Gut lavage fluid protein concentrations: objective measures of disease activity in inflammatory bowel disease

Biomarkers for the Evaluation of Pouch Inflammation: A Systematic Review

Background

Ileal pouch inflammation is a common problem following ileal pouch-anal anastomosis (IPAA). Despite its prevalence, diagnosis remains multimodal and requires endoscopy. The use of biomarkers in the prediction of and/or association with pouchitis has not been well characterized. We performed a systematic review to summarize the available evidence.

Method

A search of Ovid, MEDLINE, Cochrane Library, EMBASE, and Web of Science was conducted. Inclusion criteria included studies evaluating biomarkers for the evaluation and prediction of inflammation in patients with IPAA utilizing pouchoscopy as the gold standard. Exclusion criteria included studies on the role of the microbiome or genetic markers.

Results

A total of 28 studies, 5 case-control studies, and 23 observational cohort studies were identified. Fecal biomarkers were assessed in 23 studies, of which fecal calprotectin was the most commonly studied with sensitivities ranging from 57% to 92% and specificities from 19% to 92%. Six studies examined serum biomarkers. None of the serum biomarkers demonstrated a high sensitivity or specificity in association with pouch inflammation. Six studies described the longitudinal assessment of biomarkers. Of these studies, only three reported a predictive role of biomarkers in diagnosing endoscopic inflammation.

Conclusions

Biomarkers have emerged as a potential option to improve the management of pouchitis given the relative ease of sampling compared to pouchoscopy. Unfortunately, the evaluated biomarkers have not consistently demonstrated accuracy in predicting inflammation. Moreover, these biomarkers have not been reliably shown to be sensitive or specific in association with endoscopic pouch inflammation to merit their widespread use in clinical practice.

Dietary exposure to chlorpyrifos inhibits the polarization of regulatory T cells in C57BL/6 mice with dextran sulfate sodium-induced colitis

Inflammatory bowel disease (IBD) is associated with loss of immune tolerance to antigens originating from the diet and from the gut microflora. T cells play crucial roles in the pathogenesis of IBD. Chlorpyrifos (CPF) is one of the most ubiquitous organophosphate pesticides in the world. The aim of the study was to investigate the effects of dietary exposure to CPF on T-cell populations in C57BL/6 mice with dextran sulfate sodium (DSS)-induced colitis. Mice received distilled water containing 3% DSS for 6 days to induce acute colitis, which was then replaced with distilled water for 21 days, allowing progression to chronic inflammation. During the experimental period, mice were given either an AIN-93-based control diet or a CPF diet-containing 7, 17.5, or 35 ppm of CPF. Results showed that dietary exposure to CPF significantly increased circulating neutrophils in colitic mice. CPF-exposed groups had lower percentages of blood and spleen T cells without altering the proportions of CD4⁺ and CD8⁺ T-cell subsets. The percentage of blood regulatory T (Treg) cells, as well as splenic expressions of Treg-related genes, were suppressed in CPF-exposed mice. CPF upregulated the colonic gene expression of tumor necrosis factor-α. Meanwhile, plasma haptoglobin, colon weights, and luminal immunoglobulin G levels were higher in CPF-exposed groups. Histopathological analyses also observed that colon injury was more severe in all CPF-exposed mice. These results suggest that dietary exposure to CPF aggravated tissue injuries in mice with DSS-induced chronic colitis by suppressing T-cell populations and Treg polarization.

Serum γ-globulin and albumin concentrations predict secondary loss of response to anti-TNFα in inflammatory bowel disease patients

BACKGROUND

Loss of response to anti-TNFα treatment occurs frequently in IBD- patients. We evaluatedthe predictive value of serum albumin and γ-globulin concentrations for treatment failure.

METHODS

Prospectively, all patients treated for the first time with either infliximab or adalimumab for IBD between 2007 and 2018 were included. All patients were tested for serum albumin and γ-globulin concentrations and were followed up until June 2018.

RESULTS

128 patients (95 Crohn's disease, 67 females, age 40.1 ± 13.7 years) were included in the study. 81patients (63.3%) received infliximab and 47 (36.7%) adalimumab first line. Eight patients (6.3%) were primary non-responders, 50 patients (39.0%) showed a sustained clinical remission and 70 patients (54.7%) developed a secondary loss of response. Meantime to develop secondary loss of response was 24.5 ± 20.5 months. Albumin serum concentrations in the clinical response group were significantly higher than in the secondary loss of response group (39.8 ± 5.7 g/L vs. 35.0 ± 5.4 g/L). γ-globulin serum concentrations in the sustained response group were significantly lower than in the secondary loss of response group (11.8 ± 2.8 g/L vs. 14.7 ± 4.5 g/L). Hypoalbuminemia and hypergammaglobulinemia were associated with the loss of response. Immunosuppressant co-medication in patients with high γ-globulin serum concentrations reduced the risk of secondary loss of response.

CONCLUSION

Low albumin and increased γ-globulin serum concentrations are strongly associated with a higher risk for loss of response to an anti-TNFα treatment. Increased serum γ-globulin concentrations may have a higher risk to produce anti-drug antibodies or a different phenotype of disease less responsive to anti-TNFα treatment.

Investigation of the Influence of Protein-Losing Enteropathy on Monoclonal Antibody Pharmacokinetics in Mice

Protein losing enteropathy (PLE), which is characterized by substantial loss of plasma proteins into the gastrointestinal (GI) tract, is a complication of a variety of GI diseases, including inflammatory bowel disease. Clinical studies have found that the clearance of monoclonal antibodies (mAb) is often increased in subjects with diseases known to cause PLE; however, direct relationships between PLE and mAb pharmacokinetics have not been demonstrated. This study employed a murine model of colitis to examine the influence of PLE on mAb pharmacokinetics. Mice were given dextran sodium sulfate (DSS, 2% w/v) supplemented tap water as drinking source for 6 days to induce colitis and PLE. Mice were then intravenously injected with 8C2, a murine IgG1 mAb. 8C2 plasma concentrations were measured up to 14 days post injection. Fecal alpha-1-antitrypsin (A1AT) clearance was measured as biomarker for PLE. DSS-treated mice developed PLE of clinically relevant severity. They also showed a transient increase in 8C2 plasma clearance and a decrease in 8C2 plasma exposure. The area under the 8C2 plasma concentration-time curve for the length of the study (AUC_0-14d) reduced from 1368 ± 255 to 594 ± 224 day μg/ml following DSS treatment (p = 0.001). A quantitative relationship between A1AT clearance and 8C2 clearance was obtained via population pharmacokinetic modeling. DSS treatment substantially increased 8C2 clearance and reduced 8C2 exposure. Increased mAb plasma clearance was highly correlated with A1AT fecal clearance, suggesting the possible utility of A1AT fecal clearance as a mechanistic biomarker to predict the pharmacokinetics of therapeutic antibodies.

Fecal biomarkers in inflammatory bowel disease

Over the last two decades, knowledge on fecal biomarkers has substantially increased. Nowadays, these non-invasive markers of inflammation have significant clinical utility in the management of inflammatory bowel disease. Their use informs the decision to perform endoscopy before diagnosis is made right through to influencing therapeutic choices and the need for interval endoscopic assessment. In this review, the roles of two S100 proteins, calprotectin, and S100A12 are described along with that of lactoferrin, in the context of inflammatory bowel disease.

Rectal effluent as a research tool

Studies of localized secretions are generally superior to those of blood because they contain higher concentrations of molecules specific to the organ of interest. A common method used to analyze localized secretions is lavage. The flow of fluid over the lining of a cavity picks up both cells and soluble factors, and the effluent can be collected for study. Gastrointestinal (GI) lavage is easily and noninvasively performed by the administration of gut lavage solutions such as those routinely given to patients prior to colonoscopy, with GI lavage fluid being the copious, watery rectal effluent subsequently induced. Residual effluent is currently suctioned from the colon and discarded during colonoscopy. With millions of routine colonoscopies performed per year, GI lavage fluid is a rich and largely untapped resource for basic and clinical research. Rectal effluent can also be easily collected in a toilet receptacle without need for a colonoscopy. Rectal effluent generated in this manner has been used to study diarrheal disease, mucosal immunology, inflammatory bowel disease, celiac disease, and cancer. It is often referred to as gut lavage, colon lavage, GI lavage, or whole gut lavage fluid, which makes it challenging to locate previous studies in the literature and there are currently no comprehensive reviews of its use as a research tool. This review attempts to fill this void by discussing previous applications of rectal effluent in research and the methods that have been developed for its collection, stabilization, and analysis.

Effects of dietary glutamine on the homeostasis of CD4+ T cells in mice with dextran sulfate sodium-induced acute colitis

This study investigated the effects of dietary glutamine (Gln) on T-helper (Th) and T regulatory (Treg) cell homeostasis and colonic inflammatory mediator expression in mice with dextran sulfate sodium (DSS)-induced colitis. Mice were randomly assigned to 4 groups with 2 normal control (C and G) and 2 DSS-treated groups (DC and DG). The C and DC groups were fed a common semipurified diet, while the G and DG groups received an identical diet except that part of the casein was replaced by Gln, which provided 25% of the total amino acid nitrogen. Mice were fed the diets for 10 days. On day 6, mice in the normal control groups were given distilled water, while those in the DSS groups were given distilled water containing 1.5% DSS for 5 d. At the end of the experiment, the mice were sacrificed for further examination. Results showed that DC group had higher plasma haptoglobin, colonic weight, immunoglobulin G, inflammatory cytokine and nuclear factor (NF)-κB protein levels. Gln administration lowered inflammatory mediators and NF-κB/IκBα ratio in colitis. Compared with the DC group, the percentages of interleukin-17F and interferon-γ in blood and transcription factors, T-bet and RAR-related orphan receptor-γt, gene expressions in mesenteric lymph nodes were lower, whereas blood Foxp3 was higher in the DG group. Also, DG group had lower colon injury score. These results suggest that Gln administration suppressed Th1/Th17 and Th-associated cytokine expressions and upregulated the expression of Tregs, which may modulate the balance of Th/Treg and reduce inflammatory reactions in DSS-induced colitis.

Alanyl-glutamine administration suppresses Th17 and reduces inflammatory reaction in dextran sulfate sodium-induced acute colitis

T helper (Th) cells play a major role in the pathogenesis of inflammatory bowel disease (IBD). Glutamine (Gln) is known to have immunomodulatory effects in metabolic stressed conditions. This study investigated the effects of post-treatment of alanyl-glutamine (Ala-Gln) on Th cell-associated cytokine expressions and inflammatory reaction in dextran sulfate sodium (DSS)-induced colitis. C57BL/6 mice received distilled water containing 3% DSS for 5 days to induce colitis, whereas the normal control (NC) group received distilled water. After induction of colitis, one of the colitis groups (DG) was intraperitoneally injected with an Ala-Gln solution (0.5 g Gln/kg/d), and the saline DSS group (DS) received an identical volume of saline. After treatment for 3 days, mice were sacrificed, and the blood and tissue samples were collected for further analysis. DSS colitis resulted in higher percentages of blood interleukin (IL)-17-secreting Th cells and greater expression of Th cell-associated cytokine messenger RNA (mRNA) in the mesenteric lymph nodes (MLN). Also, luminal immunoglobin (Ig) G, keratinocyte-derived chemokine, and macrophage chemoattractant protein-1 levels were higher in the DS group than the NC group, whereas these parameters did not differ between the DG and NC groups. The DG group had lower blood IL-17A, 17F, MLN IL-17 mRNA and macrophage percentage in the peritoneal lavage fluid than those of the DS group. These results suggest that post-treatment with Ala-Gln suppressed Th17-associated cytokine expressions, reduced macrophage infiltration into the peritoneal cavity and decreased pro-inflammatory cytokine production in the colon, thus may have attenuated inflammatory response in DSS-induced colitis.

Pretreatment with alanyl-glutamine suppresses T-helper-cell-associated cytokine expression and reduces inflammatory responses in mice with acute DSS-induced colitis

T-helper (Th) cells play a major role in initiating and shaping the pathologic response in inflammatory bowel disease (IBD). Glutamine (GLN) is a nutrient with immune-modulating effects. This study investigated the effect of GLN on cytokine expressions and inflammatory responses of three subsets of Th cells in dextran sulfate sodium (DSS)-induced IBD. There were one normal control (NC) and two DSS groups. Mice in the DSS groups drank distilled water containing 3% DSS for 5 days, whereas the NC group received distilled water. Mice in the G-DSS group were given intraperitoneal injection of 0.5 g GLN/kg/d for 3 days before receiving DSS water. The other DSS group (C-DSS) received an identical amount of amino acid solution without GLN. After induction of IBD, the mice were allowed to recover for 3 days and then were sacrificed. Blood and colon samples were collected for further analysis. The C-DSS group had higher percentages of blood interleukin (IL)-17A, IL-17F, IL-22, IL-4 and interferon-γ than the NC group. The G-DSS group had lower Th1/Th17/Th2 cytokine expressions, which showed no differences from the NC group. Plasma haptoglobin, colon immunoglobin G and chemokine levels and myeloperoxidase activities were higher in the DSS groups than the NC group. These parameters were significantly lower in the G-DSS than the C-DSS group. These results suggest that pretreatment with GLN suppressed Th-associated cytokine expressions and may consequently reduce inflammatory mediator production and leukocyte infiltration into tissues, thus ameliorating the severity of acute DSS-induced colitis.

Questions and answers on the role of fecal lactoferrin as a biological marker in inflammatory bowel disease

Among the available fecal biomarkers for the diagnosis and monitoring of inflammatory bowel disease (IBD), only calprotectin and lactoferrin have translated into useful clinical tools. Lactoferrin can be detected using simple and cheap techniques and it has excellent stability in feces over a long period of time. Fecal lactoferrin has a good diagnostic precision for separating organic and functional intestinal disease. However, a negative fecal lactoferrin test should be interpreted merely as the absence of significant neutrophilic intestinal inflammation. The mean sensitivity and specificity of the fecal lactoferrin determination for the diagnosis of IBD is 80% and 82%, respectively. Some studies have suggested a lower accuracy of lactoferrin when compared with calprotectin for the diagnosis of IBD, indicating that more studies on this topic are necessary. A parallel between fecal lactoferrin levels and IBD activity estimated with clinical, endoscopic, and histological parameters has been confirmed. However, this correlation seems to be lower in Crohn's disease than in ulcerative colitis, mainly when Crohn's disease patients with purely ileal disease are considered. Fecal lactoferrin determination may be useful in predicting impending clinical relapse in IBD patients. Fecal lactoferrin may be a helpful noninvasive diagnostic tool for monitoring therapeutic efficacy, mainly on mucosal healing, as a decreasing concentration of lactoferrin can be interpreted as a marker of therapeutic response. Finally, in patients with Crohn's disease who have undergone ileocolonic resection, those with higher lactoferrin fecal levels might be more prone to postsurgical recurrence.

Endoscopy for upper gastrointestinal bleeding: how urgent is it?

Early endoscopy has been advocated for the management of upper gastrointestinal bleeding, but the optimal timing for early endoscopy is still uncertain. The aim of this Review is to evaluate the optimal timing of early endoscopy by examining the findings of randomized clinical trials and retrospective cohort studies that used comparable outcome measures and have been reported in the literature. Outcome measurements included recurrent bleeding, surgery, mortality, length of hospital stay, and blood transfusion. Studies were categorized into those in which endoscopy was performed within 2-3 h, 6-8 h, 12 h or 24 h of the patient's presentation to hospital. We conclude that early endoscopy aids risk stratification of patients and reduces the need for hospitalization. However, it may also expose additional cases of active bleeding and hence increase the use of therapeutic endoscopy. No evidence exists that very early endoscopy (within a few hours of presentation) can reduce the risk of rebleeding or improve survival.

Stability of faecal hepatocyte growth factor determination

In order to evaluate the accuracy and reproducibility of determination of hepatocyte growth factor (HGF) levels in faeces, the stability of HGF in samples processed in different ways was investigated. An ELISA method was used for determination of HGF concentrations. Faeces samples from healthy controls and patients with infectious diarrhoea were studied. It was found that faeces HGF concentration remained stable irrespective of whether samples were freeze-thawed several times, kept for 6, 12 or 24 h at room temperature or refrigerated for 6, 12, 24 or 36 h; the levels of HGF did not change significantly when samples were freeze-dried. Adding protease inhibitor to the faeces samples did not affect the HGF levels. There were no significant differences between HGF levels using phosphate buffered saline (PBS) (pH 7.4) or NaCL as buffer, but it was observed that levels of HGF were significantly lower in the samples that were diluted in distilled water. Although both HGF and albumin through various mechanisms may increase in faeces during infectious diarrhoea, there was no significant correlation between faeces HGF levels and albumin levels, which might indicate local production of HGF in the bowel in response to infection. It is concluded that determination of faeces HGF levels is feasible with a high degree of stability. Increased HGF levels in faeces might represent a local production of HGF during bowel injury and might be of use as a diagnostic and monitoring assay.

The Manitoba IBD Index: evidence for a new and simple indicator of IBD activity

OBJECTIVES

A single-item indicator of disease activity over an extended period of time, the Manitoba Inflammatory Bowel Disease Index (MIBDI), is introduced and compared against several standard measures for assessing activity in patients with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

Participants enrolled in the Manitoba IBD Cohort Study, a population-based longitudinal cohort study (N=353), were assessed semiannually by survey, clinical interview, and blood sample during a 2-year period. The MIBDI is based on patient self-reports of symptom persistence for the previous 6 months, using a 6-level response format.

RESULTS

The MIBDI had good sensitivity compared with the Harvey-Bradshaw Index (HB; 0.88), Powell-Tuck Index (PT; 0.84), and Inflammatory Bowel Disease Questionnaire (IBDQ; 0.89), which was maintained at two subsequent annual measurements. Test-retest reliability was also strong (Spearman's r=0.81). Discriminant function analyses identified common discriminating variables of active disease for CD and UC that included HB, PT, and IBDQ subscales of bowel and systemic symptoms, prolonged symptom severity (e.g., abdominal and joint pain, tiredness, diarrhea), and recent persistent pain related to IBD. Unique discriminators included weight problems (CD) and blood in stool (UC).

CONCLUSIONS

A single-item, patient-defined disease activity measure, the MIBDI, showed a high degree of sensitivity for classifying individuals with regard to disease status over time compared with the existing disease activity measures, and strong convergent validity with expected proxy measures of disease. These relationships remained consistent over time. Thus, the MIBDI shows promise as a valid, brief tool for measuring disease activity over an extended period.

Review of fecal biomarkers in inflammatory bowel disease

PURPOSE

We reviewed potential fecal biomarkers of inflammatory bowel disease and assessed their utility in a range of clinical applications.

METHODS

A literature search using PubMed, MEDLINE, and Embase database was performed, locating all language articles on fecal biomarkers, including calprotectin and lactoferrin. The references of these papers were searched manually for further references.

RESULTS

A wide range of fecal biomarkers have been evaluated in the research setting. Only fecal calprotectin and lactoferrin have translated into useful clinical tools. These biomarkers have demonstrated high sensitivity for organic intestinal disease and good correlation with other measures of disease activity in inflammatory bowel disease.

CONCLUSIONS

Fecal calprotectin and lactoferrin are useful triage tools to differentiate organic intestinal disorders from functional disorders. They also have a role in monitoring inflammatory bowel disease activity and predicting relapse.

Enzymes in feces: useful markers of chronic inflammatory bowel disease

BACKGROUND

Ulcerative colitis and Crohn's disease are characterized by a chronic intestinal inflammation. Since the precise etiology is still unknown, current therapies are aimed at reducing or eliminating inflammation.

METHODS

Endoscopy and histology on biopsy specimens remain the gold standard methods for detecting and quantifying bowel inflammation. These technique are expensive, invasive and not well tolerated by patients since the need of repeated examinations affects their quality of life. Although disease activity scores and laboratory inflammatory markers are widely used they showed unreliable relations with endoscopy and histology. Fecal markers have been investigated in inflammatory bowel disease (IBD) by many authors for diagnostic purposes, to assess disease activity and of risk of complications, to predict relapse or recurrence, and to monitor the effect of therapy. Many inflammatory mediators have been detected in the feces such as leukocytes, cytokines and proteins from neutrophil activation. Some of these, particularly lactoferrin and calprotectin, have been demonstrated to be useful in detecting active inflammatory bowel disease, in predicting recurrence of disease after surgery or monitoring the effects of medical therapy. Calprotectin and lactoferrin are remarkably stable and easily detect in stool using ELISA so they appear to be equally recommendable as inflammation markers in the lower gastrointestinal tract especially in IBD patients.

CONCLUSION

Fecal markers are non-invasive, simple, cheap, sensitive and specific parameters and are useful to detect strointestinal inflammation.

Long-term treatment with anti-α4 integrin antibodies aggravates colitis in Gαi2-deficient mice

Targeted deletion of the heterotrimeric G protein, Galphai2, in mice induces lethal colitis closely resembling ulcerative colitis. In chronic colitis, migration of circulating leukocytes into the intestinal mucosa is partially dependent on alpha4 integrins. In previous studies, short-term administration of anti-alpha4 integrin antibodies has been shown to attenuate intestinal inflammation, and here we elucidate the effect of long-term administration of anti-alpha4 integrin antibodies on colitis in Galphai2(-/- )mice. Long-term blockade of alpha4 integrin significantly increased the severity of colitis in Galphai2(-/-) mice. The inflammation was confined to the colon, associated with increased cancer in situ, destruction of crypt architecture, and increased production of IL-1beta, TNF-alpha and IFN-gamma. Blockade of alpha4 integrin reduced the recruitment of activated T cells to the small intestine. In strong contrast, there were significantly higher numbers of activated T cells in the colonic lamina propria and epithelium, most probably due to in situ proliferation. Furthermore, treatment with alpha4 integrin antibodies induced decreased levels of total IgA and IgG in sera, whereas total IgM levels were unchanged. These new findings may have implications in the understanding of the progression of chronic intestinal inflammation.

Is portal hypertension associated with protein-losing enteropathy?

BACKGROUND AND AIM

Hypoalbuminemia in patients with decompensated cirrhosis has traditionally been assumed to be a result of to impaired liver synthesis; however, protein-losing enteropathy (PLE) may also contribute. The aim of this study was to assess whether hypoalbuminemic cirrhotic patients with portal hypertension had evidence of PLE.

METHODS

Sixteen patients with alcoholic cirrhosis, hypoalbuminemia and portal hypertension underwent whole gut lavage with polyethylene glycol solution. The effluent obtained was analyzed for albumin, immunoglobulin (Ig)G and alpha1-antitrypsin (alpha1-AT). Serum C-reactive protein (CRP) was also measured to assess the systemic inflammatory response.

RESULTS

Twelve of the 16 enrolled patients had a persistently low albumin concentration at the time of lavage. Only one patient (who was subsequently found to have celiac disease) had elevated concentrations of lavage albumin, alpha1-AT and IgG levels. There was a significant correlation between lavage albumin and alpha1-AT (r = 0.671, P = 0.024), and between lavage albumin and IgG (r = 0.614, P = 0.045). There was no correlation between serum albumin and lavage proteins. Six patients had elevated serum CRP levels, but serum albumin or lavage protein concentrations did not correlate with serum CRP.

CONCLUSION

There is no evidence of a significant PLE in patients with alcoholic cirrhosis, hypoalbuminemia and portal hypertension.

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.

Lactoferrin in whole gut lavage fluid as a marker for disease activity in inflammatory bowel disease: comparison with other neutrophil-derived proteins

OBJECTIVES

We investigated which neutrophil-derived proteins in whole gut lavage fluid (WGLF) most accurately reflect disease activity in inflammatory bowel disease.

METHODS

WGLF was obtained from patients undergoing whole gut lavage as a bowel preparation for colonoscopy. Twenty-seven patients with ulcerative colitis (UC), 23 patients with Crohn's disease (CD), and 35 control subjects were examined. The concentrations of lactoferrin, polymorphonuclear neutrophil elastase (PMN-E), myeloperoxidase, and lysozyme in WGLF were measured by ELISA. For the assessment of stability, WGLF samples were stored at 37 degrees C for various periods.

RESULTS

In UC, the concentrations of lactoferrin, myeloperoxidase, and lysozyme in WGLF had good correlations with colonoscopic grading. Zero, 12, five, and 10 of 28 samples from active UC patients showed normal concentrations of lactoferrin, PMN-E, myeloperoxidase, and lysozyme, respectively. In CD, the concentrations of lactoferrin and myeloperoxidase had good correlations with the Crohn's disease activity index. Thirteen and seven of 36 samples from inactive CD patients (Crohn's disease activity index < or = 150) showed high concentrations of lactoferrin and myeloperoxidase, respectively. Most of them (11/13, 6/7) were found to have ulceration by colonoscopy or small bowel x-ray. The ratio of the lactoferrin concentration in the WGLF supernatant to that in total WGLF was highest among these proteins in all disease groups and control subjects. Lactoferrin and myeloperoxidase showed good stability in WGLF, whereas PMN-E and lysozyme did not.

CONCLUSION

Lactoferrin is the most suitable of these proteins for use as a neutrophil-derived WGLF marker of intestinal inflammation.

Topical and oral anti-inflammatory activity of budesonide compared with oral prednisolone in an animal model using allergen-induced gut mucosal exudation of plasma as a marker

BACKGROUND

Development of topically active glucocorticosteroids with minimal systemic effects is paramount in improving therapy in inflammatory bowel disease. Our experimental model in the rat has proved useful for assessing topical versus systemic anti-inflammatory potency of glucocorticosteroids on the inflamed gut.

METHODS

Experiments were performed on allergen-sensitized perfused rat ileum in vivo. Mucosal exudation of plasma, induced by local allergen perfusion, was measured as the appearance of circulating 125I-labelled albumin in the gut lumen. Experiments compared the anti-exudative effects of oral budesonide (0.1 mg/kg) with oral prednisolone (1, 3.3 or 10 mg/kg) and saline, given by oral gavage 24 h prior to allergen challenge, and of topical budesonide (3 x 10(-5) mol/L) with saline, administered in the perfusate 4 h prior to allergen challenge. Systemic glucocorticosteroid activity was assessed by weighing thymus glands after sacrifice.

RESULTS

Allergen-induced plasma exudation was significantly reduced by oral budesonide, oral prednisolone (dose-dependently) and topically applied budesonide; topical budesonide was effective within 4 h. While prednisolone significantly reduced the relative thymus weight at both 3.3 and 10 mg/kg, budesonide given orally, 0.1 mg/kg, or topically, 3 x 10(-5) mol/L, had no significant effect.

CONCLUSION

Budesonide, administered orally or topically, shows higher selectivity for the gut mucosa than prednisolone and produces local anti-inflammatory responses comparable to prednisolone, without the accompanying systemic effects.

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.

Modified wick method using Weck-Cel sponges for collection of human rectal secretions and analysis of mucosal HIV antibody

Weck-Cel sponges were examined for suitability as an absorbent material for nontraumatic collection of rectal secretions in humans. Sponges were tested in vitro and determined by quantitative enzyme-linked immunosorbent assay (ELISA) to be capable of releasing 100% of absorbed albumin and all immunoglobulin subtypes after treatment with detergent-supplemented buffer. Protein composition in rectal secretions collected from normal women with dry sponges (DS) or with sponges previously softened by moistening with saline (MS) was subsequently compared. DS secretions showed evidence of contamination with blood and interstitial fluid-derived albumin, immunoglobulin G (IgG), and monomeric IgA. MS secretions appeared to represent local mucosal secretions more accurately because they contained negligible blood, a greater percentage of secretory IgA within the total IgA, and both lower albumin/IgG ratios and more dramatic alterations in IgG subclass distribution compared with corresponding serum. Anti-HIV IgG, IgM, IgA, and antibodies with secretory component could be demonstrated by ELISA in rectal secretions collected with moist sponges from 8 of 8, 1 of 8, 5 of 8, and 3 of 8 HIV-infected women, respectively. The data show that Weck-Cel sponges, if premoistened, can be used to collect rectal fluids nontraumatically and to obtain quantitative information about concentrations of immunoglobulins and specific antibodies on rectal mucosal surfaces.

Relation between food provocation and systemic immune activation in patients with food intolerance

We found that food provocation in food intolerant patients was characterised by a general and systemic immune activation accompanied by an increase in systemic symptoms. Our findings might be important for the understanding of the mechanisms involved in the pathogenesis of food intolerance.

Immunoglobulin G and albumin levels in whole gut lavage fluid provide an objective measure of pouch ileitis

BACKGROUND

Gut protein loss is a characteristic of inflammatory bowel disease (IBD), and immunoglobulin (Ig) G, albumin and alpha1-antitrypsin concentrations in whole gut lavage fluid (WGLF) correlate with clinical disease activity. If inflammation in ileoanal pouches is similar to IBD, then measurement of protein-losing enteropathy by analysis of WGLF may provide an objective assessment of disease activity in pouches.

METHODS

Forty-two patients who had restorative proctocolectomy for ulcerative colitis underwent whole gut lavage with a polyethylene glycol-electrolyte solution. The first clear effluent was filtered, processed by the addition of protease inhibitors and stored at - 70 degrees C. IgG, albumin and alpha1-antitrypsin were assayed in WGLF. The Pouchitis Disease Activity Index (PDAI) was calculated after pouchoscopy and biopsy; the Moskowitz criteria for pouchitis were also applied.

RESULTS

There was a significant correlation of the pouchoscopy score and the PDAI with the concentration of WGLF IgG. All patients with 'pouchitis' according to the Moskowitz criteria had a WGLF IgG concentration greater than 10 microg/ml. The WGLF albumin level also showed a significant correlation with the PDAI, but alpha1-antitrypsin concentration did not.

CONCLUSION

Analysis of WGLF for IgG and albumin may be useful in the assessment of disease activity in pouch inflammation.

Intestinal inflammation in cystic fibrosis

BACKGROUND

There is controversy about whether the inflammatory response observed in the cystic fibrosis (CF) lung occurs secondary to bacterial infection or is caused by a dysregulation of the inflammatory response associated with the basic cellular defect of CF.

AIMS

To study the inflammatory response in the gastrointestinal tract of children with CF; and to investigate whether there is increased inflammation in the gastrointestinal tract of CF children with fibrosing colonopathy.

METHODS

Whole gut lavage was performed on 21 pancreatic insufficient children with CF, who were clinically well, five children with CF and fibrosing colonopathy, and 12 controls. Intestinal outputs of plasma derived proteins (albumin, alpha(1) antitrypsin, IgG), secretory immunoglobulins (IgA and IgM), cellular constituents (eosinophil cationic protein and neutrophil elastase), and cytokines (interleukin 8 and interleukin 1beta) were measured.

RESULTS

Compared to controls, the 21 CF patients, with no intestinal complications, had increased intestinal outputs of albumin, IgG, IgM, eosinophil cationic protein, neutrophil elastase, interleukin 1beta, and interleukin 8. Similar values were obtained for the CF patients with fibrosing colonopathy.

CONCLUSIONS

These data suggest that there is immune activation in the gastrointestinal mucosa of children with cystic fibrosis, which may result from the basic cellular defect. Fibrosing colonopathy does not appear to be associated with increased inflammation.

Distal proctocolitis and n-3 polyunsaturated fatty acids (n-3 PUFAs): the mucosal effect in situ

It has been postulated that patients with ulcerative colitis (UC) have altered reactivity of gut-associated lymphoid tissue. In such cases there is intense infiltration of the mucosa with immune competent cells and associated tissue damage. We have shown previously that the dietary supplementation with the n-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) results in significant systemic immune suppression. The aim of this study, therefore, was to evaluate the in situ effect of n-3 PUFAs on distal proctocolitis. Each patient received either fish oil extract (EPA 3.2 g, DHA 2.4 g) (n = 9) or sunflower oil (n = 9) daily in a double blind manner for six months. Monthly assessment included: (1) disease activity using clinical, sigmoidoscopic, and histological scores and (2) immunohistochemical analysis (immunoglobulins, CD profiles) of rectal biopsy specimens (before and after six months supplementation) using monoclonal antibodies and quantitative computer-assisted video image analysis. Prior to receiving supplementation, patients with proctocolitis (n = 18) showed significantly higher numbers of cells expressing CD3 (pan T cells) and HLA-DR and IgM containing cells compared with non-colitic controls (n = 8). Six months supplementation with n-3 PUFAs resulted in significant reduction in the number of cells expressing CD3 and HLA and the percentage of cells containing IgM. There was no significant change in the CD20 nor the percentage of IgG or IgA containing cells in either group of patients with procto-colitis. In patients receiving n-3 PUFA supplementation, there was improvement in the disease activity and histological scores, compared with pretreatment evaluation. This study has demonstrated both evidence of suppression of in situ immune reactivity and concurrent reduction in disease activity in patients with proctocolitis receiving n-3 PUFA supplementation. This may have important implication for therapy in patients with ulcerative colitis.

Crohn's disease: nutrition and nutritional therapy

Disordered nutrition is common in Crohn's disease and is multifactorial. Regular and systematic monitoring of at least a minimum set of nutrition data is an essential component of care of children and adults with Crohn's disease. However, even in children, monitoring of growth and development may be deficient. Multiple macro- and micronutrient deficiencies are common in Crohn's disease, especially in those with extensive small bowel deficiencies or after multiple surgical resections. Body composition analysis may show differences from simple starvation, and metabolic effects of inflammation are increasingly being recognized. Nutritional support is part of the management of all patients with Crohn's disease, but nutritional intervention with defined formula liquid diet is an effective specific anti-inflammatory therapy. Although meta-analysis of published trials suggest that steroids are more effective than defined formula liquid diets, objective evidence from whole gut lavage fluid analysis and from faecal excretion of radiolabelled leukocytes shows unequivocal benefit of elemental diet based on measuring parameters of tissue damage. Enteral feeding with liquid diets should be considered in patients with incomplete small bowel obstruction, severe painful perianal disease, failure of corticosteroids in active Crohn's disease, borderline intestinal failure and in children with active Crohn's disease or with growth failure.

Osmotic regulation of intestinal epithelial Na(+)-K(+)-Cl- cotransport: role of Cl- and F-actin

Previous data indicate that adenosine 3',5'-cyclic monophosphate activates the epithelial basolateral Na(+)-K(+)-Cl- cotransporter in microfilament-dependent fashion in part by direct action but also in response to apical Cl- loss (due to cell shrinkage or decreased intracellular Cl-). To further address the actin dependence of Na(+)-K(+)-Cl- cotransport, human epithelial T84 monolayers were exposed to anisotonicity, and isotopic flux analysis was performed. Na(+)-K(+)-Cl- cotransport was activated by hypertonicity induced by added mannitol but not added NaCl. Cotransport was also markedly activated by hypotonic stress, a response that appeared to be due in part to reduction of extracellular Cl- concentration and also to activation of K+ and Cl- efflux pathways. Stabilization of actin with phalloidin blunted cotransporter activation by hypotonicity and abolished hypotonic activation of K+ and Cl- efflux. However, phalloidin did not prevent activation of cotransport by hypertonicity or isosmotic reduction of extracellular Cl-. Conversely, hypertonic but not hypotonic activation was attenuated by the microfilament disassembler cytochalasin D. The results emphasize the complex interrelationship among intracellular Cl- activity, cell volume, and the actin cytoskeleton in the regulation of epithelial Cl- transport.

Antiinflammatory effects of enterically coated amoxicillin-clavulanic acid in active ulcerative colitis

The inflammatory activity of colonic mucosal lesions may be stimulated by intraluminal bacteria. Our aim was to investigate whether administration of broad-spectrum antibiotics decreases inflammatory activity in ulcerative colitis. To this end, we performed a randomized, 5-day study with either oral enterically coated amoxicillin-clavulanic acid (1 g + 250 mg, t.i.d.); i.v. methylprednisolone (40 mg/day) and oral placebo (t.i.d.); or both i.v. methylprednisolone and oral amoxicillin-clavulanic acid as above, in 30 patients with clinically active ulcerative colitis. Before and after 5 days of treatment, intestinal inflammation was assessed by the quantification of mucosal release of eicosanoids and interleukin-8 by rectal dialysis in each patient. Breath H2 excretion after oral lactulose was determined as an index of metabolic activity of colonic flora. The total release of (IL-8) interleukin-8 and eicosanoids significantly decreased in patients treated with antibiotic or steroids and antibiotic. Antibiotic treatment, but not steroids, markedly inhibited breath H2 excretion. In conclusion, short-term treatment with enteric-coated amoxicillin-clavulanic acid decreases the intraluminal release of IL-8 and other inflammatory mediators.

The effect of endoscopic injection therapy on the clinical outcome of patients with benign peptic ulcer bleeding

BACKGROUND

Our aim was to investigate the effect of endoscopic injection therapy on the clinical outcome of patients with benign peptic ulcer bleeding.

METHODS

In this study 1203 patients admitted with peptic ulcer bleeding over a 5-year period (January 1987 to April 1991) before endoscopic therapy and 1028 patients admitted with peptic ulcer bleeding after introduction of endoscopic therapy (May 1991 to March 1996) were assessed. Endoscopic therapy was performed in all patients with active bleeding or non-bleeding visible vessels during emergency endoscopy with injection of adrenaline, 1:10,000 in 0.9% saline.

RESULTS

The introduction of injection therapy was associated with a reduction in transfusion requirements (from 5.1 +/- 2.6 to 3.4 +/- 1.8 units), hospitalization days (from 10.8 +/- 6.5 to 7.8 +/- 5.1 days), surgical interventions (from 50.6% to 23.6%), and mortality (from 12.9% to 4.6%) in patients with active bleeding or non-bleeding visible vessels (P < 0.05) but remained unchanged in the rest. Patients with gastric ulcer had a more pronounced reduction in emergency surgical haemostasis and mortality than patients with duodenal ulcer. There were no deaths or procedure-related complications.

CONCLUSION

Endoscopic injection therapy with adrenaline/saline is a simple, low-cost, and safe method that improves the clinical outcome and reduces the mortality in patients with peptic ulcer bleeding.

Increased eosinophil granule proteins in gut lavage fluid from patients with inflammatory bowel disease

OBJECTIVE

To explore the potential role of eosinophils in the pathogenesis of inflammatory bowel disease (IBD).

DESIGN

We measured the concentrations of eosinophil granule proteins-namely, major basic protein, eosinophil peroxidase, eosinophil cationic protein, and eosinophil-derived neurotoxin-in gut lavage fluid.

MATERIAL AND METHODS

Ten healthy persons and 17 patients with IBD (9 with Crohn's disease and 8 with ulcerative colitis) underwent gut lavage. Each study subject submitted an early specimen when lavage effluent became liquid and a late specimen when the output became clear. The concentrations of the granule proteins were measured by immunoassay.

RESULTS

The median concentrations of eosinophil-derived neurotoxin and eosinophil cationic protein were significantly higher in patients with IBD than in control subjects for both early and late lavage specimens. Excretion of eosinophil peroxidase was also significantly higher in patients with IBD than in the healthy control subjects, but only in the early specimens. No differences were noted in the concentrations of any of the proteins between patients with ulcerative colitis and those with Crohn's disease.

CONCLUSION

Concentrations of eosinophil granule proteins were increased in whole gut lavage fluid from patients with IBD in comparison with healthy control subjects. These results encourage further studies of the role of eosinophils in the pathogenesis of IBD.

Characterization of mucin in whole-gut lavage fluid obtained from patients with inflammatory bowel disease

Whole-gut lavage fluid, collected by administering an electrolyte lavage solution orally, was found to be an excellent and easily collectable source of abundant mucin. Furthermore, the biochemical features of the mucin from patients with ulcerative colitis and Crohn's disease were investigated. The mucin was separated into four fractions by Sepharose CL-4B, Sepharose CL-2B, and DEAE Sephacel chromatography. Compared with healthy subjects, the total yields of mucin from ulcerative colitis patients were low due to a deficiency of neutral mucin, whereas those from Crohn's disease patients were high, which was attributable mainly to high-molecular-weight mucin. The fucose and sulfate contents were low in ulcerative colitis, but only the former was low in Crohn's disease. The different biochemical features of the mucin obtained from whole gut lavage fluid appear to reflect mucosal pathological changes associated with inflammatory bowel disease.

Investigation of neutrophils in the gut lumen by assay of granulocyte elastase in whole-gut lavage fluid

BACKGROUND

Intestinal neutrophils can be studied by radiolabelling techniques and by cytology of whole-gut lavage fluid. Our aim was to evaluate the use of a biochemical test for the presence of these cells in whole-gut lavage fluid.

METHOD

Whole-gut lavage was performed by having the patients drink a polyethylene-glycol-electrolyte solution; the clear fluid passed per rectum after complete bowel cleansing had been collected. In 203 patients granulocyte elastase was assayed in sonicated unfiltered lavage fluid, using the specific enzyme substrate L-pyroglutamyl-I-prolyl-L-valine-p-nitroanilide. Free granulocyte elastase was also assayed in filtered (that is, cell-free) lavage fluid in 39 of the 43 patients in whom the enzyme was present in unfiltered fluid. In 47 of the patients, cells were also separated by density gradient centrifugation, and counted.

RESULTS

Granulocyte elastase concentration correlated significantly with cell count (r = 0.80, p < 0.001). Granulocyte elastase concentration was high (> 100 nkat/l) in fluid from 25 of 68 inflammatory bowel disease patients and 6 of 135 others with radiation colitis, diverticulitis, pericolic abscess, and use of non-steroidal anti-inflammatory drugs. In patients with detectable total granulocyte elastase, cell-free granulocyte elastase was present in 11 of 29 with inflammatory bowel disease and 1 of 10 others.

CONCLUSION

Whole-gut lavage fluid samples can readily be used to investigate luminal inflammatory cells.

Soluble Fc gamma receptor III (CD 16) and eicosanoid concentrations in gut lavage fluid from patients with inflammatory bowel disease: reflection of mucosal inflammation

BACKGROUND

Activated neutrophils cause tissue injury in inflammatory bowel disease (IBD). Upon activation, they shed soluble Fc gamma IIIb receptors (sFc gamma RIIIb). The subsequent inflammatory response is modulated by several mediators, including neutrophil derived leukotriene B4 (LTB4), thromboxane B2 (TXB2), and prostaglandin E2 (PGE2). The aim of this study was to determine the value of gut lavage sFc gamma RIII and eicosanoid measurements for the assessment of mucosal inflammation in IBD.

METHODS

A total of 18 patients with active IBD, 10 ulcerative colitis (UC), and eight Crohn's disease (CD), and 12 control patients underwent whole gut lavage. Disease activity, endoscopic appearance, and histopathology were graded. Samples were processed for the determination of sFc gamma RIIIb, LTB4, PGE2, and TXB2.

RESULTS

Soluble Fc gamma RIIIb concentrations were increased in both IBD groups. Significant correlations were seen between sFc gamma RIIIb and LTB4 values with histology scores. Mean eicosanoid lavage fluid concentrations in control patients were 14.1 pg/ml for LTB4, 5.6 pg/ml for PGE2, and 397 pg/ml for TXB2. Concentrations of all eicosanoids in IBD patients were significantly increased: LTB4 in UC: mean 73.2 pg/ml, in CD: 96.4 pg/ml (both p < 0.01 v controls). PGE2 in UC: 20.2 pg/ml, in CD: 43.4 pg/ml (p < 0.01). TXB2 in UC: 719.3 pg/ml, in CD: 180.6 pg/ml (both p < 0.05).

CONCLUSIONS

Whole gut lavage fluid analysis is an effective method to study mucosal eicosanoid production. Soluble Fc gamma RIIIb concentrations in gut lavage fluid closely correlate with histological signs of mucosal inflammation and with lavage LTB4 concentration. These data suggest that lavage Fc gamma RIIIb assessment may be used as a simple assay to estimate mucosal neutrophil infiltration in IBD.

Mucosal antibodies in inflammatory bowel disease are directed against intestinal bacteria

In contrast with normal subjects where IgA is the main immunoglobulin in the intestine, patients with active inflammatory bowel disease (IBD) produce high concentrations of IgG from intestinal lymphocytes, but the antigens at which these antibodies are directed are unknown. To investigate the specificities of these antibodies mucosal immunoglobulins were isolated from washings taken at endoscopy from 21 control patients with irritable bowel syndrome, 10 control patients with intestinal inflammation due to infection or ischaemia, and 51 patients with IBD: 24 Crohn's disease (CD, 15 active, nine quiescent), 27 ulcerative colitis (UC, 20 active, seven inactive). Total mucosal IgG was much higher (p < 0.001) in active UC (median 512 micrograms/ml) and active CD (256 micrograms/ml) than in irritable bowel syndrome controls (1.43 micrograms/ml), but not significantly different from controls with non-IBD intestinal inflammation (224 micrograms/ml). Mucosal IgG bound to proteins of a range of non-pathogenic commensal faecal bacteria in active CD; this was higher than in UC (p < 0.01); and both were significantly greater than controls with non-IBD intestinal inflammation (CD p < 0.001, UC p < 0.01) or IBS (p < 0.001 CD and UC). This mucosal IgG binding was shown on western blots and by enzyme linked immunosorbent assay (ELISA) to be principally directed against the bacterial cytoplasmic rather than the membrane proteins. Total mucosal IgA concentrations did not differ between IBD and controls, but the IgA titres against faecal bacteria were lower in UC than controls (p < 0.01). These experiments show that there is an exaggerated mucosal immune response particularly in active CD but also in UC directed against cytoplasmic proteins of bacteria within the intestinal lumen; this implies that in relapse of IBD there is a breakdown of tolerance to the normal commensal flora of the gut.

Enzymes in intestinal juice from patients with liver diseases and colon polyps: measurement of bilirubin, alkaline phosphatase, aspartate aminotransferase and lactate dehydrogenase

Since the amounts of hepatogenous enzymes discharged into the intestinal tract remain unknown, this study was initiated to evaluate the amounts of the enzymes in the intestinal tract. Whole gut lavage fluid (polyethyleneglycol electrolyte solution) was administered orally to 42 subjects, consisting of 5 patients with hepatoma, 10 with chronic hepatitis, 10 with colon polyps, and 17 control subjects without liver disease. Two hr after the large intestinal lavage, the digestive tract juice was aspirated by colonoscopy, and the bilirubin (Bil), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in the aspirates were measured. A positive correlation between the AST and LDH values was found, and a significant difference in these values between the hepatic disorders and the normal controls was noticed. A significant positive correlation between the ALP and Bil values was found, and a statistical difference in these values between the group of colon polyps and the controls and other groups was observed. This lavage fluid technique enables to estimate the amounts of hepatic enzymes discharged into the intestinal tract, thereby opening a new avenue for future enzyme research.

Selective IgA deficiency, hypothyroidism and congenital lymphoedema

The occurrence of selective IgA deficiency and hypothyroidism with congenital lymphoedema has never previously been documented, although the association of hypogammaglobulinaemia with congenital lymphoedema has previously been reported and can result in recurrent respiratory infections. We report a 34 year old woman with congenital lymphoedema who was found to have symptomatic autoimmune hypothyroidism and asymptomatic selective IgA deficiency.

Lipocortin-1 autoantibody concentration in children with inflammatory bowel disease

BACKGROUND

Corticosteroids are widely used to treat children with inflammatory bowel disease although the response is variable, side-effects are common, and many patients develop a partial or complete steroid resistance. The mechanism underlying these phenomena are unclear. Corticosteroids mediate some of their actions through lipocortin-1, and the induction of autoantibodies to lipocortin has been proposed as a possible mechanism by which steroid efficacy is suboptimal in vivo.

PATIENTS AND METHODS

We have measured serum lipocortin-1 antibody concentration by ELISA in 38 children with Crohn's disease, 12 with ulcerative colitis and in 15 controls.

RESULTS

IgG and IgA anti-lipocortin-1 antibody levels were higher in the Crohn's group than in the ulcerative colitis or control groups. Elevated concentrations did not relate to disease activity, history of steroid therapy or steroid-responsiveness. Lipocortin IgM antibody status was similar in all three groups.

CONCLUSION

It is therefore unlikely that serum antibodies to lipocortin-1 have a role in the development of steroid-resistance in children with inflammatory bowel disease.

Technical report: results of immunological tests on faecal extracts are likely to be extremely misleading

Clinical investigation of gut immunity is difficult because of the need to study intestinal tissues or secretions directly. Others have reported that immunoglobulins, antibodies and cytokines can be detected in saline extracts of faeces. We have assessed the validity of this approach by measuring immunoglobulins, albumin, alpha 1-antitrypsin and isotype-specific antibodies in matched samples of faeces and whole gut lavage fluid. Results were compared as estimated output per day, and by using haemoglobin as a common reference substance. Samples were obtained from 10 patients with active inflammatory bowel disease and 10 with other benign GI diseases. For immunoglobulins, albumin and antibodies, the amount detected in faeces varied from < 0.01% to 35.5% (based on estimated daily output) and < 0.01% to 18.5% (based on haemoglobin) of the amount known to be produced in the gut from results of assays on whole gut lavage fluid (WGLF); there were significantly higher rates of recovery in faecal specimens from patients with active gut inflammation than from other patients. Detection rates and titres of specific antibody in faeces were even lower than those for immunoreactive IgA. These data indicate that immunological tests on saline extracts of faeces do not represent the true status of the gut humoral immune system, and such studies should be strongly discouraged.

Treatment of inflammatory bowel disease from now to the millennium

After decades of therapeutic stasis, treatment advances are occurring in inflammatory bowel disease. Recognition that mesalazine was the active moiety of sulphasalazine has led to a number of new methods of delivering mesalazine without sulphapyridine, with improved toxicity ratios. Current attempts to deliver topical steroids directly to the large bowel have yet to be established as therapeutically effective. Immunosuppressive treatment has been used for many years but recent evidence has firmly established its value and cyclosporin has recently been added to the therapeutic armamentarium. Increasing understanding of the basic processes of inflammation has yielded targets for anti-inflammatory treatments aimed both at the processes of immune activation and of attraction by chemotaxis of neutrophils from the circulation to the lamina propria. Some of these novel treatments, which will be assessed in forthcoming years, involve large molecular weight bioengineered peptides and antibodies that are likely to be expensive and difficult to administer. Other treatment, e.g. 5-lipoxygenase or thromboxane synthesis inhibitors or platelet-activating factor antagonists, are conventional lower molecular weight compounds that are easier to produce and are orally active. It is predicted that 5-lipoxygenase inhibitors will be the next therapeutic advance in inflammatory bowel disease. Such a prediction may founder if blanket suppression of multiple inflammatory mechanisms, rather than targeted actions, is required in inflammation.