Marisa Iborra

MicroRNAs in autoimmunity and inflammatory bowel disease: Crucial regulators in immune response

MicroRNAs (miRNAs) have recently emerged as a new class of modulators of gene expression at the post-transcriptional level. The function of miRNA is the control of protein production by targeting mRNAs for translational repression or degradation. MiRNAs play a critical role in many biological processes such as cellular proliferation and maturation, apoptosis, regulation of chronic inflammation and development of cancer. It has recently been discovered that miRNAs are differentially expressed in autoimmune diseases (AID) and miRNA regulation may impact in the development or prevention of AID. In this paper we review the importance of miRNAs in AID in particular in inflammatory bowel disease (IBD). IBD is an AID whose pathophysiology remains uncertain. It is generally hypothesized that IBD is caused by the enteric microflora in genetically predisposed patients with an immune dysregulation in the gastrointestinal tract. Knowing the typical miRNA pattern of IBD will improve our knowledge of the pathogenesis of this disease and will lead to future well-focused projects to study the regulatory function of such miRNAs. Furthermore, it is possible that some miRNAs are specific to IBD and could serve as biomarkers with clinical applications for the diagnosis or assessment of disease activity.

Mitochondrial dysfunction, persistent oxidative damage, and catalase inhibition in immune cells of naïve and treated Crohn's disease

Background: Oxidative stress is considered a potential etiological factor for Crohns disease (CD). We characterized the reactive oxygen species (ROS) generated in immune peripheral cells of CD patients, as well as their antioxidant enzyme status and the presence of oxidative damage. In addition, mitochondrial function (&Dgr;&ggr;m) was analyzed to detect the possible origin of ROS. Methods: Cells were obtained from patients at the onset of disease, prior to any treatment. Experiments were repeated when patients were in clinical remission. A set of experiments was carried out in a group of CD patients in persistent morphological remission. Controls were healthy volunteers who were not receiving any treatment at the time. The generation of superoxide, hydrogen peroxide (H2O2) and nitric oxide, &Dgr;&ggr;m, superoxide dismutase (SOD) and catalase (CAT) activities, and concentrations of malondyaldehyde (MDA) and 8‐oxo‐deoxyguanosine (8‐oxo‐dG) were measured. Results: SOD activity and H2O2 production were significantly higher during active CD but returned to control levels in remission. &Dgr;&ggr;m was inhibited during active CD and, although it returned to control levels, its recovery took longer than clinical remission. CAT activity was permanently inhibited during CD, independent of the disease activity. MDA and 8‐oxo‐dG were permanently elevated. Conclusions: Oxidative stress during active CD depends on H2O2 production. The inhibition of &Dgr;&ggr;m suggests that this organelle is a source of ROS. CAT is permanently inhibited in CD, the biological significance of which is under study. The persistent oxidative damage detected may have implications for the evolution of the disease. Inflamm Bowel Dis 2010

Adalimumab in prevention of postoperative recurrence of Crohn's disease in high-risk patients

AIM To evaluate the effectiveness of adalimumab in preventing recurrence after intestinal resection for Crohns disease in high-risk patients. METHODS A multicenter, prospective, observational study was conducted from June 2009 until June 2010. We consecutively included high-risk Crohns disease patients who had undergone an ileal/ileocolonic resection. High-risk patients were defined as two or more criteria: smokers, penetrating pattern, one or more previous surgical resections or prior extensive resection. Subcutaneous adalimumab was administered 2 wk (± 5 d) after surgery at a dose of 40 mg eow, with an initial induction dose of 160/80 mg at weeks 0 and 2. Demographic data, previous and concomitant treatments (antibiotics, 5-aminosalicylates, corticosteroids, immunomodulators or biologic therapies), smoking status at the time of diagnosis and after the index operation and number of previous resections (type and reason for surgery) were all recorded. Biological status was assessed with C-reactive protein, erythrocyte sedimentation rate and fecal calprotectin. One year (± 3 mo) after surgery, an ileocolonoscopy and/or magnetic resonance enterography was performed. Endoscopic recurrence was defined as Rutgeerts score ≥ i2. Morphological recurrence was based on magnetic resonance (MR) score ≥ MR1. RESULTS Twenty-nine patients (55.2% males, 48.3% smokers at diagnosis and 13.8% after the index operation), mean age 42.3 years and mean duration of the disease 13.8 years were included in the study. A mean of 1.76 (range: 1-4) resections previous to adalimumab administration and in 37.9% was considered extensive resection. 51.7% had previously received infliximab. Immunomodulators were given concomitantly to 17.2% of patients. Four of the 29 (13.7%) developed clinical recurrence, 6/29 (20.7%) endoscopic recurrence and 7/19 (36.8%) morphological recurrence after 1-year. All patients with clinical recurrence showed endoscopic and morphological recurrence. A high degree of concordance was found between clinical-endoscopic recurrence (κ = 0.76, P < 0.001) and clinical-morphological recurrence (κ = 0.63, P = 0.003). Correlation between endoscopic and radiological findings was good (comparing the 5-point Rutgeerts score with the 4-point MR score, a score of i4 was classified as MR3, i3 as MR2, and i2-i1 as MR1) (P < 0.001, r(s) = 0.825). During follow-up, five (17.2%) patients needed adalimumab dose intensification (40 mg/wk); Mean time to intensification after the introduction of adalimumab treatment was 8 mo (range: 5 to 11 mo). In three cases (10.3%), a biological change was needed due to a worsening of the disease after the dose intensification to 40 mg/wk. One patient suffered an adverse event. CONCLUSION Adalimumab seems to be effective and safe in preventing postoperative recurrence in a selected group of patients who had undergone an intestinal resection for their CD.

Role of oxidative stress and antioxidant enzymes in Crohn's disease.

There is increasing interest in oxidative stress being a potential aetiological factor and/or a triggering factor in Crohns disease, rather than a concomitant occurrence during the pathogenesis of the disease. Recent research has shown that the immune mononuclear cells of Crohns disease patients are induced to produce hydrogen peroxide (H2O2). Similarly, the regulation of antioxidant enzymes during disease in these cells has been unravelled, showing that SOD (superoxide dismutase) activity and GPx (glutathione peroxidase) activity is increased during active disease and returns to normal in remission phases. However, catalase remains constantly inhibited which supports the idea that catalase is not a redox-sensitive enzyme, but a regulator of cellular processes. ROS (reactive oxygen species) can be produced under the stimulus of different cytokines such as TNFα (tumour necrosis factor α). It has been shown in different experimental models that they are also able to regulate apoptosis and other cellular processes. The status of oxidative stress elements in Crohns disease and their possible implications in regulating cellular processes are reviewed in the present paper.

Infliximab and adalimumab-induced psoriasis in Crohn's disease: a paradoxical side effect.

Treatment with antitumor necrosis factor-alpha (anti-TNF-α) offers a significant improvement in several immune-based diseases, including Crohns disease (CD) and psoriasis. Different cutaneous side effects have been described for anti-TNF-α therapy such as psoriasis. Previous reports showed that inhibition of TNF-α can induce over expression of cutaneous IFN-α, which in turn caused a predisposition to psoriasis. We report a 31-year-old woman with extensive CD and perianal lesions, without response to conventional treatment. She paradoxically developed a cutaneous eruption with psoriasiform morphology and distribution during treatment with both anti-TNF-α approved in Europe for CD, infliximab and adalimumab. These lesions cleared after topical application of corticosteroids and cessation of the anti-TNF-α treatment. Due to uneffectiveness of pharmacological treatment on disease, the patient had to undergo surgery. TNF-induced psoriasis in patients with CD is rare and has been previously documented with infliximab or adalimumab. The reason for this apparently paradoxical effect of the therapy is still unclear. This is the first case of psoriasis induced first by infliximab and later by adalimumab in the same CD patient. We would like to review and to draw attention about psoriasis as a cutaneous side effect with anti-TNF-α treatments.

Assessing an Improved Protocol for Plasma microRNA Extraction

The first step in biomarkers discovery is to identify the best protocols for their purification and analysis. This issue is critical when considering peripheral blood samples (plasma and serum) that are clinically interesting but meet several methodological problems, mainly complexity and low biomarker concentration. Analysis of small molecules, such as circulating microRNAs, should overcome these disadvantages. The present study describes an optimal RNA extraction method of microRNAs from human plasma samples. Different reagents and commercially available kits have been analyzed, identifying also the best pre-analytical conditions for plasma isolation. Between all of them, the column-based approaches were shown to be the most effective. In this context, miRNeasy Serum/Plasma Kit (from Qiagen) rendered more concentrated RNA, that was better suited for microarrays studies and did not require extra purification steps for sample concentration and purification than phenol based extraction methods. We also present evidences that the addition of low doses of an RNA carrier before starting the extraction process improves microRNA purification while an already published carrier dose can result in significant bias over microRNA profiles. Quality controls for best protocol selection were developed by spectrophotometry measurement of contaminants and microfluidics electrophoresis (Agilent 2100 Bioanalyzer) for RNA integrity. Selected donor and patient plasma samples and matched biopsies were tested by Affymetrix microarray technology to compare differentially expressed microRNAs. In summary, this study defines an optimized protocol for microRNA purification from human blood samples, increasing the performance of assays and shedding light over the best way to discover and use these biomarkers in clinical practice.

Fecal Calprotectin in Ileal Crohn's Disease: Relationship with Magnetic Resonance Enterography and a Pathology Score.

Background:Magnetic resonance enterography (MRE) is an effective method of assessing small bowel Crohns disease (CD). Fecal calprotectin (FC) correlates well with endoscopic disease activity. We aimed to evaluate the correlation between FC and disease activity according to MRE and surgical pathology in small bowel CD. Methods:One hundred twenty consecutive patients with ileal CD who underwent MRE assessment were included. Clinical data, C-reactive protein and FC, radiological and histological variables were obtained. Clinical activity was evaluated by the Harvey–Bradshaw Index and FC by enzyme-linked immunosorbent assay. MRE activity was assessed by means of the Magnetic Resonance Index of Activity score. Chioreans score was used to grade pathological inflammation in surgical specimens. Results:Seventy-five patients (62.5%) were in clinical remission (Harvey–Bradshaw Index < 5) and 45 (37.5%) had active disease (Harvey–Bradshaw Index ≥ 5). The Magnetic Resonance Index of Activity score was significantly associated with FC levels (P < 0.01), with a moderate overall correlation (Spearmans r = 0.56, P < 0.001). FC reflected MRE inflammatory activity with an area under the receiver operating characteristic curve of 0.914 (confidence interval, 0.849–0.958; P < 0.001). A cutoff value of 166.50 &mgr;g/g had 90% sensitivity, 74% specificity, 89% positive predictive value, and 76% negative predictive value for diagnosis of inflammation. Twenty-eight of 120 patients were operated. Surgical pathology showed a good agreement with FC for moderate (P = 0.03) and severe (P = 0.01) Chioreans index. No relationship was detected for C-reactive protein. Conclusions:FC correlates with the degree of MRE inflammatory activity and with surgical pathology damage in ileal CD. Thus, FC could be a surrogate marker of disease control used to select patients for MRE assessment and therapeutic adjustment.

Incidence, Clinical Characteristics, and Management of Psoriasis Induced by Anti-TNF Therapy in Patients with Inflammatory Bowel Disease: A Nationwide Cohort Study

Background:Psoriasis induced by anti–tumor necrosis factor-&agr; (TNF) therapy has been described as a paradoxical side effect. Aim:To determine the incidence, clinical characteristics, and management of psoriasis induced by anti-TNF therapy in a large nationwide cohort of inflammatory bowel disease patients. Methods:Patients with inflammatory bowel disease were identified from the Spanish prospectively maintained Estudio Nacional en Enfermedad Inflamatoria Intestinal sobre Determinantes genéticos y Ambientales registry of Grupo Español de Trabajo en Enfermedad de Croh y Colitis Ulcerosa. Patients who developed psoriasis by anti-TNF drugs were the cases, whereas patients treated with anti-TNFs without psoriasis were controls. Cox regression analysis was performed to identify predictive factors. Results:Anti-TNF–induced psoriasis was reported in 125 of 7415 patients treated with anti-TNFs (1.7%; 95% CI, 1.4–2). The incidence rate of psoriasis is 0.5% (95% CI, 0.4–0.6) per patient-year. In the multivariate analysis, the female sex (HR 1.9; 95% CI, 1.3–2.9) and being a smoker/former smoker (HR 2.1; 95% CI, 1.4–3.3) were associated with an increased risk of psoriasis. The age at start of anti-TNF therapy, type of inflammatory bowel disease, Montreal Classification, and first anti-TNF drug used were not associated with the risk of psoriasis. Topical steroids were the most frequent treatment (70%), achieving clinical response in 78% of patients. Patients switching to another anti-TNF agent resulted in 60% presenting recurrence of psoriasis. In 45 patients (37%), the anti-TNF therapy had to be definitely withdrawn. Conclusions:The incidence rate of psoriasis induced by anti-TNF therapy is higher in women and in smokers/former smokers. In most patients, skin lesions were controlled with topical steroids. More than half of patients switching to another anti-TNF agent had recurrence of psoriasis. In most patients, the anti-TNF therapy could be maintained.

The effects of thiopurine therapy on health-related quality of life in Inflammatory Bowel Disease patients

BackgroundThe effect of thiopurine immunomodulators on health-related quality of life (HRQoL) in patients with inflammatory bowel disease (IBD) has been controversial. The aims were to evaluate the HRQoL in patients with IBD treated with thiopurines and assess the short- and long-term impacts of the treatment on HRQoL.MethodsNinety-two consecutive patients who started treatment with thiopurines were prospectively included. Evaluation of HRQoL was performed at months 0, 6, and 12 using two questionnaires, the Short-Form Health Survey (SF-36) and the Inflammatory Bowel Disease Questionnaire (IBDQ).ResultsBaseline score of IBDQ was 4,6, range (2,31-6,84), with an impairment of the five dimensions of HRQoL compared with inactive patients. Results obtained in 8 dimensions of SF-36 showed worse HRQoL than Spanish general population. At 6 months patients had a significant improvement in overall IBDQ score -5,8 (1,58 -6,97)- and also in all IBDQ dimensions. All the 8 dimensions of SF-36 obtained a significant improvement. At twelve months score of IBDQ was 6,1, range (2,7-6,98), with improvement in all dimensions compared with baseline and 6 months. SF-36 showed a similar significant improvement in all subscales.ConclusionsThiopurine immunomodulators alone or with other treatments have a positive and long lasting impact on HRQoL of IBD patients.

Erratum to: Effectiveness of adalimumab for the treatment of ulcerative colitis in clinical practice: comparison between anti-tumour necrosis factor-naïve and non-naïve patients

Background Ulcerative colitis (UC) treatment is focused to achieve mucosal healing, avoiding disease progression. The study aimed to evaluate the real-world effectiveness of adalimumab (ADA) in UC and to identify predictors of remission to ADA.