Pain and inflammatory bowel disease

Role of TRPV1 and TRPA1 in visceral hypersensitivity to colorectal distension during experimental colitis in rats

The aim of the present study is to investigate the effects of TRPV1 and TRPA1 receptor antagonists and their synergism on the visceromotor responses during experimental colitis in rats. Colitis was induced in rats by a TNBS/ethanol enema at day 0 and was assessed at day 3 using endoscopy, histology and a myeloperoxidase assay. The visceromotor response to colorectal distension (10-80 mmHg) was evaluated in conscious rats before (control condition) and 3 days after 2,4,6-trinitrobenzene sulfonic acid (TNBS) administration (colitis condition). At day 3, visceromotor responses were assessed before and after treatment with a TRPV1 (BCTC) or TRPA1 (TCS-5861528) receptor antagonist either alone or in combination and either after intraperitoneal or intrathecal administration. Endoscopy, microscopy and myeloperoxidase activity indicated severe colonic tissue damage 3 days after TNBS administration. Colorectal distension-evoked visceromotor responses demonstrated a 2.9-fold increase during acute colitis (day 3) compared to control conditions. Intraperitoneal and intrathecal administration of BCTC or TCS-5861528 partially reversed the colitis-induced increase in visceromotor responses compared to control conditions (P<0.05). Intraperitoneal blockade of TRPA1 plus TRPV1 further decreased the enhanced visceromotor responses at high distension pressures (40-80 mmHg) compared to blockade of either TRPV1 or TRPA1 alone. This synergistic effect was not seen after combined intrathecal blockade of TRPA1 plus TRPV1. The present study demonstrates that in the rat, TRPV1 and TRPA1 play a pivotal role in visceral hypersensitivity at the peripheral and spinal cord level during acute TNBS colitis. Target interaction, however, is presumably mediated via a peripheral site of action.

Abdominal pain and health related quality of life in pediatric inflammatory bowel disease

OBJECTIVE

To summarize rates of abdominal pain in pediatric inflammatory bowel disease, and to examine associations of abdominal pain, disease activity, and health-related quality of life (HRQoL).

METHODS

44 youths aged 11-18 years completed ratings of abdominal pain, whereas youths and mothers provided ratings of HRQoL at Time 1 (T1) and Time 2 (T2; 6 months later). Disease activity was rated by physicians at T1.

RESULTS

At T1, 55% of participants reported pain in the past week, with most in clinical remission. Approximately one-third reported abdominal pain at neither (absent), either (transient), or both (chronic) T1 and T2, respectively. T1 abdominal pain did not contribute significant variance to T1 HRQoL beyond disease activity. However, pain group uniquely predicted T2 HRQoL, with chronic abdominal pain associated with lower HRQoL.

CONCLUSIONS

Abdominal pain is prevalent in pediatric inflammatory bowel disease, even during clinical remission. Interventions to address abdominal pain also may enhance HRQoL.

Pain management in patients with inflammatory bowel disease: insights for the clinician

Abdominal pain is a common symptom in patients with inflammatory bowel disease (IBD) and has a profound negative impact on patients' lives. There are growing data suggesting that pain is variably related to the degree of active inflammation. Given the multifactorial etiologies underlying the pain, the treatment of abdominal pain in the IBD population is best accomplished by individualized plans. This review covers four clinically relevant categories of abdominal pain in patients with IBD, namely, inflammation, surgical complications, bacterial overgrowth, and neurobiological processes and how pain management can be addressed in each of these cases. The role of genetic factors, psychological factors, and psychosocial stress in pain perception and treatment will also be addressed. Lastly, psychosocial, pharmacological, and procedural pain management techniques will be discussed. An extensive review of the existing literature reveals a paucity of data regarding pain management specific to IBD. In addition, there is growing consensus suggesting a spectrum between IBD and irritable bowel syndrome (IBS) symptoms. Thus, this review for adult and pediatric clinicians also incorporates the literature for the treatment of functional abdominal pain and the clinical consensus from IBD and IBS experts on pharmacological, behavioral, and procedural methods to treat abdominal pain in this population.

Identification of areas of functioning and disability addressed in inflammatory bowel disease-specific patient reported outcome measures

BACKGROUND AND AIMS

Patient-reported outcome measures (PROMs) make it possible to assess health-status problems from the perspective of persons suffering from a disease. The objective of the paper is to examine and compare the contents of PROMs related to IBD based on the World Health Organization's International Classification of Functioning, Disability and Health (ICF) as the frame of reference.

METHODS

A systematic literature review (1999-2009) in the databases Medline, EMBASE, PsycINFO, CINAHL and CENTRAL was performed to select IBD-specific PROMs. Abstracts and full-text articles were checked applying predefined eligibility criteria; IBD-specific PROMs were identified. The contents of the identified PROMs were examined by linking the items to ICF categories. The linked ICF categories of the PROMs were then compared.

RESULTS

The review resulted in the selection of eight IBD-specific PROMs (e.g., Cleveland Global Quality of Life, Inflammatory Bowel Disease Quality of Life Questionnaire, Inflammatory Bowel Disease Questionnaire-32, Rating Form of IBD Patient Concerns, Short Inflammatory Bowel Disease Questionnaire). In total, 129 items were identified, the majority of which (n=90; 69.8%) could be linked to specific ICF categories. None of the linked categories were contained in all PROMs. The most frequently identified categories were 'b1300 Energy level', 'b5254 Flatulence', 'd910 Community life' and 'd920 Recreation and leisure'.

CONCLUSION

The present study provides an overview of IBD-specific PROMs and their items. The results of the content comparison provide valuable information to facilitate and account for the selection of appropriate PROMs for different purposes of data collection in clinical and research settings.

Pain and opioid use in chronic pancreatitis

OBJECTIVE

Opioid therapy for pain in chronic pancreatitis (CP) is associated with tolerance and possibly opioid-induced hyperalgesia. We thus examined opioid use and pain rating in CP patients.

METHODS

Medical records of patients with established CP treated at the University of Pittsburgh Medical Center's Digestive Disorders Center between April 2008 and December 2009 were retrospectively reviewed.

RESULTS

Two hundred nineteen unique patients (53% men; age, 50 ± 1 years) were identified. At least moderate pain was initially present in 37% of the patients. Half (51%) of the patients received opioids (average morphine equivalent, 78.1 ± 12.4 mg/d). Pain severity correlated with age (r = -0.22), history of alcohol abuse (r = 0.14), affective spectrum disorders (r = 0.14), presence of coexisting pain syndromes (r = 0.24), opioid use (r = 0.49), and days with concerns about physical (r = 0.55) or mental problems (r = 0.35). In contrast, computed tomography-defined pancreatic abnormalities (calcification, pseudocysts, ductal stones, or dilation) did not correlate with pain rating. Regression analysis identified age, days with physical problems, and a coexisting chronic pain syndrome as best independent predictors of pain.

CONCLUSIONS

Chronic pancreatitis etiology, especially alcohol use, and psychosocial factors are important determinants of pain severity in CP. Successful management thus needs to go beyond treatment of changes in pancreatic morphology to effectively improve quality of life and utilization of medical resources.

Acute experimental endotoxemia induces visceral hypersensitivity and altered pain evaluation in healthy humans

Growing evidence suggests that systemic immune activation plays a role in the pathophysiology of pain in functional bowel disorders. By implementing a randomized crossover study with an injection of endotoxin or saline, we aimed to test the hypothesis that endotoxin-induced systemic inflammation increases visceral pain sensitivity in humans. Eleven healthy men (mean ± standard error of the mean age 26.6 ± 1.1 years) received an intravenous injection of either lipopolysaccharide (LPS; 0.4 ng/kg) or saline on 2 otherwise identical study days. Blood samples were collected 15 min before and 1, 2, 3, 4, and 6h after injection to characterize changes in immune parameters including proinflammatory cytokines. Rectal sensory and pain thresholds and subjective pain ratings were assessed with barostat rectal distensions 2h after injection. LPS administration induced an acute inflammatory response indicated by transient increases in tumor necrosis factor alpha, interleukin 6, and body temperature (all P<.001). The LPS-induced immune activation increased sensitivity to rectal distensions as reflected by significantly decreased visceral sensory and pain thresholds (both P<.05) compared to saline control. Visceral stimuli were rated as more unpleasant (P<.05) and inducing increased urge to defecate (P<.01). Pain thresholds correlated with interleukin 6 at +1h (r=0.60, P<.05) and +3h (r=0.67, P<.05) within the LPS condition. This report is novel in that it demonstrates that a transient systemic immune activation results in decreased visceral sensory and pain thresholds and altered subjective pain ratings. Our results support the relevance of inflammatory processes in the pathophysiology of visceral hyperalgesia and underscore the need for studies to further elucidate immune-to-brain communication pathways in gastrointestinal disorders.

Managing pain in inflammatory bowel disease

Pain is a common complaint in inflammatory bowel disease, and it has significant consequences for patients' quality of life. A thorough evaluation to determine the source of patients' pain should include clinical, laboratory, radiologic, and endoscopic assessments as indicated. Differentiating among active inflammation, secondary complications, and functional pain can be complicated. Even when all active disease is adequately treated, clinicians are often left with the difficulty of managing chronic pain. This paper will review the benefits and limitations of several commonly used treatments and promising future therapies. A suggested treatment algorithm will provide some guidance in this challenging area of inflammatory bowel disease management.

Brain functional changes in patients with ulcerative colitis: a functional magnetic resonance imaging study on emotional processing

BACKGROUND

Ulcerative colitis (UC) is associated with psychological stress and poor emotional functioning. The neural emotional processing involves the complex integration of several cortical and subcortical brain structures. The amygdala plays a fundamental role in the neural processing of emotional stimuli and is a core structure of the brain-gut axis (BGA) that represents the anatomo-functional substrate for the bidirectional influences between emotions and gastrointestinal functions. The aim of this study was to investigate the brain emotional processing in UC patients compared to healthy people.

METHODS

Ten UC patients in remission and 10 matched healthy controls underwent a functional magnetic resonance imaging (fMRI) scan while performing a task involving emotional visual stimuli. A set of negative, positive, and neutral pictures were used to study brain-related emotional responses.

RESULTS

A significantly reduced blood oxygen level-dependent (BOLD) signal in UC patients relative to controls was found in the amygdala, thalamic regions, and cerebellar areas (P < 0.05 corrected for multiple comparisons). The group-related differences were detected in the brain activity in response to positive emotional stimuli.

CONCLUSIONS

UC is associated with an emotional dysfunction characterized by decreased sensitivity to emotions with a positive content. The previous intestinal inflammatory activity in UC patients might have contributed to determine the functional changes of the amygdala that we found. On the other hand, the dysfunction of the amygdala may influence the course of the disease.

Enteric nervous system in the small intestine: pathophysiology and clinical implications

The digestive system is endowed with its own, local nervous system, referred to as the enteric nervous system (ENS). Given the varied functions of small intestine, its ENS has developed individualized characteristics relating to motility, secretion, digestion, and inflammation. The ENS regulates the major enteric processes such as immune response, detecting nutrients, motility, microvascular circulation, intestinal barrier function, and epithelial secretion of fluids, ions, and bioactive peptides. Remarkable progress has been made in understanding the signaling pathways in this complex system and how they work. In this article, we focus on recent advances that have led to new insights into small intestinal ENS function and the development of new therapies.

Qualidade de vida de pacientes portadores de doença inflamatória intestinal

OBJETIVOS: Avaliar a qualidade de vida (QV) de portadores de doenças inflamatórias intestinais (DII) e relacionar dados sociodemográficos e mórbidos à QV. MÉTODOS: Estudo transversal, realizado com 103 portadores de DII, cadastrados na farmácia de alto custo de Cuiabá - Mato Grosso que responderam ao Prontuário-Padrão, ao questionário de QV geral SF36 e ao específico IBDQ. RESULTADOS: Dentre os 103 pacientes com DII, 62 tinham retocolite ulcerativa idiopática e 41 doença de Crohn; 62% eram mulheres; 69,9%, casados; 48,5%, pardos; 49,5%, fumantes, 37,9% necessitaram de cirurgia e 40,8% apresentavam doença em atividade. Foi observada alteração significativa da QV em homens, fumantes e entre aqueles com doença em atividade. CONCLUSÃO: DII afetam a QV em diversos aspectos. Medidas para manutenção da QV, suporte psicológico, social e educacional devem ser considerados para portadores de DII.

Chronic fatigue is associated with impaired health-related quality of life in inflammatory bowel disease

BACKGROUND

Fatigue is reported to reduce health-related quality of life (HRQOL) in chronic diseases. Studies on the importance of fatigue and its implications for the patient's HRQOL in inflammatory bowel disease (IBD) remain scarce and need to be explored.

AIM

To investigate the influence of chronic fatigue on both generic and disease-specific HRQOL in IBD.

METHODS

Patients in remission, with mild and moderate IBD completed the Fatigue Questionnaire, the Short-Form 36 (SF-36) and the Norwegian version of the Inflammatory Bowel Disease Questionnaire (N-IBDQ). In addition, demographic and clinical variables were obtained.

RESULTS

In total, 140 patients were included; the mean age of patients with chronic fatigue was 44.2 years (s.d. = 15.8), that of nonfatigued was 44.7 years (s.d. = 16.0). Ulcerative colitis (UC)/Crohn's disease (CD) = 92/48. Chronic fatigue was associated, after controlling for covariates, with a reduction of HRQOL scores in 6/8 SF-36 dimensions in UC and 5/8 dimensions in CD. In N-IBDQ, chronic fatigue was associated with a reduction of HRQOL in four subdimensions and total score in CD and all dimensions in UC.

CONCLUSIONS

Fatigue is associated with reduction of HRQOL scores in IBD. The physical HRQOL domains are particularly affected. The impact of fatigue on disability, sick leave, school and work attendance has to be studied further.

Endothelins implicated in referred mechanical hyperalgesia associated with colitis induced by TNBS in miceThis article is one of a selection of papers published in the two-part special issue entitled 20 Years of Endothelin Research

This study evaluated the contribution of endothelins to changes in sensitivity to mechanical stimulation of the lower abdomen and hind paw associated with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. The frequency of withdrawal responses to 10 consecutive applications of von Frey probes to the lower abdomen (0.07 g) or hind paw (0.4 g) was assessed in male BALB/c mice before and after intracolonic TNBS injection (0.5 mg in 100 µL of 35% ethanol). TNBS (0.5 mg) induced referred mechanical hyperalgesia in the abdomen (response frequencies at 24 h: saline 11.0% ± 3.1%, TNBS 48.0% ± 6.9%) and hind paw (frequencies at 24 h: saline 12.5% ± 4.7%, TNBS 47.1% ± 7.1%) lasting up to 72 and 48 h, respectively. Mice receiving 1.0 or 1.5 mg TNBS assumed hunch-backed postures and became immobile during abdominal mechanical stimulation, suggestive of excessive ongoing pain. Atrasentan (ETA receptor antagonist; 10 and 30 mg/kg, i.v.) given 24 h after TNBS abolished hind paw and abdominal mechanical hyperalgesia for 2–3 h. A-192621 (ETB receptor antagonist; 20 mg/kg, i.v.) attenuated abdominal mechanical hyperalgesia at the 3 h time point only. Thus, endothelins contribute importantly to abdominal and hind paw referred mechanical hyperalgesia during TNBS-induced colitis mainly through ETA receptor-signaled mechanisms.