Early MOnitoring of REsponse (MORE) to Golimumab Therapy: Results of a Multicentre, Prospective Observational Trial

BACKGROUND

The therapeutic goal of clinical remission in patients with moderate to severe ulcerative colitis (UC) is achieved after biological therapy only in 16-39%. Individualization of therapeutic intervention would benefit from prediction of early response.

STUDY OBJECTIVE

The primary objective of our study was to assess golimumab (GLM) trough serum level of ≥2.5 μg/mL in combination with a reduction of faecal calprotectin (FC) of ≥50% at week 6 compared to baseline to predict clinical response at week 26 after regular GLM intake.

METHODS

Patients with moderate to severe active UC and planned GLM treatment were recruited for a prospective, multicentre, observational study in Germany. Prediction of clinical response was assessed by FC and GLM trough level. Missing data were imputed as therapy failure according to the last observation carried forward method.

RESULTS

Fifty nine patients have been enrolled. 54% of patients were anti-TNF naïve. Clinical response at week 6 was a significant predictor for achieving clinical response at week 26 (odds ratio [OR] 10.97, confidence interval [CI], 2.96-40.68; p < 0.001). Moreover, patients with a GLM trough level of ≥2.5 μg/mL and a ≥50% reduction of FC at week 6 had an OR of 5.33 (95% CI, 0.59-47.84) to achieve clinical response at week 26.

CONCLUSION

Clinical response at week 6 is the best predictive marker for achieving clinical response at week 26. Consideration of significant reduction of FC and trough GLM serum levels could improve prediction of response.

A Prospective Multicenter Study on the Prevalence of Fructose Malabsorption in Patients with Chronic Inflammatory Bowel Disease

BACKGROUND AND AIMS

Patients with chronic inflammatory bowel disease (IBD) might have a higher prevalence of fructose malabsorption than healthy controls. This study's aim was to determine the prevalence and symptom severity of fructose malabsorption in patients with active and inactive IBD.

METHODS

The present study was a multicenter noninterventional diagnostic pilot trial. Two hundred fifty-one participants were recruited from 12 outpatient clinics for internal medicine across Germany and from the University of Kiel. Fructose malabsorption was diagnosed by hydrogen breath testing. Patients diagnosed with bacterial overgrowth, non-H2 producers, and patients who were tested positive for lactose malabsorption were excluded. Gastrointestinal symptoms during breath testing were evaluated using four-point subjective items to determine severity of bloating, abdominal pain, and diarrhea.

RESULTS

Two hundred five patients (45 with active IBD, 80 with IBD in remission, and 81 healthy controls) were analyzed. The number of patients diagnosed with fructose malabsorption - 35/44 (79.6%) in patients with active IBD, 59/80 (73.8%) inactive IBD, and 66/81 (81.5%) in healthy controls - did not differ between the groups (χ2 [2, N = 205] = 1.48, p = 0.48). However, abdominal pain was more frequent in patients with active IBD than patients with IBD in remission (z = -2.936, p = 0.010), and diarrhea was more frequent in patients with active IBD than in healthy controls (z = 2.489, p = 0.038).

CONCLUSIONS

Fructose malabsorption is not more common among patients with IBD than healthy subjects. However, the greater prevalence of patient-reported symptoms among patients with IBD may be of pathological and therapeutic relevance.

Perceived distress, personality characteristics, coping strategies and psychosocial impairments in a national German multicenter cohort of patients with Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS

 This study examined differences in personality, psychological distress, and stress coping in inflammatory bowel disease (IBD) depending on type of disease and disease activity. We compared patients suffering from Crohn's disease (CD) and ulcerative colitis (UC) with controls. While the literature is replete with distinctive features of the pathogenesis of IBD, the specific differences in psychological impairments are not well studied.

METHODS

 In this German national multicenter study, participants were recruited from 32 centers. Two hundred ninety-seven questionnaires were included, delivering vast information on disease status and psychological well-being based on validated instruments with a total of 285 variables.

RESULTS

 CD patients were more affected by psychological impairments than patients suffering from UC or controls. Importantly, patients with active CD scored higher in neuroticism (p < 0.01), psychological distress (p < 0.001) and maladaptive stress coping (escape, p = 0.03; rumination, p < 0.03), but less need for social support (p = 0.001) than controls. In contrast, patients suffering from active UC showed psychological distress (p < 0.04) and maladaptive coping (avoidance, p < 0.03; escape, p = 0.01). Patients in remission seemed to be less affected. In particular, patients with UC in remission were not inflicted by psychological impairments. The group of CD patients in remission however, showed insecurity (p < 0.01) and paranoid ideation (p = 0.04).

CONCLUSIONS

 We identified specific aspects of psychological impairment in IBD depending on disease and disease activity. Our results underscore the need for psychological support and treatment particularly in active CD.

Microbial Spectrum of Intra-Abdominal Abscesses in Perforating Crohn's Disease: Results from a Prospective German Registry

BACKGROUND

Intra-abdominal abscesses [IAAs] are common life-threatening complications in patients with Crohn's disease [CD]. In addition to interventional drainage and surgical therapy, empirical antibiotic therapy represents a cornerstone of treatment, but contemporary data on microbial spectra and antimicrobial resistance are scarce.

METHODS

We recruited 105 patients with CD and IAAs from nine German centres for a prospective registry in order to characterize the microbiological spectrum, resistance profiles, antibiotic therapy and outcome.

RESULTS

In 92 of 105 patients, microbial investigations of abscess material revealed pathogenic microorganisms. A total of 174 pathogens were isolated, with a median of 2 pathogens per culture [range: 1-6]. Most frequently isolated pathogens were E. coli [45 patients], Streptococcus spp. [28 patients], Enterococci [27 patients], Candida [13 patients] and anaerobes [12 patients]. Resistance to third-generation cephalosporins, penicillins with beta-lactamase inhibitors and quinolones were observed in 51, 36 and 35 patients, respectively. Seven patients had multiple-drug-resistant bacteria. Thirty patients received inadequate empirical treatment, and this was more frequent in patients receiving steroids or immunosuppression [37%] than in patients without immunosuppression [10%: p = 0.001] and was associated with a longer hospital stay [21 days vs 13 days, p = 0.003].

CONCLUSION

Based on antimicrobial resistance profiles, we herein report a high rate of inadequate empirical first-line therapy for IAAs in CD, especially in patients receiving immunosuppression, and this is associated with prolonged hospitalization.

Vedolizumab in the treatment of chronic, antibiotic-dependent or refractory pouchitis

BACKGROUND

The most common complication after ileal pouch anal anastomosis in up to 50% of patients is an acute pouchitis. The majority of patients respond to antibiotic treatment. However, 10%-15% develops chronic antibiotic-dependent or refractory pouchitis which is usually hard to treat.

AIM

To evaluate the effectiveness of vedolizumab in patients with chronic pouchitis.

METHODS

Patients with chronic antibiotic-dependent or refractory pouchitis were treated with vedolizumab (300 mg at week 0, 2, 6 and 10) in 10 IBD centres and retrospectively registered. Data were recorded until week 14 of vedolizumab treatment. In total 20 patients (12 male, median age 43 years) were included for analysis. The effectiveness was measured using the Oresland Score (OS) at week 2, 6, 10 and 14 and the pouch disease activity index (PDAI) at week 0 and 14.

RESULTS

The mean OS declined from 6.8 (range 2-12) to 3.4 (range 0-11). Concordantly, the mean PDAI after 14 weeks of treatment dropped from 10 (range 5-18) to 3 (range 0-10). Only three patients reported moderate side effects. No serious side effects were recorded. In addition, symptomatic co-medication such as loperamide and tincture of opium could be terminated in 8 out of 12 patients as well as antibiotic treatment could be stopped in 17 out of 19 patients.

CONCLUSION

Our data indicate that vedolizumab could be an option in the treatment of patients with chronic, antibiotic-dependent or refractory pouchitis.

Cyclophosphamide Pulse Therapy in Severe Refractory Crohn's Disease: A Retrospective Multicenter Case Series

Background and Aims

In Crohn's disease (CD) patients still remain refractory to current regimens, including biologicals. Previous data from small single-center studies indicated cyclophosphamide pulse therapy (CPT) to be effective for induction of remission at least in steroid-refractory cases. The aim of the present study was to study the efficacy and safety of CPT in mainly tumor necrosis factor (TNF)-refractory complicated CD patients.

Methods

Patients with refractory CD undergoing CPT were identified in 13 centers of the German IBD Study Group and retrospectively registered. In total, 41 patients (12 male, 29 female, median age 36 years, range 18-72 years) were included for analysis. Seventy-eight percent of these had previously been treated with thiopurines and 90% had previously received anti-TNF antibodies. Former steroid treatment was found throughout the cohort.

Results

Patients received a median number of 5 (1-13) pulses every 28 (13-54) days in a period of 120 (12-411) days. A median dose of 766 (600-1,200) mg and a median cumulative dose of 4,500 (750-9,750) mg was given. A clinical response (reduction in the Harvey-Bradshaw Index [HBI] ≥2 points) was found in 68% of the patients and clinical remission (HBI <5 points) in 32%. Steroids could be reduced from 31 to 12 mg per day over all patients. Side effects were recorded in 71% (n = 29) of the patients. Three patients terminated CPT due to side effects. No patient died.

Conclusion

Our data point to CPT as a therapeutic alternative for induction of remission in patients with severe refractory courses of CD including TNF antagonists. CPT might serve as bridging for maintenance treatment.

Quality of care in inflammatory bowel disease: results of a prospective controlled cohort study in Germany (NETIBD)

Background/aims

Patients with inflammatory bowel disease (IBD) need comprehensive, interdisciplinary and cross-sectoral health care. In Germany, evidence-based care pathways have been developed to improve the quality of care of IBD patients. We aimed to evaluate the effects of the implementation of some of these recommendations on patient-related outcomes.

Methods

In a region of North Germany, outpatients with IBD were recruited by gastroenterologists (intervention group). Three activities based on the recommendations of the IBD pathways were implemented, namely, 1) patient participation in a questionnaire-based assessment of 22 somatic and psychosocial problems combined with individualized care recommendations (patient activation procedure); 2) patient invitation to participate in a 2-day patient education program and 3) invitation to their gastroenterologists to participate in periodic interdisciplinary case conferences. For the control group, IBD patients receiving standard care at gastroenterology practices outside the specified region were recruited by their doctors. At baseline, 6- and 12-month follow-up, study patients were invited to complete questionnaires. Generic health-related quality of life, social participation and self-management skills were the main outcomes.

Results

At baseline, 349 patients were included in the study (intervention group: 189; control group: 160); 142 patients from the former and 140 from the latter group returned completed questionnaires at the 12-month follow-up. Over time, improvement in health-related quality of life and social participation was similar in both groups. Participants of the intervention group demonstrated improved self-management skills and more often followed steroid-free medication regimens.

Conclusion

In a real-world clinical context, patient activation procedure combined with patient education and case conferences was less effective than expected. The observed beneficial effects, however, encourage the evaluation of more intensive and addressee-centered activities.

Azathioprine allows glucocorticoid withdrawal - post hoc results of a prospective study in patients with inflammatory bowel diseases

Background Azathioprine is recommended as first-line immunosuppressant in patients with steroid-dependent inflammatory bowel diseases (IBDs). However, data on steroid withdrawal after induction therapy in IBD patients are sparse. Methods In this post-hoc analysis of a prospective multicenter study, we analyzed the proportion and clinical characteristics of 324 azathioprine-tolerant patients as to whether they could terminate the glucocorticoid therapy after initiation of treatment with azathioprine. Results Systemic steroid therapy was required in 190 patients (58.6 %) at baseline and in 40 patients (12.3 %) at the end of the follow-up period (p < 0.001). The median daily dose was 30 mg at baseline and 10 mg at follow-up. At baseline, only 122 patients (37.2 %) were advised to take at least the lowest recommended dose of 2 mg/kg per day. At follow-up, 221 patients (68.2 %) were prescribed at least the recommended maintenance dosage. Conclusion The majority of patients with thiopurine-naïve IBDs that needed systemic steroids at baseline were able to discontinue steroids after 3 - 6 months of azathioprine therapy. These data support the continued high value of azathioprine in the immunosuppressive therapy of IBD.

Differential expression of GPR15 on T cells during ulcerative colitis

G protein-coupled receptor 15 (GPR15) was recently highlighted as a colon-homing receptor for murine and human CD4+ T cells. The aim of this study was to explore the functional phenotype of human GPR15+CD4+ T cells, focusing on Tregs and effector T cells (Teffs), and to determine whether GPR15 is the driver for the migration of T cells to the colon during ulcerative colitis (UC). In the peripheral blood, GPR15 was expressed on Tregs and Teffs; both GPR15+ T cell subsets produced less IFN-γ and IL-4 but more IL-17 after stimulation and showed a higher migration activity compared with GPR15-CD4+ T cells. In UC patients, GPR15 expression was increased on Tregs in the peripheral blood but not on Teffs. Interestingly, the expression of GPR15 was significantly enhanced on colonic T cells of UC patients in noninflamed biopsies but not in inflamed biopsies. The differential expression of GPR15 in UC patients was accompanied by a significant reduction of bacterial immunoregulatory metabolites in the feces. In conclusion, GPR15 expression on CD4+ T cells is altered in UC patients, which may have implications for the development of therapeutic approaches to target T cell trafficking to the colon.

Germ cell proliferation and cluster behavior in ovarioles of Sialis flavilatera (Megaloptera: Sialidae) during larval growth

Telotrophic meroistic insect ovaries are assigned to four different types. The Sialis type is found in Sialidae (Megaloptera), Raphidioptera and a coleopteran subgroup (Myxophaga: Hydroscaphidae). King and Büning (1985) proposed a hypothetical model for the development of this ovariole type; however, a detailed description of ovarian development in Sialis was missing so far. Using light and electron microscopy, we investigated developing ovaries of Sialis flavilatera starting in the 10th month of the biennial larval phase until adulthood. At least from the 10th month onwards, a Sialis ovariole anlage contains a single germ cell syncytium, whose growth is promoted by a mitotic cell population maintained in its anterior compartment. The stem-like, dividing germ cells form synchronous sub-clusters consisting of 2-16 cystocytes, which are spatially arranged in bigger rosettes that stay connected to each other via cytoplasmic tubes. Within individual rosettes, cells communicate by centrally gathering intercellular bridges. Following each round of cystocyte division and subsequent rosette formation, plasma membrane wrinkles sprout near newborn bridges, elongate, and interdigitate with the preexisting membrane tubes. In this way the membrane labyrinth emerges and grows. Germ cells leaving the proliferation zone posteriorly enter meiotic prophase. Hypotheses on the phylogenetic origin of this ovary type are discussed in the light of our results.

Combining aneuploidy and dysplasia for colitis' cancer risk assessment outperforms current surveillance efficiency: a meta-analysis

PURPOSE

Cancer risk assessment for ulcerative colitis patients by evaluating histological changes through colonoscopy surveillance is still challenging. Thus, additional parameters of high prognostic impact for the development of colitis-associated carcinoma are necessary. This meta-analysis was conducted to clarify the value of aneuploidy as predictor for individual cancer risk compared with current surveillance parameters.

METHODS

A systematic web-based search identified studies published in English that addressed the relevance of the ploidy status for individual cancer risk during surveillance in comparison to neoplastic mucosal changes. The resulting data were included into a meta-analysis, and odds ratios (OR) were calculated for aneuploidy or dysplasia or aneuploidy plus dysplasia.

RESULTS

Twelve studies addressing the relevance of aneuploidy compared to dyplasia were comprehensively evaluated and further used for meta-analysis. The meta-analysis revealed that aneuploidy (OR 5.31 [95 % CI 2.03, 13.93]) is an equally effective parameter for cancer risk assessment in ulcerative colitis patients as dysplasia (OR 4.93 [1.61, 15.11]). Strikingly, the combined assessment of dysplasia and aneuploidy is superior compared to applying each parameter alone (OR 8.99 [3.08, 26.26]).

CONCLUSIONS

This meta-analysis reveals that aneuploidy is an equally effective parameter for individual cancer risk assessment in ulcerative colitis as the detection of dysplasia. More important, the combined assessment of dysplasia and aneuploidy outperforms the use of each parameter alone. We suggest image cytometry for ploidy assessment to become an additional feature of consensus criteria to individually assess cancer risk in UC.

Development of ovary structures in the last larval and adult stages of psyllids (Insecta, Hemiptera, Sternorrhyncha: Psylloidea)

The development and organization of the ovaries of ten species from four Psylloidea families (Psyllidae, Triozidae, Aphalaridae and Liviidae) have been investigated. The ovaries of the last larval stage (i.e. fifth instar) of all examined species are filled with numerous clusters of cystocytes which undergo synchronous incomplete mitotic division. Cystocytes of the given cluster are arranged into a rosette with polyfusome in the centre. These clusters are associated with single somatic cells. At the end of the fifth instar, the clusters begin to separate from each other, forming spherical ovarioles which are surrounded by a single layer of somatic cells. In the ovarioles of very young females all cystocytes enter the prophase of meiosis and differentiate shortly thereafter into oocytes and trophocytes (nurse cells). Meanwhile, somatic cells differentiate into cells of the inner epithelial sheath surrounding the trophocytes and into the prefollicular cells that encompass the oocytes. During this final differentiation, the trophocytes lose their cell membranes and become syncytial. Oocytes remain cellular and most of them (termed arrested oocytes) do not grow. In the ovarioles of older females, one oocyte encompassed by its follicle cells starts growing, still connected to the syncytial tropharium by a nutritive cord. After the short phase of previtellogenesis alone, the oocyte enters its vitellogenic the growth phase in the vitellarium. At that time, the second oocyte may enter the vitellarium and start its previtellogenic growth. In the light of the obtained results, the phylogeny of psyllids, as well as phylogenetic relationships between taxa of Hemiptera: Sternorrhyncha are discussed.

Long-term Outcomes in Steroid-refractory Ulcerative Colitis Treated with Tacrolimus Alone or in Combination with Purine Analogues

BACKGROUND AND AIMS

Tacrolimus is recommended for the treatment of steroid-refractory ulcerative colitis (UC). Concomitantly started purine analogues (PAs) are used for the maintenance of remission, though their therapeutic relevance remains uncertain. Here we studied the role of PAs in the long-term outcome of steroid-refractory UC after tacrolimus treatment.

METHODS

In five centres, charts of tacrolimus-treated UC patients with a steroid-refractory moderate to severe course were reviewed. Long-term efficacy was determined by colectomy rates and clinical remission in cases of colectomy-free survival for 3 months.

RESULTS

We identified 156 patients (median age 34 years) with a median Lichtiger score of 12 (4-17) and pancolitis (E3) in 65% (101). The Kaplan-Meier curve for colectomy-free survival after month 3 showed a benefit in the PA group (p = 0.02). In patients treated with PA clinical remission was achieved in 82% (65/79) vs 67% (39/58) in those not treated with PA (p = 0.02). Time to colectomy was 2 years (median, 0.7-5.8) in the PA group and 0.8 years (0.3-4.7) in the group not treated with PAs (p = 0.02). Time to relapse was 1.2 years (median, 0.3-6.2) in patients with PA treatment and 0.5 years (0.3-3.9) in those without PA treatment (p = 0.05). Overall, clinical remission was achieved in 67% (104/156) of patients. Colectomy was performed in 29% (45/156) 0.5 years (median, 0.04-5.79) after initiation of tacrolimus. Ten (6%) patients had to stop tacrolimus due to adverse events and two (without PA treatment) died.

CONCLUSIONS

Our study supports the efficacy of tacrolimus in steroid-refractory UC. Purine analogues appear to be beneficial for the long-term outcome of these patients.

Azathioprine-induced Acute Pancreatitis in Patients with Inflammatory Bowel Diseases--A Prospective Study on Incidence and Severity

BACKGROUND AND AIMS

Azathioprine [AZA] is recommended for maintenance of steroid-free remission in inflammatory bowel disease IBD. The aim of this study has been to establish the incidence and severity of AZA-induced pancreatitis, an idiosyncratic and major side effect, and to identify specific risk factors.

METHODS

We studied 510 IBD patients [338 Crohn's disease, 157 ulcerative colitis, 15 indeterminate colitis] with initiation of AZA treatment in a prospective multicentre registry study. Acute pancreatitis was diagnosed in accordance with international guidelines.

RESULTS

AZA was continued by 324 [63.5%] and stopped by 186 [36.5%] patients. The most common cause of discontinuation was nausea [12.2%]. AZA-induced pancreatitis occurred in 37 patients [7.3%]. Of these: 43% were hospitalised with a median inpatient time period of 5 days; 10% had peripancreatic fluid collections; 24% had vomiting; and 14% had fever. No patient had to undergo nonsurgical or surgical interventions. Smoking was the strongest risk factor for AZA-induced acute pancreatitis [p < 0.0002] in univariate and multivariate analyses.

CONCLUSIONS

AZA-induced acute pancreatitis is a common adverse event in IBD patients, but in this study had a mild course in all patients. Smoking is the most important risk factor.

Does etiology of acute pancreatitis matter? A review of 391 consecutive episodes

CONTEXT

Acute pancreatitis can be triggered by a variety of factors ranging from short lasting to sustained disruptions. It is plausible that the characteristics and course of disease differ among etiologies. Data distinguishing characteristics of patients with pancreatitis of biliary, alcoholic, idiopathic or other origin are scarce and conflicting.

OBJECTIVE

To compare patients' characteristics, baseline parameters on admission, and outcome in patients with an episode of acute pancreatitis in whom the etiology was thoroughly determined.

DESIGN

Retrospective study.

SETTING

Single center.

PATIENTS

Three-hundreds and 91 consecutive episodes of acute pancreatitis through the years 2008 to 2011.

MAIN OUTCOME MEASURES

Gender, age, body mass index, Charlson comorbidity index, history of pancreatitis, heart rate, blood pressure, plasma lipase, hematocrit, plasma creatinine, white blood cell count, rate of persistent organ failure and necrosis, maximum C-reactive protein, duration of hospitalization, mortality.

RESULTS

There were marked differences between the groups. Biliary etiology was associated with higher age and body weight, female predominance, higher plasma lipase, and a favourable outcome. Alcoholic etiology had male predominance, a tendency for initial hemoconcentration, a lower plasma lipase, and the highest rate of necrosis. Idiopathic etiology had the highest rate of persistent organ failure and the highest mortality.

CONCLUSIONS

Biliary, alcoholic and idiopathic acute pancreatitis should be treated as distinct entities. While alcoholic episodes have the highest risk of necrosis, the worst outcome was observed in the idiopathic group. Hence, finding no causality for an episode of acute pancreatitis after thorough investigation might be a predictor for poor outcome. Larger studies are warranted to confirm this.

Detrimental effect of high volume fluid administration in acute pancreatitis - a retrospective analysis of 391 patients

BACKGROUND

Early fluid resuscitation is recommended for the therapy of acute pancreatitis in order to prevent complications. There are, however, no convincing data supporting this approach.

METHODS

We reviewed 391 consecutive cases of confirmed acute pancreatitis. Admitting physicians had been advised to administer an aggressive fluid resuscitation in the early phase of disease, if possible. We tested whether disease severity according to the revised Atlanta Classification, local complications, and maximum C-reactive protein levels were predictable by the initial volume therapy in logistic and linear regression models, respectively. We also determined which parameters on admission encouraged a more aggressive fluid resuscitation.

RESULTS

The recorded fluid administered within the first 24 h was 5300 [3760; 7100] ml (median [1st; 3rd quartile]). More aggressive volume therapy was associated with disease severity and a higher rate of local complications. There was a linear relationship between administered volume and the maximum C-reactive protein. The amount of administered fluid was significantly attributed to age, hematocrit, and white blood cell count on admission. When adjusted for these parameters the impact of administered volume on outcome was still present but attenuated.

CONCLUSIONS

We found detrimental effects of fluid therapy on major outcome parameters throughout the whole range of administered volume. More volume was administered in younger patients and in patients with evidence of hemoconcentration and inflammation. The adverse effects of volume therapy persisted after elimination of these parameters. Caution should therefore be advised with regards to volume therapy in patients with acute pancreatitis.

Carboxypeptidase E modulates intestinal immune homeostasis and protects against experimental colitis in mice

Enteroendocrine cells (EEC) produce neuropeptides, which are crucially involved in the maintenance of the intestinal barrier. Hence, EEC dysfunction is suggested to be involved in the complex pathophysiology of inflammatory bowel disease (IBD), which is characterized by decreased intestinal barrier function. However, the underlying mechanisms for EEC dysfunction are not clear and suitable models for a better understanding are lacking. Here, we demonstrate that Carboxypeptidase E (CPE) is specifically expressed in EEC of the murine colon and ileum and that its deficiency is associated with reduced intestinal levels of Neuropeptide Y (NPY) and Peptide YY (PYY), which are both produced by EEC. Moreover, cpe^−/− mice exhibit an aggravated course of DSS-induced chronic colitis compared to wildtype littermates. In addition, we observed elevated mucosal IL-6 and KC transcript levels already at baseline conditions in cpe^−/− mice. Moreover, supernatants obtained from isolated intestinal crypts of cpe^−/− mice lead to increased IL-6 and KC expression in MODE-K cells in the presence of LPS. This effect was reversible by co-administration of recombinant NPY, suggesting a CPE mediated immunosuppressive effect in the intestines by influencing the processing of specific neuropeptides. In this context, the chemotaxis of bone marrow derived macrophages towards respective supernatants was enhanced. In conclusion, our data point to an anti-inflammatory role of CPE in the intestine by influencing local cytokine levels and thus regulating the migration of myeloid immune cells into the mucosa. These findings highlight the importance of EEC for intestinal homeostasis and propose EEC as potential therapeutic targets in IBD.

Mitochondrial gene polymorphisms that protect mice from colitis

BACKGROUND & AIMS

Dysregulated energy homeostasis in the intestinal mucosa frequently is observed in patients with ulcerative colitis (UC). Intestinal tissues from these patients have reduced activity of the mitochondrial oxidative phosphorylation (OXPHOS) complex, so mitochondrial dysfunction could contribute to the pathogenesis of UC. However, little is known about the mechanisms by which OXPHOS activity could be altered. We used conplastic mice, which have identical nuclear but different mitochondrial genomes, to investigate activities of the OXPHOS complex.

METHODS

Colitis was induced in C57BL/6J wild-type (B6.B6) and 3 strains of conplastic mice (B6.NZB, B6.NOD, and B6.AKR) by administration of dextran sodium sulfate or rectal application of trinitrobenzene sulfonate. Colon tissues were collected and analyzed by histopathology, immunohistochemical analysis, and immunoblot analysis; we also measured mucosal levels of adenosine triphosphate (ATP) and reactive oxygen species, OXPHOS complex activity, and epithelial cell proliferation and apoptosis.

RESULTS

We identified mice with increased mucosal OXPHOS complex activities and levels of ATP. These mice developed less-severe colitis after administration of dextran sodium sulfate or trinitrobenzene sulfonate than mice with lower mucosal levels of ATP. Colon tissues from these mice also had increased enterocyte proliferation and transcription factor nuclear factor-κB activity, which have been shown to protect the mucosal barrier-defects in these processes have been associated with inflammatory bowel disease.

CONCLUSIONS

Variants in mitochondrial DNA that increase mucosal levels of ATP protect mice from colitis. Increasing mitochondrial ATP synthesis in intestinal epithelial cells could be a therapeutic approach for UC.

Inflammatory bowel diseases influence major histocompatibility complex class I (MHC I) and II compartments in intestinal epithelial cells

Antigen presentation by intestinal epithelial cells (IEC) is crucial for intestinal homeostasis. Disturbances of major histocompatibility complex class I (MHC I)- and II-related presentation pathways in IEC appear to be involved in an altered activation of CD4(+) and CD8(+) T cells in inflammatory bowel disease. However, a comprehensive analysis of MHC I- and II-enriched compartments in IEC of the small and large bowel in the healthy state as opposed to inflammatory bowel diseases is lacking. The aim of this study was to characterize the subcellular expression of MHC I and II in the endocytic pathway of IEC throughout all parts of the intestinal tract, and to identify differences between the healthy state and inflammatory bowel diseases. Biopsies were taken by endoscopy from the duodenum, jejunum, ileum and colon in healthy individuals (n = 20). In Crohn's disease (CD), biopsies were obtained from the ileum and colon and within the colon from ulcerative colitis (UC) patients (n = 15). Analysis of IEC was performed by immunoelectron microscopy. MHC I and II were identified in early endosomes and multi-vesicular, multi-lamellar, electrondense and vacuolar late endosomes. Both molecules were enriched in multi-vesicular bodies. No differences were found between the distinct parts of the gut axis. In CD and UC the expression of MHC I and II showed a shift from multi-vesicular bodies towards the basolateral membranes. Within the multi-vesicular bodies, MHC I and II moved from internal vesicles to the limiting membranes upon inflammation in CD and UC. MHC I- and II-enriched compartments in IEC were identical in all parts of the small and large bowel. CD and UC appear to modulate the MHC I- and II-related presentation pathways of exogenous antigens in IEC.

The "North German Tumor Bank of Colorectal Cancer": status report after the first 2 years of support by the German Cancer Aid Foundation

PURPOSE

Research projects and clinical trials strongly rely on high-quality biospecimens which are provided by biobanks. Since differences in sample processing and storage can strongly affect the outcome of such studies, standardization between biobanks is necessary to guarantee reliable results of large, multicenter studies. The German Cancer Aid Foundation (Deutsche Krebshilfe e.V.) has therefore initiated the priority program "tumor tissue banks" in 2010 by funding four biobank networks focusing on central nervous system tumors, melanomas, breast carcinomas, and colorectal carcinomas. The latter one, the North German Tumor Bank of Colorectal Cancer (ColoNet) is managed by surgeons, pathologists, gastroenterologists, oncologists, scientists, and medical computer scientists.

METHODS AND RESULTS

The ColoNet consortium has developed and harmonized standard operating procedures concerning all biobanking aspects. Crucial steps for quality assurance have been implemented and resulted in certification according to DIN EN ISO 9001. A further achievement is the construction of a web-based database for exploring available samples. In addition, common scientific projects have been initiated. Thus, ColoNet's repository will be used for research projects in order to improve early diagnosis, therapy, follow-up, and prognosis of colorectal cancer patients. Apart from the routine sample storage at -170 °C, the tumor banks' unique characteristic is the participation of outpatient clinics and private practices to further expand the sample and clinical data collection.

CONCLUSION

The first 2 years of funding by the German Cancer Aid Foundation have already led to a closer scientific connection between the participating institutions and to a substantial collection of biospecimens obtained under highly standardized conditions.

Short-term efficacy of tacrolimus in steroid-refractory ulcerative colitis - experience in 130 patients

BACKGROUND

Steroid-refractory ulcerative colitis (UC) remains a challenging condition warranting surgery upon failure of pharmacological treatment. Calcineurin inhibitors or infliximab are alternatives in this situation. Data on the efficacy and safety of tacrolimus in this setting are limited.

AIM

To study the short-term efficacy and safety of tacrolimus in moderate-to-severe steroid-refractory UC. The role of thiopurines in this situation and predictors of colectomy were evaluated.

METHODS

In three centers, all charts from tacrolimus-treated patients with steroid-refractory UC were reviewed. Efficacy was assessed by colectomy-free survival and clinical remission at 3 months.

RESULTS

We identified 130 patients with pancolitis in 75 (59%), left-sided disease in 35 (27%) and proctitis in 18 patients (14%) (disease localisation not obtainable in two patients). The median age was 40 (range: 18-81). Clinical activity according to the median Lichtiger score decreased from 13 (range: 4-17) at baseline to 3 (0-14) at week 12. Eighteen patients underwent colectomy within the first 3 months of treatment with tacrolimus (14%). Clinical remission was achieved in 94 patients (72%) in this period. Thiopurines given in parallel to tacrolimus tended to limit colectomy and significantly increased remission (P = 0.002) in the short-term. No other predictors of colectomy or remission were identified. Side effects were noticed in 53% of patients and no severe events occurred.

CONCLUSION

This large survey confirms the efficacy and safety of tacrolimus in patients with steroid-refractory ulcerative colitis.

A novel multiplex-protein array for serum diagnostics of colon cancer: a case-control study

BACKGROUND

More than 1.2 million new cases of colorectal cancer are reported each year worldwide. Despite actual screening programs, about 50% of the patients are diagnosed at advanced tumor stages presenting poor prognosis. Innovative screening tools could aid the detection at early stages and allow curative treatment interventions.

METHODS

A nine target multiplex serum protein biochip was generated and evaluated using a training- and validation-set of 317 highly standardized, liquid nitrogen preserved serum samples comprising controls, adenomas, and colon cancers.

RESULTS

Serum levels of CEA, IL-8, VEGF, S100A11, MCSF, C3adesArg, CD26, and CRP showed significant differences between cases and controls. The largest areas under the receiver operating characteristics curve were observed for CEA, IL-8, and CRP. At threshold levels yielding 90% specificity, sensitivities for CEA, IL-8 and CRP were 26%, 22%, and 17%, respectively. The most promising marker combinations were CEA + IL-8 reaching 37% sensitivity at 83% specificity and CEA + CRP with 35% sensitivity at 81% specificity. In an independent validation set CEA + IL-8 reached 47% sensitivity at 86% specificity while CEA + CRP obtained 39% sensitivity at 86% specificity. Early carcinomas were detected with 33% sensitivity for CEA + IL-8 and 28% for CEA + CRP.

CONCLUSIONS

Apart from CEA, IL-8, and CRP, the screening value of additional blood markers and the potential advantage of combining serum biochip testing with fecal occult blood testing needs to be studied. Multiplex biochip array technology utilizing serum samples offers an innovative approach to colorectal cancer screening.

Validation of treatment strategies for enterohaemorrhagic Escherichia coli O104:H4 induced haemolytic uraemic syndrome: case-control study

OBJECTIVE

To evaluate the effect of different treatment strategies on enterohaemorrhagic Escherichia coli O104:H4 induced haemolytic uraemic syndrome.

DESIGN

Multicentre retrospective case-control study.

SETTING

23 hospitals in northern Germany.

PARTICIPANTS

298 adults with enterohaemorrhagic E coli induced haemolytic uraemic syndrome.

MAIN OUTCOME MEASURES

Dialysis, seizures, mechanical ventilation, abdominal surgery owing to perforation of the bowel or bowel necrosis, and death.

RESULTS

160 of the 298 patients (54%) temporarily required dialysis, with only three needing treatment long term. 37 patients (12%) had seizures, 54 (18%) required mechanical ventilation, and 12 (4%) died. No clear benefit was found from use of plasmapheresis or plasmapheresis with glucocorticoids. 67 of the patients were treated with eculizumab, a monoclonal antibody directed against the complement cascade. No short term benefit was detected that could be attributed to this treatment. 52 patients in one centre that used a strategy of aggressive treatment with combined antibiotics had fewer seizures (2% v 15%, P = 0.03), fewer deaths (0% v 5%, p = 0.029), required no abdominal surgery, and excreted E coli for a shorter duration.

CONCLUSIONS

Enterohaemorrhagic E coli induced haemolytic uraemic syndrome is a severe self limiting acute condition. Our findings question the benefit of eculizumab and of plasmapheresis with or without glucocorticoids. Patients with established haemolytic uraemic syndrome seemed to benefit from antibiotic treatment and this should be investigated in a controlled trial.

[CEUS as a tool to uncover an unusual cause of obstructive jaundice]

Aneurysms within the visceral arteries are rare. Among these, aneurysms of the splenic artery occur most frequently followed by aneurysms of the hepatic arteries. An early diagnosis is easily missed and almost all patients become symptomatic with an acute rupture associated with high mortality. Here we demonstrate the case of a 76-year-old patient who presented with acute upper abdominal pain accompanied by a single episode of vomiting and pyrexia of 39 °C. Laboratory results presented the picture of an obstructive jaundice without evidence for accompanying pancreatitis. Inflammatory markers were within normal limits at onset, but increased dramatically within the next few days. An acute calculous cholecystitis was diagnosed on abdominal ultrasound whereas gastroscopy revealed no relevant changes. Computed tomography was suspicious for pancreatitis of the head with obstruction of the bile duct. Choledocholithiasis was ruled out by ERCP, but symptoms persisted despite papillotomy. Due to raising inflammatory markers and an ongoing impairment of the patients condition, an abdominal CT scan was repeated which revealed the suspicion of a ruptured aneurysm of the common hepatic artery. At the time of transferral we were able to confirm the diagnosis by contrast-enhanced ultrasound and angiography. The patient was immediately forwarded to surgery due to lack of satisfactory endovascular procedures. In summary, the patient suffered from a ruptured spurial aneurysm of the right gastric artery thereby obstructing the common bile duct. Beside CT scans and angiography, this case documents a pivotal role for contrast-enhanced ultrasound in the work-up of visceral artery aneurysms.

Association between azithromycin therapy and duration of bacterial shedding among patients with Shiga toxin-producing enteroaggregative Escherichia coli O104:H4

CONTEXT

An outbreak of Shiga toxin-producing enteroaggregative Escherichia coli (STEC O104:H4) infection with a high incidence of hemolytic uremic syndrome (HUS) occurred in Germany in May 2011. Antibiotic treatment of STEC infection is discouraged because it might increase the risk of HUS development. However, antibiotic therapy is widely used to treat enteroaggregative E coli infection. In the German outbreak, a substantial number of patients received prophylactic azithromycin treatment as part of a therapeutic regimen with the C5 antibody eculizumab.

OBJECTIVE

To analyze the duration of bacterial shedding in patients with STEC infection who did and did not receive oral azithromycin therapy.

DESIGN, SETTING, AND PATIENTS

At a single center in Lübeck, Germany, 65 patients with STEC infection, including patients with HUS as well as STEC-infected outpatients without manifestation of HUS, were investigated between May 15 and July 26, 2011, and were monitored for a mean of 39.3 days after onset of clinical symptoms.

MAIN OUTCOME MEASURE

Carriage of STEC after azithromycin therapy.

RESULTS

Twenty-two patients received oral azithromycin and 43 patients did not receive antibiotic treatment. Among antibiotic-treated patients, long-term STEC carriage (>28 days) was observed in 1 of 22 patients (4.5%; 95% CI, 0%-13.3%) compared with 35 of 43 patients (81.4%; 95% CI, 69.8%-93.0%) who were not treated with antibiotics (P < .001). All 22 patients receiving azithromycin treatment had at least 3 STEC-negative stool specimens after the completion of treatment, and no recurrence of STEC was observed in these patients. As proof of principle, 15 patients who initially were not treated with antibiotics and were long-term STEC carriers were treated with oral azithromycin given for 3 days and subsequently had negative stool specimens.

CONCLUSION

Treatment with azithromycin was associated with a lower frequency of long-term STEC O104:H4 carriage.

Cyclophosphamide therapy in Sweet's syndrome complicating refractory Crohn's disease − Efficacy and mechanism of action

BACKGROUND

Sweet's syndrome is a rare extraintestinal manifestation of Crohn's disease that is usually treated by corticosteroids. Cyclophosphamide therapy has been shown to be effective in steroid-refractory Crohn's disease with extraintestinal manifestations. The mechanism of action remains obscure. Here, we report about a case of steroid-refractory Sweet's syndrome accompanying Crohn's colitis treated by cyclophosphamide.

METHODS

At baseline and two weeks after initiating cyclophosphamide pulse therapy, clinical symptoms were evaluated and apoptosis in mononuclear cells of the colon mucosa was quantified via immunofluorescence TUNEL-labeling. Ongoing clinical follow-up lasts for more than three years.

RESULTS

Cyclophosphamide pulse therapy resulted in complete resolution of luminal activity and extraintestinal manifestations. TUNEL-marked CD4(+), CD8(+) and CD68(+) cells in intestinal biopsies showed a 338% increase as compared to baseline.

CONCLUSIONS

Cyclophosphamide therapy was highly effective in steroid-refractory Crohn's colitis accompanied by Sweet's syndrome for induction of remission. Furthermore, apoptosis of mononuclear cells in the colon mucosa, including CD68(+) macrophages as well as CD4(+) and CD8(+) cells, appears to be a component of the anti-inflammatory effect of cyclophosphamide in Crohn's disease.

Infliximab as rescue medication for patients with severe ulcerative/indeterminate colitis refractory to tacrolimus

BACKGROUND

The calcineurin inhibitor tacrolimus and the anti-TNF-antibody infliximab are established options in steroid-refractory ulcerative colitis (UC).

AIM

To evaluate the efficacy of infliximab-salvage therapy in patients with refractory UC failing to respond to tacrolimus.

METHODS

Twenty-four patients were enrolled in this evaluation. Reasons for tacrolimus therapy were steroid-refractory disease in 19 patients and steroid-dependency in five patients. All patients receiving infliximab had tacrolimus-refractory active disease (Lichtiger score >10) and were treated with 5 mg/kg at weeks 0, 2 and 6 and every 8 weeks thereafter, if tolerated.

RESULTS

Six of 24 patients (25%) achieved remission following infliximab infusion and four of 24 (17%) had an initial response only, but underwent proctocolectomy later because of loss of response (3) or development of a delayed hypersensitivity reaction (1). Fourteen patients (58%) completely failed to respond with 10 undergoing colectomy. Eight patients experienced side effects under infliximab, including two infectious complications (herpes zoster and herpes pneumonia).

CONCLUSIONS

Infliximab offers a therapeutic option as rescue therapy in about a quarter of patients with active UC after failing to respond to tacrolimus. This benefit has to be weighed against the risks of infectious complications.

Endocytotic segregation of gliadin peptide 31-49 in enterocytes

OBJECTIVE

Coeliac disease (CD) is a multisystemic autoimmune inflammation of the intestinal tract induced by wheat gluten and related cereals in human leucocyte antigen (HLA)-DQ2/8-positive individuals. The molecular mechanisms relevant to oral tolerance induction towards toxic cereals such as gliadin remain poorly understood. Enterocytes, which express predominantly HLA-DR proteins, are capable of processing, transcytosing and presenting food antigens from the intestinal lumen to T lymphocytes of the lamina propria.

METHODS

Epitope-specific monoclonal antigliadin antibodies are utilised to unravel the intraepithelial transport processes of gliadin peptides in human duodenal biopsy specimens from patients with CD and reconstitute the transepithelial and endocytic pathways of gliadin in intestinal epithelial HT29 cells.

RESULTS

The gliadin peptide AA 31-49 is segregated from the peptides AA 56-68 and AA 229-246 along the endosomal pathway. Thus, AA 31-49 bypasses HLA-DR-positive late endosomes in intestinal cells and in biopsy specimens of patients with untreated CD. Further, it is localised in early endosomes and consequently escapes antigen presentation at the basolateral membrane, unlike peptides AA 56-68 and AA 229-246 that reach HLA-DR-positive late endosomes. Strikingly, forms of gliadin peptide AA 31-49 conjugated to cholera toxin B are sorted into late endosomes of HT29 cells.

CONCLUSIONS

Endocytic segregation of gliadin peptide AA 31-49 seems to be a constitutive process. It explains why this peptide cannot stimulate gluten-sensitive T cells. Presentation of gliadin peptides by HLA-DR proteins via late endosomes within enterocytes might induce a tolerogenic effect and constitutes a potentially promising therapeutic approach for induction of tolerance towards gliadin.

Crohn's targeted therapy: myth or real goal?

The broad spectrum of chronic inflammatory bowel diseases encompasses the two main entities Crohn's disease (CD) and ulcerative colitis (UC). Rapid action and long-term duration is the superordinate goal in most therapeutic approaches facing chronic inflammation including inflammatory bowel diseases (IBD) for induction and maintenance of remission. The availability of antibodies targeting TNF-alpha or alpha 4 integrin has recently offered new opportunities apart from classical remedies for the treatment of CD, a major challenge for future therapeutic concepts. Classical way of treating CD is an escalation scheme ("step-up") whereas the novel and still controverse approach ("top-down") favors a biological as initial drug. Today, four biologicals have proven efficacy and safety in CD treatment strategies and have received approval by FDA and, with the exception of natalizumab and certolizumab, by EMEA. Infliximab was the first TNF-alpha blocker and extended the care in CD. Adalimumab and certolizumab pegol followed as humanized second generation TNF-alpha blockers. Another targeted therapy option is natalizumab, an alpha 4 integrin monoclonal antibody, which blocks the migration of leukocytes into inflamed gut tissue. Nevertheless, a considerable number of patients remain refractory, lose response or render intolerant to these biologicals. An overall long lasting remission of less than 30% with scheduled administration of TNF-alpha blockers in patients with steroid dependent or refractory CD seems to be lifelike and alternative therapeutic options are warranted. Broad acting antimetabolites come into focus again and recent data provide substantial evidence for the efficacy and safety of cyclophosphamide pulse therapy in ileocolonic, refractory CD. This therapeutic option should be kept in mind as a reasonable agent to target the inflammatory process in severely disabled patients. Hence, targeted therapy in CD seems to be still a myth at present owing to the complex nature of disease.

The CD40-CD40L pathway contributes to the proinflammatory function of intestinal epithelial cells in inflammatory bowel disease

In inflammatory bowel diseases (IBD), intestinal epithelial cells (IECs) are involved in the outbalanced immune responses toward luminal antigens. However, the signals responsible for this proinflammatory capacity of IECs in IBD remain unclear. The CD40/CD40L interaction activates various pathways in immune and nonimmune cells related to inflammation and was shown to be critical for the development of IBD. Here we demonstrate CD40 expression within IECs during active IBD. Endoscopically obtained biopsies taken from Crohn's disease (n = 112) and ulcerative colitis patients (n = 67) consistently showed immunofluorescence staining for CD40 in IECs of inflamed ileal or colonic mucosa. In noninvolved mucosa during active disease, tissue obtained during Crohn's disease or ulcerative colitis in remission and biopsies from healthy controls (n = 38) IECs almost entirely lacked CD40 staining. Flow cytometry and RT-PCR analysis using different intestinal epithelial cell lines (HT29, SW480, and T84) showed IFN-gamma to effectively induce CD40 in IECs. Cells were virtually unresponsive to LPS or whole E. coli regarding CD40 expression. In addition, a moderate induction of CD40 was found in response to TNF-alpha, which exerted synergistical effects with IFN-gamma. CD40 ligation by CD40L-transfected murine fibroblasts or soluble CD40L increased the secretion of IL-8 in IFN-gamma pretreated HT29 cells. Our findings provide evidence for the epithelial expression and modulation of CD40 in IBD-affected mucosa and indicate its involvement in the proinflammatory function of IECs.

Cannabinoid type 1 receptor blockade induces transdifferentiation towards a brown fat phenotype in white adipocytes

AIM

The endocannabinoid (EC) system is a major component in the control of energy homeostasis. It mediates a positive energy balance via central and peripheral pathways. Blockade of the cannabinoid type 1 receptor induces weight reduction and improves cardiovascular risk factors in overweight patients. Cannabinoid receptor type 1 (CB1R)-deficient mice are resistant to diet-induced obesity. The mechanisms responsible for these effects remain only partially elucidated. We hypothesized peripheral effects via direct modulation of adipocyte function to be an integral part of EC action on energy metabolism and insulin sensitivity.

METHODS

SV40 immortalized murine white and brown adipocytes were used for all experiments. We investigated the effect of CB1R blockade by stimulating the cells acutely and chronically with rimonabant, a selective antagonist for the CB1R, or by knocking down the receptor with small interfering RNA (siRNA). Changes in thermogenic mRNA and protein expression as well as mitochondrial biogenesis and function were assessed by real-time RT-PCR, immunoblotting, fluorescent staining techniques, electron microscopy and by measuring oxygen consumption.

RESULTS

Acute and chronic blockade of the CB1R with the selective antagonist rimonabant or by siRNA in murine white adipocytes strongly induced the thermogenic uncoupling protein-1 (UCP-1). UCP-1 expression was increased in a time- and dose-dependent manner both at the RNA and protein level. Furthermore, this effect was paralleled by enhanced peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha) expression. In accordance with these findings, AMP-activated protein kinase (AMPK) phosphorylation was also increased after rimonabant treatment. Mitochondria-specific fluorescent staining demonstrated an augmentation in the number of mitochondria. This was confirmed by electron microscopy images. Moreover, rimonabant treatment enhanced the cytochrome c oxidase activity and increased cellular oxygen consumption.

CONCLUSIONS

Taken together, our data demonstrate that inhibition of peripheral CB1R action in adipocytes directly promotes transdifferentiation of white adipocytes into a mitochondria-rich, thermogenic brown fat phenotype. Enhanced thermogenesis and insulin sensitivity may represent a peripheral mechanism contributing to weight loss and improved glucose homeostasis in rimonabant-treated patients.

Clinical trial: cyclophosphamide pulse therapy - a promising therapeutic alternative in refractory Crohn's disease

BACKGROUND

In severe steroid-refractory Crohn's disease (CD), established therapies fail in a relevant proportion of patients. Recent pilot studies indicated the efficacy of cyclophosphamide pulse therapy in these patients.

AIM

To provide further and substantial evidence for the rationale to apply cyclophosphamide pulse therapy as therapeutic option in severe courses of CD.

METHODS

Fifteen patients with steroid-refractory (n = 13) or steroid-dependent (n = 2) CD received 2-6 (median 3) monthly pulses of 750 mg cyclophosphamide in an open-label fashion. Eleven patients were on concomitant immunosuppression (azathioprine/mercaptopurine n = 9; methotrexate n = 2).

RESULTS

Thirteen of 15 patients (87%) had a clinical response (CDAI decrease >100). Ten patients (67%) went into remission (CDAI <150) after 8 weeks. Steroid-free remission was achieved in eight patients (54%). Two patients (13%) failed to respond. Median CDAI decreased from 420 (245-550) to 100 (26-538) at week 8. Remission lasted 16 months (median, range 4-40). In three patients, arthritis, erythema nodosum and episcleritis completely resolved. Cyclophosphamide pulse therapy administration was well tolerated in all subjects.

CONCLUSIONS

Cyclophosphamide pulse therapy is safe and highly effective for induction and maintenance of remission in steroid-refractory/-dependent CD. There is a strong need for additional experience to improve the setting of the encouraging cyclophosphamide treatment in CD.

Multivesicular bodies in intestinal epithelial cells: responsible for MHC class II-restricted antigen processing and origin of exosomes

In normal conditions intestinal epithelial cells (IECs) constitutively stimulate regulatory CD4(+) T cells. However, in Crohn's disease (CD), this major histocompatibility complex (MHC) class II-restricted antigen presentation results in stimulation of proinflammatory CD4(+) T cells. We hypothesized that these alternative functions might be mediated by differential sorting and processing of antigens into distinct MHC II-enriched compartments (MIICs). Accordingly, we analysed the endocytic pathways of lumenally applied ovalbumin (OVA) in IECs of the jejunum and ileum of wild-type (WT) and TNFDeltaARE/WT mice that develop a CD-resembling ileitis. Using quantitative reverse transcription polymerase chain reaction, we found that messenger RNA levels of interferon-gamma, tumour necrosis factor-alpha, interleukin-17 and interleukin-10 were significantly up-regulated in the inflamed ileum of TNFDeltaARE/WT mice, confirming CD-like inflammation. Fluorescence and immunoelectron microscopy revealed the presence of MHC II and invariant chain throughout the late endocytic compartments, with most molecules concentrated in the multivesicular bodies (MVB). OVA was targeted into MVB and, in contrast to other MIICs, accumulated in these structures within 120 min of exposure. The IEC-specific A33 antigen localized to internal vesicles of MVB and A33/class II-bearing exosomes were identified in intercellular spaces. Remarkably, the expression pattern of MHC II/invariant chain molecules and the trafficking of OVA were independent of mucosal inflammation and the specific region in the small intestine. MVB seem to be principally responsible for class II-associated antigen processing in IECs and to constitute the origin of MHC II-loaded exosomes. The distinctive functions of IECs in antigen presentation to CD4(+) T cells might arise as a result of differential processing within the MVB identified here.

Luminal antigens access late endosomes of intestinal epithelial cells enriched in MHC I and MHC II molecules: in vivo study in Crohn's ileitis

In contrast to healthy conditions, intestinal epithelial cells (IECs) stimulate proinflammatory CD4+ and CD8+ T cells during Crohn's disease (CD). The underlying regulatory mechanisms remain unknown. Here we investigated the epithelial expression of major histocompatibility complex (MHC) I and MHC II and its interference with endocytic pathways, in vivo. During ileoscopy, ovalbumin (OVA) was sprayed onto ileal mucosa of CD patients (ileitis and remission) and controls. The epithelial traffic of OVA and MHC I/II pathways were studied in biopsies using fluorescence and electron microscopy. We found MHC I and MHC II to accumulate within multivesicular late endosomes (MVLE) of IECs. Faint labeling for these molecules was seen in early endosomes and lysosomes. MVLE were entered by OVA 10 min after exposure. Exosomes carrying MHC I, MHC II, and OVA were detected in intercellular spaces of the epithelium. OVA trafficking and labeling patterns for MHC I and MHC II in IECs showed no differences between CD patients and controls. Independent of inflammatory stimuli, MHC I and MHC II pathways intersect MVLE in IECs, which were efficiently targeted by luminal antigens. Similar to MHC II-enriched compartments in professional antigen presenting cells, these MVLE might be critically involved in MHC I- and MHC II-related antigen processing in IECs and the source of epithelial-released exosomes. The access of luminal antigens to MHC I in MVLE might indicate that the presentation of exogenous antigens by IECs must not be restricted to MHC II but might also occur as "cross-presentation" via MHC I to CD8+ T cells.

Germ-cell cluster formation in the telotrophic meroistic ovary of Tribolium castaneum (Coleoptera, Polyphaga, Tenebrionidae) and its implication on insect phylogeny

Tribolium castaneum has telotrophic meroistic ovarioles of the Polyphaga type. During larval stages, germ cells multiply in a first mitotic cycle forming many small, irregularly branched germ-cell clusters which colonize between the anterior and posterior somatic tissues in each ovariole. Because germ-cell multiplication is accompanied by cluster splitting, we assume a very low number of germ cells per ovariole at the beginning of ovariole development. In the late larval and early pupal stages, we found programmed cell death of germ-cell clusters that are located in anterior and middle regions of the ovarioles. Only those clusters survive that rest on posterior somatic tissue. The germ cells that are in direct contact with posterior somatic cells transform into morphologically distinct pro-oocytes. Intercellular bridges interconnecting pro-oocytes are located posteriorly and are filled with fusomes that regularly fuse to form polyfusomes. Intercellular bridges connecting pro-oocytes to pro-nurse cells are always positioned anteriorly and contain small fusomal plugs. During pupal stages, a second wave of metasynchronous mitoses is initiated by the pro-oocytes, leading to linear subclusters with few bifurcations. We assume that the pro-oocytes together with posterior somatic cells build the center of determination and differentiation of germ cells throughout the larval, pupal, and adult stages. The early developmental pattern of germ-cell multiplication is highly similar to the events known from the telotrophic ovary of the Sialis type. We conclude that among the common ancestors of Neuropterida and Coleoptera, a telotrophic meroistic ovary of the Sialis type evolved, which still exists in Sialidae, Raphidioptera, and a myxophagan Coleoptera family, the Hydroscaphidae. Consequently, the telotrophic ovary of the Polyphaga type evolved from the Sialis type.

Induction of Complement-Fixing Autoantibodies against Type VII Collagen Results in Subepidermal Blistering in Mice

Experimental models reproducing an autoimmune response resulting in skin blistering in immunocompetent animals are lacking. Epidermolysis bullosa acquisita (EBA) is a bullous skin disease caused by autoantibodies to type VII collagen. In this study, we describe an active disease model of EBA by immunizing mice of different strains with murine type VII collagen. All mice developed circulating IgG autoantibodies that recognized type VII collagen and bound to the lamina densa of the dermal-epidermal junction. Importantly, subepidermal blisters developed in 82% of SJL-1, 56% of BALB/c mice, and 45% of Fc gammaRIIb-deficient mice, but not in SKH-1 mice. In susceptible animals, deposits of IgG1, IgG2, and complement C3 were detected at the dermal-epidermal junction. In contrast, in the nondiseased mice, tissue-bound autoantibodies were predominantly of the IgG1 subclass and complement activation was weak or absent. This active disease model reproduces in mice the clinical, histopathological, and immunopathological findings in EBA patients. This robust experimental system should greatly facilitate further studies on the pathogenesis of EBA and the development of novel immunomodulatory therapies for this and other autoimmune diseases.

The larval development of the telotrophic meroistic ovary in the bug Dysdercus intermedius (Heteroptera, Pyrrhocoridae)

Bug ovaries are of the telotrophic meroistic type. Nurse cells are restricted to the anterior tropharium and are in syncytial connection with the oocytes via the acellular trophic core region into which cytoplasmic projections of oocytes and nurse cells open. The origin of intercellular connections in bug ovaries is not well understood. In order to elucidate the cellular processes underlying the emergence of the syncytium, we analysed the development of the ovary of Dysdercus intermedius throughout the five larval instars. Up to the third instar, the germ cell population of an ovariole anlage forms a single, tight rosette. In the center of the rosette, phosphotyrosine containing proteins and f-actin accumulate. This center is filled with fusomal cytoplasm and closely interdigitating cell membranes known as the membrane labyrinth. With the molt to the fourth instar germ cells enhance their mitotic activity considerably. As a rule, germ cells divide asynchronously. Simultaneously, the membrane labyrinth expands and establishes a central column within the growing tropharium. In the fifth instar the membrane labyrinth retracts to an apical position, where it is maintained even in ovarioles of adult females. The former membrane labyrinth in middle and posterior regions of the tropharium is replaced by the central core to which nurse cells and oocytes are syncytially connected. Germ cells in the most anterior part of the tropharium, i.e. those in close proximity to the membrane labyrinth remain proliferative. The posterior-most germ cells enter meiosis and become oocytes. The majority of the ovarioles' germ cells, located in between these two populations, endopolyploidize and function as nurse cells. We conclude that the extensive multiplication of germ cells and their syncytial assembly during larval development is achieved by incomplete cytokineses followed by massive membrane production. Membranes are degraded as soon as the trophic core develops. For comparative reasons, we also undertook a cursory examination of early germ cell development in Dysdercus intermedius males. All results were compatible with the known basic patterns of early insect spermatogenesis. Germ cells run through mitotic and meiotic divisions in synchronous clusters emerging from incomplete cytokineses. During the division phase, the germ cells of an individual cluster are connected by a polyfusome rich in f-actin.

Antigen targeting to MHC class II-enriched late endosomes in colonic epithelial cells: trafficking of luminal antigens studied in vivo in Crohn's colitis patients

In Crohn's disease (CD), colonic epithelial cells (CECs) are suggested to stimulate pro-inflammatory CD4+ T cells. However, the endocytic pathways of luminal antigens involved in underlying MHC class II presentation by CECs remain unknown. Our aim was to elucidate antigen trafficking and associated MHC class II expression in CECs of CD patients in vivo. In CD patients (Crohn's colitis and remission) and healthy controls undergoing colonoscopy, ovalbumin (OVA) was sprayed onto inflamed or healthy mucosa. The subcellular localization of OVA and MHC class II was visualized in biopsies taken from OVA-incubated mucosa using fluorescence and cryoelectron microscopy. Targeting of OVA into late endosomes of CECs was found in healthy (controls and CD in remission) and inflamed mucosa (Crohn's colitis). MHC class II expression in CECs was not detected in healthy mucosa but strongly up-regulated during CD inflammation. Induced MHC class II in CECs was predominantly seen at basolateral membranes and in late endosomes, which were efficiently accessed by internalized OVA. Our data provide in vivo evidence that the endocytic pathway of luminal antigens in CECs of Crohn's colitis patients intersects MHC class II-enriched late endosomes and support the postulated role of CECs in MHC class II-associated antigen presentation during CD.

The telotrophic ovary known from Neuropterida exists also in the myxophagan beetle Hydroscapha natans

The ovary structure of the myxophagan beetle, Hycdoscapha natans, was investigated by means of light and electron microscopy for the first time. Each of the two ovaries consists of three ovarioles, the functional units of insect oogenesis. The ovary type is telotrophic meroistic but differs strongly from the telotrophic ovary found among all polyphagous beetles investigated so far. All characters found here are typical of telotrophic ovaries of Sialidae and Raphidioptera. Both taxa belong to the Neuropterida. As in all telotrophic ovaries, all nurse cells are combined in an anterior chamber, the tropharium. The tropharium houses two subsets of germ cells: numerous nurse cell nuclei are combined in a central syncytium without any cell membranes in between, surrounded by a monolayer of single-germ cells, the tapetum cells. Each tapetum cell is connected to the central syncytium via an intercellular bridge. Tapetum cells of the posterior zone, which sufficiently contact prefollicular cells, are able to grow into the vitellarium and develop as oocytes. During previtellogenic and early vitellogenic growth, oocytes remain connected with the central syncytium of the tropharium via their anterior elongations, the nutritive cords. The morphological data are discussed in the light of those derived from ovaries of other Coleoptera and from the proposed sister group, the Neuropterida. The data strongly support a sister group relationship between Coleoptera and Neuropterida. Furthermore, several switches between polytrophic and telotrophic ovaries must have occurred during the radiation of ancient insect taxa.

Interferon-gamma mediates antigen trafficking to MHC class II-positive late endosomes of enterocytes

MHC class II-positive late endosomes of enterocytes are thought to be involved in antigen presentation to CD4(+) T cells. In contrast to enterocytes of BALB/c mice, severe combined immunodeficiency (SCID) enterocytes lack MHC class II expression and fail to transport internalized ovalbumin (OVA) into late endosomes. IFN-gamma is known to induce MHC class II in enterocytes and antigen targeting to late endosomes in macrophages. In this study, we investigated the influence of IFN-gamma and MHC class II on the processes of antigen traffic in enterocytes. Subcellular targeting of OVA and MHC class II expression within enterocytes were examined in SCID, IFN-gamma-treated SCID, BALB/c and C57BL/6 MHC class II knockout (KO) mice after a single feed with OVA. Sorting of OVA into late endosomes was found in enterocytes from BALB/c, C57BL/6 KO and IFN-gamma-stimulated SCID mice, but not from untreated SCID mice. MHC class II expression was restricted to enterocytes of IFN-gamma-treated SCID and BALB/c mice, present at basolateral membranes and within endosomal compartments. These enterocytes further revealed colocalization of class II antigens and OVA in endosomes. We suggest that antigen trafficking into late endosomes of enterocytes is mediated by IFN-gamma and occurs in the absence of MHC class II.

Morphology, ultrastructure, and germ cell cluster formation in ovarioles of aphids

The structure of aphid ovaries, including ovipare and virginopare morphs of five species, was investigated by light and electron microscopy. Aphids contain telotrophic meroistic ovarioles. The amount and distribution of cytoplasmic components of nurse cells, nutritive cords, and young oocytes are nearly identical to those known from scale insects and heteropterans. Each ovariole has a constant number of nurse cells and oocytes. In ovaries of ovipare morphs, the nurse cell nuclei enlarge by endomitosis (n = 2⁸ n-2¹⁰ n), whereas in virginopare morphs the nurse cell nuclei remain small (n = 2² n-2⁴ n). Furthermore, in virginoparae the previtellogenic growth of oocytes is highly reduced, and vitellogenesis and chorionogenesis are blocked totally. Embryogenesis starts immediately after the shortened previtellogenic growth. In each ovariole, all germ cell descendants belong to one germ cell cluster that follows the 2ⁿ rule. The cluster normally contains 2⁵ = (32) cells, but other mostly smaller numbers also occur. In contrast to polytrophic meroistic ovarioles, more than one cell of each cluster will develop into an oocyte. In Drepanosiphum platanoides, 16 (2^n-1 ) nurse cells and 16 (2^n-1 ) oocytes exist in each cluster, whereas, in Metopolophium dirhodum, 8 (2^n-2 ) oocytes and 24 (2^n-1 + 2^n-2 ) nurse cells are normally found. In many ovarioles of Macrosiphum rosae, 21 nurse cells nourish 11 oocytes. Models of germ cell cluster formation in aphid ovaries are discussed.

F-actin is a component of the karyosome in neuropteran oocyte nuclei

The principles underlying the assembly of intranuclear compartments are only beginning to be understood. The karyosome is an organelle typical of oocyte nuclei. It represents the tightly packed oocyte chromosomes, arrested at the diplotene of meiotic prophase. It has been known from several insect orders that a prominent capsule of unknown materials is built around the karyosome in the course of previtellogenesis and vitellogenesis. Here we show that F-actin, detected by dye-coupled phalloidin, is a major molecular component of the karyosome capsule in Neuroptera. We investigated capsule formation in six species belonging to the family Chrysopidae. Though F-actin was present in the capsules of all six species there were striking interspecific differences in the morphological array of actin filaments and the developmental dynamics of actin deposition in the capsule. The potential biological significance of the karyosome capsule is discussed with respect to the presence of extrachromosomal rDNA in neuropteran oocytes and the molecular functions known from F-actin. Our results corroborate the still controversial hypothesis of a role for actin as a nuclear protein.