Surrogate markers of intestinal inflammation are predictive of relapse in patients with inflammatory bowel disease

Ascites fluid and plasma calprotectin concentrations in liver disease

BACKGROUND

Calprotectin, a marker of neutrophil activation, has been associated with a poor prognosis in alcohol-induced cirrhosis. The aims were to study concentrations of calprotectin in patients with various liver diseases, and to further investigate the prognostic value of calprotectin in cirrhosis.

METHODS

Plasma calprotectin concentrations were determined in 84 patients with alcohol-induced liver disease, 32 hepatitis B or C infected patients, 33 patients with liver disease of other aetiologies, 7 patients with combined aetiologies and in 24 patients with malignant disease. Thirty healthy individuals were included as controls. Ascites calprotectin concentrations were determined in patients with ascites (n = 75). Follow-up for survival was performed after a median observation period of 10 months.

RESULTS

Increased plasma and ascites calprotectin concentrations were observed in malignant disease compared to non-malignant disease (P < 0.0001). Plasma calprotectin concentrations were low in viral liver disease compared to patients with non-viral liver disease (P = 0.02) and to controls (P = 0.0002). Plasma calprotectin (>median) was a highly significant marker of poor survival in alcohol-induced cirrhosis (P = 0.001), but was of no prognostic value in non-alcohol-induced cirrhosis (P = 0.88). In decompensated cirrhosis high (>upper quartile) ascites calprotectin concentrations were associated with an increased mortality (P = 0.002), as were high (>median) plasma calprotectin levels (P = 0.009).

CONCLUSION

The prognostic importance of calprotectin in alcohol-induced cirrhosis is confirmed and demonstrated as specific for alcohol-induced liver disease. Low calprotectin levels are indicated in viral liver disease, and an association between high ascites calprotectin levels and malignant ascites was observed.

99mTc-interleukin-2 and (99m)Tc-HMPAO granulocyte scintigraphy in patients with inactive Crohn's disease

Crohn's disease (CD) is a chronic inflammatory bowel disease that may involve the whole gut. Marked intestinal T cell and macrophage activation is a key feature of the disease. Polymorphonuclear cell infiltration is also observed in the diseased gut, mainly during active inflammation. Scintigraphic detection of granulocytes and activated lymphocytes infiltrating the gut wall may be useful in identifying a subgroup of patients with clinically inactive CD who are undergoing early clinical relapse. The aims of the present study were (a) to compare the effectiveness of scintigraphy with (99m)Tc-labelled interleukin-2 ((99m)Tc-IL2) and with (99m)Tc-HMPAO labelled granulocytes ((99m)Tc-WBC) in detecting the presence and extent of bowel inflammation in patients with long-term inactive CD (>12 months) and (b) to assess the accuracy of these techniques in predicting future disease relapse. We studied 29 patients with ileal and/or colonic CD in stable clinical remission (Crohn's Disease Activity Index <150 for at least 12 months) using both (99m)Tc-IL2 and (99m)Tc-WBC scintigraphy in order to evaluate the extent of acute and chronic inflammation in the bowel. Planar and single-photon emission tomography images were acquired in each patient at 1 h p.i. For quantitative analysis of (99m)Tc-IL2 uptake, the abdomen was divided into 32 regions of interest. Despite the absence of symptoms, 18 patients (62%) showed a positive (99m)Tc-IL2 and 18 (62%) a positive (99m)Tc-WBC scan. Only 12 patients (41.4% of the total group) were positive on both scans, and the sites of IL2 and granulocyte bowel uptake were usually located in different segments, indicating that in CD, acute and chronic inflammation can be present in different sites. As far as the prognostic role of the two scans in predicting future disease relapse is concerned, both (99m)Tc-IL2 and (99m)Tc-WBC scintigraphy showed a high negative predictive value (1.00 and 0.91, respectively) but a weak positive predictive value (0.44 and 0.39, respectively). Nevertheless, Kaplan-Meier curves generated between scintigraphic findings and time free from disease relapse were statistically different only for (99m)Tc-IL2 scintigraphy (log-rank test, P=0.013). These results indicate that (99m)Tc-IL2 scintigraphy can be useful in selecting CD patients in clinical remission who could benefit from preventive therapy to avoid disease relapse.

Fecal alpha 1-antitrypsin clearance as a marker of clinical relapse in patients with Crohn's disease of the distal ileum

BACKGROUND

Crohn's disease (CD) shows a chronic relapsing course but no marker of relapse is currently available. However, fecal alpha 1-antitrypsin (alpha 1-AT) clearance (alpha 1-ATCl) is an indicator of protein loss and increases during active inflammation. We assessed the usefulness of fecal alpha 1-ATCl in predicting clinical relapse in patients with inactive ileal CD.

DESIGN

In a prospective longitudinal study, 26 patients with inactive ileal CD (Crohn's disease activity index (CDAI) < 150) (18 males, mean age 43 +/- 10, range 23-58) were enrolled. Fecal alpha 1-ATCl and concentration, daily stool weight and serum alpha 1-AT were measured at baseline (visit 1), after 1 week (visit 2) and 3 weeks (visit 3) in 24/26 patients (two drop-outs) (short-term study). In six of these 26 patients, fecal alpha 1-ATCl was also measured every 3 months for 1 year (long-term study). All patients were clinically assessed every 3 months for 1 year and every 6 months for 2 years. Ten healthy volunteers were tested as controls.

METHODS

Serum and fecal alpha 1-AT concentration was quantified by radial immunodiffusion.

RESULTS

The median fecal alpha 1-ATCl value at baseline was higher in inactive patients undergoing clinical relapse (CDAI > 200) in the next 6 months than in those remaining in remission at 6 months (P = 0.03). Fecal alpha 1-ATCl showed a 75% sensitivity, 85% specificity, 50% positive predictive value and 94% negative predictive value in predicting CD relapse in the next 6 months. In the long-term follow-up, fecal alpha 1-ATCl values increased at 12 months compared with both baseline and 6 month values (P = 0.005; P = 0.009). Fecal alpha 1-ATCl was higher in patients with raised C-reactive protein (P = 0.039).

CONCLUSIONS

Results from our study suggest that fecal alpha 1-ATCl is an indicator of clinical relapse in patients with CD of the distal ileum under regular surveillance.

Calcium-binding proteins MRP 8 and 14 in a Staphylococcus aureus infection model: role of therapy, inflammation, and infection persistence

Concentrations of the calcium-binding proteins of the S100 family, myeloid-related proteins 8 and MRP 14 (MRP8/14), are elevated in chronic infections, yet the role of these proteins is not clearly defined. Using commercial and developed enzyme immunoassays, we assayed for MRP8/14 in sterile-filtered abscess fluid from tissue-cage-implanted rats and rabbits. Staphylococcus aureus abscesses were created 6 weeks after the intraperitoneal implantation of tissue cages. Leukocytes, bacteria, and non-protein-bound calcium and zinc were measured in the infection exudate at day 3 or 5 of infection and after 8 days of treatment with antimicrobials beta-lactams (18 rabbits, 35 rats) and fluoroquinolone-rifampin (6 rabbits). Half of the infected rats were depleted of neutrophils; these rats exhibited significantly lower MRP 8/14 concentrations on all days sampled, regardless of the level of infection. The level of abscess MRP 8/14 is high early in the course of infection but decreases with effective antimicrobial treatment by as much as 100-fold. Thirty-day-old abscesses with log 6 bacterial counts and low neutrophil counts showed low concentrations of MRP 8/14 in these models. In abscess fluid, interleukin-6, as a representative marker of inflammation, correlated with MRP8/14, whereas ionized calcium and zinc did not. Our data suggest that infection and inflammation are not equal stimuli for MRP 8/14. The neutrophil appears to be the main source of MRP8/14 in this model.

A critical assessment of items on the Pediatric Crohn's Disease Activity Index

OBJECTIVES

Questions have been raised about the discriminative value of the three laboratory items (hematocrit, erythrocyte sedimentation rate, and albumin) and three physical items (height, perirectal disease, and extraintestinal manifestations) included in the Pediatric Crohn's Disease Activity Index (PCDAI). The aim of this study was to analyze the value of these six "criticized" items to the discriminative properties of the PCDAI.

METHODS

Data from 71 children with Crohn's disease visiting an outpatient clinic were analyzed. Physician global assessment of disease activity was used as the gold standard. A "basic index" was calculated by subtracting the score of the six criticized items from the score of the PCDAI calculated in the standard fashion. Multivariate logistic regression procedures identified which items significantly contributed to the "basic index". Receiver operating characteristic curves were produced comparing the standard PCDAI score to the "basic index" and a new "clinical index" which included only the criticized items truly contributing to the discriminatory ability of the "basic index".

RESULTS

Logistic regression models identified only perirectal disease as contributing to the discriminative abilities of the basic index. The clinical index therefore consists of the three history items (abdominal pain, number of liquid stools, and general well-being), three physical examination items (weight loss, abdominal examination, and perirectal disease) and no laboratory tests. The clinical index had an area under the curve not significantly inferior to that of the original PCDAI (0.93 [95% confidence interval, 0.89-0.99] vs. 0.96 [95% confidence interval, 0.92-0.99]).

CONCLUSIONS

A clinical index consisting of three history items and three physical examination items has an accuracy equal to the standard PCDAI in distinguishing children with disease in remission from those with a relapse.

Leukocyte adsorptive apheresis for the treatment of active ulcerative colitis: a prospective, uncontrolled, pilot study

BACKGROUND AND AIMS

Active ulcerative colitis (UC) is characterized by infiltration of activated granulocytes and monocytes/macrophages (GM) within the large bowel mucosa. GM are major sources of inflammatory cytokines, and in UC they are elevated with increased survival time. We investigated the possibility that reducing the level of these cells might promote remission of active UC.

METHODS

Thirty-one patients with active corticosteroid refractory (refractory) UC, mean age of 42 years, duration of UC 6 years, clinical activity index (CAI) of 15, disease activity index (DAI) of 10, and 8 corticosteroid naive patients (naive), mean age of 36 years, duration of UC 2 years, CAI of 11, DAI of 8 were recruited. Each patient was treated with up to 11 cycles of granulocyte and monocyte adsorptive apheresis over 11 weeks by using a 335-mL capacity column filled with cellulose acetate beads that adsorb GM.

RESULTS

At week 12, 81% of refractory (CAI, 3; P < 0.001 and DAI, 4; P < 0.001) and 88% of naive (CAI, 1; P = 0.012 and DAI, 3; P = 0.011) patients achieved remission. Early relapse was not a feature, and at 12 months, 26 of 33 patients had maintained their remission. The treatment was well tolerated, and no severe side effects were observed.

CONCLUSIONS

The outcome of this study suggests that reduction of circulating granulocytes and monocytes results in alleviation of inflammation and promotes clinical remission in patients with severe active UC that has not responded to intensive corticosteroid treatment. These data suggest that formal controlled studies are warranted.

Faecal calprotectin levels in infants with infantile colic, healthy infants, children with inflammatory bowel disease, children with recurrent abdominal pain and healthy children

This study investigated faecal calprotectin concentration, a measure of intestinal inflammation, in infants and children with abdominal pain. Faecal calprotectin was measured by an enzyme-linked immunosorbent assay kit in spot stool samples in 76 infants with typical infantile colic, 7 infants with transient lactose intolerance and 27 healthy infants. All infants were 2-10 wk of age. In addition, 19 children with recurrent abdominal pain (RAP; mean age 11.5 y), 17 with inflammatory bowel disease (IBD; mean age 11.1 y; 10 had Crohn's disease and 7 ulcerative colitis) and 24 healthy children (mean age 5.3 y) were studied. In infants with infantile colic the mean faecal calprotectin concentration was not different from that in healthy infants (278 +/- 105 vs 277 +/- 109 mg kg(-1), p = 0.97) or in infants with transient lactose intolerance (300.3 +/- 124 mg kg(-1), p = 0.60). The calprotectin level was similar in boys and girls and fell significantly with age (p = 0.04). Children with IBD had faecal calprotectin levels (293 +/- 218 mg kg(-1)) much higher than healthy children (40 +/- 28 mg kg(-1), p < 0.0001) and children with RAP without identified organic disease (18 +/- 24 mg kg(-1), p < 0.0001).

CONCLUSION

Faecal calprotectin may differentiate between functional abdominal pain and IBD in school-aged children. In young infants high faecal calprotectin levels are normal.

Use of surrogate markers of inflammation and Rome criteria to distinguish organic from nonorganic intestinal disease

BACKGROUND & AIMS

Differentiating symptoms of irritable bowel syndrome (IBS) from those of organic intestinal disease is a familiar problem for physicians. The aim of this study was to assess the sensitivity, specificity, and odds ratios (ORs) of fecal calprotectin, small intestinal permeability, Rome I criteria, and laboratory markers of inflammation (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], blood count) in distinguishing organic from nonorganic intestinal disease.

METHODS

A total of 602 new referrals to a gastroenterology clinic who had symptoms suggestive of IBS or organic intestinal disease were studied for these parameters. All patients underwent invasive imaging (barium/endoscopic examination) and other investigations as appropriate, with physicians blinded to the results of fecal calprotectin and intestinal permeability.

RESULTS

A total of 263 patients were diagnosed with organic disease and 339 with IBS. At 10 mg/L, the sensitivity and specificity of calprotectin for organic disease were 89% and 79%, respectively, and that of intestinal permeability for small intestinal disease were 63% and 87%, respectively. Sensitivity of positive Rome criteria for IBS was 85% with a specificity of 71%. An abnormal calprotectin test had an OR for disease of 27.8 (95% confidence interval [CI], 17.6-43.7; P < 0.0001) compared with ORs of 4.2 (95% CI, 2.9-6.1; P < 0.0001) and 3.2 (95% CI, 2.2-4.6; P < 0.0001) for elevated CRP and ESR values. An abnormal permeability test gave an OR of 8.9 (95% CI, 5.8-14.0; P < 0.0001) for small intestinal disease. The OR for IBS with positive Rome criteria was 13.3 (95% CI, 8.9-20.0).

CONCLUSIONS

Fecal calprotectin, intestinal permeability, and positive Rome I criteria provide a safe and noninvasive means of helping differentiate between patients with organic and nonorganic intestinal disease.

Faecal calprotectin: a marker of inflammation throughout the intestinal tract

Only a small proportion of patients with abdominal discomfort have organic disease, but a correct diagnosis can seldom be made by simple clinical examination. Additional diagnostic procedures must be employed, but these are expensive and demanding and carry a certain risk. Assessment of faecal concentrations of the neutrophil granulocyte-derived protein calprotectin can be used as a screening test--an 'ESR of the gut'--to select patients for further examination. The test can be performed on 1-2 g of random stool samples that can be sent to the laboratory by ordinary mail since the protein is remarkably stable in stools. The test has high sensitivities and specificities for gastrointestinal cancers and inflammatory bowel disease (IBD). Faecal calprotectin levels reflect the disease activity in IBD and can be used to monitor the response to treatment and detect relapses.

Review article: monitoring the activity of Crohn's disease

Crohn's disease is characterized by a chronic inflammation of the intestine of unknown aetiology. One of the main problems when treating patients with Crohn's disease, is the identification of patients undergoing early clinical relapse, for timely treatment and the possible prevention of complications. No sub-clinical markers are currently available that predict relapse during remission. Several parameters have been proposed for this purpose. Although none have proven useful, growing evidence suggests a possible benefit in the clinical management of Crohn's disease. Among these, we may identify: clinical behaviour, the characteristics of the host, clinical activity, markers of intestinal inflammation and markers of immune activation. In particular, the possible relationship between cytokine pattern and the clinical behaviour of Crohn's disease has been addressed. Overall, these observations suggest that mucosal immune activation is a feature of Crohn's disease, and may persist in the form of activated immunocompetent cells during remission. On the basis of this evidence, studies are currently investigating whether the down-regulation of immune activation markers is associated with clinical remission in Crohn's disease. It has been shown that higher mucosal levels of TNF-alpha and an increased state of activation of lamina propria mononuclear cells in patients with inactive Crohn's disease, are significantly associated with an earlier clinical relapse of the disease. These observations suggest that a persistent local immune activation during remission may represent a marker of early clinical relapse of Crohn's disease.

Whole gut lavage fluid interleukin-1beta and interleukin-8 in smokers and non-smokers with Crohn's disease in clinical remission

INTRODUCTION

Smoking in patients with Crohn's disease is associated with more frequent relapse. The mechanism responsible is unknown but a direct pro-inflammatory action on intestinal mucosa has been postulated. Mucosal inflammation in clinically inactive Crohn's disease predicts forthcoming relapse. Whole gut lavage fluid obtained after bowel cleansing with a polyethylene glycol electrolyte solution is an assessment of gut inflammation and immunity.

AIM

To assess whether whole gut lavage fluid interleukin-1beta and interleukin-8 differed between smokers and non-smokers with clinically inactive Crohn's disease.

METHODS

A total of 34 patients with inactive Crohn's disease (Crohn's disease activity index <150 and whole gut lavage fluid IgG concentration of <10 mg/ml) underwent whole gut lavage with interleukin-1beta and interleukin-8 analysed by enzyme-linked immunosorbent assay. Clinical details and blood markers of inflammation were collected.

RESULTS

In this series, 14 patients smoked (10 females, mean age 44.3+/-14.3 years), 20 did not (12 females, mean age 40.7+/-14.3). Surgical resection was more common in smokers (12/14 vs 8/20, p<0.008). Whole gut lavage fluid IgG was significantly lower in smokers (median 1.5 mg/ml (range 1.0-8.0 mg/ml) vs median 3.5 mg/ml (range 1.0-7.0 mg/ml), p<0.05). Whole gut lavage fluid interleukin-1beta was also lower in smokers [median 14.5 pg/ml (range 2-72 pg/ml) vs 26 pg/ml (range 7-1700 pg/ml)], p<0.03.

CONCLUSION

Markers of mucosal inflammation in inactive Crohn's disease are lower in smokers than non-smokers. This is against the hypothesis that nicotine exerts a direct pro-inflammatory action via interleukin-1beta and interleukin-8. Further research is required to elucidate the exact mechanisms involved.

p38 mitogen-activated protein kinase is activated and linked to TNF-alpha signaling in inflammatory bowel disease

Inflammatory bowel diseases (IBD)--Crohn's disease and ulcerative colitis--are relapsing chronic inflammatory disorders which involve genetic, immunological, and environmental factors. The regulation of TNF-alpha, a key mediator in the inflammatory process in IBD, is interconnected with mitogen-activated protein kinase pathways. The aim of this study was to characterize the activity and expression of the four p38 subtypes (p38alpha-delta), c-Jun N-terminal kinases (JNKs), and the extracellular signal-regulated kinases (ERK)1/2 in the inflamed intestinal mucosa. Western blot analysis revealed that p38alpha, JNKs, and ERK1/2 were significantly activated in IBD, with p38alpha showing the most pronounced increase in kinase activity. Protein expression of p38 and JNK was only moderately altered in IBD patients compared with normal controls, whereas ERK1/2 protein was significantly down-regulated. Immunohistochemical analysis of inflamed mucosal biopsies localized the main expression of p38alpha to lamina propria macrophages and neutrophils. ELISA screening of the supernatants of Crohn's disease mucosal biopsy cultures showed that incubation with the p38 inhibitor SB 203580 significantly reduced secretion of TNF-alpha. In vivo inhibition of TNF-alpha by a single infusion of anti-TNF-alpha Ab (infliximab) resulted in a highly significant transient increase of p38alpha activity during the first 48 h after infusion. A significant infliximab-dependent p38alpha activation was also observed in THP-1 myelomonocytic cells. In human monocytes, infliximab enhanced TNF-alpha gene expression, which could be inhibited by SB 203580. In conclusion, p38alpha signaling is involved in the pathophysiology of IBD.

Review article: is clinical remission the optimum therapeutic goal in the treatment of Crohn's disease?

Currently, the therapeutic end-point in the treatment of Crohn's disease is the remission of symptoms, but recent data confirm that mucosal inflammation may continue in the absence of symptoms. Furthermore, emerging evidence indicates that such subtle, sub-clinical mucosal inflammation leads to clinical relapse. The assessment of mucosal inflammation has become easier with the availability of faecal calprotectin assay. Current anti-inflammatory therapy often leaves low-grade mucosal inflammation untreated, and therefore recurrent relapses occur. We need to investigate whether the therapeutic end-point of anti-inflammatory medications needs to be more rigorous and to aim at complete mucosal healing, confirmed by the normalization of mucosal inflammatory markers such as faecal calprotectin concentrations. Immunosuppressive therapy with azathioprine/ 6-mercaptopurine currently offers the best mucosal healing treatment with reduction of relapses, but newer biological agents might offer less toxic therapy. Clinical trials to test the feasibility and efficacy of such a paradigm shift in the medical management of Crohn's disease are now warranted.

Intestinal permeation and gastrointestinal disease

The gastrointestinal tract constitutes one of the largest sites of exposure to the outside environment. The function of the gastrointestinal tract in monitoring and sealing the host interior from intruders is called the gut barrier. A variety of specific and nonspecific mechanisms are in operation to establish the host barrier; these include luminal mechanisms and digestive enzymes, the epithelial cells together with tight junctions in between them, and the gut immune system. Disruptions in the gut barrier follow injury from various causes including nonsteroidal anti-inflammatory drugs and oxidant stress, and involve mechanisms such as adenosine triphosphate depletion and damage to epithelial cell cytoskeletons that regulate tight junctions. Ample evidence links gut barrier dysfunction to multiorgan system failure in sepsis and immune dysregulation. Additionally, contribution of gut barrier dysfunction to gastrointestinal disease is an evolving concept and is the focus of this review. An overview of the evidence for the role of gut barrier dysfunction in disorders such as Crohn's disease, celiac disease, food allergy, acute pancreatitis, non-alcoholic fatty liver disease, and alcoholic liver disease is provided, together with critical insight into the implications of this evidence as a primary disease mechanism.

Review article: the concept of entero-colonic encephalopathy, autism and opioid receptor ligands

There is growing awareness that primary gastrointestinal pathology may play an important role in the inception and clinical expression of some childhood developmental disorders, including autism. In addition to frequent gastrointestinal symptoms, children with autism often manifest complex biochemical and immunological abnormalities. The gut-brain axis is central to certain encephalopathies of extra-cranial origin, hepatic encephalopathy being the best characterized. Commonalities in the clinical characteristics of hepatic encephalopathy and a form of autism associated with developmental regression in an apparently previously normal child, accompanied by immune-mediated gastrointestinal pathology, have led to the proposal that there may be analogous mechanisms of toxic encephalopathy in patients with liver failure and some children with autism. Aberrations in opioid biochemistry are common to these two conditions, and there is evidence that opioid peptides may mediate certain aspects of the respective syndromes. The generation of plausible and testable hypotheses in this area may help to identify new treatment options in encephalopathies of extra-cranial origin. Therapeutic targets for this autistic phenotype may include: modification of diet and entero-colonic microbial milieu in order to reduce toxin substrates, improve nutritional status and modify mucosal immunity; anti-inflammatory/immunomodulatory therapy; and specific treatment of dysmotility, focusing, for example, on the pharmacology of local opioid activity in the gut.

Review article: faecal markers in the assessment of activity in inflammatory bowel disease

The fundamental pathological process behind ulcerative colitis and Crohn's disease is intestinal inflammation. As the precise cause of this is not yet completely understood, current treatment strategies are aimed at reducing or eliminating the inflammation. Endoscopic examination and histological analysis of biopsy specimens remain the 'gold standard' methods for detecting and quantifying bowel inflammation; however, these techniques are costly, invasive, and repeated examinations are unpopular with patients. Disease activity questionnaires and laboratory 'inflammatory markers', although widely used, show an unreliable correlation with endoscopy and histology. New markers need to be developed to detect and quantify bowel inflammation. These would be of use diagnostically and also an aid to pharmacological treatment.

Randomized controlled trial of clarithromycin and ethambutol in the treatment of Crohn's disease

BACKGROUND

A mycobacterial infection may be the cause of Crohn's disease in some patients. Measurement of intestinal permeability may identify Crohn's disease patients with a high likelihood of relapse and may quantify the severity of intestinal injury.

AIM

To assess the effect of 3 months of clarithromycin and ethambutol on the disease activity and intestinal permeability in patients with Crohn's disease at high risk of relapse.

METHODS

Patients with Crohn's disease, with a lactulose-mannitol permeability test above 0.03, were randomly assigned to receive either clarithromycin, 500 mg twice daily, and ethambutol, 15 mg/kg daily, or identically appearing placebo for 3 months in addition to their regular therapy. The Harvey-Bradshaw index and the lactulose-mannitol test were assessed in a blind fashion every 3 months for 12 months.

RESULTS

Thirty-one patients were randomized to receive either drugs (n=15) or placebo (n=16). The groups were similar in age, sex, duration of disease, location of disease, past complications and disease severity. Specifically, there was no difference between the drug or placebo groups in the mean Harvey-Bradshaw index (4.8 vs. 4.4), number with active disease (33% vs. 44%) and mean lactulose-mannitol test (0.06 vs. 0.10). During the 12-month follow-up period, there were no consistent, statistically significant differences in the mean Harvey-Bradshaw index or lactulose-mannitol test between treatment and placebo groups. Individual patients showed either improvement or worsening of these indices, but these were not related to study medication. Specifically, no 'cures' were noted with anti-mycobacterial treatment.

CONCLUSIONS

Three months of treatment with clarithromycin and ethambutol does not benefit Crohn's disease patients who are receiving standard medical therapy.

Frequency of continuing mucosal inflammation in clinically inactive Crohn's disease

The treatment goal in Crohn's disease is clinical remission, not complete mucosal healing. The incidence of mucosal inflammation in Crohn's disease patients in clinical remission is not known. Whole gut lavage is an objective method of assessing mucosal inflammation. We aimed to assess levels of mucosal inflammatory activity in a group of patients with clinically inactive Crohn's disease. We prospectively assessed 30 patients with inactive Crohn's disease and 28 controls. Inactive disease was defined as Crohn's disease activity index of less than 150. All underwent whole put lavage, with analysis of whole gut lavage fluid IgG, haemoglobin, interleukin-1 beta, interleukin-8 and granulocyte elastase. Serum inflammatory parameters were collected for comparison. Of the 30 patients with Crohn's disease, 10 (33%) had an abnormal immunoglobulin G, 21 (70%) had an elevated interleukin-1 beta 20 (66%) interleukin-8 and 10 (33%) granulocyte elastase in the whole gut lavage fluid. 58% of patients had either 1 or 2 abnormal results. In contrast only 10% had 1 or 2 abnormal serum results. Few abnormalities were present in lavage fluid or serum of the control population. We concluded that ongoing mucosal inflammation is detectable in whole gut lavage fluid of up to 2/3 of Crohn's disease patients in clinical remission.

Non-invasive investigation of inflammatory bowel disease

The assessment of inflammatory activity in intestinal disease in man can be done using a variety of different techniques. These range from the use of non-invasive acute phase inflammatory markers measured in plasma such as C reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) (both of which give an indirect assessment of disease activity) to the direct assessment of disease activity by intestinal biopsy performed during endoscopy in association with endoscopic scoring systems. Both radiology and endoscopy are conventional for the diagnosis of inflammatory bowel disease (IBD). However these techniques have severe limitations when it comes to assessing functional components of the disease such as activity and prognosis. Here we briefly review the value of two emerging intestinal function tests. Intestinal permeability, although ideally suited for diagnostic screening for small bowel Crohn’s disease, appears to give reliable predictive data for imminent relapse of small bowel Crohn’s disease and it can be used to assess responses to treatment. More significantly it is now clear that single stool assay of neutrophil specific proteins (calprotectin, lactoferrin) give the same quantitative data on intestinal inflammation as the 4-day faecal excretion of 111Indium labelled white cells. Faecal calprotectin is shown to be increased in over 95% of patients with IBD and correlates with clinical disease activity. It reliably differentiates between patients with IBD and irritable bowel syndrome. More importantly, at a given faecal calprotectin concentration in patients with quiescent IBD, the test has a specificity and sensitivity in excess of 85% in predicting clinical relapse of disease. This suggests that relapse of IBD is closely related to the degree of intestinal inflammation and suggests that targeted treatment at an asymptomatic stage of the disease may be indicated.

Enteropathic arthritis: how do the joints talk with the gut?

Enteropathic arthritis is a label for conditions in which gut pathology is believed to be of pathogenic importance for the developing joint disease. Impaired barrier function, as well as immunogenetic mechanism, are implicated. Recent publications have highlighted strong new support for the homing of lymphocytes from the gut mucosa to joint tissue, persistence of antigen- and cytokine-based immune deficiency. A convincing argument was made for the interesting observation that two distinct types of joint involvement with different class II HLA backgrounds occur in patients with inflammatory bowel disease. A new mechanism implicating dimeric HLA-B27 heavy chains in the pathogenesis of enteropathic arthritis is also presented. Despite evidence for persisting antigen presence, antimicrobial therapy seems ineffective in reactive arthritis.

Inflammatory bowel disease: immunodiagnostics, immunotherapeutics, and ecotherapeutics

Treatment options for inflammatory bowel disease (IBD) reflect a continuing shift from empiricism to strategies based on improved understanding of the pathophysiology of disease. In susceptible individuals, IBD appears to be the result of defective regulation of mucosal immune interactions with the enteric microflora. This has prompted research directed at the interface of the traditional disciplines of immunology, microbiology, and epithelial cell biology. Whereas immunodiagnostics have been of limited clinical value in IBD, assessments of mucosal rather than systemic immune function are promising. Therapeutically, there is an increasing trend toward more aggressive and earlier use of immunomodulatory agents, particularly for prevention of relapse, with cytokine manipulation as a bridge therapy to achieve remission in patients with acute severe disease. Although most drug treatments are directed toward altering the host response, the rationale for manipulating the enteric flora appears sound and will be the basis of additional future therapeutic strategies. Notwithstanding the widening range of options for drug therapy in IBD, other outcome modifiers and well-established principles of managing chronic disease are as important as ever.

Serum lysozyme in inflammatory gastric and enteric diseases and in functional dyspepsia

Serum lysozyme was reevaluated in inflammatory bowel disease and other gastrointestinal disorders. A total of 109 patients were divided into six groups: ulcerative colitis (28), Crohn's disease (9), simple atrophic gastritis (16), atrophic gastritis and pernicious anemia (23), functional dyspepsia (17), and controls (16). Elevated levels of lysozyme, compared with control levels, were found not only in ulcerative colitis and Crohn's disease but also in atrophic gastritis with or without pernicious anemia and in functional dyspepsia. The elevation of lysozyme, since it results from the product of granulocytes and macrophages present in increased amounts in the mucosa of inflammatory bowel diseases, is easily explained. The cellular infiltration in atrophic gastritis may also explain the elevated lysozyme levels. The higher lysozyme levels in some patients with functional dyspepsia could possibly reflect an underlying latent inflammatory process.