Five-Year Efficacy and Safety of Ustekinumab Treatment in Crohn's Disease: The IM-UNITI Trial.

BACKGROUND & AIMS: The IM-UNITI study and long-term extension (LTE) evaluated the long-term efficacy, safety, and immunogenicity of subcutaneous ustekinumab maintenance therapy in patients with Crohn's disease. Here, we report the final results of IM-UNITI LTE through 5 years. METHODS: Patients completing safety and efficacy evaluations at week 44 of the maintenance study were eligible to participate in the LTE and continue the treatment they were receiving. Unblinding occurred after completion of maintenance study analyses (August 2015), and patients receiving placebo were discontinued from the study after unblinding. No dose adjustment occurred in the LTE. Efficacy assessments were conducted every 12 weeks until unblinding and at dosing visits thereafter through week 252. Serum ustekinumab concentrations and antidrug antibodies were evaluated through weeks 252 and 272, respectively. RESULTS: Using an intent-to-treat analysis of all patients randomized to ustekinumab at maintenance baseline, 34.4% of patients in the every-8-weeks group and 28.7% in the every-12-weeks group were in clinical remission at week 252. Corresponding remission rates among patients who entered the LTE were 54.9% and 45.2%. Overall, adverse event rates (per 100 patient-years) from maintenance week 0 through the final visit generally were similar in the placebo and combined ustekinumab groups for all adverse events (440.3 vs 327.6), serious adverse events (19.3 vs 17.5), infections (99.8 vs 93.8), and serious infections (3.9 vs 3.4). Serum ustekinumab concentrations were maintained throughout the LTE. Antidrug antibodies occurred in 5.8% of patients who received ustekinumab during induction and maintenance and continued in the LTE. CONCLUSIONS: Patients receiving subcutaneous ustekinumab maintained clinical remission through 5 years. No new safety signals were observed. ClinicalTrials.gov number NCT01369355.

Serum Amyloid A Promotes Inflammation-Associated Damage and Tumorigenesis in a Mouse Model of Colitis-Associated Cancer.

BACKGROUND & AIMS: Identifying new approaches to lessen inflammation, as well as the associated malignant consequences, remains crucial to improving the lives and prognosis of patients diagnosed with inflammatory bowel diseases. Although it previously has been suggested as a suitable biomarker for monitoring disease activity in patients diagnosed with Crohn's disease, the role of the acute-phase protein serum amyloid A (SAA) in inflammatory bowel disease remains unclear. In this study, we aimed to assess the role of SAA in colitis-associated cancer. METHODS: We established a model of colitis-associated cancer in wild-type and SAA double-knockout (Saa1/2-/-) mice by following the azoxymethane/dextran sulfate sodium protocol. Disease activity was monitored throughout the study while colon and tumor tissues were harvested for subsequent use in cytokine analyses, Western blot, and immunohistochemistry +experiments. RESULTS: We observed attenuated disease activity in mice deficient for Saa1/2 as evidenced by decreased weight loss, increased stool consistency, decreased rectal bleeding, and decreased colitis-associated tissue damage. Macrophage infiltration, including CD206+ M2-like macrophages, also was attenuated in SAA knockout mice, while levels of interleukin 4, interleukin 10, and tumor necrosis factor-ɑ were decreased in the distal colon. Mice deficient for SAA also showed a decreased tumor burden, and tumors were found to have increased apoptotic activity coupled with decreased expression for markers of proliferation. CONCLUSION: Based on these findings, we conclude that SAA has an active role in inflammatory bowel disease and that it could serve as a therapeutic target aimed at decreasing chronic inflammation and the associated risk of developing colitis-associated cancer.

The Link Between Bacterial Inflammagens, Leaky Gut Syndrome and Colorectal Cancer.

There is a causal relationship between cancer (including colorectal cancer), chronic systemic inflammation and persistent infections, and the presence of dysregulated circulating inflammatory markers. It is known that aberrant clot formation and coagulopathies occur in systemic inflammation. In colorectal cancer, there is a close link between gut dysbiosis and an inflammatory profile. In this review, we present evidence of the connection between gut dysbiosis, the entry of bacteria into the internal environment, and the presence of their highly potent inflammagenic molecules, such as lipopolysaccharide and lipoteichoic acid, in circulation. These bacterial components may act as one of the main drivers of the inflammatory process (including hypercoagulation) in colorectal cancer. We review literature that points to the role of these bacterial inflammagens and how they contribute to colorectal carcinogenesis. Insight into the factors that promote carcinogenesis is crucial to effectively prevent and screen for colorectal cancer. Early diagnosis of an activated coagulation system and the detection of bacterial components in circulation and also in the tumour microenvironment, could therefore be important, and may also, together with modulation of the gut microbiota, serve as potential therapeutic targets.

Serum amyloid A and inflammasome activation: A link to breast cancer progression?

Breast cancer is the most frequently diagnosed cancer in women globally. Although there have been many significant advances made in the diagnosis and treatment of breast cancer, numerous unresolved challenges remain, which include prevention, early diagnosis, metastasis and recurrence. The role of inflammation in cancer development is well established and is believed to be one of the leading hallmarks of cancer progression. Recently, the role of the inflammasome, a cytosolic multiprotein complex, has received attention in different cancers. By contributing to the activation of inflammatory cytokines the inflammasome intensifies the inflammatory cascade. The inflammasome can be activated through several pathways, which include the binding of pattern associated molecular patterns (PAMPs) and damage associated molecular patterns (DAMPs) to toll-like receptors (TLRs). Serum amyloid A (SAA), a non-specific acute-phase protein, can function as an endogenous DAMP by binding to pattern recognition receptors like TLRs on both breast cancer cells and cancer associated fibroblasts (CAFs). SAA can thus stimulate the production of IL-1ß, thereby creating a favourable inflammatory environment to support tumour growth. The aim of this review is to highlight the possible role of SAA as an endogenous DAMP in the tumour microenvironment (TME) thereby promoting breast cancer growth through the activation of the NLRP3 inflammasome.

Colorectal cancer is associated with increased circulating lipopolysaccharide, inflammation and hypercoagulability.

Gut dysbiosis contributes to the development of a dysfunctional gut barrier, facilitating the translocation of bacteria and inflammagens, and is implicated in colorectal cancer (CRC) pathogenesis. Such 'leaky gut' conditions result in systemic inflammation, of which a hallmark is increased hypercoagulability. Fluorescence antibody confocal microscopy was used to determine circulating levels of lipopolysaccharide (LPS) in control and CRC populations. Here we showed that circulating levels of LPS are significantly elevated in the CRC population. We also showed that markers of inflammation and hypercoagulability are increased in this population. Furthermore, anomalous blood clotting and structural changes in blood components are presented. Importantly, the association between LPS levels, inflammation, and hematological dysfunction was analysed. Statistical regression models were applied to identify markers with strong association with CRC, and to investigate the correlation between markers. A core aim is enhanced biomarker discovery for CRC. We conclude that circulating LPS can promote systemic inflammation and contribute to the development of a pathological coagulation system, with resulting chronic inflammation and an activated coagulation system implicated in tumorigenesis. Blood-based screening tools are an emerging research area of interest for CRC screening. We propose the use of additional (novel) biomarkers to effectively screen for CRC.

IM-UNITI: Three-year Efficacy, Safety, and Immunogenicity of Ustekinumab Treatment of Crohn's Disease.

BACKGROUND AND AIMS: Following induction/maintenance treatment in the UNITI/IM-UNITI studies of ustekinumab for Crohn's disease, patients entered a long-term extension for up to 5 years from induction. Efficacy through 152 and safety through 156 weeks are reported. METHODS: At IM-UNITI Week 44, 567 ustekinumab-treated patients entered the long-term extension and continued to receive blinded subcutaneous ustekinumab on their assigned dose interval, without any subsequent dose adjustment. Placebo-treated patients discontinued after study unblinding [after IM-UNITI Week 44 analyses]. Efficacy data in the long-term extension [LTE] were collected every 12 weeks [q12w] before unblinding and then at q12w/q8w dosing visits. RESULTS: Through Week 156, 29.6% of ustekinumab-treated patients discontinued. In an intent-to-treat analysis of randomised patients from IM-UNITI Weeks 0-152, 38.0% of ustekinumab induction responders receiving the drug q12w and 43.0% q8w were in remission at Week 152. Among patients entering the long-term extension in their original randomised groups, 61.9% of q12w and 69.5% of q8w patients were in remission at Week 152. Across all ustekinumab-treated patients [randomised and non-randomised] entering the long-term extension, remission rates at Week 152 were 56.3% and 55.1% for q12w and q8w, respectively. Safety events [per 100 patient-years] were similar among all ustekinumab-treated patients entering the long-term extension and placebo [overall adverse events 389.70 vs 444.17; serious adverse events, 18.97 vs 19.54; serious infections, 4.21 vs 3.97]. Rates of antibodies to ustekinumab through Week 156 remained low, 4.6% in all randomised ustekinumab-treated patients; lowest among patients in the original randomised q8w group [2/82, 2.4%]. CONCLUSIONS: Continued treatment with subcutaneous ustekinumab maintained clinical response and remission through 3 years in a majority of patients who responded to induction therapy and was well-tolerated. ClinicalTrials.gov number NCT01369355.

Serum amyloid A binds to fibrin(ogen), promoting fibrin amyloid formation.

Complex associations exist between inflammation and thrombosis, with the inflammatory state tending to promote coagulation. Fibrinogen, an acute phase protein, has been shown to interact with the amyloidogenic ß-amyloid protein of Alzheimer's disease. However, little is known about the association between fibrinogen and serum amyloid A (SAA), a highly fibrillogenic protein that is one of the most dramatically changing acute phase reactants in the circulation. To study the role of SAA in coagulation and thrombosis, in vitro experiments were performed where purified human SAA, in concentrations resembling a modest acute phase response, was added to platelet-poor plasma (PPP) and whole blood (WB), as well as purified and fluorescently labelled fibrinogen. Results from thromboelastography (TEG) suggest that SAA causes atypical coagulation with a fibrin(ogen)-mediated increase in coagulation, but a decreased platelet/fibrin(ogen) interaction. In WB scanning electron microscopy analysis, SAA mediated red blood cell (RBC) agglutination, platelet activation and clumping, but not platelet spreading. Following clot formation in PPP, the presence of SAA increased amyloid formation of fibrin(ogen) as determined both with auto-fluorescence and with fluorogenic amyloid markers, under confocal microcopy. SAA also binds to fibrinogen, as determined with a fluorescent-labelled SAA antibody and correlative light electron microscopy (CLEM). The data presented here indicate that SAA can affect coagulation by inducing amyloid formation in fibrin(ogen), as well as by propelling platelets to a more prothrombotic state. The discovery of these multiple and complex effects of SAA on coagulation invite further mechanistic analyses.

Correlative Light-Electron Microscopy detects lipopolysaccharide and its association with fibrin fibres in Parkinson's Disease, Alzheimer's Disease and Type 2 Diabetes Mellitus.

Many chronic diseases, including those classified as cardiovascular, neurodegenerative, or autoimmune, are characterized by persistent inflammation. The origin of this inflammation is mostly unclear, but it is typically mediated by inflammatory biomarkers, such as cytokines, and affected by both environmental and genetic factors. Recently circulating bacterial inflammagens such as lipopolysaccharide (LPS) have been implicated. We used a highly selective mouse monoclonal antibody to detect bacterial LPS in whole blood and/or platelet poor plasma of individuals with Parkinson's Disease, Alzheimer's type dementia, or Type 2 Diabetes Mellitus. Our results showed that staining is significantly enhanced (P < 0.0001) compared to healthy controls. Aberrant blood clots in these patient groups are characterized by amyloid formation as shown by the amyloid-selective stains thioflavin T and Amytracker™ 480 or 680. Correlative Light-Electron Microscopy (CLEM) illustrated that the LPS antibody staining is located in the same places as where amyloid fibrils may be observed. These data are consistent with the Iron Dysregulation and Dormant Microbes (IDDM) hypothesis in which bacterial inflammagens such as LPS are responsible for anomalous blood clotting as part of the aetiology of these chronic inflammatory diseases.

Ustekinumab as Induction and Maintenance Therapy for Crohn's Disease.

BACKGROUND: Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin-12 and interleukin-23, was evaluated as an intravenous induction therapy in two populations with moderately to severely active Crohn's disease. Ustekinumab was also evaluated as subcutaneous maintenance therapy. METHODS: We randomly assigned patients to receive a single intravenous dose of ustekinumab (either 130 mg or approximately 6 mg per kilogram of body weight) or placebo in two induction trials. The UNITI-1 trial included 741 patients who met the criteria for primary or secondary nonresponse to tumor necrosis factor (TNF) antagonists or had unacceptable side effects. The UNITI-2 trial included 628 patients in whom conventional therapy failed or unacceptable side effects occurred. Patients who completed these induction trials then participated in IM-UNITI, in which the 397 patients who had a response to ustekinumab were randomly assigned to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 8 weeks or every 12 weeks) or placebo. The primary end point for the induction trials was a clinical response at week 6 (defined as a decrease from baseline in the Crohn's Disease Activity Index [CDAI] score of ≥100 points or a CDAI score <150). The primary end point for the maintenance trial was remission at week 44 (CDAI score <150). RESULTS: The rates of response at week 6 among patients receiving intravenous ustekinumab at a dose of either 130 mg or approximately 6 mg per kilogram were significantly higher than the rates among patients receiving placebo (in UNITI-1, 34.3%, 33.7%, and 21.5%, respectively, with P≤0.003 for both comparisons with placebo; in UNITI-2, 51.7%, 55.5%, and 28.7%, respectively, with P<0.001 for both doses). In the groups receiving maintenance doses of ustekinumab every 8 weeks or every 12 weeks, 53.1% and 48.8%, respectively, were in remission at week 44, as compared with 35.9% of those receiving placebo (P=0.005 and P=0.04, respectively). Within each trial, adverse-event rates were similar among treatment groups. CONCLUSIONS: Among patients with moderately to severely active Crohn's disease, those receiving intravenous ustekinumab had a significantly higher rate of response than did those receiving placebo. Subcutaneous ustekinumab maintained remission in patients who had a clinical response to induction therapy. (Funded by Janssen Research and Development; ClinicalTrials.gov numbers, NCT01369329 , NCT01369342 , and NCT01369355 .).

Green Tea Polyphenols and Sulfasalazine have Parallel Anti-Inflammatory Properties in Colitis Models.

BACKGROUND: There is no cure for autoimmune chronic inflammatory bowel disease (IBD). IBD patients commonly use complementary and alternative medications of which the safety, efficacy, and interaction with standard-of-care therapies are not fully known. Thus the consequences can become life-threatening. Sulfasalazine commonly used in IBD, potentially has severe adverse effects, including infertility, pulmonary fibrosis, lack of response, and ultimately patients may require intestinal resection. We hypothesized that green tea polyphenols (GrTP, EGCG) and sulfasalazine have similar anti-inflammatory properties. METHODS: BALB/c mice received Dextran sodium sulfate (DSS) to induce colitis (ulcerative colitis model). Exposure of IL-10 deficient mice (BALB/c-background) to normal microbiota provoked enterocolitis (mimics Crohn's disease). Animals were treated with agents incorporated into daily diets. Control animals received sham treatment. RESULTS: DSS-treated animals developed severe bloody diarrhea and colitis (score 0-4, 3.2 ± 0.27). IL-10 deficient mice developed severe enterocolitis as manifested by diarrhea, rectal prolapse, and colonic lesions. Animals tolerated regimens (GrTP, EGCG, sulfasalazine) with no major side effects, and further developed less severe colitis. IL-10 deficient animals became moribund on high dose, while tolerated low and Mid doses with significant improved symptoms of enterocolitis. GrTP, EGCG, and sulfasalazine significantly ameliorated colonic damage and histological scores in treated animals in a similar manner (GrTP vs. DSS p < 0.05; EGCG, sulfasalazine vs. DSS p < 0.01). The inflammatory markers TNFα (3-fold), IL-6 (14-fold), and serum amyloid A (40-fold) increased in colitic animals and significantly decreased with treatment regiments. In contrast, circulatory leptin levels decreased in colitic animals (twofold). EGCG additionally reduced leptin levels (p < 0.01) while GrTP and sulfasalazine had no effect on leptin levels (p < 0.05). Hepatic and colonic antioxidants were significantly depleted in colitic animals and treatment regiments significantly restored antioxidants levels. CONCLUSION: GrTP and EGCG improved antioxidants levels and attenuated severity of colitis analogous to sulfasalazine. Future studies will reveal whether polyphenols can become an alternative/additive therapy for IBD therapy in humans.

Dietary medium-chain triglycerides promote oral allergic sensitization and orally induced anaphylaxis to peanut protein in mice.

BACKGROUND: The prevalence of peanut allergies is increasing. Peanuts and many other allergen sources contain significant amounts of triglycerides, which affect absorption of antigens but have unknown effects on sensitization and anaphylaxis. We recently reported that dietary medium-chain triglycerides (MCTs), which bypass mesenteric lymph and directly enter portal blood, reduce intestinal antigen absorption into blood compared with long-chain triglycerides (LCTs), which stimulate mesenteric lymph flow and are absorbed in chylomicrons through mesenteric lymph. OBJECTIVE: We sought to test how dietary MCTs affect food allergy. METHODS: C3H/HeJ mice were fed peanut butter protein in MCT, LCT (peanut oil), or LCT plus an inhibitor of chylomicron formation (Pluronic L81). Peanut-specific antibodies in plasma, responses of the mice to antigen challenges, and intestinal epithelial cytokine expression were subsequently measured. RESULTS: MCT suppressed antigen absorption into blood but stimulated absorption into Peyer patches. A single gavage of peanut protein with MCT, as well as prolonged feeding in MCT-based diets, caused spontaneous allergic sensitization. MCT-sensitized mice experienced IgG-dependent anaphylaxis on systemic challenge and IgE-dependent anaphylaxis on oral challenge. MCT feeding stimulated jejunal-epithelial thymic stromal lymphopoietin, Il25, and Il33 expression compared with that seen after LCT feeding and promoted T(H)2 cytokine responses in splenocytes. Moreover, oral challenges of sensitized mice with antigen in MCT significantly aggravated anaphylaxis compared with challenges with the LCT. Importantly, the effects of MCTs could be mimicked by adding Pluronic L81 to LCTs, and in vitro assays indicated that chylomicrons prevent basophil activation. CONCLUSION: Dietary MCTs promote allergic sensitization and anaphylaxis by affecting antigen absorption and availability and by stimulating T(H)2 responses.

Ustekinumab induction and maintenance therapy in refractory Crohn's disease.

BACKGROUND: In patients with Crohn's disease, the efficacy of ustekinumab, a human monoclonal antibody against interleukin-12 and interleukin-23, is unknown. METHODS: We evaluated ustekinumab in adults with moderate-to-severe Crohn's disease that was resistant to anti-tumor necrosis factor (TNF) treatment. During induction, 526 patients were randomly assigned to receive intravenous ustekinumab (at a dose of 1, 3, or 6 mg per kilogram of body weight) or placebo at week 0. During the maintenance phase, 145 patients who had a response to ustekinumab at 6 weeks underwent a second randomization to receive subcutaneous injections of ustekinumab (90 mg) or placebo at weeks 8 and 16. The primary end point was a clinical response at 6 weeks. RESULTS: The proportions of patients who reached the primary end point were 36.6%, 34.1%, and 39.7% for 1, 3, and 6 mg of ustekinumab per kilogram, respectively, as compared with 23.5% for placebo (P=0.005 for the comparison with the 6-mg group). The rate of clinical remission with the 6-mg dose did not differ significantly from the rate with placebo at 6 weeks. Maintenance therapy with ustekinumab, as compared with placebo, resulted in significantly increased rates of clinical remission (41.7% vs. 27.4%, P=0.03) and response (69.4% vs. 42.5%, P<0.001) at 22 weeks. Serious infections occurred in 7 patients (6 receiving ustekinumab) during induction and 11 patients (4 receiving ustekinumab) during maintenance. Basal-cell carcinoma developed in 1 patient receiving ustekinumab. CONCLUSIONS: Patients with moderate-to-severe Crohn's disease that was resistant to TNF antagonists had an increased rate of response to induction with ustekinumab, as compared with placebo. Patients with an initial response to ustekinumab had significantly increased rates of response and remission with ustekinumab as maintenance therapy. (Funded by Janssen Research and Development; CERTIFI ClinicalTrials.gov number, NCT00771667.).

Pegylated arginine deiminase downregulates colitis in murine models.

UNLABELLED: Arginine deiminase (ADI), an arginine-metabolizing enzyme involved in cell signaling, is dysregulated in multiple inflammatory diseases and cancers. We hypothesized that pegylated ADI (ADI-PEG) provide protection against colitis. METHODS: Dextran sodium sulfate colitis was induced in IL-10-deficient and BALB/c (WT) mice. ADI-PEG was administered i.p., and inflammatory mediators and pathology were evaluated. RESULTS: Acute colitis in mice was manifested by increases in inflammatory biomarkers, such as serum amyloid A (SAA, P < 0.001), IL-12 p40, and disease index (3-Fold). In contrast, ADI-PEG significantly decreased clinical disease index, SAA levels, and inflammatory cytokines in blood as well as in colonic explants. Animals developed moderate (2.2 ± 0.3 WT) to severe (3.6 ± 0.5 IL-10 deficient) colonic pathology; and ADI-PEG treatment significantly improved the severity of colitis (P < 0.05). Marked infiltration of CD68+ macrophages and iNOS expression were detected in colonic submucosa in colitic animals but not detected in ADI-PEG-treated animals. CONCLUSION: ADI-PEG attenuated inflammatory responses by suppression of macrophage infiltration and iNOS expression in colitic animals. ADI-PEG can serve as a potential therapeutic value in IBD.

Long-term infliximab maintenance therapy for ulcerative colitis: the ACT-1 and -2 extension studies.

BACKGROUND: The aim was to evaluate long-term efficacy, quality of life, and safety in ulcerative colitis patients who received infliximab during the ACT-1 and -2 extension studies. METHODS: Adults with moderate-to-severely active ulcerative colitis in the 54-week ACT-1 and 30-week ACT-2 studies who achieved benefit from infliximab were eligible to participate in extension studies and receive up to 3 additional years of therapy. Patients received randomized study medication until all sites were unblinded; placebo-treated patients were discontinued. Patients receiving 5 or 10 mg/kg infliximab continued to receive open-label infliximab every 8 weeks. Patients receiving infliximab 10 mg/kg could decrease to 5 mg/kg; patients receiving infliximab 5 mg/kg could increase to 10 mg/kg if response was lost. RESULTS: A total of 229 of 484 infliximab-treated patients from the ACT-1 and ACT-2 main studies entered the long-term extensions. Overall, 70 (30.6%) patients discontinued infliximab infusions for adverse events (24 [10.5%]), lack of efficacy (11 [4.8%]), required a colectomy (1 [0.4%]), or for other reasons (34 [14.8%]). Proportions of patients whose Physician's Global Assessment scores were indicative of no or mild disease (score = 0 or 1) were maintained during the extension studies; 76.5% at Extension week 0 and ranged between 90.0% and 94.3% through Extension week 152. Improvement in Inflammatory Bowel Disease Questionnaire scores observed in the main studies was maintained. During the long-term extension, the infliximab safety profile was consistent with that of the main studies; no new or unexpected safety signals were observed. CONCLUSIONS: Long-term treatment with infliximab for up to 3 additional years was effective and well tolerated.

Osteopontin ablation attenuates progression of colitis in TNBS model.

INTRODUCTION: OPN has been implicated in the inflammatory response to Crohn's disease. We hypothesized that OPN deficiency protects against different stages of TNBS-induced colitis in a modified model that mimics Crohn's disease. MATERIAL AND METHODS: OPN-deficient and wildtype mice were treated intracolonically with TNBS and euthanized during acute, sub-acute and chronic colitis. RESULTS: TNBS-treated wildtype mice developed severe colitis, but OPN-deficient mice were significantly protected. Wildtype mice showed significant infiltration of inflammatory cells including macrophages, and colonic transmural thickening that progressed to strictures, increased matrix collagen deposits (X2 fold), and granuloma formation. These pathological findings were partially attenuated by OPN deficiency. The inflammatory marker, serum amyloid A (SAA), markedly increased in sub-acute stages regardless of OPN status. Conversely, OPN deficiency significantly reduced concentration of SAA in the acute and chronic stages. Secretory OPN was upregulated particularly in acute stage in wildtypes (P < 0.001) and as expected not present in OPN-deficient animals. Flow cytometry analysis of splenic macrophages revealed significant increases in scavenger receptors, macrosialin and F4/80 markers' expression in wildtypes. CONCLUSIONS: Our data support the role of OPN in induction of inflammation and establishment of chronic colitis. Therefore, OPN may represent a target for therapeutic intervention in Crohn's disease.

Autoimmune enteropathy with a CD8+ CD7- T-cell small bowel intraepithelial lymphocytosis: case report and literature review.

BACKGROUND: Adult onset autoimmune enteropathy (AIE) is a rare condition characterized by diarrhea refractory to dietary therapy diagnosed in patients with evidence of autoimmune conditions. Auto-antibodies to gut epithelial cells and other tissues are commonly demonstrated. Despite increasing awareness, the pathogenesis, histologic, immunologic and clinical features of AIE remain uncertain. There remains controversy regarding the diagnostic criteria, the frequency and types of auto-antibodies and associated autoimmune conditions, and the extent and types of histologic and immunologic abnormalities. CD4+ T-cells are thought to at least responsible for this condition; whether other cell types, including B- and other T-cell subsets are involved, are uncertain. We present a unique case of AIE associated with a CD8+CD7- lymphocytosis and review the literature to characterize the histologic and immunologic abnormalities, and the autoantibodies and autoimmune conditions associated with AIE. CASE PRESENTATION: We present a case of immune mediated enteropathy distinguished by the CD8+CD7- intra-epithelial and lamina propria lymphocytosis. Twenty-nine cases of AIE have been reported. The majority of patients had auto-antibodies (typically anti-enterocyte), preferential small bowel involvement, and predominately CD3+ CD4+ infiltrates. Common therapies included steroids or immuno-suppressive agents and clinical response with associated with histologic improvement. CONCLUSIONS: AIE is most often characterized (1) IgG subclass anti-epithelial cell antibodies, (2) preferential small bowel involvement, and (3) CD3+ alphabeta TCR+ infiltrates; there is insufficient evidence to conclude CD4+ T-cells are solely responsible in all cases of AIE.

TNF-α and the development of the neonatal immune system: implications for inhibitor use in pregnancy.

Inflammatory bowel diseases, Crohn's disease, and ulcerative colitis have an unpredictable course during and after pregnancy (1). There is a great deal of interest in treating moderate to severe active inflammatory bowel disease with anti-tumor necrosis factor (anti-TNF) biologics in pregnant women (2). We lack definitive information about the effects of these agents on the development of the immune system of the human fetus and the newborn baby. Anti-TNF agents fall within US Food and Drug Administration's (FDA) category B regarding fetal risk, indicating that no adequate and well-controlled studies have been conducted in pregnant or nursing women. Here, we review animal studies (of both mice and nonhuman primates) that examine the role of TNF and its inhibitors in the normal development of the immune system.

Adiponectin and plant-derived mammalian adiponectin homolog exert a protective effect in murine colitis.

BACKGROUND: Hypoadiponectinemia has been associated with states of chronic inflammation in humans. Mesenteric fat hypertrophy and low adiponectin have been described in patients with Crohn's disease. We investigated whether adiponectin and the plant-derived homolog, osmotin, are beneficial in a murine model of colitis. METHODS: C57BL/6 mice were injected (i.v.) with an adenoviral construct encoding the full-length murine adiponectin gene (AN+DSS) or a reporter-LacZ (Ctr and V+DSS groups) prior to DSS colitis protocol. In another experiment, mice with DSS colitis received either osmotin (Osm+DSS) or saline (DSS) via osmotic pumps. Disease progression and severity were evaluated using body weight, stool consistency, rectal bleeding, colon lengths, and histology. In vitro experiments were carried out in bone marrow-derived dendritic cells. RESULTS: Mice overexpressing adiponectin had lower expression of proinflammatory cytokines (TNF, IL-1ß), adipokines (angiotensin, osteopontin), and cellular stress and apoptosis markers. These mice had higher levels of IL-10, alternative macrophage marker, arginase 1, and leukoprotease inhibitor. The plant adiponectin homolog osmotin similarly improved colitis outcome and induced robust IL-10 secretion. LPS induced a state of adiponectin resistance in dendritic cells that was reversed by treatment with PPARγ agonist and retinoic acid. CONCLUSION: Adiponectin exerted protective effects during murine DSS colitis. It had a broad activity that encompassed cytokines, chemotactic factors as well as processes that assure cell viability during stressful conditions. Reducing adiponectin resistance or using plant-derived adiponectin homologs may become therapeutic options in inflammatory bowel disease.

Role of the xenobiotic receptor in inflammatory bowel disease.

BACKGROUND: Gene-environment interplay modulates inflammatory bowel diseases (IBD). Dioxin-like compounds can activate the aryl hydrocarbon receptor (AhR) and alter macrophage function as well as T-cell polarization. We hypothesized that attenuation of the AhR signaling pathway will ameliorate colitis in a murine model of IBD. METHODS: Dextran sulfate sodium (DSS) colitis was induced in C57BL/6 AhR null mice (AhR(-/-) ), heterozygous mice (AhR(-/+) ), and their wildtype (WT) littermates. Clinical and morphopathological parameters were used to compare the groups. PATIENTS: AhR pathway activation was analyzed in biopsy specimens from 25 IBD patients and 15 healthy controls. RESULTS: AhR(-/-) mice died before the end of the treatment. However, AhR(-/+) mice exhibited decreased disease activity compared to WT mice. The AhR(-/+) mice expressed less proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α) (6.1- versus 15.7-fold increase) and IL17 (23.7- versus 67.9-fold increase) and increased antiinflammatory IL-10 (2.3-fold increase) compared with the AhR(+/+) mice in the colon. Colonic macrophage infiltration was attenuated in the AhR(-/+) group. AhR and its downstream targets were significantly upregulated in IBD patients versus control (CYP1A1 -19.9, and IL8- 10-fold increase). CONCLUSIONS: Attenuation of the AhR receptor expression resulted in a protective effect during DSS-induced colitis, while the absence of AhR exacerbated the disease. Abnormal AhR pathway activation in the intestinal mucosa of IBD patients may promote chronic inflammation. Modulation of AhR signaling pathway via the diet, cessation of smoking, or administration of AhR antagonists could be viable strategies for the treatment of IBD.

The macrophage pattern recognition scavenger receptors SR-A and CD36 protect against microbial induced pregnancy loss.

OBJECTIVES AND DESIGN: Microbial products can act via stress-induced signaling cascades to link dysregulated endogenous microbiota to immune activation (e.g., macrophages) and pregnancy loss. Our previous studies demonstrated that mice deficient in the macrophage pattern recognition scavenger receptors, SR-A and CD36, are more susceptible to inflammatory complications including gut leakiness and experimental colitis. We hypothesized that bacterial penetration of the maternal mucosal surfaces and replication in embryonic fluids compromise the fetal status and can result in miscarriage. MATERIALS AND METHODS: Eighty pregnant ICR and SR-A/CD36-deficient mice were injected via tail vein or intraperitoneally with commensal bacteria (Streptococcus cricetus and/or Actinobacillus sp.) or sham controls. Dams were monitored daily for physical distress, pain and abortion. RESULTS: Dams injected with single dose bacterial inoculum did not develop clinical symptoms. Day old pups injected with bacteria developed internal focal abscesses, lost weight but recovered after 1 week. Dams receiving a second bacterial inoculum delivered dead fetuses. However, SR-A/CD36-deficnet dams demonstrated 100% fetal death via aborted fetuses, and significant up-regulation of the proinflammatory markers (IL-6, serum Amyloid A) 24-74 h after single inoculum. CONCLUSIONS: These data indicate that macrophage scavenger receptors are required for the fetal protection against microbial attack and support that maternal transfer of innate immunity contributes to this protection.