Serum IL-13 Predicts Response to Golimumab in Bio-Naïve Ulcerative Colitis.

A certain number of patients with ulcerative colitis (UC) are refractory to anti-TNF-α antibodies; biomarkers are thus needed to predict treatment efficacy. This study aimed to evaluate whether serum biomarkers that were reported to be associated with UC or anti-TNF-α antibody could predict the response to golimumab, a human anti-TNF-α monoclonal antibody, in bio-naïve patients with UC. We prospectively enrolled 23 consecutive patients with UC who were treated with golimumab. Serum samples were collected before the first golimumab dose. Eleven molecules were measured by electrochemiluminescence (ECL) or enzyme-linked immunosorbent assay (ELISA) and their association with efficacy after 10 weeks of golimumab treatment. Among the serum biomarkers, IL-13 levels were significantly higher in the non-remission group than in the remission group (p = 0.014). IL-15 levels were significantly lower in the non-response group than in the response group (p = 0.04). For clinical remission at week 10, the IL-13 0.20 concentration of pg/mL was associated with a sensitivity and specificity of 82.4% and 83.3%, respectively. Serum IL-13 may be a biomarker to predict golimumab efficacy in biologic-naïve patients with UC, and thus may help to tailor personalized treatment strategies.

Therapeutic Drug Monitoring of Golimumab for the Prediction of Long-Term Clinical Remission in Patients with Ulcerative Colitis.

BACKGROUND AND AIMS: A considerable number of patients with ulcerative colitis (UC) who initially respond to golimumab (GLM), an anti-TNF-α antibody, gradually lose clinical response. Therapeutic drug monitoring has been proposed to optimize serum anti-TNF-α antibody concentrations before the loss of response; however, little is known about ideal serum GLM concentrations. We aimed to evaluate whether the serum GLM trough levels (TLs) early after the initiation of induction therapy affect the long-term outcomes in UC and to identify the early GLM TLs that should be targeted for better long-term outcomes. METHODS: Thirty-one patients were prospectively evaluated. The primary outcome was clinical remission at 54 weeks, and we measured the serum GLM TLs at weeks 6, 10, and 14. Receiver operating characteristic (ROC) curves were constructed to identify optimal GLM TL thresholds early after induction therapy that were associated with clinical remission at week 54. RESULTS: The GLM TL at week 14, but not at weeks 6 or 10, was significantly associated with clinical remission at week 54 (median [IQR] 1.6 [1.3-1.6] µg/mL vs. 0.9 [0.6-1.3] µg/mL; p = 0.04). The area under the ROC curve for GLM TLs at week 14 was 0.78. We identified a week-14 GLM TL of 1.1 µg/mL as the target threshold for achieving clinical remission at week 54. CONCLUSION: Our results demonstrate the value of early serum GLM TLs in predicting the long-term outcomes of GLM for patients with UC.

Endoscopic diagnosis of Whipple disease in a patient without gastrointestinal symptoms: A case report.

Whipple's disease is a systemic chronic bacterial infection caused by Tropheryma whipplei, a gram-positive bacillus. T. whipplei infection in the small intestine often causes malabsorption and is often accompanied by gastrointestinal symptoms such as diarrhea and abdominal pain. In this report, we describe our experience with a case of Whipple's disease in which the affected patient did not have the typical gastrointestinal symptoms. The patient was an 80-year-old male who presented with complaints of weight loss and lower leg edema due to malabsorption and shortness of breath during exertion. A blood test revealed a decreased albumin level and an elevated C-reactive protein level. Endoscopic images revealed diffuse white villi, the presence of which extended from the duodenum to the upper jejunum. We made a diagnosis of Whipple's disease based on pathological findings associated with the duodenum, electron microscopic findings, and findings of polymerase chain reaction (PCR) tests (performed using mucosal tissue). Clinical symptoms and endoscopic findings improved with antibiotics. Real-time PCR tests were performed for a quantitative evaluation of the effect of treatment. Endoscopy is useful for diagnosing Whipple's disease when there is an absence of gastrointestinal symptoms, and hypoalbuminemia of unknown etiology is observed.

Induction of brain-derived neurotrophic factor in enteric glial cells stimulated by interleukin-1ß via a c-Jun N-terminal kinase pathway.

Brain-derived neurotrophic factor exhibits neurotropic and neuroprotective functions and is increased in the colonic mucosa of patients with irritable bowel syndrome in correlation with the severity and frequency of abdominal pain. However, there are no reports of brain-derived neurotrophic factor expression in enteric glial cells. We evaluated the mRNA and protein expressions of brain-derived neurotrophic factor in enteric glial cells and culture medium and levels of mitogen-activated protein kinase after stimulation with interleukin-1ß. Brain-derived neurotrophic factor mRNA expression was increased by interleukin-1ß (3.125-75 ng/ml) and time-dependently increased 3-fold (24 h) and 4-fold (48 h) by interleukin-1ß (50 ng/ml). Pro- and mature brain-derived neurotrophic factor proteins were both significantly increased at 48 h by interleukin-1ß. However, the mature form was predominant in the cultured medium. Interleukin-1ß increased phosphorylated-p38 mitogen-activated protein kinase expressions 2-fold higher at 5 and 15 min, and also phosphorylated-c-Jun N-terminal kinase expression 5-fold at 5 min and 10-fold at 15 min. Prior treatment with phosphorylated-c-Jun N-terminal kinase inhibitors decreased interleukin-1ß-induced brain-derived neurotrophic factor by 50%. Thus, brain-derived neurotrophic factor expression was induced by interleukin-1ß in enteric glial cells via a phosphorylated-c-Jun N-terminal kinase pathway, which might affect the enteric nervous system during stress.

Autophagy deficiency exacerbates colitis through excessive oxidative stress and MAPK signaling pathway activation.

BACKGROUND AND AIM: Autophagy is an essential process involved in the pathogenesis of inflammatory bowel disease (IBD). Although there are many data showing the roles of autophagy in intestinal epithelial cells (IECs), the mechanisms involved remain to be fully elucidated. We investigated the influence of autophagy in IECs on gastrointestinal tract inflammation. METHODS: Mice with conditional knockout of Atg5 in IECs (Atg5flox/flox/villin-Cre mice) were subjected to dextran sulfate sodium (DSS)-induced colitis and analyzed for colitis susceptibility. Additionally, we used Atg5-silenced rat IECs (IEC6shAtg5 cells) for in vitro assays. RESULTS: Sensitivity to DSS markedly increased in Atg5flox/flox/villin-Cre mice compared to that in wild-type mice. In IEC6shAtg5 cells, apoptosis was enhanced, and cell viability significantly decreased compared to IEC-6 cells. The expression of proinflammatory cytokines increased upon suppression of autophagy. Furthermore, silencing of Atg5 was associated with inflammation of IECs, activation of the mitogen-activated protein kinase (MAPK) signaling pathway by the intracellular reactive oxygen species accumulation, and NF-κB p65 phosphorylation. CONCLUSIONS: Autophagy in IECs plays an essential role in the maintenance of intestinal homeostasis, and autophagy deficiency triggers inflammation. Development of methods targeting autophagy might be beneficial in the treatment of IBD.

Augmented O-GlcNAcylation alleviates inflammation-mediated colon carcinogenesis via suppression of acute inflammation.

Colon cancer prevalence is high worldwide. O-GlcNAcylation has been associated with tumor growth in various tissues, including the colon; however, its link to carcinogenesis is not fully understood. We investigated the association of O-GlcNAcylation with colon carcinogenesis using a 1,2-dimethylhydrazine/dextran sodium sulfate-induced colon carcinogenesis model in wild type and O-GlcNAc transferase-transgenic (Ogt-Tg) mice. The incidence of colon cancer was significantly lower in Ogt-Tg than in wild type mice. The colonic length was not shortened in Ogt-Tg mice, and NF-κB p65 phosphorylation was strongly suppressed, indicating that reduction of inflammation might be related to the alleviation of colon carcinogenesis. Dextran sodium sulfate-induced acute colitis mice were used to evaluate the effect of O-GlcNAcylation on inflammation at the maximal inflammation period. In Ogt-Tg mice, NF-κB p65 phosphorylation and interleukin-1ß mRNA expression were suppressed. Histochemical staining demonstrated shedding of colon epithelial cells in wild type mice a few days after dextran sodium sulfate treatment, whereas they remained essentially intact in Ogt-Tg mice. There were no significant differences on histochemical staining in the remaining epithelia between groups. These data suggest that O-GlcNAcylation could prevent colon carcinogenesis through reducing acute maximum inflammation, suggesting modulation of O-GlcNAcylation as a novel therapeutic option.