Nanotechnology in the treatment of inflammatory bowel diseases.

BACKGROUND AND AIMS: Treatment of inflammatory bowel diseases (IBD) is only aimed to block or inhibit the pathogenetic steps of the inflammatory cascade. Side effects of systemic therapies, poor targeting of orally administered topical drug and low adherence to prescription represent frequent therapeutic challenges. Recent observations suggest that nanotechnology could provide amazing advantage in this field since particles having dimension in the nanometer scale (nanoparticles) can modify pharmacokinetic step of biologic and conventional therapeutic agents with a better delivery of drugs within the intestinal inflammatory cells. The aim of this review was to provide the clinician with an insight into the potential role of nanotechnology in the treatment of IBD. METHODS: A systematic search (PubMed) for experimental studies on the treatment of intestinal inflammation using nanotechnology for the delivery of drugs. RESULTS AND CONCLUSIONS: The size of the pharmaceutical formulation is inversely related to specificity for inflammation. Nanoparticles can penetrate epithelial and inflammatory cells resulting in much higher, effective and long-acting concentrations than can be obtained using conventional delivery systems. From a practical point of view, this should lead to improvements in both efficacy and adherence to treatment, providing patients with the prospect of stable and prolonged remissions with reduced drug loadings. Reduced systemic side effects could also be expected.

Predictive factors of clinical response in steroid-refractory ulcerative colitis treated with granulocyte-monocyte apheresis.

AIM: To identify factors predicting the clinical response of ulcerative colitis patients to granulocyte-monocyte apheresis (GMA). METHODS: Sixty-nine ulcerative colitis patients (39 F, 30 M) dependent upon/refractory to steroids were treated with GMA. Steroid dependency, clinical activity index (CAI), C reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), values at baseline, use of immunosuppressant, duration of disease, and age and extent of disease were considered for statistical analysis as predictive factors of clinical response. Univariate and multivariate logistic regression models were used. RESULTS: In the univariate analysis, CAI (P = 0.039) and ESR (P = 0.017) levels at baseline were singled out as predictive of clinical remission. In the multivariate analysis steroid dependency [Odds ratio (OR) = 0.390, 95% Confidence interval (CI): 0.176-0.865, Wald 5.361, P = 0.0160] and low CAI levels at baseline (4 < CAI < 7) (OR = 0.770, 95% CI: 0.425-1.394, Wald 3.747, P = 0.028) proved to be effective as factors predicting clinical response. CONCLUSION: GMA may be a valid therapeutic option for steroid-dependent ulcerative colitis patients with mild-moderate disease and its clinical efficacy seems to persist for 12 mo.

Eating the enemy in Crohn's disease: an old theory revisited.

Several old and new observations suggest the existence in Crohn's disease of a phagocytic disorder of macrophages related to impaired bactericidal activity of host cells or to the presence of invasive bacteria that have developed strategies to counteract macrophage killing. It was recently reported that disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease. Secretion of proinflammatory cytokines by CD macrophages was impaired in response to E. coli or specific Toll-like receptor agonists. In addition, major advances in the etiology of Crohn's disease came from the existence of polymorphism in NOD2 and autophagy-related susceptibility genes (ATG16L1 and IRGM) in patients and from the identification of the presence of adherent-invasive E. coli (AIEC) colonizing the CD ileal mucosa and able to resist to macrophage killing. The role of impaired autophagy in Crohn's disease patients has been recently reinforced by the observation that the peptidoglycan receptor NOD2, in addition to sense intracellular bacteria, can induce autophagy by recruiting the critical autophagy protein ATG16L1 to the plasma membrane during bacterial internalization. Defects in autophagy might be the key element of the pathogenic pathway that lead to defective microbial killing, increased exposure to commensal and pathogenic intestinal bacteria and T cell activation. Defects in Paneth cells secreting lysozyme and antimicrobial peptides are observed in patients with ATG16L1 risk allele. Thus, the induction of autophagy or administration of preparations that mirrors the secretion of Paneth cells or both may be regarded as new therapeutic avenues for the treatment of Crohn's disease.

Advances in the pathogenesis of inflammatory bowel diseases: Capri 2010.

The 5th International Meeting of Inflammatory Bowel Diseases was held in Capri (Italy) at Gran Hotel Quisisana from April 8 to 10, 2010. The meeting was restricted to 130 participants including invited speakers, authors of selected papers and key opinion leaders. The structure of the meeting consisted of eight sessions covering selected basic aspects of inflammatory bowel disease, and were designed to be very interactive and more focused on basic science than purely clinical aspects.

IL-1beta-511 and IL-1RN*2 polymorphisms in inflammatory bowel disease: An Italian population study and meta-analysis of European studies.

BACKGROUND: Several studies have tried to find possible associations between genetic polymorphisms and inflammatory bowel disease prevalence and/or phenotype. Our objectives were to test the frequency and phenotypic association of two polymorphisms of the interleukin-1 pathway, IL-1beta-511 and IL-1RN*2, in inflammatory bowel disease patients and controls from an Italian population, and to compare our data with previously published similar studies in Europe. METHODS: We screened 290 inflammatory bowel disease patients (178 ulcerative colitis and 112 Crohn's disease) and 106 controls for IL-1beta-511 and IL-1RN*2 polymorphisms by polymerase chain reaction (PCR)-based methods. The prevalence of the IL-1beta-511 and IL-1RN*2 polymorphisms in European inflammatory bowel disease patients was calculated by a meta-analysis of previously published studies using the Mantel-Haenszel method. RESULTS: No correlation between the IL-1 polymorphisms and inflammatory bowel disease prevalence was found in our study population. Crohn's disease patients with the IL-1beta-511 mutation had a higher rate of complicated disease. A trend for an association between the IL-1RN*2 mutation and a higher risk for inflammatory bowel disease has been found only in studies with Northern European populations. CONCLUSIONS: The IL-1beta-511 mutation can be associated with complex disease behaviour in Italian Crohn's disease patients. The IL-1RN*2 mutation may play a role in Northern European people with inflammatory bowel disease.

The long journey of salicylates in ulcerative colitis: The past and the future.

The advent of salicylates in the treatment of ulcerative colitis started in 1938 with the discovery of Salazopyrin by Nanna Svartz. This drug offered for the first time a therapeutic chance to patients with ulcerative colitis. In this paper we describe the fascinating history of Salazopyrin and salicylates from the first serendipitous observations to the last randomized clinical trials. Attention was paid to the pharmacokinetics and the mechanism of action of 5-aminosalicylates and, in particular, to the issue of the mucosal concentrations of 5-aminosalicylates and its therapeutic efficacy. Moreover a look at the new oral mesalazine formulations that allow the homogenous distribution of 5-aminosalicylate through all the large bowel was taken. Lastly, the possible use of mesalazine in the prevention of colorectal cancer was reviewed.

Cytomegalovirus infection in inflammatory bowel disease patients undergoing anti-TNFalpha therapy.

BACKGROUND: Cytomegalovirus infection and disease is associated with poor prognosis and steroid refractoriness in inflammatory bowel disease patients. The unfavourable effect of steroids and immunosuppressive therapy on CMV infection is well known but few data are available concerning anti-TNFalpha therapy (Infliximab). Aim of the study was to evaluate the presence and severity of CMV infection and disease in Infliximab-treated IBD patients. PATIENTS AND METHODS: The severity of active CMV infection and disease was assessed in 11 consecutive patients with ileocolonic/colonic disease and 4 patients with ulcerative colitis before and after a standard 3-infusion course of Infliximab. Active CMV infection was evaluated by serology and diagnosed by means of pp65-antigenemia (pp65 AG), and quantification of CMV DNA isolated from biopsy specimens of colonic tissue. CMV disease was assessed on haematoxylin/eosin-stained colonic biopsies and immunohistochemical stains. RESULTS: Of the 11 patients, nine were CMV seropositive. As far as concerns CMV infection, only one patient had positive pp65 AG, before and after Infliximab. CMV DNA was detected in the colonic biopsies of three patients. In 2, CMV DNA persisted also after therapy with 410 and 1300 copies/microg of DNA, respectively, albeit with no evidence of worsening of the colonic disease. In the remaining patient, CMV DNA load became undetectable. Conventional histology and immunohistochemical stains were negative for CMV in all the patients, without evidence of CMV disease. CONCLUSIONS: Active CMV infection did not progress to disease following Infliximab therapy. Although these preliminary observations require confirmation, the response to Infliximab therapy does not appear to be influenced by, or influence the course of, CMV infection/disease.

Historical evolution of the management of severe ulcerative colitis.

Ulcerative colitis was first described in 1859, but it was not until the early 20th century that it became a well recognized clinical entity. The patients of the old series showed high mortality rate ranging from 30% in the severe forms to 60% in the fulminating forms. The introduction of corticosteroids in the 1950s dramatically improved the prognosis of patients with severe ulcerative colitis. The strategy based on intensive medical treatment, early detection of risk factors and early surgery progressively reduced the mortality rate to less than 1%. Tachycardia, fever, reduced number of intestinal sounds, hypoalbuminaemia, hypokalaemia metabolic alkalosis and elevated C-reactive protein were recognized to be the most useful risk factors. Plain abdominal X-ray remains the very reliable suitable tool to detect early complications of severe colitis. Once reduced the mortality near to zero, treatment has been addressed to avoid colectomy. Cyclosporine and Infliximab are currently used as rescue therapy, however, despite the high remission rates achieved with both drugs, about 50% of the treated patients ultimately will come to colectomy over the next few years.

Why does Crohn's disease usually occur in terminal ileum?

Crohn's disease can affect any part of the gastrointestinal tract, but terminal ileum is the most frequent localization. The reason why Crohn's disease is primarily located in the distal part of the ileum remains unexplained. In this article it has been attempted to provide a compelling explanation why Crohn's disease usually occurs in terminal ileum. Recent data indicate that some individuals are genetically predisposed to develop ileal Crohn's disease. Two genetic alterations, the polymorphism of Caspase Associated Recruitment Domain (CARD15) and Carcinoembryonic Antigen-related Cell Adhesion Molecule 6 (CEACM6), favour the colonization of terminal ileum by entero adherent-invasive Escherichia coli (AIEC). The adhesion of these bacteria to epithelial intestinal cells depends on Carcinoembryonic Antigen-related Cell Adhesion Molecule 6 expression in ileal epithelial cells and on the reduced ileal defensins expressed in a CARD15 dependent manner. Genetic defects in Authophagy-related 16-like gene (ATG16L1) and Immunity-related Guanosine Triphospatase (IRGM) recently found in ileal CD patients lead to a reduction of bacterial killing by macrophages and consequent continuous immunological upstimulation, cytokine secretion, chronic inflammation of the ileum and tissue injury. On the basis of all these data Crohn's disease of the ileum seems to be a subset of the disease mainly genetically determined.

Natalizumab in the treatment of Crohn's disease.

The pathogenesis of Crohn's disease (CD) is multifactorial and the activation of specific pathways of immunological system is important. In particular, the adhesion molecules (integrins) mediate the selective binding between the leukocytes and the endothelial cells regulating the migration of leukocytes into the normal and inflamed intestine. Selective adhesion molecule inhibitors interfere with the migration of leukocytes to the sites of inflammation by targeting adhesion molecules (alpha4-integrin or alpha4beta7-integrin). Natalizumab is a humanized IgG4 anti-alpha4-integrin monoclonal antibody that inhibits both alpha4beta7-integrin/mucosal addressin-cell adhesion molecule-1 (MadCAM-1) interaction and alpha4beta1/vascular-cell adhesion molecule-1 (VCAM-1) binding. Pooled data from the four studies, analyzed in a Cochrane review, suggest that natalizumab is effective for induction of clinical response and remission in patients with moderately to severely active CD. In particular, natalizumab may be beneficial for patients with active inflammation or chronically active disease despite the use of conventional therapies with high level of C-reactive protein values at baseline time. Nevertheless, many problems about the utilization of natalizumab in CD remain unsolved (such as the high placebo response, the final definition of dosage and timing schedule, the definition of outcomes and the development of adverse events).

Biological agents for ulcerative colitis: hypes and hopes.

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colonic mucosa. Over the last decade, the increasing knowledge on the pathogenic mechanisms underlying intestinal inflammation has led to the development of a number of biological agents, mainly addressed to molecules and/or pathways demonstrated to have a pathogenic role in UC. In UC, clinical course and therapeutic decisions mainly depend on disease activity and extent. While therapeutic approach to mild-to-moderate UC by using aminosalicylates and corticosteroids has been well established, treatment of severe UC is far from being satisfactory. A severe attack of UC remains a challenge to be managed jointly by gastroenterology, surgery, and intensive care units. However, the recent introduction of biological therapies has led to promising changes in the management of UC patients. Aim of this paper is to review the recent advances and future perspectives for the use of biological agents in UC.

Medical therapy for Crohn's disease: top-down or step-up?

The emergency of effective biological therapy in the treatment of Crohn's disease (CD) has led to a clinical debate about 'step-up versus top-down strategy'. Step-up refers to the classic therapeutic approach, namely progressive intensification of treatment as disease severity increases. Top-down refers to the early introduction, in all CD patients, of intensive therapies, including biological agents and immunosuppressive drugs, with the aim of avoiding complications and improving quality of life, starting from the assumption that these drugs may interfere with the natural history of the disease. Very recently the Belgian IBD research group together with the Gut Club of North Holland designed 'the Step Up versus Top Down Trial'. Combination of infliximab with immunosuppressives at onset was better than the current standard approach in terms of both induction and maintenance of remission. However, several observations still limit the use of infliximab as first-line treatment in adult CD patients. In particular, the epidemiological observation that over 50% of CD patients have a mild disease over time and will never require aggressive therapies is against the indiscriminate use of top-down strategy. Lack of markers able to identify high-risk patients, discussions about long-term safety and the high costs of infliximab are further factors supporting a more careful approach to the management of CD.