short bowel syndrome (SBS). STUDY DESIGN: Serum was obtained between 8:00 a.m. and 11:00 a.m. from 100 healthy children (52% males, 9 months to 18 years of age) after 10 hours of fasting. Pediatric patients with SBS served as disease controls (n = 12). Following solid-phase extraction and purification, C4 was determined by high-performance liquid chromatography using a ultraviolet detector at a wavelength of 241 nm. The upper limit of normal for C4 concentrations was defined as the mean plus 2 SD of the log-normal distribution. RESULTS: The mean concentration and SD of C4 in healthy children was 22.8 ± 15.8 ng/mL with no relation to age or sex and an upper limit of normal of 66.5 ng/mL. Normal C4 values were found in 97 of 100 healthy children, and all 12 patients with SBS had C4 concentrations above 100 ng/mL (mean 299.6 ± 167.8 ng/mL; range 105.7-562.1 ng/mL, P < .0001 compared with controls). CONCLUSIONS: The determined upper limit of normal for C4 concentration in healthy children corresponds to previously published levels in healthy adults and is independent of age and sex. The consistently elevated C4 concentrations in our patients with SBS confirm the reliability of this noninvasive, nonisotopic method to assess bile acid malabsorption in children.

Pathophysiological preconditions promoting mixed "black" pigment plus cholesterol gallstones in a DeltaF508 mouse model of cystic fibrosis.

Gallstones are frequent in patients with cystic fibrosis (CF). These stones are generally "black" pigment (i.e., Ca bilirubinate) with an appreciable cholesterol admixture. The pathophysiology and molecular mechanisms for this "mixed" gallstone in CF are unknown. Here we investigate in a CF mouse model with no overt liver or gallbladder disease whether pathophysiological changes in the physical chemistry of gallbladder bile might predict the occurrence of "mixed" cholelithiasis. Employing a DeltaF508 mouse model with documented increased fecal bile acid loss and induced enterohepatic cycling of bilirubin (Am J Physiol Gastrointest Liver Physiol 294: G1411-G1420, 2008), we assessed gallbladder bile chemistry, morphology, and microscopy in CF and wild-type mice, with focus on the concentrations and compositions of the common biliary lipids, bilirubins, Ca(2+), and pH. Our results demonstrate that gallbladder bile of CF mice contains significantly higher levels of all bilirubin conjugates and unconjugated bilirubin with lower gallbladder bile pH values. Significant elevations in Ca bilirubinate ion products in bile of CF mice increase the likelihood of supersaturating bile and forming black pigment gallstones. The risk of potential pigment cholelithogenesis is coupled with higher cholesterol saturations and bile salt hydrophobicity indexes, consistent with a proclivity to cholesterol phase separation during pigment gallstone formation. This is an initial step toward unraveling the molecular basis of CF gallstone disease and constitutes a framework for investigating animal models of CF with more severe biliary disease, as well as the human disease.

Pathophysiological basis of liver disease in cystic fibrosis employing a DeltaF508 mouse model.

The molecular pathogenesis of cystic fibrosis (CF) liver disease is unknown. This study investigates its earliest pathophysiological manifestations employing a mouse model carrying DeltaF508, the commonest human CF mutation. We hypothesized that, if increased bile salt spillage into the colon occurs as in the human disease, then this should lead to a hydrophobic bile salt profile and to "hyperbilirubinbilia" because of induced enterohepatic cycling of unconjugated bilirubin. Hyperbilirubinbilia may then lead to an increased bile salt-to-phospholipid ratio in bile and, following hydrolysis, precipitation of divalent metal salts of unconjugated bilirubin. We document in CF mice elevated fecal bile acid excretion and biliary secretion of more hydrophobic bile salts compared with control wild-type mice. Biliary secretion rates of bilirubin monoglucuronosides, bile salts, phospholipids, and cholesterol are increased significantly with an augmented bile salt-to-phospholipid ratio. Quantitative histopathology of CF livers displays mild early cholangiopathy in approximately 53% of mice and multifocal divalent metal salt deposition in cholangiocytes. We conclude that increased fecal bile acid loss leads to more hydrophobic bile salts in hepatic bile and to hyperbilirubinbilia, a major contributor in augmenting the bile salt-to-phospholipid ratio and endogenous beta-glucuronidase hydrolysis of bilirubin glucuronosides. The confluence of these perturbations damages intrahepatic bile ducts and facilitates entrance of unconjugated bilirubin into cholangiocytes. This study of the earliest stages of CF liver disease provides a framework for investigating the molecular pathophysiology of more advanced disease in murine models and in humans with CF.

Endothelial effects of 3-hydroxyglutaric acid: implications for glutaric aciduria type I.

Infants with glutaric aciduria type 1 (GA1) are subject to intracranial vascular dysfunction. Here, we demonstrate that the disease-specific metabolite 3-hydroxyglutaric acid (3-OH-GA) inhibits basal and vascular endothelial growth factor (VEGF)-induced endothelial cell migration. 3-OH-GA affects the morphology of VEGF-induced endothelial tubes in vitro because of partial disintegration of endothelial cells. These effects correlate with Ve-cadherin loss. Remarkably, 3-OH-GA treatment of human dermal microvascular endothelial cells leads to disruption of actin cytoskeleton. Local application of 3-OH-GA alone or in combination with VEGF in chick chorioallantoic membrane induces abnormal vascular dilatation and hemorrhage in vivo. The study demonstrates that 3-OH-GA reduces endothelial chemotaxis and disturbs structural vascular integrity in vitro and in vivo. These data may provide insight in the mechanisms of 3-OH-GA-induced vasculopathic processes and suggest N-methyl-D-aspartate receptor-dependent and -independent pathways in the pathogenesis of GA1.