A population physiologically-based pharmacokinetic model to characterize antibody disposition in pediatrics and evaluation of the model using infliximab

AIMS

In order to better predict the pharmacokinetics (PK) of antibodies in children, and to facilitate dose optimization of antibodies in paediatric patients, there is a need to develop systems PK models that integrate ontogeny-related changes in human physiological parameters.

METHODS

A population-based physiological-based PK (PBPK) model to characterize antibody PK in paediatrics has been developed, by incorporating age-related changes in body weight, organ weight, organ blood flow rate and interstitial volumes in a previously published platform model. The model was further used to perform Monte Carlo simulations to investigate clearance vs. age and dose-exposure relationships for infliximab.

RESULTS

By estimating only one parameter and associated interindividual variability, the model was able to characterize clinical PK of infliximab from two paediatric cohorts (n = 141, 4-19 years) reasonably well. Model simulations demonstrated that only 50% of children reached desired trough concentrations when receiving FDA-labelled dosing regimen for infliximab, suggesting that higher doses and/or more frequent dosing are needed to achieve target trough concentrations of this antibody.

CONCLUSION

The paediatric PBPK model presented here can serve as a framework to characterize the PK of antibodies in paediatric patients. The model can also be applied to other protein therapeutics to advance precision medicine paradigm and optimize antibody dosing regimens in children.

Enhancing IgG distribution to lung mucosal tissue improves protective effect of anti-Pseudomonas aeruginosa antibodies

IgG antibodies are abundantly present in the vasculature but to a much lesser extent in mucosal tissues. This contrasts with antibodies of the IgA and IgM isotype that are present at high concentration in mucosal secretions due to active delivery by the polymeric Ig receptor (pIgR). IgG is the preferred isotype for therapeutic mAb development due to its long serum half-life and robust Fc-mediated effector function, and it is utilized to treat a diverse array of diseases with antigen targets located in the vasculature, serosa, and mucosa. As therapeutic IgG antibodies targeting the luminal side of mucosal tissue lack an active transport delivery mechanism, we sought to generate IgG antibodies that could be transported via pIgR, similarly to dimeric IgA and pentameric IgM. We show that an anti-Pseudomonas aeruginosa IgG fused with pIgR-binding peptides gained the ability to transcytose and be secreted via pIgR. Consistent with these results, pIgR-binding IgG antibodies exhibit enhanced localization to the bronchoalveolar space when compared with the parental IgG antibody. Furthermore, pIgR-binding mAbs maintained Fc-mediated functional activity and promoted enhanced survival compared with the parental mAb in a P. aeruginosa acute pneumonia model. Our results suggest that increasing IgG accumulation at mucosal surfaces by pIgR-mediated active transport can improve the efficacy of therapeutic mAbs that act at these sites.

Current, experimental, and future treatments in inflammatory bowel disease: a clinical review

Inflammatory bowel diseases (IBDs) may result from dysregulated mucosal immune responses directed toward the resident intestinal microbiota. This review describes the hallmark immunobiology of Crohn's disease and ulcerative colitis as well as therapeutic targets and mechanisms of action for current, experimental, and future treatments in IBD. Conventional therapies include 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and methotrexate. Since 1997, monoclonal antibodies have gained widespread use. These consist of antibodies directed against pro-inflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-12, and IL-23, or anti-homing antibodies directed against α4β7 integrin. Emerging oral therapies include modulators of intracellular signal transduction such as Janus kinase inhibitors. Vitamin D may help to regulate innate and adaptive immune responses. Modulation of the intestinal microbiota, using live microorganisms (probiotics), substrates for the colonic microbiota (prebiotics), or fecal microbiota transplantation (FMT), is in development. Dietary supplements are in widespread use, but providing evidence for their benefit is challenging. Stem cell treatment and nervous stimulation are promising future treatments.

Effects of Anti-TNFα Treatment on Mucosal Expression of IL-17A, IL-21, and IL-22 and Cytokine-Producing T Cell Subsets in Crohn's Disease

T helper 17 (Th17) cells produce interleukin (IL) 17-A. In addition, Th17 cells produce IL-21 and IL-22. Th17 cells have a disease-promoting role in Crohn's disease (CD). We investigated the effects of anti-TNFα treatment on mucosal gene expression (qPCR) of IL-17A, IL-21, and IL-22 as well as on the frequency of lamina propria (LP) T cell subsets producing these cytokines (flow cytometry) in 12 active CD patients before and after 4 weeks of anti-TNFα treatment with adalimumab. At baseline, in inflamed mucosa we found increased gene expression of IL-17A and IL-22 but not IL-21 when compared to noninflamed mucosa. There were increased frequencies of IL-21-producing LP T cells but no differences in the frequencies of IL-17A- or IL-22-producing LP T cells when comparing inflamed versus noninflamed mucosa at baseline. There were no changes in the mucosal gene expression of IL-17A, IL-21, and IL-22 or the frequencies of IL-17A-, IL-21- and IL-22-producing LP T cell subsets between baseline and following 4 weeks of adalimumab initiation. Our results do not support the hypothesis that anti-TNFα treatment has an early effect on the mucosal levels of IL-17A, IL-21, and IL-22 or LP T cell production of these cytokines in CD.

Joint involvement in Mexican patients with ulcerative colitis: a hospital-based retrospective study

The most frequent extra-intestinal manifestation in ulcerative colitis (UC) around the world is joint involvement. There are no previous data in Latin America that is about this aspect of disease; hence, the aim of this study was to determine the frequency and factors associated to joint involvement in Mexican patients with UC. A total of 295 patients with histological diagnosis of UC were studied, divided into two groups: (1) 154 cases with at least one joint affection (arthralgia, peripheral, or axial arthropathy (sacroilitis (SI) or ankylosing spondylitis (AS))) and (2) 141 controls that had never presented any joint involvement during the clinical course of UC. Demographic, clinical, and laboratory variables were collected from the clinical records, at the time of presentation of the joint involvement for the cases and with the last information available for controls. A total of 52.2% of the patients had joint involvement, which was also the most frequent extra-intestinal manifestation (EIM). The frequency of peripheral arthralgia was 46.8% and of axial arthropathy was 5.4% (2.7% AS, 2.4% SI, and 0.3% both). The female gender (P = 0.01, OR = 3.061 95% CI: 1.311-7.15), elevated erythrocyte sedimentation rate (ESR) (P = 0.07, OR = 8.04 95% CI: 1.759-36.764), and moderate disease activity by Truelove and Witts criteria (P = 0.024, OR = 4.37 95% CI: 1.211-15.78) were factors associated at the time of presentation of the joint affection. Joint involvement is the most frequent EIM in Mexican patients with UC. The female gender, elevated ESR, and disease activity are factors associated with its presentation.

A native-like bispecific antibody suppresses the inflammatory cytokine response by simultaneously neutralizing tumor necrosis factor-alpha and interleukin-17A

Anti-tumor necrosis factor (TNF) therapies are successful in the treatment of inflammatory disorders. However, some patients with rheumatoid arthritis (RA) fail to response anti-TNF drugs due to the compensation of other inflammatory signals. In this study, to reduce compensatory responses of interleukin-17A (IL-17A) during TNF-α inhibition, we generated an IgG-like bispecific antibodiy (bsAb) against TNF-α and IL-17A through a combination method of electrostatic Fc pairing and light chain crossover. This bsAb exhibited relatively high stability comparable to natural IgG antibodies, and retained the unaltered affinities to both of two targets. BsAb significantly decreased not only the expression level of neutrophil or Th17 chemokines, but also the secretion of IL-6/IL-8 on fibroblast-like synoviocytes (FLS) from a patient with RA. Meanwhile, TNF-α-mediated cellular cytotoxicity of fibroblasts was neutralized by bsAb. Importantly, we demonstrate that the combined blockade of TNF-α and IL-17A is more efficient than inhibition of either factor alone. Our results suggest the IgG-like anti-TNF-α/IL-17A bispecific molecule overcome the limited therapeutic responses using anti-TNF drugs. It may be a promising therapeutic agent for the treatment of autoimmune diseases.

Reduced numbers of mucosal DR(int) macrophages and increased numbers of CD103(+) dendritic cells during anti-TNF-α treatment in patients with Crohn's disease

OBJECTIVE

Anti-TNF-α treatment constitutes a mainstay in the treatment of Crohn's disease (CD), but its mechanisms of action are not fully understood. We aimed to investigate the effects of adalimumab, a human monoclonal TNF-α antibody, on macrophage (MQ) and dendritic cell (DC) subsets in mucosal biopsies and peripheral blood.

MATERIAL AND METHODS

Intestinal biopsies and blood samples were obtained from 12 different CD patients both before and 4 weeks after the initiation of the induction of adalimumab treatment. Endoscopic disease activity was estimated by the Simple Endoscopic Score for Crohn's Disease. Biopsies were obtained from inflamed and non-inflamed areas. The numbers of lamina propria CD14 (+) DR(int) and CD14 (+) DR(hi) MQs, CD141(+), CD141(-) and CD103(+) DCs subsets, and circulating monocytes and DCs were analyzed using flow cytometry.

RESULTS

At baseline, we observed higher numbers of DR(int) MQs and lower numbers of CD103(+) DCs in inflamed versus non-inflamed mucosa [843 vs. 391/10(5) lamina propria mononuclear cells (LPMCs) (p < 0.05) and 9 vs. 19 × 10(5) LPMCs (p = 0.01), respectively]. After four weeks of adalimumab treatment, the numbers of DR(int) MQs decreased [843 to 379/10(5) LPMCs (p = 0.03)], whereas the numbers of CD103(+) DCs increased [9-20 × 10(5) LPMCs (p = 0.003)] compared with baseline. In peripheral blood, no alterations were observed in monocyte or DC numbers between baseline and week 4.

CONCLUSIONS

In CD, mucosal inflammation is associated with high numbers of DR(int) MQs and low numbers of CD103(+) DCs. This composition of intestinal myeloid subsets is reversed by anti-TNF-α treatment. These results suggest that DR(int) MQs play a pivotal role in CD inflammation.

Farewell to Animal Testing: Innovations on Human Intestinal Microphysiological Systems

The human intestine is a dynamic organ where the complex host-microbe interactions that orchestrate intestinal homeostasis occur. Major contributing factors associated with intestinal health and diseases include metabolically-active gut microbiota, intestinal epithelium, immune components, and rhythmical bowel movement known as peristalsis. Human intestinal disease models have been developed; however, a considerable number of existing models often fail to reproducibly predict human intestinal pathophysiology in response to biological and chemical perturbations or clinical interventions. Intestinal organoid models have provided promising cytodifferentiation and regeneration, but the lack of luminal flow and physical bowel movements seriously hamper mimicking complex host-microbe crosstalk. Here, we discuss recent advances of human intestinal microphysiological systems, such as the biomimetic human "Gut-on-a-Chip" that can employ key intestinal components, such as villus epithelium, gut microbiota, and immune components under peristalsis-like motions and flow, to reconstitute the transmural 3D lumen-capillary tissue interface. By encompassing cutting-edge tools in microfluidics, tissue engineering, and clinical microbiology, gut-on-a-chip has been leveraged not only to recapitulate organ-level intestinal functions, but also emulate the pathophysiology of intestinal disorders, such as chronic inflammation. Finally, we provide potential perspectives of the next generation microphysiological systems as a personalized platform to validate the efficacy, safety, metabolism, and therapeutic responses of new drug compounds in the preclinical stage.

Plasma-induced signatures reveal an extracellular milieu possessing an immunoregulatory bias in treatment-naive paediatric inflammatory bowel disease

The inflammatory state associated with Crohn's disease (CD) and ulcerative colitis (UC) remains incompletely defined. To understand more clearly the extracellular milieu associated with inflammatory bowel disease (IBD), we employed a bioassay whereby plasma of treatment naive paediatric IBD patients (n = 22 CD, n = 15 UC) and unrelated healthy controls (uHC, n = 10) were used to induce transcriptional responses in a healthy leucocyte population. After culture, gene expression was measured comprehensively with microarrays and analysed. Relative to uHC, plasma of CD and UC patients induced distinct responses consisting, respectively, of 985 and 895 regulated transcripts [|log2 ratio| ≥ 0·5 (1·4-fold); false discovery rates (FDR) ≤ 0·01]. The CD:uHC and UC:uHC signatures shared a non-random, commonly regulated, intersection of 656 transcripts (χ(2)  = P < 0·001) and were highly correlative [Pearson's correlation coefficient = 0·96, 95% confidence interval (CI) = 0.96, 0.97]. Despite sharing common genetic susceptibility loci, the IBD signature correlated negatively with that driven by plasma of type 1 diabetes (T1D) patients (Pearson's correlation coefficient = -0·51). Ontological analyses revealed the presence of an immunoregulatory plasma milieu in IBD, as transcripts for cytokines/chemokines, receptors and signalling molecules consistent with immune activation were under-expressed relative to uHC and T1D plasma. Multiplex enzyme-linked immunosorbent assay (ELISA) and receptor blockade studies confirmed transforming growth factor (TGF)-β and interleukin (IL)-10 as contributors to the IBD signature. Analysis of CD patient signatures detected a subset of transcripts associated with responsiveness to 6-mercaptopurine treatment. Through plasma-induced signature analysis, we have defined a unique, partially TGF-β/IL-10-dependent immunoregulatory signature associated with IBD that may prove useful in predicting therapeutic responsiveness.

Pharmacological treatment of spondyloarthritis: exploring the effectiveness of nonsteroidal anti-inflammatory drugs, traditional disease-modifying antirheumatic drugs and biological therapies

Spondyloarthritis represents a heterogeneous group of articular inflammatory diseases that share common genetic, clinical and radiological features. The therapy target of spondyloarthritis relies mainly in improving patients' quality of life, controlling articular inflammation, preventing the structural joints damage and preserving the functional abilities, autonomy and social participation of patients. Among these, traditional disease-modifying antirheumatic drugs have been demonstrated to be effective in the management of peripheral arthritis; moreover, in the last decade, biological therapies have improved the approach to spondyloarthritis. In patients with axial spondyloarthritis, tumor necrosis factor α inhibitors are currently the only effective therapy in patients for whom conventional therapy with nonsteroidal anti-inflammatory drugs has failed. The aim of this review is to summarize the current experience and evidence about the pharmacological approach in spondyloarthritis patients.

Systematic Review of the Clinical Disease Severity Indices for Inflammatory Bowel Disease

BACKGROUND

Clinical disease severity indices are increasingly being used in choosing treatment and monitoring the response of patients with inflammatory bowel disease (IBD). The aim of this study was to systematically review the clinical disease severity indices in IBD and to appraise their measurement properties and methodological quality.

METHODS

We searched the MEDLINE, Embase, and PsycINFO databases for original articles describing the development and/or evaluation of one or more of the measurement properties of clinical disease severity indices used in IBD. We assessed these properties (e.g., internal consistency, reliability, validity, responsiveness) using a standardized checklist.

RESULTS

We examined the full text of 142 articles that we deemed potentially eligible and identified 22 clinical disease severity indices in IBD. No clinical disease index has met all the required measurement properties. All of the validation studies were not descriptive enough to allow assessment of their methodology.

CONCLUSIONS

Although commonly used in multiple clinical trials, none of the clinical disease severity indices in IBD had all the required measurement properties. Further validation studies are required.

Products for the treatment of inflammatory bowel disease: a patent review (2013 - 2014)

INTRODUCTION

Inflammatory bowel disease (IBD) consists of Crohn's disease, ulcerative colitis and an unspecific IBD. The unclear etiology of IBD is a limiting factor that complicates the development of new pharmacological treatments and explains the high frequency of refractory patients to current drugs, including both conventional and biological therapies. In view of this, recent progress on the development of novel patented products to treat IBD was reviewed.

AREAS COVERED

Evaluation of the patent literature during the period 2013 - 2014 focused on chemical compounds, functional foods and biological therapy useful for the treatment of IBD.

EXPERT OPINION

Majority of the patents are not conclusive because they were based on data from unspecific methods not related to intestinal inflammation and, when related to IBD models, few biochemical and molecular evaluations that could be corroborating their use in human IBD were presented. On the other hand, methods and strategies using new formulations of conventional drugs, guanylyl cyclase C peptide agonists, compounds that influence anti-adhesion molecules, mAbs anti-type I interferons and anti-integrin, oligonucleotide antisense Smad7, growth factor neuregulin 4 and functional foods, particularly fermented wheat germ with Saccharomyces cerevisiae, are promising products for use in the very near future.

Identification of inflammatory mediators in patients with Crohn's disease unresponsive to anti-TNFα therapy

BACKGROUND

Anti-tumour necrosis factor α (TNFα) therapy effectively induces and maintains remission in Crohn's disease (CD). Up to 40% of patients, however, fail to respond to anti-TNFα.

OBJECTIVE

To identify the mechanisms underlying the persistence of mucosal lesions in patients who fail to respond to anti-TNFα therapy.

DESIGN

An observational study based on whole-genome transcriptional analysis was carried out using intestinal biopsy specimens from patients with CD receiving (n=12) or not (n=10) anti-TNFα therapy. The transcriptional signature of responders was compared with that of non-responders after anti-TNFα therapy. Controls with non-inflammatory bowel disease (non-IBD) (n=17) were used for comparisons. Genes of interest were validated by real-time RT-PCR in an independent cohort of patients with CD receiving (n=17) or not (n=16) anti-TNFα and non-IBD controls (n=7).

RESULTS

We confirmed that response to anti-TNFα is accompanied by significant regulation of a large number of genes, including IL1B, S100A8, CXCL1, which correlated with endoscopic activity. Remarkably, patients who failed to respond to anti-TNFα showed a mixed signature, maintaining increased expression of IL1B, IL17A and S100A8, while showing significant modulation of other genes commonly upregulated in active CD, including IL6 and IL23p19.

CONCLUSIONS

Our results show that anti-TNFα therapy significantly downregulates a subset of inflammatory genes even in patients who fail to achieve endoscopic remission, suggesting that these genes may not be dominant in driving inflammation in non-responders. On the other hand, we identified IL1B and IL17A as genes that remained altered in non-responders, pointing to potentially more relevant targets for modulating mucosal damage in refractory patients.

Soluble CD163, a specific macrophage activation marker, is decreased by anti-TNF-α antibody treatment in active inflammatory bowel disease

Activated macrophages shed the haemoglobin-haptoglobin scavenger receptor CD163 into the circulation as soluble(s)-CD163. We measured sCD163 as an in vivo macrophage activation marker in patients with Crohn's disease (CD) or ulcerative colitis (UC) receiving antitumour necrosis factor (TNF)-α antibody or prednisolone treatment. We also investigated the CD163 expression on circulating monocytes. 58 patients with CD, 40 patients with UC and 90 healthy controls (HC) were included. All patients had active disease at inclusion and were followed for 6 weeks of anti-TNF-α antibody or prednisolone treatment. We measured plasma sCD163 levels at baseline, 1 day, 1 week and 6 weeks after initiating treatment. CD163 expression on circulating CD14(+) monocytes was measured in 21 patients with CD receiving anti-TNF-α antibody treatment. Baseline sCD163 levels were elevated in patients with CD [1.99 (1.80-2.18) mg/l] and in patients with UC [2.07 (1.82-2.32) mg/l] compared with HC [1.51 (1.38-1.63) mg/l] (P < 0.001). Anti-TNF-α antibody treatment induced a rapid decrease in sCD163 levels in patients with CD and in patients with UC 1 day after treatment initiation (P < 0.05). One week of prednisolone treatment did not induce a reduction in sCD163 levels. Anti-TNF-α treatment normalized sCD163 levels in patients with UC, whereas patients with CD exhibited sustained increased sCD163 levels. In patients with CD, CD163 expression on CD14(+) monocytes was increased compared with HC. This study highlights that active CD and UC are associated with increased macrophage activation, as indicated by elevated sCD163 levels and monocytic CD163 expression. Anti-TNF-α antibody treatment induced a rapid decrease in sCD163 levels, suggesting a specific effect on macrophage activation in inflammatory bowel diseases.

Cytokines and chemokines: At the crossroads of cell signalling and inflammatory disease

Inflammation occurs as a result of exposure of tissues and organs to harmful stimuli such as microbial pathogens, irritants, or toxic cellular components. The primary physical manifestations of inflammation are redness, swelling, heat, pain, and loss of function to the affected area. These processes involve the major cells of the immune system, including monocytes, macrophages, neutrophils, basophils, dendritic cells, mast cells, T-cells, and B-cells. However, examination of a range of inflammatory lesions demonstrates the presence of specific leukocytes in any given lesion. That is, the inflammatory process is regulated in such a way as to ensure that the appropriate leukocytes are recruited. These events are in turn controlled by a host of extracellular molecular regulators, including members of the cytokine and chemokine families that mediate both immune cell recruitment and complex intracellular signalling control mechanisms that characterise inflammation. This review will focus on the role of the main cytokines, chemokines, and their receptors in the pathophysiology of auto-inflammatory disorders, pro-inflammatory disorders, and neurological disorders involving inflammation.

Biological therapies for spondyloarthritis

Biological therapies and new imaging techniques have changed the therapeutic and diagnostic approach to spondyloarthritis. In patients with axial spondyloarthritis, tumor necrosis factor α (TNFα) inhibitor treatment is currently the only effective therapy in patients for whom conventional therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) has failed. TNFα inhibitor treatment is more effective in preventing articular damage in peripheral joints than in axial ones. It is important to treat patients at an early stage of disease to reduce disease progression; moreover it is necessary to identify causes of therapy inefficacy in preventing joint damage in the axial subset.

Implementable strategies and exploratory considerations to reduce costs associated with anti-TNF therapy in inflammatory bowel disease

A health care system is needed where care is based on the best available evidence and is delivered reliably, efficiently, and less expensively (best care at lower cost). In gastroenterology, anti-tumor necrosis factor agents represent the most effective medical therapeutic option for patients with moderate-to-severe inflammatory bowel disease (IBD), but are very expensive and account for nearly a quarter of the cost of IBD care, representing a major area of present and future impact in direct health care costs. The ImproveCareNow Network, consisting of over 55 pediatric IBD centers, seeks ways to improve the value of care in IBD, curtailing unnecessary costs and promoting better health outcomes through systematic and incremental quality improvement initiatives. This report summarizes the key evidence to facilitate the cost-effective use of anti-tumor necrosis factor agents for patients with IBD. Our review outlines the scientific rationale for initiating cost-reducing measures in anti-tumor necrosis factor use and focuses on 3 implementable strategies and 4 exploratory considerations through practical clinical guidelines, as supported by existing evidence. Implementable strategies can be readily integrated into today's daily practice, whereas exploratory considerations can guide research to support future implementation.

Inflammatory bowel disease and demyelination: more than just a coincidence?

Infliximab and other anti-TNF-α agents have been implicated for drug-induced demyelination in patients with inflammatory bowel diseases (IBDs). We evaluated existing data from MEDLINE and EMBASE and conducted a narrative review to investigate further the aforementioned association. Our literature search highlighted 34 case reports, 3 case-control studies, 1 prospective and 7 retrospective cohort studies published in English. Available data suggest that IBD patients can manifest demyelinating events in both central and peripheral nervous system, however, they are still insufficient to conclude whether anti-TNF-α therapies are an independent risk factor for demyelination. Prospective cohort studies with internal control groups are needed to estimate the true incidence of demyelinating disorders in patients with IBD and to elucidate if anti-TNF-α therapy increases further the risk of demyelination.

Bacterial translocation - impact on the adipocyte compartment

Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn’s disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called “creeping fat.” The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system.

Cost-effectiveness of biological agents used in ulcerative colitis

Ulcerative colitis (UC) produces bloody diarrhoea, severe abdominal pain, and need for clinic visits, hospitalizations, and surgeries. UC results in reduced health-related quality of life for patients and large direct medical and indirect costs for health systems and employers. Patients with the most severe disease require the most medical services, and these patients have larger costs than patients with mild or moderate disease. Despite biological therapies being quite expensive, they are indicated for patients unresponsive to initial standard therapies. Future hospitalizations may be reduced by starting a biological treatment. Cost-effectiveness results vary between countries, health systems, and model designs. Since restorative proctocolectomy can be curative, this surgery dominates biological therapy by being both less costly and more effective when measuring health system costs and patient quality-adjusted life years for 20 years. However the dose, duration, and effectiveness of biological treatments significantly impact estimates of their cost-effectiveness.

Rheumatic manifestations in inflammatory bowel disease

Musculoskeletal symptoms (articular, periarticular and muscular involvement, osteoporosis and related fractures, and fibromyalgia) are the most common frequent extra-intestinal manifestations of inflammatory bowel disease (IBD) and affect 6-46% of patients. IBD-related arthropathy is one of a group of inflammatory arthritides known as seronegative spondyloarthropathies (SpA), which also includes idiopathic ankylosing spondylitis (AS), reactive arthritis, psoriatic arthritis, and undifferentiated SpA. The articular involvement in IBD significantly affects the patients' quality of the life. Although magnetic resonance imaging (MRI) is still the gold standard for assessing entheseal involvement, ultrasonography (US) is a non-invasive and easily reproducible means of detecting early pathological changes in SpA patients. It can identify characteristic features of SpA such as enthesitis, bone erosions, synovitis, bursitis, and tenosynovitis and is therefore helpful for diagnostic purposes. Anti-TNF drugs should be used to treat AS patients with axial and peripheral symptoms (arthritis and enthesitis) who have persistently high levels of disease activity despite conventional treatment, and adalimumab and infliximab can also be beneficially used in patients with IBD.