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

The logics of leukocytapheresis as a natural biological therapy for inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD) are debilitating idiopathic inflammatory bowel diseases (IBDs) with symptoms that impair ability to function and quality of life. The aetiology of IBD is inadequately understood and, therefore, drug therapy has been empirical instead of based on sound understanding of the disease mechanisms. This has been a major factor for poor drug efficacy and treatment-related side effects that often add to disease complications. The development of biologicals, notably infliximab, to block TNF-alpha reflects some progress, but there is major concern about their side effects and lack of long-term safety and efficacy profiles. However, IBD by its very nature is exacerbated and perpetuated by inflammatory cytokines, including TNF-alpha, IL-6 and IL-12, for which activated peripheral blood lymphocytes, monocytes/macrophages and granulocytes are major sources. Hence, activated leukocytes should be appropriate targets of therapy. At present, three strategies are available for removing excess and activated leukocytes by leukocytapheresis: centrifugation, Adacolumn and Cellsorba. Centrifugation can deplete lymphocytes or total leukocytes, whereas Adacolumn selectively adsorbs granulocytes and monocytes together with a smaller fraction of lymphocytes (FcgammaR- and complement receptor-bearing leukocytes), and Cellsorba non-selectively removes all three major leukocyte populations. Efficacy has ranged from 'none' to an impressive 93% together with excellent safety profiles and downmodulation of inflammation factors. Furthermore, leukocytapheresis has shown strong drug-sparing effects and reduced the number of patients requiring colectomy or exposure to unsafe immunosuppressants, such as cyclosporin A. Leukocytapheresis removes from the body cells that contribute to IBD and, therefore, unlike drugs, it is not expected to induce dependency or refractoriness.

Asymptomatic ileitis: past, present, and future

We critically review the limited data on an emerging clinical entity, asymptomatic ileitis. We discuss some of the current theorized etiologies of this phenomenon, including subclinical Crohn's disease, nonsteroidal anti-inflammatory drugs, and spondylarthropathies. Finally, we discuss future areas of investigation that may better help identify and evaluate this increasingly common finding.

Combined use of noninvasive tests is useful in the initial diagnostic approach to a child with suspected inflammatory bowel disease

OBJECTIVE

To assess the effectiveness of the combined use of fecal calprotectin (FC), anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear staining antineutrophil antibody (pANCA), small intestinal permeability test (IP), and bowel wall ultrasonography measurement (BWUS) in the diagnostic work-up of children with suspected inflammatory bowel disease (IBD).

METHODS

All children referred for initial assessment of possible IBD were eligible. Patients with symptoms or signs (right-lower quadrant mass, perianal disease, or hematochezia) mandating a complete work-up for IBD were excluded. All enrolled patients underwent a clinical, laboratory, radiographic, and endoscopic evaluation including biopsy examinations. The immunoglobulin (Ig)G and IgA ASCA, IgG pANCA, FC, IP, and BWUS were tested in all patients at the initial assessment.

RESULTS

A final diagnosis of IBD was made in 27 patients: 17 Crohn disease and 10 ulcerative colitis. Eighteen children had other gastrointestinal diagnoses (8 functional bowel disorders, 5 food allergy-mediated diseases, 4 infectious enterocolitis, 1 familial Mediterranean fever). In patients with simultaneous abnormal values of FC, BWUS, and ASCA/pANCA, the estimated probability of having IBD was 99.47%. Patients with negative results on all tests had a 0.69% of probability of IBD.

CONCLUSIONS

The incorporation of noninvasive diagnostic tests into the initial diagnostic approach may avoid unnecessary invasive procedures and facilitate clinical decision-making when the diagnosis of IBD in children is initially uncertain.

Developments in the apheresis procedure for the treatment of inflammatory bowel disease

Initially used to treat rheumatoid arthritis, nonselective therapeutic leukocytapheresis was applied to the treatment of inflammatory bowel disease (IBD) as early as the 1980s. Since then, the process has been further refined and 2 blood perfusion systems using membrane filtration are presently employed in Japan and Europe for the selective removal of leukocytes in patients with IBD: Cellsorba is a column of polyethylenephtarate fibers that captures lymphocytes and granulocytes, and Adacolumn is a column of cellulose acetate beads that selectively adsorb granulocytes and monocytes. These systems overcome the limitations of centrifugation. Leukocytapheresis has been shown to exert an overall anti-inflammatory effect, as peripheral leukocytes demonstrated a diminished capacity to produce inflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1, IL-6, IL-8, and IL-1beta. In addition, down-regulation in the expression of adhesion molecule L-selectin and a shift toward a more immature granulocyte phenotype were observed in the peripheral blood. The safety and beneficial therapeutic effect of leukocytapheresis in IBD are being investigated further.

Preliminary data on the use of apheresis in inflammatory bowel disease

In patients with inflammatory bowel disease (IBD), centrifugation has been attempted to remove leukocyte components from whole blood; however, the use of selective filters has proved to result in more active modification of cellular immunity in that 4 times as many white blood cells are removed, which may result in a greater therapeutic effect. Selective apheresis for treatment of IBD, in particular ulcerative colitis (UC), has been used in Japan and some European countries for several years; pilot studies with Adacolumn, a selective therapeutic granulocyte/monocyte apheresis device, in patients with IBD have recently been completed in the United States with favorable results. Unlike conventional pharmacological treatments, selective apheresis may be associated with a relatively low rate of adverse events. Multiple studies have suggested that selective apheresis may be of benefit as a steroid-sparing treatment. In an unblinded randomized trial in 69 steroid-dependent patients with active UC randomized to selective apheresis with Adacolumn or an increased dose of prednisolone, 83% of patients receiving Adacolumn achieved remission compared with 65% of those receiving an increased dose of prednisolone. In another uncontrolled study of 60 patients with active UC, treatment with Adacolumn selective apheresis enabled nearly 70% of steroid-dependent patients to discontinue prednisolone. An unblinded randomized controlled trial of a different selective apheresis device (Cellsorba) versus high-dose prednisolone in patients with active UC showed a greater therapeutic effect (74%) than high-dose prednisolone (38%) and lower frequency of adverse effects (24% versus 68%).

Adacolumn for selective leukocytapheresis as a non-pharmacological treatment for patients with disorders of the immune system: an adjunct or an alternative to drug therapy?

Inflammatory and/or autoimmune diseases like ulcerative colitis (UC) or Crohn's disease (CD) are debilitating chronic disorders that poorly respond to pharmacological interventions. Further, drug therapy has adverse effects that add to disease complications. The current thinking is that disorders like inflammatory bowel disease (IBD) reflect an over exuberant immune activation driven by cytokines including TNF-alpha. Major sources of cytokines include myeloid leukocytes (granulocytes, monocytes/macrophages), which in IBD are elevated with activation behavior and are found in vast numbers within the inflamed intestinal mucosa. Accordingly, myeloid cells should be the targets of therapy. Adacolumn is filled with cellulose acetate beads that selectively adsorb and deplete myeloid cells and a small fraction of lymphocytes (FcgammaR and complement receptors bearing cells). In one study, 20 steroid naive patients with moderate (n = 14) or severe (n = 6) UC according to Rachmilewitz despite 1.5-2.25 g/day of 5-aminosalicylic acid received 6 to 10 Adacolumn sessions at 2 sessions/week. Efficacy was assessed 1 week after the last session. The majority of patients responded to 6 sessions, 17 (85%) achieved remission. In 2 of the 3 non-responders, CAI was 8 and 12 in 1; all 3 had deep colonic ulcers at study initiation. Decreases were seen in total leukocytes (P = 0.003), % neutrophils (P = 0.003), % monocytes (P = 0.004), an increase in lymphocytes (P = 0.001), decreases in C-reactive protein (P = 0.0002), and rises in blood levels of soluble TNF-alpha receptors I (P = 0.0007), II (P = 0.0045). In a separate study, a case with very severe steroid refractory UC who received up to 11 sessions responded well and avoided colectomy. Further, myeloid cell purging with Adacolumn has been associated with the release of IL-1 receptor antagonist, suppression of TNF-alpha, IL-1beta, IL-6, IL-8, down-modulation of L-selectin and the chemokine receptor CXCR3. In conclusion, selective depletion of myeloid cells appears to induce anti-inflammatory effects and represents a non-pharmacological treatment for patients with active IBD. The treatment has a clear drug-sparing role. Changes in blood levels of inflammatory and anti-inflammatory factors are thought to contribute to the efficacy of this procedure.

Abrogation of IFN-gamma mediated epithelial barrier disruption by serine protease inhibition

The intestinal barrier function is often impaired in a variety of diseases including chronic inflammatory bowel disease. Increased intestinal permeability during episodes of active disease correlates with destruction or rearrangement of the tight junction protein complex. IFN-gamma has been widely studied for its effect on barrier function and tight junction structures but its mode of action remains unclear. Since the claudin family of tight junction proteins is proposed to be involved in barrier maintenance we studied the effect of IFN-gamma on claudin expression in relation to epithelial barrier function. Cycloheximide and protease inhibitors were used to study mechanisms of IFN-gamma mediated barrier disruption. Intestinal epithelial cells were exposed to IFN-gamma and permeability was evaluated by horse radish peroxidase (HRP) and 4 kD FITC-dextran fluxes. Occludin and claudin-1, -2, -3, and -4 tight junction protein expression was determined by Western blotting. Occludin and claudin-2 protein expression was dramatically reduced after IFN-gamma exposure, which correlated with increased permeability for HRP and FITC-dextran. Interestingly, cleavage of claudin-2 was observed after incubation with IFN-gamma. Serine protease inhibitor AEBSF completely abrogated IFN-gamma mediated barrier disruption which was associated with preservation of claudin-2 expression. Moreover, IFN-gamma induced loss of barrier integrity was found to affect claudin-2 and occludin expression through different mechanisms. Since inhibition of serine protease activity abrogates IFN-gamma mediated barrier disruption this may be an important target for therapeutic intervention.

Faecal calprotectin in children with chronic gastrointestinal symptoms

AIMS

Faecal calprotectin, a neutrophil cytosolic protein, is raised in inflammatory bowel disease. We assessed this investigation in evaluating children with chronic intestinal symptoms.

METHODS

Stool samples from 100 children aged 5-17 years (referrals to the regional paediatric gastroenterology service) were tested using a commercially available kit.

RESULTS

Calprotectin was higher in inflammatory bowel disease than normal children (p<0.0001) or in those with functional constipation (p<0.0001). The overall specificity for organic bowel disorders was 85%. Calprotectin correlated with C-reactive protein in inflammatory bowel disease (p=0.001), and clinical disease activity in ulcerative colitis (p=0.017), but not with disease activity in Crohn's disease.

CONCLUSION

Raised faecal calprotectin should prompt further assessment in children with chronic intestinal symptoms, since an organic bowel disorder is likely. However, calprotectin cannot be regarded as a specific test for idiopathic inflammatory bowel disease.

Comparison of 4 neutrophil-derived proteins in feces as indicators of disease activity in ulcerative colitis

BACKGROUND

To evaluate the diagnostic use of fecal concentrations of lactoferrin (Lf), calprotectin (Cal), polymorphonuclear neutrophil-elastase (PMN-e), and lysozyme (Lys) as indicators of disease activity in patients with active and inactive ulcerative colitis (UC).

METHODS

A total of 76 fecal specimens were collected from 31 patients with UC in times of active and inactive status of disease. Disease activity was determined with the colitis activity index (CAI; Rachmilewitz index), which includes a combination of laboratory parameters and clinical symptoms, with a score of at least 6 indicating active disease. Fecal Lf, Cal, PMN-e, and Lys were measured and reported as micrograms per milliliter feces. Levels of more than 7.25, more than 6.00, at least 0.062, and at least 0.6 for Lf, Cal, PMN-e, and Lys, respectively, were considered elevated as specified by the manufacturers.

RESULTS

Based on the CAI classification, 25 of the samples were from patients with active disease status and 51 were from patients with inactive status. Lf, PMN-e, and Cal but not Lys showed increased levels in samples from patients in active disease compared with those in remission (median for Lf: 28.12 +/- 110.86 versus 179.54 +/- 334.09, P < 0.001; median for Cal: 15.13 +/- 30.27 versus 116.23 +/- 182.29, P < 0.001; median for PMN-e: 0.21 +/- 0.44 versus 1.02 +/- 0.89, P < 0.001; median for Lys: 1.54 +/- 2.39 versus 3.75 +/- 5.39, P > 0.05). All 4 parameters correlated with the CAI (Lf: r = 0.441, P < 0.001; Cal: r = 0.505, P < 0.001; PMN-e: r = 0.604, P < 0.001; Lys: r = 0.295, P < 0.05). Introducing a composite index based on Lf, Cal, and PMN-e, the specificity was 72.5% and the sensitivity 88% compared with the CAI.

CONCLUSIONS

Among the neutrophil-derived proteins in feces, PMN-e, Cal, and Lf represent useful markers of disease activity in patients with UC. Using all 3 markers in a composite index may be an additional noninvasive tool for the management of ambulant patients with UC.

Technology insight: calprotectin, lactoferrin and nitric oxide as novel markers of inflammatory bowel disease

Distinguishing patients with inflammatory bowel disease from those with irritable bowel syndrome can be difficult. A simple and reliable test that detects intestinal inflammation would therefore be very useful in the clinic. If such a test parameter correlated with the intensity of the inflammatory reaction it could also be used to monitor disease activity. Calprotectin, lactoferrin and nitric oxide are produced and released locally in much greater quantities in the inflamed gut than in the noninflamed gut. These compounds can be readily measured in fecal samples (calprotectin and lactoferrin) or directly in the intestinal lumen (nitric oxide gas). Here, we discuss what is known about these markers, how they could be used in clinical practice and how they can complement existing techniques used for the diagnosis and monitoring of inflammatory bowel disease.

Appendix is a priming site in the development of ulcerative colitis

AIM: The role of the appendix has been highlighted in the pathogenesis of ulcerative colitis (UC). The aims of this study were to elucidate the immuno-imbalances in the appendix of UC patients, and to clarify the role of the appendix in the development of UC.

METHODS: Colonoscopic biopsy specimens of the appendix, transverse colon, and rectum were obtained from 86 patients with UC: active pancolitis (A-Pan; n = 15), active left-sided colitis (A-Lt; n = 25), A-Lt with appendiceal involvement (A-Lt/Ap; n = 10), inactive pancolitis (I-Pan; n = 14), and inactive left-sided colitis (I-Lt; n = 22), and from controls. In the isolated mucosal T cells, the CD4/CD8 ratio and proportion of activated CD4+ T cells were investigated, and compared with controls.

RESULTS: In the appendix, the CD4/CD8 ratio significantly increased in A-Lt and A-Lt/Ap. The ratio in the appendix also tended to increase in A-Pan. In the rectum, the ratio significantly increased in all UC groups. In the appendix, the proportion of CD4+CD69+ (early activation antigen) T cells significantly increased in all UC groups. In the rectum, the proportion of CD4+CD69+ T cells significantly increased only in A-Pan. The proportion of CD4+HLA-DR+ (mature activation antigen) T cells significantly increased only in the rectum of A-Pan, but not in the other areas of any groups.

CONCLUSION: The increased CD4/CD8 ratio and predominant infiltration of CD4+CD69+ T cells in the appendix suggest that the appendix is a priming site in the development of UC.

Infliximab reverses growth hormone resistance associated with inflammatory bowel disease

BACKGROUND

Increasing evidence shows that inflammation plays a major role in the aetiology of catabolism and wasting observed in inflammatory bowel disease via growth hormone resistance.

AIM

To evaluate the effect of infliximab treatment on the growth hormone/insulin-like growth factor-1 axis.

METHODS

Fourteen adults with active Crohn's disease or ulcerative colitis underwent three infliximab infusions at a dose of 5 mg/kg for induction of remission, plus two maintenance infusions 8 weeks apart. Blood samples were collected for the analysis of serum growth hormone, insulin-like growth factor-1, insulin-like growth factor-binding protein-3 and acid labile subunit.

RESULTS

Serum insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 concentrations, which were significantly lower in inflammatory bowel disease patients before treatment compared with controls (P < 0.01), significantly increased during the induction phase (+58% and +29%, respectively, after the second infusion, P < 0.01), and dropped to baseline levels during maintenance therapy. Both insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 showed significant negative correlations with C-reactive protein (rho = -0.37, P = 0.002; rho = -0.35, P = 0.01, respectively). Growth hormone and acid labile subunit levels were not statistically different between controls and inflammatory bowel disease patients either at baseline or during treatment.

CONCLUSIONS

Infliximab induction treatment reverses growth hormone resistance observed in active inflammatory bowel disease through the suppression of systemic inflammation. The restored growth hormone/insulin-like growth factor-1 axis is impaired again following the prolonged interval between maintenance infusions, possibly because of the subclinical reactivation of the inflammatory process.

Colorectal inflammation is well predicted by fecal calprotectin in children with gastrointestinal symptoms

OBJECTIVES

The protein calprotectin is mainly derived from neutrophils. Increased fecal excretion of calprotectin has been reported in inflammatory bowel disease. The recommended cut-off level in adults (<50 microg/g feces) seems to be applicable in children aged 4 to 17 years. The aim of this study was to evaluate the use of fecal calprotectin to detect colorectal inflammation in children with gastrointestinal symptoms.

METHODS

We obtained stool samples on thirty-six children with gastrointestinal symptoms and suspected inflammation of the colon before they underwent colonoscopy. The samples were examined with an improved fecal calprotectin enzyme-linked immunosorbent assay method (Calprest, Eurospital). The results were correlated with the histopathologic findings in the colon.

RESULTS

In children with colorectal inflammation (n = 22) the median fecal calprotectin concentration was 349 microg/g (range, 15.4-1860 microg/g). The most common diagnosis in this group was inflammatory bowel disease. Median fecal calprotectin was 16.5 microg/g (range, 5.0-65 microg/g) in children with no inflammation (n = 14). When <50 microg/g was used as upper reference limit the fecal calprotectin test had a sensitivity of 95%, specificity 93%, positive predictive value 95% and negative predictive value 93% to detect colorectal inflammation.

CONCLUSIONS

The improved fecal calprotectin enzyme-linked immunosorbent assay is a simple test with potential use in children. Increased fecal calprotectin strongly predicted the presence of colorectal inflammation in children with gastrointestinal symptoms. Fecal calprotectin can be used to select patients who should undergo diagnostic colonoscopy for investigation of colorectal inflammation, including inflammatory bowel disease.

Leukocytapheresis (LCAP) for management of fulminant ulcerative colitis with toxic megacolon

Leukocytapheresis (LCAP) is a method of therapeutic apheresis to remove patients' peripheral leukocytes by extracorporeal circulation. Previous studies showed that LCAP for the treatment of ulcerative colitis (UC) was more effective and had fewer adverse effects compared to high-dose steroid therapy. However, there are no reports on the application of LCAP for UC patients with toxic megacolon (TM). This study reports the effectiveness and safety of LCAP in treating patients with severe or fulminant UC with TM. Six patients were enrolled in this study and LCAP sessions were performed three times per week for 2 weeks, followed by four further times in the next 4 weeks. After completion of therapy, four patients improved in TM and went into the remission stage of UC. The average Rachmilewitz clinical activity index of these four patients improved from 19.5 to 1. The remaining two patients had to undergo colectomy, however, the symptoms had been mitigated by LCAP and the operations were completed without any problems. These results suggest that LCAP is an additional effective and safe option for TM management in preventing colectomy or for bridging to a safer operation.

Phagocyte-specific calcium-binding S100 proteins as clinical laboratory markers of inflammation

The EF-hand homolog family of S100 proteins comprises the largest group of calcium-binding proteins. Within this S100 family, the phagocyte-specific calcium-binding proteins are pro-inflammatory molecules expressed and secreted by phagocytes, which play a pivotal role within the innate immune system. Although the exact biological functions of these proteins still remain to be defined in greater detail, there is evidence that they are involved in a pro-inflammatory axis associated with various inflammatory conditions. The three members of this group, S100A8, S100A9 and S100A12 are overexpressed at local sites of inflammation. High concentrations are found in synovial fluid, sputum, stool and blood plasma/serum during inflammation. Both the S100A8/S100A9 complex and S100A12 have been proven to be useful as diagnostic markers of inflammation especially in non-infectious inflammatory diseases such as arthritis, chronic inflammatory lung and bowel disease. They indicate phagocyte activation more sensitively than conventional parameters of inflammation. As a consequence, there is a strong correlation to the inflammation of various acute and chronic disorders, making these proteins sensitive parameters for the monitoring of disease activity and response to treatment in individual patients. The phagocyte-specific S100 proteins are able to indicate minimal residual inflammation, which is not detected by other diagnostic tests, and they may even be prospective markers for the outcome of patients. In this review, pro-inflammatory functions of S100 proteins and their usefulness as biomarkers of inflammation are presented.

Mesenteric pulsatility index analysis predicts response to azathioprine in patients with Crohn's disease

OBJECTIVE

Mesenteric blood flow measurement has been found to predict relapse after steroid-induced remission in patients with Crohn's disease (CD) and ulcerative colitis (UC). Therefore, we assessed prospectively the possible relationship between changes in mesenteric blood flow and prognosis in chronically active patients with need of immunosuppressive therapy with azathioprine (AZA) or 6-mercaptopurine (6-MP).

METHODS

Doppler ultrasound (DUS) measurements of the pulsatility index (PI) of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) were performed in 52 patients with chronically active inflammatory bowel disease (CD 31 patients; UC 21 patients) before beginning therapy with AZA/6-MP (US1) and during clinical remission (CD activity index <150, Truelove index score I) (US2). Patients were weaned from concomitant therapy with corticosteroids as soon as possible and were followed up for 12 months.

RESULTS

After 1 year, 16 patients with CD (51.6%) and 13 patients with UC (61.9%) were in remission, whereas 23 patients had recurrent disease or had undergone surgery. A decreased SMA PI at US2 predicted clinical relapse in all patients with CD [100%; P < 0.001; mean (+/-SD) 77 +/- 67 d after US1], but only 4 of 8 patients (50%; difference not significant; mean 84 +/- 75 d after US1) with UC. Conversely, an increase of SMA PI was associated with sustained remission in the majority of CD patients (12/16 patients; 75%; P < 0.002), but in only 7 of 13 patients (54%) with UC. Flow measurements in the IMA and postprandial values for both arteries were less reliable.

CONCLUSION

Repeated DUS measurements of the SMA PI predict response to AZA/6-MP in patients with chronic active CD.

Stool decay-accelerating factor as a marker for monitoring the disease activity during leukocyte apheresis therapy in patients with refractory ulcerative colitis

BACKGROUND AND AIMS

We have shown previously that concentrations of stool decay-accelerating factor (DAF; CD55), a complement regulatory protein, in patients with ulcerative colitis (UC) are increased in relation to the severity of the colonic mucosal inflammation. In the present study, we evaluated the usefulness of stool DAF as a marker for monitoring disease activity in patients with steroid-resistant active UC being treated with leukocyte apheresis performed with a centrifugal cell separator.

METHODS

Twenty-one patients with active and steroid-resistant UC were treated with leukocyte apheresis once a week for 4 weeks, and stool DAF concentrations were determined weekly by immunoassay.

RESULTS

After treatment, 11 (52%) of the 21 UC patients went into remission. Stool DAF concentrations decreased promptly and steadily in the responsive group. The difference reached statistical significance as soon as after the second apheresis session (P < 0.003), compared with values before the therapy and corresponding values in the non-responsive group (P = 0.024). The reduction in stool DAF concentrations after the second apheresis session was significantly greater in the responsive group (median 90%, range 22-90%) than in the non-responsive group (median -13%, range -307-94%) (P = 0.008). Hematological tests, that is, white blood cell (WBC) count and C-reactive protein, declined significantly during the apheresis therapy, but not in relation to therapeutic response.

CONCLUSION

Stool DAF concentration is a useful marker in the clinical response of UC patients to treatment with leukocyte apheresis.

Clinical evaluation of granulocyte/monocyte apheresis therapy for active ulcerative colitis

BACKGROUND

Recent evidence suggests that peripheral blood granulocytes and monocytes/macrophages have a major role in the exacerbation of ulcerative colitis.

AIMS

Our objective was to investigate if selective granulocyte and monocyte adsorptive apheresis with Adacolumn promotes remission of active ulcerative colitis and spares corticosteroid.

SUBJECTS

Sixty patients with active ulcerative colitis were studied, of whom 39 had relapsing-remitting ulcerative colitis, 15 had chronic continuous and 6 had their first episode of ulcerative colitis.

METHODS

Granulocytapheresis was done with an Adacolumn filled with cellulose acetate beads as apheresis carriers that adsorb FcgammaR and complement receptors bearing leucocytes (granulocytes, monocytes and a small fraction of lymphocytes). Patients received up to 10 Adacolumn sessions over 12 weeks, one session was 60-90 min at 30 mL/min. No additional medication was given. Efficacy was assessed with Seo's activity index (AI) [Seo M, Okada M, Yao T. An index of disease activity in patients with ulcerative colitis. Am J Gastroenterol 1992;87:971-6]. The mean AL was 197.5 and range 154.4-277.7. AI < 150 was considered significant improvement and AI < 100 was considered clinical remission.

RESULTS

Of 60 patients, 50 (83.3 %) improved, 14 achieved remission, granulocytapheresis was most effective in steroid-dependent patients. At entry, the mean dose of prednisolone was 15.3 mg/day per patient and was reduced to 3.6 mg/day after 10 sessions. Granulocytapheresis was well tolerated and no serious side-effects were observed.

CONCLUSION

Based on our experience in patients with diverse ulcerative colitis disease expression and long-term exposure to conventional drug therapy, we believe that granulocytapheresis is an effective adjunct to conventional medication for promoting remission and sparing steroids in patients with active ulcerative colitis.

Clinical Assessment of Disease Activity for Canine Inflammatory Bowel Disease

Clinical indices, consisting of gastrointestinal signs and laboratory parameters, are widely used for assessing disease activity in human inflammatory bowel disease (IBD). The development of a standardized scoring index for use in dogs with IBD would be useful in the management of clinical cases, both at diagnosis and in response to medical therapy. This review provides a synopsis of current strategies used to assess IBD activity in humans and companion animals. The clinical application of a simple scoring index (e.g., canine IBD activity index [CIBDAI]) for measurement of canine IBD activity is also reviewed.

Diagnostic accuracy of faecal calprotectin estimation in prediction of abnormal small bowel radiology

BACKGROUND

[corrected] Patients being investigated for symptoms of abdominal pain, diarrhoea and or weight loss often undergo small bowel radiology as part of their diagnostic workup mainly to exclude inflammatory bowel disease.

AIM

To assess and compare the utility of a single faecal calprotectin estimation to barium follow through as well as conventional inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein in exclusion of intestinal inflammation.

METHODS

Seventy-three consecutive cases undergoing barium follow through for investigation of symptoms of diarrhoea and or abdominal pain with or without weight loss were studied. The control group comprised 25 cases with known active Crohn's disease (positive controls), 26 normal healthy volunteers (negative controls) and 25 cases of irritable bowel syndrome diagnosed by Rome II criteria. Symptoms, erythrocyte sedimentation rate and C-reactive protein were recorded at recruitment and a single stool sample assayed for calprotectin within 7 days prior to or after barium follow through.

RESULTS

The median calprotectin value in the active Crohn's group, irritable bowel syndrome group and normal volunteers was 227 microg/g of stool, 19 and 10 microg/g respectively (P < 0.0001). A faecal calprotectin above a cut-off value of 60 microg/g was able to predict all nine cases with an abnormal barium follow through as well as all six cases with a normal barium follow through but with organic intestinal disease. The negative predictive value of a single calprotectin result below 60 microg/g of stool was 100% compared with 91% each for erythrocyte sedimentation rate > 10 mm and C-reactive protein > 6 mg/L and 84% for a combination of erythrocyte sedimentation rate and C-reactive protein in predicting absence of organic intestinal disease.

CONCLUSION

A single stool calprotectin value < 60 microg/g of stool obviates the need for further barium radiology of the small bowel, is more accurate than measurement of erythrocyte sedimentation rate or C-reactive protein and effectively excludes Crohn's disease or non-functional gastrointestinal disease.

Correlation of serum soluble TNF-alpha receptors I and II levels with disease activity in patients with ulcerative colitis

OBJECTIVES

TNF-alpha has a major role in inflammatory bowel disease via two receptors, p55 (RI) and p75 (RII) expressed on many cell types, in particular neutrophils and monocytes (GM). Upon activation of these leukocytes, RI and RII are shed into the medium and can neutralize TNF. Accordingly, soluble RI and RII (s-RI/RII) are believed to have potent antiinflammatory actions. Further, in active UC, GM are elevated with activation behavior and recently adsorptive GM apheresis (GMA) in patients with severe UC was associated with a dramatic efficacy. In this study, we investigated the effects of GMA on serum s-RI/RII.

METHODS

Thirty-one patients with UC, clinical activity index (CAI) 11.1 were treated with GMA by using the Adacolumn. In the column, leukocytes which bear the FcgammaR and complement receptors adhere to the column apheresis carriers (neutrophils, monocytes, and a small fraction of lymphocytes). One GMA session was 60 min at 30 mL/min and each patient could receive up to 11 sessions over 8 wk. Serum s-RI/II were measured in the blood at the column inflow (peripheral blood, time 0 and 60 min) and outflow at 60 min.

RESULTS

Serum s-RI/RII showed strong correlation with CAI, r = 0.849 (p < 0.001) and r = 0.867 (p < 0.001), respectively and were greater than when patients were in remission or the levels in controls (p < 0.001). s-RI/RII at the column outflow were higher compared with inflow (p < 0.05) suggesting that RI/RII were shed from leukocytes which adhere to the carriers. Similarly s-RI/RII were significantly increased in the peripheral blood at the end of the 60 min GMA session compared with time 0. After 11 GMA sessions, CAI fell to remission level in 26 of 31 patients accompanied by falls of s-RI/RII.

CONCLUSIONS

The sources of s-RI/RII are believed to be activated monocytes and neutrophils with further release when these leukocytes adhere to the column carriers. s-RI/RII released during GMA should contribute to the clinical efficacy of this procedure.

Effects of disease activity on anti-Saccharomyces cerevisiae antibodies: implications for diagnosis and follow-up of children with Crohn's disease

BACKGROUND

To determine diagnostic accuracy of anti-Saccharomyces cerevisiae antibodies (ASCA) in identifying children with inflammatory bowel disease (IBD) and to differentiate Crohn's disease (CD) from other IBD forms; and to determine the effect of medical or surgical treatment and of disease location and activity on ASCA titers.

METHODS

Serum samples were obtained from 196 IBD children and 142 controls. ASCA IgA and IgG titers were measured by ELISA. Measurements were repeated during the follow up of CD children.

RESULTS

ASCA titers were significantly higher in CD than in other IBD and in control patients. Combination of IgA and IgG ASCA positivity was highly specific for CD. Medical treatment and disease location did not influence assay results. Significantly lower ASCA titers were obtained in CD children with intestinal resection compared to CD-affected children who did not undergo surgical resection. ASCA titers correlated significantly with disease activity, and children with severe active disease showed higher ASCA values compared to those in remission. A significant reduction of ASCA was observed during the follow-up of CD children when clinical remission was achieved.

CONCLUSIONS

The diagnostic accuracy of ASCA is influenced by disease activity and this suggests an additional use for the follow-up of CD children of this assay.

Granulocytapheresis is useful as an alternative therapy in patients with steroid-refractory or -dependent ulcerative colitis

BACKGROUND

Recently, granulocyte and monocyte adsorption apheresis (GCAP) has been shown to be safe and effective for active ulcerative colitis (UC). We analyzed the safety and efficacy of GCAP (G-1 Adacolumn) in patients with steroid-refractory and -dependent UC. G-1 Adacolumn is filled with cellulose acetate carriers that selectively adsorb granulocytes and monocytes/macrophages.

METHODS

Forty-four patients with UC were treated with GCAP. These patients received 5 apheresis sessions over 4 weeks. Twenty patients had steroid-refractory UC (group 1) and 10 had steroid-dependent UC (group 2). Fourteen patients who did not want readministration of steroids were treated with GCAP at the time of relapse, just after discontinuation of steroid therapy (group 3).

RESULTS

Of 44 patients treated with GCAP, 24 (55%) obtained remission (CAI < or = 4), 9 (20%) showed a clinical response, and 11 (25%) remained unchanged. Only 2 of 10 patients (20%) with severe steroid-refractory UC (CAI > or = 12) achieved remission, whereas 7 of 10 patients (70%) with moderate steroid-refractory UC achieved remission (p < 0.05). The dose of corticosteroids was tapered in 9 of 10 (90%) patients with steroid-dependent UC after GCAP therapy. Twelve (86%) of 14 patients in group 3 showed an improvement in symptoms and could avoid re-administration of steroids after GCAP. No severe adverse effects occurred.

CONCLUSIONS

The findings of this study suggest that GCAP may be a useful alternative therapy for patients with moderate steroid-refractory or -dependent UC, although cyclosporin A or colectomy is necessary in patients with severe UC. GCAP may also be useful for avoiding re-administration of steroids at the time of relapse. Randomized, controlled clinical trials are needed to confirm these findings.

Mucosal cytokine production during remission after resection for Crohn's disease and its relationship to future relapse

AIM

To examine whether mucosal cytokine production during remission after resection for Crohn's disease is a predictor of future relapse.

METHODS

Thirty-six patients who remained in remission after resection for terminal ileal or ileo-caecal Crohn's disease were included. At enrollment, blood and mucosal (ileal and rectal biopsies) samples were collected. All patients were followed up regularly for 1 year after enrollment and the disease activity was assessed according to the Crohn's disease activity index.

RESULTS

Twenty patients remained in remission and 16 patients relapsed during the 1-year follow-up. Interleukin-1 beta, interleukin-6 and tumour necrosis factor-alpha levels in the ileal mucosa were significantly higher in relapsed patients than in patients in remission. These cytokine levels in the rectal mucosa were not associated with relapse. Conventional blood markers and plasma cytokine levels did not correlate with relapse. Amongst the clinical parameters, a younger age, short disease duration before operation and fistulating disease were risk factors for relapse. In multivariate analysis, only the ileal interleukin-6 level was an independent significant predictor for relapse.

CONCLUSIONS

The interleukin-6 level in the ileal mucosa during remission after resection for ileal or ileo-caecal Crohn's disease is an independent significant predictor for future relapse.

Maintenance of Remission in Crohn???s Disease

Crohn's disease is a chronic inflammatory bowel disorder with a relapsing and remitting course. Once remission is achieved, the main aim of the management of Crohn's disease is maintenance of that remission. Significant advances have been made into understanding the aetiology and pathogenesis of inflammatory bowel disease. With these advances in understanding come increasing numbers of new agents and therapies, aimed both at active disease and the subsequent maintenance of remission in Crohn's disease. Current therapeutic strategies in maintaining remission in Crohn's disease include 5-aminosalicylates (e.g. sulfasalazine, mesalazine), thiopurines (e.g. azathioprine, 6-mercaptopurine [mercaptopurine]), methotrexate and infliximab. The 5-aminosalicylates appear to have efficacy limited to either surgically induced remission and/or limited small bowel Crohn's disease. The immunomodulators now have an established role in Crohn's maintenance. Azathioprine and 6-mercaptopurine are effective in chronic active disease and corticosteroid-dependent Crohn's disease. Methotrexate has similar indications, although it appears to be an alternative in patients who are intolerant of, or resistant to, the thiopurines. The most recent breakthrough has been in the field of biological therapy for maintenance of remission in Crohn's disease. Treatment of patients with the anti-tumour necrosis factor (TNF)-alpha antibody infliximab has been shown already to be effective in inducing remission. Recent studies have now confirmed a role for infliximab in delaying relapse and maintaining remission in patients responsive to infliximab induction therapy. However, results with soluble TNF alpha receptors have been disappointing. A number of other biological and nonbiological agents have shown potential, though trials of the 'newer' biological agents have thus far been disappointing, in the maintenance of remission in Crohn's disease. The evidence for theses agents is currently limited, in many cases to treating active disease; however, these data are discussed in this article in order to provide an overview of future potential therapies. The aim of this review is to provide clinicians with an insight into current and emerging therapeutic agents for the maintenance of remission of Crohn's disease.

Biopsy assessment of drug efficacy in the gastrointestinal tract

When using biopsy pathology in clinical pharmacology to assess drug efficacy in the gastrointestinal tract, a number of questions must be answered: Is the biopsy necessary or more effective than macroscopic views by endoscopy? Can we extract maximal information from the specimen? Are there surrogate serum or other markers that give an overall measure of disease and/or improvement? Indeed, clinicopathological correlation is of paramount importance. If biopsy is to be used, it is important to utilize appropriate scoring systems. Many grading systems use continuous spectra, which are ordinal categorical variables and therefore a grading system of assigned 'numbers' which cannot be used in processes that require continuous variables such as linear regression. The use of grading vs a 'true' score with real numbers must be carefully considered, the site and number of biopsies must be precisely chosen and interobserver reproducibility of results evaluated before undertaking drug trials. Immunocytochemistry and in situ hybridization, however, can provide quantifiable molecular information related to mechanisms of drug action. The biopsy is of significant value as it is a true in vivo assessment if the above caveats are taken into account. However, further work is needed to determine sound histological criteria to assess the efficacy of drugs for use in gastrointestinal disease.

Virtual colonoscopy compared with conventional colonoscopy for stricturing postoperative recurrence in Crohn's disease

BACKGROUND

The place of virtual colonoscopy (VC) in patients with Crohn's disease (CD) requiring endoscopic follow-up after surgery is unknown. The authors compared findings from VC versus conventional colonoscopy (CC) for assessing the postoperative recurrence of CD.

METHODS

Sixteen patients with ileocolonic anastomosis for CD were prospectively enrolled from January 2001 to January 2002. Recurrence was assessed by CC according to Rutgeerts et al. VC was performed with a computed tomography scanner, with images examined by three radiologists who were unaware of the endoscopic findings.

RESULTS

CC showed perianastomotic recurrence in 15 of 16 patients. Perianastomotic narrowing or stenosis was detected by VC in 11 of these 15 patients. There were 11 true positive, 1 true negative, 0 false-positive, and 4 false-negative findings (73% sensitivity, 100% specificity, 100% positive predictive value, 20% negative predictive value, 75% accuracy). Among the eight patients showing a rigid stenosis of the anastomosis not allowing passage of the colonoscope, VC detected narrowing or stenosis in seven patients.

CONCLUSIONS

The current findings suggest that although the widespread use of VC in CD is currently not indicated because of possible false-negative findings, this technique may represent an alternative to CC in noncompliant postsurgical patients with a rigid stenosis not allowing passage of the endoscope.

Evaluation of new therapies for inflammatory bowel disease

The pathophysiology of inflammatory bowel disease (IBD) is gradually being unravelled and new therapies are being developed to target the disturbed biological processes. This article outlines the clinical features of IBD, its current therapy and pathogenesis. The difficulties for clinical pharmacologists and gastroenterologists associated with designing, executing and interpreting clinical trials in IBD are then discussed. The final section reviews methods that can used to demonstrate the pharmacological actions of new treatments in patients with IBD. It is emphasized that proof of the therapeutic efficacy of a novel agent with a specific mechanism of action yields not only clinical benefit to patients with IBD, but also indicates the importance of the targeted biochemical pathway in the pathogenesis of the disease.

Prospective evaluation of fecal calprotectin as a screening biomarker for colorectal neoplasia

OBJECTIVES

Stool testing is a well established method of screening for colorectal neoplasia. Emerging data suggest that novel biomarkers may offer performance advantages over fecal occult blood. In this large, prospective study, we assessed fecal calprotectin (a leukocyte-derived protein) as a screening biomarker for colorectal neoplasia. Fecal calprotectin was directly compared to fecal hemoglobin (Hb) and colonoscopy as the existing criterion standards for stool screening and structural evaluation, respectively.

METHODS

Subjects included colonoscopy patients with a personal history of colorectal neoplasia, family history of colorectal cancer, or iron deficiency anemia. Stool specimens were collected before purgation, processed appropriately, and quantitatively analyzed for calprotectin (Nycomed Pharma, Oslo, Norway) and for Hb (Mayo Medical Laboratories, Rochester, MN) by masked technicians. Colonoscopies were performed by experienced endoscopists without prior knowledge of the fecal assay results.

RESULTS

Among 412 subjects, 97 (24%) subjects had one or more colorectal neoplasms (including three with adenocarcinomas). Fecal calprotectin levels did not differ significantly between subjects with versus subjects without colorectal neoplasms (p = 0.33). Neither tumor number (p = 0.85) nor tumor size (p = 0.86) significantly influenced the observed fecal calprotectin concentrations. Estimates of the sensitivity, specificity, and positive and negative predictive values of fecal calprotectin for any colorectal neoplasms were 37%, 63%, 23%, and 76%, respectively. Comparable performance estimates for fecal Hb were 3%, 97%, 27%, and 77%, respectively.

CONCLUSIONS

In this cohort of colonoscopy patients at above average risk, fecal calprotectin was a poor screening biomarker for colorectal neoplasia. Further investigation of tumor-derived, rather than blood-based, biomarkers may be a more rewarding approach to stool screening for colorectal neoplasia.

Role of faecal calprotectin as non-invasive marker of intestinal inflammation

BACKGROUND/AIM

Faecal calprotectin, a neutrophil granulocyte cytosol protein, is considered a promising marker of intestinal inflammation. We assessed and compared the faecal calprotectin concentration in patients with organic and functional chronic intestinal disorders.

PATIENTS AND METHODS

The study was carried out, using a commercially available ELISA test, measuring calprotectin in stool samples collected from 131 patients with inflammatory bowel diseases, 26 with intestinal neoplasms, 48 with irritable bowel syndrome and 34 healthy subjects.

RESULTS

Median faecal calprotectin was significantly increased in Crohn's disease (231 microg/g, 95% confidence interval (CI) 110-353 microg/g), ulcerative colitis (167 microg/g, 95% CI 59-276 microg/g), and neoplasms (105 microg/g, 95% CI 0-272 microg/g), whereas normal values were found in patients with irritable bowel syndrome (22 microg/g, 95% CI 9-35 microg/g) and in healthy subjects (11 microg/g, 95% CI 3-18 microg/g). A positive correlation was observed with clinical activity scores in Crohn's disease and ulcerative colitis. In both groups, patients with clinically active disease showed higher calprotectin levels than those observed in patients with quiescent disease (405 microg/g, 95% CI 200-610 microg/g vs. 213 microg/g, 95% CI 85-341 microg/g in CD patients, p<0.05, and 327 microg/g, 95% CI 104-550 microg/g vs. 123 microg/g, 95% CI 40-206 microg/g in UC patients, p<0.001).

CONCLUSIONS

Faecal calprotectin appears to be a promising and non-invasive biomarker of intestinal inflammation. If these findings are confirmed, it may provide a useful test for the diagnosis and follow up of inflammatory bowel diseases.

Association of perinuclear antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibodies with Vienna classification subtypes of Crohn's disease

BACKGROUND

The Vienna classification of Crohn's disease (CD) subdivides patients according to their age at diagnosis (A), disease location (L), and disease behavior (B). AIM The aim of this study was to test whether perinuclear antineutrophil cytoplasmic antibodies (pANCAs) or anti-Saccharomyces cerevisiae antibodies (ASCAs) correlate to subtypes of CD according to this classification.

METHODS

pANCA, ASCA-immunoglobulin (Ig) A, and ASCA-IgG were detected by indirect immunofluorescence in 120 sera of patients with CD and compared with their Vienna classification.

RESULTS

Patients with diagnosis of CD at an age of 40 years or older (A2) were more frequently pANCA-positive than those whose disease started at a younger age (A1) (19% vs. 5%, p < 0.05). pANCA-positive patients almost exclusively belonged to the nonpenetrating disease groups (B1 and B2); only one patient had penetrating disease (B3) (B3 vs. non-B3: p = 0.02). There was a cluster of pANCA-positive patients within the A1 B2 L3 subgroup (B2: stricturing disease; L3: ileocolonic involvement). Only 7.5% of ASCA-IgA-positive patients presented with CD that was limited to the colon (L2). ASCA-IgA and ASCA-IgG were more frequently found in patients with upper gastrointestinal disease (L4) (ASCA-IgA: 66.7% vs. 31.5% in non-L4, p < 0.05; ASCA-IgG: 44.4% vs. 27.9%, p < 0.05).

CONCLUSION

pANCA and ASCA may be useful in predicting subtypes of CD. They therefore may be helpful in developing subtype-specific disease management strategies.

The mechanisms of prednisone inhibition of inflammation in Crohn's disease involve changes in intestinal permeability, mucosal TNFalpha production and nuclear factor kappa B expression

BACKGROUND

The clinical course of Crohn's disease after the induction of remission with medical therapy is characterized by unpredictable relapse.

AIM

To evaluate three surrogate markers, intestinal permeability, mucosal TNFalpha and nuclear factor (NF)-kappaB/IkappaBalpha expression, in order to determine the relationship of these parameters to clinical relapse.

METHODS

Thirty patients with active Crohn's disease were treated with a 10 week course of prednisone using a tapering dosing regimen. Intestinal permeability (lactulose/mannitol [L/M ratio]) was determined at baseline and at the end of prednisone tapering. TNFalpha production and the levels of expression of NF-kappaB/IkappaBalpha were measured in colonic mucosal biopsies obtained after the induction of remission.

RESULTS

Twenty-two patients (73%) achieved remission and 50% of patients experienced a clinical relapse during the ensuing 12 months. Treatment with prednisone resulted in a significant decrease in the L/M ratio. Of the patients that relapsed, 75% had a raised L/M ratio at the time of remission compared with 20% of patients with a normal L/M ratio (P < 0.008; hazard ratio = 6.094; CI 1.55, 17.43). Mucosal TNFalpha production was greater in relapsers compared with those who remained in remission. The levels of NF-kappaB in relapsers were significantly greater and levels of cytosolic IkappaBalpha were significantly lower compared with those measured in patients who remained in remission.

CONCLUSIONS

These findings underscore the importance of incorporating biological parameters of inflammation in determining the clinical course of Crohn's disease.

Emerging role of calprotectin in gastroenterology

Calprotectin is a calcium and zinc binding protein of the S100 family derived predominantly from neutrophils and monocytes. It is detectable in body fluids and tissue samples and is emerging as a valuable marker in the diagnosis, and the monitoring and determining of the prognosis of commonly encountered gastroenterological conditions. Fecal calprotectin, in particular, has for a long time been regarded as a promising marker of gastrointestinal pathology and has now been established as a routine test in Norway and at several centers in the UK.

Review article: Crohn's disease: monitoring disease activity

A global measurement of Crohn's disease activity, comprising clinical, endoscopic, biochemical and pathological features is not available yet and perhaps is unobtainable. In this review we analyse the most used and validated clinical indices (Crohn's Disease Activity Index [CDAI], Perianal Disease Activity Index [PDAI], fistula drainage assessment), quality of life scores (Inflammatory Bowel Disease Questionnaire [IBDQ]), sub-clinical markers (C-reactive protein, faecal calprotectin, intestinal permeability) and endoscopic indices (Crohn's Disease Endoscopic Index of Severity [CDEIS]/Simple Endoscopic Score for Crohn's Disease [SES-CD], Rutgeeerts' score for postsurgical recurrence). We also review the main advantages and disadvantages of each of these scoring systems. All these indices are rather complex and time-consuming, therefore their use is limited to clinical trials. In everyday clinical practice most gastroenterologists rely on their global clinical judgement, which is less reproducible, but simpler for decision-making.

Review article: maintenance treatment of Crohn's disease

The aetiology of Crohn's disease is unknown and therefore no curative treatments are available for the disease. The natural history of Crohn's disease is characterized by recurrent flare-ups of symptoms. Several drug treatments are effective in inducing clinical remission. However, no drug treatments are available in order to prevent clinical relapses, although several drug regimens may delay clinical flare-ups. Crohn's disease treatment for maintaining clinical remission needs to be tailored in relation to specific characteristics of each patient. The frequency of clinical relapse indeed shows marked variations in subgroups of patients, as the likelyhood of relapse is higher in patients in clinical remission for less than 6 months. Treatment strategies for maintaining remission may therefore differ among inactive patients. In chronically active, steroid-dependent or steroid-refractory Crohn's disease patients immunomodulatory drugs (azathioprine 2-2.5 mg/kg by mouth, 6-mercaptopurine 1-1.5 mg/kg by mouth, or methotrexate 15-25 mg/i.m./week) should be added to oral mesalazine (2.4 g/day), while in long-term inactive Crohn's disease patients mesalazine alone may be effective in delaying relapse. Recently, treatment with anti-tumour necrosis factor-alpha monoclonal antibodies (Infliximab or CDP571) has shown efficacy in delaying relapse in responsive patients. One other issue which needs to be considered before selecting drug treatments for maintaining remission in Crohn's disease, is that Crohn's disease activity is currently assessed on the basis of standard clinical scores which may not appropriately reflect the biological activity of the disease. Clinical remission as defined by standardized scores may include heterogeneous subgroups of patients showing different endoscopic and histological activity or persistence of activated immunocompetent cells within the gut. Several sub-clinical markers of relapse have indeed been reported in quiescent Crohn's disease, although their usefulness in clinical practice in currently uncertain.

Subclinical intestinal inflammation: an inherited abnormality in Crohn's disease relatives?

BACKGROUND & AIMS

One approach to unraveling the genetics of complex inherited disease, such as Crohn's disease, is to search for subclinical disease markers among unaffected family members. We assessed the possible presence, prevalence, and inheritance pattern of subclinical intestinal inflammation in apparently healthy relatives of patients with Crohn's disease.

METHODS

A total of 49 patients with Crohn's disease, 16 spouses, and 151 (58%) of 260 available first-degree relatives underwent a test for intestinal inflammation (fecal calprotectin concentration). The mode of inheritance was assessed from 36 index patients (by variance component analysis) when more than 50% of relatives were studied.

RESULTS

Fecal calprotectin concentrations in patients with Crohn's disease (47 mg/L; confidence interval [CI], 27-95 mg/L) and relatives (11 mg/L; CI, 9-14 mg/L) differed significantly (P < 0.0001) from controls (4 mg/L; CI, 3-5 mg/L), whereas that of the spouses did not (4 mg/L; CI, 3-6 mg/L; P > 0.5). Fecal calprotectin concentration was increased in 49% of all relatives studied. The increased fecal calprotectin concentration among the relatives of the 36 index patients had an inheritance pattern that was most consistent with an additive inheritance pattern.

CONCLUSIONS

There is a high prevalence of subclinical intestinal inflammation in first-degree relatives of patients with Crohn's disease that conforms best to an additive inheritance pattern. The genetic basis for this abnormality may represent a risk factor for Crohn's disease.

Intestinal barrier: an interface between health and disease

The intestine constitutes the largest interface between a person and his or her environment, and an intact intestinal barrier is thus essential in maintaining health and preventing tissue injury and several diseases. The intestinal barrier has various immunological and non-immunological components. The epithelial barrier is one of the most important non-immunological components. Hyperpermeability of this barrier is believed to contribute to the pathogenesis of several gastrointestinal disorders including inflammatory bowel disease, celiac disease and food allergy. Hence, assessing barrier integrity is of the utmost importance. One of the more quantitative gauges for this assessment is transepithelial permeability of various molecular probes, among which sugars are commonly used. Measures of intestinal permeability might also be useful as markers for assessment of prognosis and follow up in various gastrointestinal disorders. The present article is a review of the normal and abnormal functioning of the intestinal barrier, the diseases that can result from loss of barrier integrity, and some promising agents and strategies for restoring barrier normality and integrity.