Immune response induced by coinfection of the sea louse Caligus rogercresseyi and the intracellular bacteria Piscirickettsia salmonis in vaccinated Atlantic salmon.

Recently, we showed that Atlantic salmon vaccinated against Piscirickettsia salmonis lose their protection upon coinfection with Caligus rogercresseyi (sea lice). However, the causes of the overriding effect of C. rogercresseyi infection have not been elucidated, and the molecular basis of the cellular and humoral immune responses upon C. rogercresseyi infection has not been described for vaccinated salmon. Therefore, we studied changes in the transcription of immune genes in vaccinated Atlantic salmon that were experimentally challenged by co-infecting them with C. rogercresseyi and P. salmonis. In general, coinfection treatments showed immune gene expression similar to treatments with a single P. salmonis infection, showing a decreased cellular response. However, a high variance was found between individual fish in the case of crucial cellular immune genes, with a few fish reacting overwhelmingly highly compared to the majority. This supports our previous findings on vaccination response variation and reinforces the idea that vaccination failures in the field might be caused by an overwhelming amount of vaccinated fish that display a deficient immune response to the infection.

Infliximab in inflammatory bowel disease. Is premedication necessary? / Infliximab en enfermedad inflamatoria intestinal. ¿Es necesario premedicar?

BACKGROUND: The use of infliximab (IFX) in inflammatory bowel disease (IBD) has been associated with a 1-6% risk of infusion reactions. The usefulness of premedication with corticosteroids, paracetamol and /or antihistamines is controversial. AIM: The aim of this study is to assess, in IBD patients on IFX, whether there are differences in secondary reactions to the infusion between those who use premedication or not. METHODS: A retrospective cohort study was performed identifying patients with a diagnosis of IBD who received IFX at our institution between January 2009 and July 2019. Acute reactions were defined as those that occurred in the first 24 hours postinfusion and late reactions for more than 24 hours. Infusion reactions were classified as mild, moderate and severe. Descriptive and association statistics were used (χ2; p < 0.05). RESULTS: Sixty-four patients were included with 1,263 infusions in total, 52% men. Median infusions per patient was 22 (2-66). All induction infusions were administered with premedication, and in maintenance in 57% of them. Premedication was given with hydrocortisone, chlorphenamine and paracetamol. Most of reactions were acute, mild or moderate in severity and no patient needed to discontinue IFX. In the maintenance group, there were 9/718 (1.2%) infusion reactions with premedication and 4/358 (1.1%) without it (p = 0.606). In the induction group, there were 8/187 (4.3%) infusion reactions, significantly higher when compared with both maintenance groups. CONCLUSIONS: In this group, premedication use during maintenance was not effective at reducing the rate of infusion reactions. These results suggest that premedication would not be necessary.

Pregnancy in Inflammatory Bowel Disease: Experience of a Chilean cohort. / Embarazo en enfermedad inflamatoria intestinal: experiencia en una cohorte chilena.

BACKGROUND: In inflammatory bowel disease (IBD) a high percentage of women are diagnosed during their reproductive age. IBD in remission is the ideal scenario when planning a pregnancy. AIMS: To describe the clinical characteristics of pregnancy/newborn and assess disease activity at the time of conception and throughout the pregnancy in patients with IBD treated at a tertiary centre in Chile. METHODS: We retrospectively reviewed women diagnosed with IBD who were pregnant or delivered between 2017 and 2020. Demographic, clinical, obstetric and delivery data were obtained from the IBD registry, approved by the local IRB. Descriptive statistics and association tests were performed (χ2, p ≤ 0.05). RESULTS: Sixty women with IBD were included. At the beginning of pregnancy, 21 (35%) had active disease and 39 (65%) were in remission. Of those with active disease, 16 (66%) remained active and 6 had spontaneous abortions. In those who were in remission, 26 (69%) remained in this condition. Nine patients (15%) discontinued treatment, and 6 of these had inflammatory activity during pregnancy. Preconception counselling was performed in 23 of the 60 patients, being higher in the group that remained in remission during pregnancy (65% vs. 35%, p = 0.02). Patients who had a flare during pregnancy had more probability of preterm birth (<37 weeks) and newborn with lower weight compared with the group that always remained in remission (89% vs. 74%, p = 0.161) and (2.885 vs 3.370 g; p = 0.0014). CONCLUSION: Remission presents better outcomes in pregnancy and preconception counselling would allow a better IBD control during pregnancy.

Are patients with inflammatory bowel disease receiving adequate immunisation? / ¿Están recibiendo los pacientes con enfermedad inflamatoria intestinal una adecuada inmunización?

INTRODUCTION: Inflammatory Bowel Disease (IBD) treatment may increase the risk of infections. Vaccines are part of the comprehensive IBD patient care. The aim of this study was to describe indications and adherence of immunizations in IBD and identify possible associated factors. METHODS: A cross-sectional, analytic study was conducted in patients from an IBD Program of a tertiary center in Chile, between April - June 2019. Patients were asked to answer a vaccine survey and information also was obtained from the National Immunization Registry. Descriptive and association statistic were used (χ2; p<0.05). RESULTS: A total of 243 patients were included (148 ulcerative colitis (UC), 86 Crohn's disease (CD) and 9 non-classifiable IBD). Only six patients (2%) of IBD patients received a complete immunization schedule. The highest vaccine rates were against influenza (67%), hepatitis B virus (40%), 13-valent pneumococcal (34%) and 23-polysaccharide pneumococcal (16%). The influenza vaccine rate has significantly increased, reaching 67% in 2019. The survey showed that 23% of patients have not been immunized with any vaccine, mainly due to lack of time, lack of medical prescription and high cost. CONCLUSIONS: In this cohort, although vaccination rates are higher than previously reported, adherence to IBD immunization program would be improved, being considered since diagnosis by the multidisciplinary team.

The Role of an Inflammatory Bowel Disease Nurse in the Follow-Up of Patients From a Latin American Inflammatory Bowel Disease Program.

Inflammatory bowel disease requires long-term treatment to maintain disease control. Favorable follow-up of patients indicates attention from a multidisciplinary team, in which the nurse's responsibilities have great importance. The aim of this observational, descriptive study was to describe the role of an inflammatory bowel disease nurse in the management of patients in a tertiary center in Chile, including all patients in follow-up between January 2016 and April 2017. Inflammatory bowel disease nurse contacts were recorded and classified. Demographic data, clinical variables, and patient satisfaction were also analyzed. A total of 597 patients (51%) were in follow-up over the 16-month period; 63% had ulcerative colitis, with a median age of 35 years. The inflammatory bowel disease nurse performed 760 contacts in 253 patients (42% of the follow-up patients). The most frequent nurse interventions were reinforcement of medical indications (42%), assessment of laboratory results (17%), and disease follow-up (12%); 49% related to education. Nurse interventions were focused in more severely ill patients; flares during the follow-up, biological therapy, immunomodulators, and steroids were all statistically significant. Of a sample of 107 patients surveyed, 96% perceived the inflammatory bowel disease program as excellent/good. The inflammatory bowel disease nurse plays an important role in the follow-up and management, specifically in education, of more severely ill patients.

[Environmental risk factors in the development and evolution of inflammatory bowel disease]. / Factores ambientales en el desarrollo y evolución de la enfermedad inflamatoria intestinal.

Environmental factors may influence the development of Inflammatory Bowel Disease and modify its natural history. The objective of this review is to evaluate current evidence about environmental factors associated with the disease. A better knowledge about the pathogenesis of the disease can lead to better treatment strategies and suggestions to prevent the disease.

Assessment of disease-related knowledge and possible factors associated with the knowledge level among Chilean patients with inflammatory bowel disease.

AIMS AND OBJECTIVES: To assess disease-related knowledge among patients with inflammatory bowel disease and to identify the factors that are possibly associated with the knowledge level. BACKGROUND: Disease-related knowledge can positively influence the acceptance of the disease, increase treatment compliance and improve the quality of life in patients with inflammatory bowel disease. DESIGN: An observational, cross-sectional study was conducted and prospectively included patients from the inflammatory bowel disease programme between October 2014-July 2015. METHODS: A Spanish-translated version of the 24-item Crohn's and Colitis Knowledge score was used to assess disease-related knowledge. Patients also completed a demographic and clinical questionnaire. RESULTS: A total of 203 patients were included, 62% were female, and 66% were diagnosed with ulcerative colitis; the median age was 34 years (range 18-79), and the median disease duration was four years. The median disease-related knowledge score was 9 (range 1-20). Only 29% of the patients answered more than 50% of the questions correctly. Lower disease-related knowledge was observed in questions related to pregnancy/fertility and surgery/complications. Patients older than 50 years, with ulcerative colitis, with disease durations less than five years and patients without histories of surgery exhibited lower disease-related knowledge. There was no association between the knowledge scores and the educational levels. CONCLUSIONS: The patients who attended our inflammatory bowel disease programme exhibited poor disease-related knowledge that was similar to the knowledge levels that have been observed in developed countries. It is necessary to assess patient knowledge to develop educational strategies and evaluate the influences of these strategies on patient compliance and quality of life. RELEVANCE TO CLINICAL PRACTICE: These results will allow the inflammatory bowel disease team to develop educational programmes that account for the disease-related knowledge of each patient. Inflammatory bowel disease nurses should evaluate their interventions to provide evidence that educating our patients contributes to improving their treatment outcomes and overall health statuses.

[Prognostic factors of ulcerative colitis at the moment of diagnosis]. / Factores pronósticos en colitis ulcerosa de reciente diagnóstico.

The clinical presentation of ulcerative colitis at the moment of diagnosis is variable, and its clinical course is difficult to predict. It can range from a quiescent to a refractory chronic course that may require hospitalization and surgical procedures. It can also have complications such as colorectal cancer. In this review we discuss the role of demographic, clinical, endoscopic, histological and associated factors, which can help to predict the clinical course of the disease at the moment of diagnosis, and to individualize therapy according to this clinical risk. Accurate identification of patients with a newly diagnosed ulcerative colitis who are at high risk of an unfavorable outcome is still a challenge. However, an effective evaluation allows an early diagnosis, a timely and effective treatment.

[Acute severe ulcerative colitis treated with accelerated infliximab induction. Case report]. / Terapia de inducción acelerada con infliximab en paciente con colitis ulcerosa grave refractaria a corticoides. Caso clínico.

Acute severe ulcerative colitis (ASUC) is a potentially life-threatening condition that requires early recognition, hospitalization and adequate treatment. Currently, the use of infliximab in ulcerative colitis (UC) is recommended in the case of severe disease refractory to corticosteroids, once that superimposed bacterial or viral infections (such as cytomegalovirus or Clostridium difficile) have been excluded. However, conventional weight-based regimens of infliximab might be insufficient for patients with ASUC. Accelerated infliximab induction regimen may increase its serum concentration levels and efficacy by reducing early colectomy rates in these patients. We report a 34 year old female presenting with an ASUC. She was initially treated with hydrocortisone 300 mg/day and mesalazine enemas 4 g/day with an unfavorable clinical response. At the fifth day of therapy, an accelerated induction therapy with infliximab was started in doses of 10 mg/kg at weeks 0, 1 and 4. After the second dose, there was a favorable response with reduction of abdominal pain, stool frequency and hematochezia. She was discharged with prednisone and azathioprine. After a year of starting infliximab, the patient remains in clinical remission.

[Natalizumab for the treatment of Crohn’s disease: Report of three cases]. / Experiencia local con natalizumab en pacientes con enfermedad de Crohn refractaria a anti-TNF: Casos clínicos.

Anti-tumor necrosis factor-α (TNF) agents have dramatically changed the management of Crohn’s Disease (CD). However, a significant number of these patients do not respond at all or cease to respond to antibodies against TNF. In this clinical situation, the options include intensification of anti-TNF therapy by either increasing the dose or by shortening the administration interval, the use of a second anti-TNF or medications with a different mechanism of action. Among the later, Natalizumab, a humanized IgG4 monoclonal antibody against α4ß1 and α4ß7 integrins, is safe and effective in inducing and maintaining remission in active CD patient’s refractory to anti-TNF. In spite of this, Natalizumab use has been limited because of an increased risk of progressive multifocal leukoencephalophaty which results from reactivation of the John Cunningham (JC) virus. However, the presence of antibodies against JC virus in serum can be used to reduce the risk for this complication. We report three patients with Crohn’s disease refractory to treatment with infliximab, who responded successfully to the use of Natalizumab.

[Presence of intracellular Escherichia coli in patients with inflammatory bowel disease]. / Presencia de Escherichia coli intracelular en mucosa intestinal de pacientes con Enfermedad Inflamatoria Intestinal y su asociación con características clínicas y el uso de corticosteroides.

BACKGROUND: Different strains of invasive Escherichia coli (E. coli), isolated from intestinal mucosa of patients, are related to the pathogenesis of inflammatory bowel diseases (IBD). AIM: To evaluate an association between intracellular E. coli and IBD; its clinical characteristics and use of steroids. MATERIAL AND METHODS: Sixty one patients with Crohn's disease and 83 with ulcerative colitis were studied. To determine the intracellular E. coli content, colonoscopy biopsies of these patients and 29 control subjects were processed using the gentamicin protection assay. Differences in the bacterial content between patient groups were evaluated using Mann-Whitney test, while the association between presence of E. coli with endoscopic activity, location/extension and use of corticosteroid as anti-inflammatory treatment were evaluated with Fisher's exact test or Chi-square test. RESULTS: E. coli strains were detected in 36.1, 39.3 and 10.3% of patients with ulcerative colitis, Crohn's disease and controls, respectively. The number of bacteria per biopsy in Crohn's disease and ulcerative colitis was significantly higher than in controls (p < 0.01 between patients and controls). In ulcerative colitis, significant associations were found between the presence of bacteria and disease location and use of corticosteroids. In Crohn's disease, no association was found. CONCLUSIONS: IBD are associated with the presence of intracellular E. coli strains in the intestinal mucosa, suggesting an alteration in the microbiota or loss of integrity of the epithelial barrier. The association of intracellular E. coli with clinical features and the use of corticosteroids in ulcerative colitis suggests that different factors could promote colonization or proliferation of these bacteria.

Impact of Smoking Cessation on the Clinical Course of Crohn's Disease Under Current Therapeutic Algorithms: A Multicenter Prospective Study.

OBJECTIVES: Given the importance of tobacco smoking (TS) as the only environmental factor repeatedly linked to the development of the Crohn's disease (CD), it is surprising that very few prospective studies have assessed whether TS is associated with an increased frequency of clinical relapse. Our aim was to evaluate the current impact of TS on disease relapse and the clinical benefit of quitting smoking in the present era of widespread use of anti-TNF drugs and immunosuppressants. METHODS: This was a multicenter prospective cohort study, which included 573 CD patients in clinical remission with various smoking habits. All smokers were advised to quit. Patients not exposed to tobacco before inclusion (non- and former smokers), continuing smokers, and quitters were compared regarding differences in disease outcomes during a follow-up of 4 years. RESULTS: A total of 148 continuing smokers, 190 nonsmokers, 160 former smokers, and 75 quitters were included. In comparison with nonsmokers, continuing smokers relapsed more frequently with an incidence rate ratio of 1.53 (95% confidence interval (CI): 1.10-2.17). Former smokers and quitters had similar relapse incidences compared with nonsmokers. Smoking was an independent predictor for disease relapse in the multivariate analysis (hazard ratio: 1.58 (95% CI 1.20-2.09). In the time-dependent analysis, continuing smokers had earlier relapse, regardless of anti-TNF or immunosuppressant use. CONCLUSIONS: Continuing smokers have more disease relapses, and patients who quit smoking have a similar relapse incidence compared with nonsmokers.

[Adverse events associated with the treatment of inflammatory bowel disease]. / Eventos adversos en la terapia farmacológica de la enfermedad inflamatoria intestinal.

BACKGROUND: The purpose of inflammatory bowel disease (IBD) treatment is to achieve resolution of symptoms and remission of disease with a minimum of adverse events (AE). AIM: To report AE of different prescriptions used for the treatment of IBD. MATERIAL AND METHODS: Analysis of a registry of patients with IBD held at a private clinic from 1976 to 2013. All used medications, the occurrence and severity of AE were recorded. RESULTS: The records of 346 patients aged 16 to 86 years, 74% with ulcerative colitis, were analyzed. The most commonly type of medications prescribed were 5-aminosalicylates (5-ASAs) in 329 patients (92%), followed by adrenal steroids in 218 (61%). Forty nine AE were recorded in the same number of patents (14%). These were more common in patients with Crohn disease (n = 19, 21%). An univariate analysis, demonstrated that extra-intestinal manifestations, hospitalizations secondary to IBD crisis, requirement of surgery and treatment with steroids, immunosuppressants or biologic agents were significantly associated with the presence of AE. AEs were more common with immunosuppressants, followed by 5-ASAs and steroids. Discontinuation of therapy was required in 79, 100 and 43% of patients taking these medications, respectively. Twenty percent of AEs were severe. Leukopenia and pancytopenia along with alopecia were the most common AEs attributable to azathioprine. CONCLUSIONS: The occurrence of AEs in patients with IBD is uncommon. Even inmunosuppressants or biologic agents have a low rate of AE and most of them mild.

[Development of malignant tumors in patients with inflammatory bowel disease]. / Desarrollo de neoplasia en pacientes con enfermedad inflamatoria intestinal.

BACKGROUND: The chronic inflammation of the intestinal mucosa, the extra-intestinal manifestations of the disease and the immunosuppressive treatment of inflammatory bowel disease may increase cancer risk. AIM: To report the demographic and clinical features of patients with IBD who developed a malignant tumor. MATERIAL AND METHODS: Retrospective analysis of an IBD patient registry of a private clinic, diagnosed between 1976 and 2014. RESULTS: 437 subjects were included, aged 15-88 years (58% women). Seventy two percent of patients had ulcerative colitis. The median time of follow up was 6 years. Ten patients (2.3%) developed a malignant tumor. In four, the tumor could be related to IBD (two colorectal cancers, one cholangiocarcinoma and one chronic myeloid leukemia (CML)). Two of 45 patients treated with biological therapy developed a tumor (CML and hypernephroma). Three of 170 patients on immunosuppressive treatment developed tumors. Only one had a tumor possibly related with the use of azathioprine (non-melanoma skin cancer). In only two patients, the treatment was changed at the time of their cancer diagnosis, from immunosuppressive medications to mesalamine. CONCLUSIONS: Only a small proportion of these patients with IBD developed a malignant tumor. The treatment of IBD has to be determined by the severity of the disease and not by the fear of developing a neoplasia. Following recommendations is fundamental to decrease the possibility of developing this complication.

[Inflammatory bowel disease. Experience in 316 patients]. / Enfermedad inflamatoria intestinal a partir de una experiencia local.

BACKGROUND: The incidence and prevalence of Inflammatory Bowel Disease (IBD) has increased. AIM: To determine demographic and clinical characteristics of patients with IBD in a Chilean private hospital. PATIENTS AND METHODS: Review of a prospective registry of patients with IBD, started on 2012. It includes clinical, imaging, endoscopical and pathological information of patients. RESULTS: Data of 316 patients with IBD, aged 16 to 86 years (56% females), were analyzed. Ulcerative Colitis (UC), Crohn´s and non-classifiable IBD were diagnosed in 230, 77 and 9 patients, respectively. The disease was diagnosed in 82% of patients in the period between 2002 and 2012. There was a peak in the diagnosis of both UC and CD between 20 and 39 years of age, without gender differences. The disease switched from UC to CD in six patients. In four, there was a change in disease behavior. Thirty eight patients were treated with biological therapy. The median lapse between the diagnosis and the use of biological therapy was 1 year in patients diagnosed after 2007, compared with 5.5 years among those patients diagnosed before 2007 (p = 0.001). There was a trend towards a higher requirement of surgery until 2006. Subsequently there was a stabilization of the requirement, concomitant with the incorporation of biological therapy. CONCLUSIONS: An adequate registry of IBD patients is necessary to improve demographic and clinical characteristics. A national registry is needed to assess the epidemiological changes of IBD in Chile.

Genetic factors conferring an increased susceptibility to develop Crohn's disease also influence disease phenotype: results from the IBDchip European Project.

OBJECTIVE: Through genome-wide association scans and meta-analyses thereof, over 70 genetic loci (Crohn's disease (CD) single nucleotide polymorphisms (SNPs)) are significantly associated with CD. We aimed to investigate the influence of CD-SNPs and basic patient characteristics on CD clinical course, and develop statistical models to predict CD clinical course. DESIGN: This retrospective study included 1528 patients with CD with more than 10 years of follow-up from eight European referral hospitals. CD outcomes of interest were ileal (L1), colonic (L2) and ileocolonic disease location (L3); stenosing (B2) or penetrating behaviour (B3); perianal disease; extraintestinal manifestations; and bowel resection. A complicated disease course was defined as stenosing or penetrating behaviour, perianal disease and/or bowel resection. Association between CD-SNPs or patient characteristics and specified outcomes was studied. RESULTS: Several CD-SNPs and clinical characteristics were statistically associated with outcomes of interest. The NOD2 gene was the most important genetic factor, being an independent predictive factor for ileal location (p=2.02 × 10(-06), OR=1.90), stenosing (p=3.16 × 10(-06), OR=1.82) and penetrating (p=1.26 × 10(-02), OR=1.25) CD behaviours, and need for surgery (p=2.28 × e-05, OR=1.73), and as such was also the strongest factor associated with a complicated disease course (p=6.86 × 10(-06), OR=2.96). Immunomodulator (azathioprine/6-mercaptopurine and methotrexate) use within 3 years after diagnosis led to a reduction in bowel stenoses (p=1.48 × 10(-06), OR=0.35) and surgical rate (p=1.71 × 10(-07), OR=0.34). Association between each outcome and genetic scores, created using significant SNPs in the univariate analysis, revealed large differences in the probability of developing fistulising disease (IL23R, LOC441108, PRDM1, NOD2; p=9.64e-4, HR=1.43), need for surgery (IRGM, TNFSF15, C13ORF31, NOD2; p=7.12 × 10(-03), HR=1.35), and stenosing disease (NOD2, JAK2, ATG16L1; p=3.01 × 10(-02), HR=1.29) among patients with low and high score. CONCLUSIONS: This large multicentre cohort study has found several genetic and clinical factors influencing the clinical course of CD. NOD2 and early immunomodulator use are the clinically most meaningful predictors for its clinical course.

Cellular and molecular mechanisms in the hypoxic tissue: role of HIF-1 and ROS.

Reactive oxygen species such as superoxide anion radicals (O2 (-) ) and hydrogen peroxide (H2 O2 ) have for long time been recognized as undesirable by-products of the oxidative mitochondrial generation of adenosine triphosphate (ATP). Recently, these highly reactive species have been associated to important signaling pathways in diverse physiological conditions such as those activated in hypoxic microenvironments. The molecular response to hypoxia requires fast-acting mechanisms acting within a wide range of partial pressures of oxygen (O2 ). Intracellular O2 sensing is an evolutionary preserved feature, and the best characterized molecular responses to hypoxia are mediated through transcriptional activation. The transcription factor, hypoxia-inducible factor 1 (HIF-1), is a critical mediator of these adaptive responses, and its activation by hypoxia involves O2 -dependent posttranslational modifications and nuclear translocation. Through the induction of the expression of its target genes, HIF-1 coordinately regulates tissue O2 supply and energetic metabolism. Other transcription factors such as nuclear factor κB are also redox sensitive and are activated in pro-oxidant and hypoxic conditions. The purpose of this review is to summarize new developments in HIF-mediated O2 sensing mechanisms and their interactions with reactive oxygen species-generating pathways in normal and abnormal physiology.