Potential Utility of Therapeutic Drug Monitoring of Adalimumab in Predicting Short-Term Mucosal Healing and Histologic Remission in Pediatric Crohn's Disease Patients.

BACKGROUND: Limited data exist regarding mucosal healing (MH) and therapeutic drug monitoring (TDM) in pediatric Crohn's disease (CD) patients treated with adalimumab (ADL). We aimed to investigate the associations between ADL trough levels (TLs) and MH, and between ADL TLs and histologic remission (HR) at 16 weeks from ADL treatment in pediatric CD patients. METHODS: This was a prospective study on moderate-to-severe luminal pediatric CD patients receiving ADL. Ileocolonoscopies and biopsies, as well as clinical activity assessments, laboratory examinations, including tests for ADL TLs and antibody to ADL, were performed 16 weeks after ADL initiation. MH was defined as a Simple Endoscopic Score for CD of 0. HR was defined as the complete absence of microscopic inflammation. RESULTS: Seventeen subjects (13 males, 4 females) were included. At 16 weeks from ADL initiation, 14 (82.4%), 8 (47.1%), and 4 (23.5%) patients achieved clinical remission, MH, and HR, respectively. ADL TLs were significantly higher in patients who achieved MH compared to those who did not (13.0 ± 6.5 vs. 6.2 ± 2.6 µ/mL, respectively; P = 0.023) and also significantly higher in patients who achieved HR compared to those who did not (17.9 ± 5.3 vs. 6.8 ± 2.5 µ/mL, respectively; P = 0.02). The optimal TL for predicting MH was 8.76 µ/mL. CONCLUSION: Serum ADL TLs at 16 weeks were significantly higher in pediatric patients with CD who achieved MH and HR, respectively. TDM may guide in optimizing treatment efficacy and better target MH in the era of treat-to-target.

Protective effect of α-mangostin against iodixanol-induced apoptotic damage in LLC-PK1 cells.

Radiographic contrast media facilitate the visibility of internal body structures, but its use to patients with lowered renal function needs to be careful because of severe side effect in kidney. The present study aims to evaluate potential protective effect and mechanism of Alpha mangostin (α-mangostin) against contrast-induced apoptotic damage in LLC-PK1 cells. As a result, α-mangostin in non-toxic concentrations improved the viability of the iodixanol-treated cells up to 90.42% against contrast-induced damage in LLC-PK1 cells. Iodixanol treatment increased the phosphorylation of p38, ERK and cleavage of caspase-3 in LLC-PK1 cells, which were significantly decreased by co-treatment with α-mangostin (2.5 and 5µM). The protective effect of α-mangostin on contrast-induced apoptotic damage was mediated by the inhibition of MAPKs and caspase activation.

Plasma adiponectin level and sleep structures in children with Prader-Willi syndrome.

Adiponectin, an adipose tissue-derived hormone, has been negatively related to obstructive sleep apnea syndrome. Besides sleep apnea, children with Prader-Willi syndrome (PWS) may have excessive daytime sleepiness and rapid eye movement (REM) sleep abnormality. The aim of this study is to determine whether changes in sleep structures are related to plasma adiponectin levels in PWS. Correlations between adiponectin level and sleep variables were analyzed in 28 children with PWS and 18 controls. Overnight polysomnography was performed. The fasting plasma adiponectin levels were higher in the children with PWS than in the controls (P = 0.0006). In the PWS, Epworth sleepiness scale was significantly higher (P = 0.002); sleep latency (P = 0.003) and REM latency (P = 0.001) were significantly shortened; the apnea-hypopnea index (AHI) was significantly increased (P = 0.0001); and the duration of non-rapid eye movement (NREM) sleep stages 3 and 4 was decreased (P = 0.005). Multiple regression analysis revealed correlations between the adiponectin level and the total sleep time (beta = 0.688, P = 0.009), AHI (beta = 1.274, P = 0.010), REM latency (beta = -0.637, P = 0.021) and the percentage of NREM sleep (beta = -7.648, P = 0.002) in PWS. In children with PWS, higher plasma adiponectin levels were independently associated with several sleep variables, which was not observed in the control group. These results suggest a potential influence of elevated adiponectin level on the sleep structures in PWS.

Effect of probiotic mix (Bifidobacterium bifidum, Bifidobacterium lactis, Lactobacillus acidophilus) in the primary prevention of eczema: a double-blind, randomized, placebo-controlled trial.

Controversy exists regarding the preventive effect of probiotics on the development of eczema or atopic dermatitis. We investigated whether supplementation of probiotics prevents the development of eczema in infants at high risk. In a randomized, double-blind, placebo-controlled trial, 112 pregnant women with a family history of allergic diseases received a once-daily supplement, either a mixture of Bifidobacterium bifidum BGN4, B. lactis AD011, and Lactobacillus acidophilus AD031, or placebo, starting at 4-8 wks before delivery and continuing until 6 months after delivery. Infants were exclusively breast-fed during the first 3 months, and were subsequently fed with breastmilk or cow's milk formula from 4 to 6 months of age. Clinical symptoms of the infants were monitored until 1 yr of age, when the total and specific IgE against common food allergens were measured. A total of 68 infants completed the study. The prevalence of eczema at 1 yr in the probiotic group was significantly lower than in the placebo group (18.2% vs. 40.0%, p=0.048). The cumulative incidence of eczema during the first 12 months was reduced significantly in probiotic group (36.4% vs. 62.9%, p=0.029); however, there was no difference in serum total IgE level or the sensitization against food allergens between the two groups. Prenatal and postnatal supplementation with a mixture of B. bifidum BGN4, B. lactis AD011, and L. acidophilus AD031 is an effective approach in preventing the development of eczema in infants at high risk of allergy during the first year of life.

The expression of iron-repressible outer membrane proteins in Helicobacter pylori and its association with iron deficiency anemia.

BACKGROUND: Helicobacter pylori infection is known to be a cause of iron deficiency anemia (IDA) that is unresponsive to iron supplements. H. pylori bind iron to a specific receptor by iron-repressible outer membrane proteins (IROMPs) under conditions of restricted iron. MATERIALS AND METHODS: We compared the expression of IROMPs from strains of H. pylori under both iron-restricted and iron-supplemented conditions to determine the difference between strains with and without IDA. One standard strain, two clinical strains, and three IDA strains were cultured; and then the IROMPs were extracted under iron-restricted and iron-supplemented conditions. We used SDS-PAGE to compare the expression of the IROMPs from each strain. RESULTS: IROMPs were found in IDA strains under iron-restricted conditions and their molecular sizes were estimated to be 56, 48, 41, and 37 kDa. In the iron-repleted media, the IROMPs were no longer present. CONCLUSION: In the iron-depleted state, specific H. pylori strains associated with IDA demonstrated an advantage in iron acquisition due to a higher expression of IROMPs. Our results can explain in part why some patients with H. pylori infection are more prone to develop clinical IDA under restricted iron conditions in the host.

Infliximab Trough Levels Are Associated With Mucosal Healing During Maintenance Treatment With Infliximab in Paediatric Crohn's Disease.

BACKGROUND AND AIMS: Mucosal healing is an important treatment goal in Crohn's disease. We investigated the association between serum infliximab trough levels and mucosal healing, and the infliximab cut-off levels required for mucosal healing in paediatric patients. METHODS: In this multicentre, retrospective, cross-sectional study, medical records and electronic data of paediatric patients with luminal Crohn's disease, who had received infliximab for ≥1 year, were examined. Ileocolonoscopy was performed on the same day as the infliximab infusion, and serum samples for trough levels were collected immediately before infusion. Mucosal healing was defined as a Simple Endoscopic Score for Crohn's Disease of 0. Univariate, multivariate logistic regression, and receiver operating characteristic curve analyses were performed. RESULTS: Overall, 105 patients [median age 14.8 years] were included, with mucosal healing observed in 48.6%. Median serum infliximab trough levels were higher in patients with mucosal healing [4.5 µg/mL] than without [3.3 µg/mL, p = 0.002]. In the final multivariate model, infliximab trough level ≥4.2 µg/mL [p = 0.002] and ≥1-year duration from diagnosis to infliximab treatment [p = 0.003] were positively and negatively associated with mucosal healing, respectively. The infliximab trough level for achieving mucosal healing with a specificity of 80% was ≥5 µg/mL. CONCLUSIONS: Associations between serum infliximab trough concentrations and mucosal healing were observed in paediatric patients. Identification of the infliximab trough level that positively associates with mucosal healing in most paediatric patients with Crohn's disease [≥5 µg/mL] may guide treatment decisions to optimise therapeutic response in the era of treat-to-target.

Effect of oral probiotics (Bifidobacterium lactis AD011 and Lactobacillus acidophilus AD031) administration on ovalbumin-induced food allergy mouse model.

Recent study has demonstrated an increasing prevalence of food allergy in Korean children. Specific probiotic bacteria may promote potentially anti-allergenic processes through induction of Th1-type immunity and enhance the regulatory lymphocyte. This study investigated whether orally administrated probiotics could suppress allergic responses in an ovalbumin (OVA)-induced allergy mouse model. Thus, female C3H/HeJ mice were orally sensitized with OVA and cholera toxin for 4 weeks. Lactobacillus acidophilus AD031, Bifidobacterium lactis AD011, and L. acidophilus AD031 plus B. lactis AD011 were fed to mice from 2 weeks before the sensitization. The OVA-induced mice that were not treated with probiotics had significantly increased serum levels of OVA-specific IgE and IgG1, and OVA-specific IgA in feces. However, the mice treated with probiotics suppressed production of the OVA-specific IgE, IgG1, and IgA. The level of IL-4 was significantly lower, and the levels of INF-gamma and IL-10 were significantly higher in the mice treated with probiotics than that in the nontreated mice. The groups treated with probiotics had decreased levels of degranulated mast cells, eosinophil granules, and tail scabs. These results indicate that L. acidophilus AD031 and B. lactis AD011 might be useful for the prevention of allergy.

Long-term Outcomes After Switching to CT-P13 in Pediatric-Onset Inflammatory Bowel Disease: A Single-Center Prospective Observational Study.

Background: The relatively high cost and patent expiry of infliximab, an anti-tumor necrosis factor monoclonal antibody used in inflammatory bowel disease (IBD), has led to the development of biosimilar versions of the reference product (RP). This study investigated the long-term efficacy, safety, pharmacokinetics, and immunogenicity of CT-P13 after switching from infliximab RP in pediatric-onset IBD patients. Methods: In this prospective observational study, patients with pediatric-onset IBD receiving maintenance infliximab RP were followed for 1 year after continuing infliximab RP (RP maintenance group) or switching to CT-P13 (CT-P13 switch group). Primary end points were the proportion of patients continuously receiving infliximab and the proportion achieving persistent remission-corticosteroid-free sustained clinical remission without dose intensification-at 1 year. Results: Thirty-six patients were recruited to the RP maintenance group and 38 to the CT-P13 switch group. At 1 year in the RP maintenance group and CT-P13 switch group, 86.1% (31/36) and 92.1% (35/38) patients had continuously received infliximab (P = 0.649), and 77.8% (28/36) and 78.9% (30/38) patients experienced persistent remission (P = 1.000), respectively. There were no statistically significant differences in any measures of disease activity, pharmacokinetics, or immunogenicity between the time of switch and 1-year postswitch in the CT-P13 switch group. Twenty-seven adverse events occurred in the maintenance group and 30 in the switch group. Conclusions: Switching from maintenance infliximab RP to CT-P13 did not result in any significant differences in efficacy, pharmacokinetics, or immunogenicity in patients with pediatric-onset IBD, and no unexpected safety issues occurred, supporting findings from randomized controlled trials.

Subtherapeutic Infliximab Trough Levels and Complete Mucosal Healing Are Associated With Sustained Clinical Remission After Infliximab Cessation in Paediatric-onset Crohn's Disease Patients Treated With Combined Immunosuppressive Therapy.

BACKGROUND AND AIMS: We aimed to investigate the outcome in paediatric-onset Crohn's disease patients who had discontinued infliximab after maintaining clinical remission with combined immunosuppression, and to determine factors associated with clinical relapse. METHODS: We conducted a retrospective observational study of 63 paediatric-onset Crohn's disease patients who had stopped scheduled infliximab during sustained corticosteroid-free clinical remission for at least 1 year with infliximab and azathioprine, and were followed up for at least 1 year thereafter. Cumulative relapse rates and the median time to relapse were estimated statistically. Factors at cessation were also evaluated for their association with clinical relapse. RESULTS: After a median follow-up period of 4.3 years [range, 1-7.5 years], 60.3% [38/63] of patients had experienced clinical relapse. According to Kaplan-Meier survival analysis, the estimated cumulative relapse rates at 1, 4, and 6 years were 19.0%, 62.2%, and 75.2%, respectively, and the median relapse time was 3.3 years from infliximab cessation. According to multivariate Cox proportional hazard regression analysis, infliximab trough levels of ≥2.5 µg/mL and incomplete mucosal healing were associated with clinical relapse (hazard ratio [HR] = 7.199, 95% confidence interval [CI] = 1.641-31.571, p = 0.009 and HR = 3.628, 95% CI = 1.608-8.185, p = 0.002, respectively). Although re-treatment with infliximab was effective in 90.9% [30/33] of patients, 7.9% [3/38] eventually underwent surgery within 1 year of relapse. CONCLUSIONS: Considering the high cumulative relapse rates in the long term and cases of severe relapse requiring surgery, discontinuing infliximab in paediatric-onset Crohn's disease patients is currently inadvisable. However, there may be a subgroup of patients who are good candidates for infliximab withdrawal.

Involvement of vesicular H+-ATPase in insulin-stimulated glucose transport in 3T3-F442A adipocytes.

In secretory cells, osmotic swelling of secretory granules is proposed to be an intermediate step in exocytic fusion of the granules with the plasma membrane. For osmotic swelling of the granule, a H (+) gradient generated by vacuolar-type H (+) -ATPase (V-ATPase) may be a driving force for accumulation of K (+) via its exchange with H (+) , concurrent with accumulation of Cl (-) and H(2)O. Here, we investigated whether a similar chemiosmotic mechanism is involved in the insulin-stimulated recruitment of GLUT4 to the plasma membrane in 3T3-F442A adipocytes. Incubating cells in a hypo-osmotic medium significantly increased 2-deoxy glucose (2-DG) uptake and the plasma membrane GLUT4 content (possibly via induction of osmotic swelling of GLUT4-containing vesicles (G4V)) and also potentiated the insulin-stimulated 2-DG uptake. Promotion of the G4V membrane ionic permeability using nigericin, an electroneutral K (+) /H (+) exchange ionophore, increased 2-DG uptake and the plasma membrane GLUT4 content. However, co-treatment with nigericin and insulin did not show an additive effect. Bafilomycin A(1), a diagnostically specific inhibitor of V-ATPase, inhibited insulin- and nigericin-stimulated 2-DG uptake. Immunoadsorption plus immunoblotting demonstrated that GLUT4 and V-ATPase co-localize in the same intracellular membranes. Together, these results indicate that V-ATPases in the G4V membrane may play an important role in the insulin-stimulated exocytic fusion of G4V with the plasma membrane via its participation in osmotic swelling of the vesicle.

Implication of phosphorylation of the myosin II regulatory light chain in insulin-stimulated GLUT4 translocation in 3T3-F442A adipocytes.

In adipocytes, insulin stimulates glucose transport primarily by promoting the translocation of GLUT4 to the plasma membrane. Requirements for Ca(2+)/calmodulin during insulin-stimulated GLUT4 translocation have been demonstrated; however, the mechanism of action of Ca(2+) in this process is unknown. Recently, myosin II, whose function in non-muscle cells is primarily regulated by phosphorylation of its regulatory light chain by the Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK), was implicated in insulin-stimulated GLUT4 translocation. The present studies in 3T3-F442A adipocytes demonstrate the novel finding that insulin significantly increases phosphorylation of the myosin II RLC in a Ca(2+)-dependent manner. In addition, ML-7, a selective inhibitor of MLCK, as well as inhibitors of myosin II, such as blebbistatin and 2,3-butanedione monoxime, block insulin-stimulated GLUT4 translocation and subsequent glucose transport. Our studies suggest that MLCK may be a regulatory target of Ca(2+)/calmodulin and may play an important role in insulin-stimulated glucose transport in adipocytes.

Isoliquiritigenin ameliorates dextran sulfate sodium-induced colitis through the inhibition of MAPK pathway.

Isoliquiritigenin (isoLQ), a chalcone found in licorice, has shown a variety of biological activity including anti-inflammatory and antioxidative effects, and the distribution of isoLQ in gastrointestinal tract was higher than any other tissues. Thus, we evaluated whether or not isoLQ attenuated the dextran sulfate sodium (DSS)-induced colitis by observing the physiological changes (body weight loss, diarrhea, bleeding stool, overall disease activity index (DAI) scores, colon length), histopathological analysis and myeloperoxidase (MPO) activities of esophagus and colon. Also, the MAPK pathways including phosphorylation of ERK1/2, p38, and AKT, and the activation of NK-κB were evaluated in colon tissue. Interestingly, the reduction of body weight and colon length, increase of diarrhea, bloody stool, DAI scores and MPO activity, and histologic disturbances in DSS-induced colitis were recovered by isoLQ treatment. Also, isoLQ treatment suppressed the phosphorylation of ERK1/2 and p38, and the activation of NK-κB compared to those in DSS-induced colitis mice. In addition, the distributions of isoLQ in colon were relatively higher in DSS-induced colitis models. All of these results suggested that isoLQ has potential activity to ameliorate the DSS-induced colitis through the inhibition of MAPK pathway.

Helicobacter pylori urease activity is influenced by ferric uptake regulator.

PURPOSE: The role of the Ferric Uptake Regulator (FUR) in the acid resistance of Helicobacter pylori (H. pylori) has been thought to be independent of urease. However, we demonstrated in this study that Fur influences urease activity. MATERIALS AND METHODS: A fur knockout mutant of H. pylori was constructed by replacing the Fur gene with a kanamycin resistant marker gene. The wild-type H. pylori and fur mutant were compared for survival. The integrity of the inner membrane of the bacteria was evaluated by confocal microscopy using membrane-permeant and -impermeant fluorescent DNA probes. Urease activity of intact H. pylori was measured between pH 3 and 8. Real time PCR of both strains was performed for urease genes including ureI, ureE, ureF, ureG, and ureH. RESULTS: The fur deletion affected the survival of H. pylori at pH 4. The urease activity curve of the intact fur mutant showed the same shape as the wild-type but was 3-fold lower than the wild-type at a pH of less than 5. Real time PCR revealed that the expression of all genes was consistently down-regulated in the fur mutant. CONCLUSION: The results of this study showed that fur appears to be involved in acid resistant H. pylori urease activity.