Mr 40,000 human colonic epithelial protein expression in colonic mucosa and presence of circulating anti-Mr 40,000 antibodies in cotton top tamarins with spontaneous colitis

Identification, evolution, and association study of a novel promoter and first exon of the human NOD2 (CARD15) gene

Mutations in the NOD2 (CARD15) gene predispose to Crohn's disease (CD), a human chronic inflammatory bowel disorder, and can cause Blau syndrome. During an investigation of an apparent correlation between a frameshifting mutation in the canonical first exon of NOD2 of marmoset and tamarin species and their susceptibility to chronic colitis, we found that, contrary to previous reports, the basal levels of NOD2 transcripts in tissues relevant to CD arise from a distinct novel promoter and first exon. The canonical first exon, by contrast, seems to be of negligible transcriptional importance under physiological conditions, and its reading frame has been disrupted twice during primate evolution. Thus the main NOD2/CARD15 protein isoform produced in humans and other primates is 27 amino acids shorter than previously reported, starting at a conserved methionine in exon 2. We show that there is no significant association between variants in the novel NOD2 promoter region and CD.

CD4+ T cells from 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rodents migrate to the recipient's colon upon transfer; down-regulation by CD8+ T cells

CD4+ T cells play an important role in the aetiology of inflammatory bowel disease (IBD), but it is not clear which factor(s) cause activation of these cells. The aim of this study was to examine the effects of adoptive transfer of splenic (CD4+) T cells from TNBS/ethanol-sensitized donor rats to naive recipients and the migration pattern of transferred T cells. For the transfer experiments, colitis was induced in rats by colonic administration of TNBS/ethanol. Seventeen days later, either total splenic T cells or CD4+, or CD8+ T cells were transferred to naive recipients. At days 1, 2 and 3 after transfer, the recipients were killed and the migration pattern of the transferred T cells was studied, as well as inflammatory cells in several organs, including the colon. To determine cytokine profiles of the T cells, colitis was induced in mice. Therefore, different combinations of 2,4-dinitrobenzene sulfonic acid (DNBS) in ethanol or saline, or ethanol alone were intrarectally administered. At day 9 after induction of colitis, mice were killed and cytokine profiles in the colon were studied by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. The results show that CD4+ T cells from donor rats with TNBS/ethanol-induced colitis migrate in particular to the colon upon transfer to naive recipients, and that this process is down-regulated by CD8+ T cells. This migration is probably caused by T cell recognition of the colonic bacterial flora and initiates an inflammatory reaction in the recipient's colon, characterized by an increase of the recipient's own T cells, macrophages, and neutrophils. In the mice experiments we showed that a second administration of DNBS/ethanol or ethanol alone, which presumably causes bacterial translocation, results in increased numbers of T cells into the colon, accompanied by an increase in Th1 cytokines. These data suggest that Th1 cells recognize the colonic bacterial flora.

Autoimmune (Hashimoto's) thyroiditis associated with Crohn's disease

We report the occurrence of autoimmune (Hashimoto's) thyroiditis in three patients with Crohn's disease. Previously, thyroid disease has been described only in association with ulcerative colitis. We review the pertinent literature on thyroid disease in inflammatory bowel disease (IBD) and suggest that this association supports the hypothesis that autoimmunity is involved in the pathogenesis of IBD. Early diagnosis and treatment of thyroid dysfunction in patients with IBD is desirable because thyroid dysfunction worsens the symptoms and course of IBD.

The technetium white cell scan as an initial imaging investigation for evaluating suspected childhood inflammatory bowel disease

BACKGROUND

The technetium white cell scan (WCS) may be a useful investigation for patients with inflammatory bowel disease (IBD). In a retrospective study we assessed the use of the WCS as an initial imaging investigation in evaluating children with suspected IBD.

METHODS

Over a 3-year period, 60 WCS were performed on 55 patients (25 boys, median age 12.1 years, age range 1.5-18 years) with known or suspected IBD. There were two clinical groups: those with previously diagnosed IBD (histologically and radiologically) and in clinical relapse (13 patients), and newly presenting patients with suspected IBD (42 patients).

RESULTS

Eighteen scans were performed on the 13 patients presenting with relapse. Seventeen were positive and one patient, subsequently shown to have an inactive stricture, had a negative scan. Seven of the 42 newly presenting patients had abnormal scans, confirmed to be due to IBD by a combination of histology and barium examinations. Of the remaining 35 scans, three were abnormal and 32 were normal. None of these patients were subsequently proven to have IBD. These results show that in detecting active IBD, a positive WCS has a 100% sensitivity (24/24) and a 91% specificity (32/35) in the diagnosis of IBD.

CONCLUSIONS

Our results show that the WCS is very useful as an initial imaging investigation in evaluating patients with suspected IBD to select patients for further investigation.

Serum levels of osteocalcin and type I procollagen in children with celiac disease

BACKGROUND

Bone metabolism may be disturbed in children with celiac disease.

METHODS

Two markers of bone turnover were used: the level of osteocalcin (BGP) and the level of carboxylterminal peptide of type I procollagen (PICP). BGP and PICP were measured by radioimmunoassays in 18 untreated children with celiac disease (mean age: 22.9 +/- 15.6 months) and in 15 control subjects (mean age 28.5 +/- 21 months). All the patients were rechecked after 1 month and again after 3 months from beginning of a gluten-free diet (GFD).

RESULTS

Compared with controls at diagnosis our patients had significantly lower serum levels of BGP and PICP (p = 0.003 and p = 0.018 by Student's t test, respectively). These levels increased markedly during the 1st 3 months of GFD.

CONCLUSIONS

The alteration in calcium phosphate homeostasis caused by celiac disease directly affects the synthesis of both components of the connective matrix of bone. Measurements of BGP and PICP provide a reliable and rapidly obtainable index of normalization of the processes of bone growth which can be achieved with a GFD.

Non-malignant complications of coeliac disease

Patients with coeliac disease are at increased risk of developing complications which increase morbidity and mortality. Emphasis on malignant complications has often overshadowed the non-malignant risks, which have received relatively little attention, although some of these can be very troublesome and even life-threatening. This article points out that a large population of unidentified or neglected coeliac patients is at potential risk. The challenge is to identify this group by case-finding or screening programmes in selected populations, so that they can be offered a gluten-free diet and other treatments which will not only improve general health but may also prevent or reduce the development of health problems. The non-malignant risks are outlined and bone and neuropsychiatric disturbances considered in more detail because of recent developments in these areas.

Oral efficacy of a leukotriene B4 receptor antagonist in colitic cotton-top tamarins

Leukotriene B4 (LTB4) is a potent neutrophil activator and chemotaxin that is present in increased concentrations in the colonic tissue and rectal dialysates of acute ulcerative colitis patients. Cotton-top tamarins (CTTs) with confirmed active colitis were treated with the second generation LTB4 receptor antagonist, SC-53228 ((+)-(S)-7-[3-(2-cyclopropyl-methyl)-3-methoxy-4-[(methylamino) carbonyl]phenoxy]propoxy]-3,4-dihydro-8-propyl-2H-1-benzopyran-2- propanoic acid), 20 mg/kg bodyweight by gavage, twice daily for 56 days. End points were body weights, stool consistency, colonic endoscopy, assay of inflammatory mediators, and haematology and clinical chemistry tests. LTB4 and prostaglandin E (PGE) values were measured in rectal dialysates at pretreatment, 28 day and 56 day time points. LTB4 concentrations were reduced from pretreatment mean (SEM) values of 37.3 (0.8) ng/ml to 3.7 (0.8) ng/ml (p < 0.001) and 2.3 (0.5) ng/ml (p < 0.01) at days 28 and 56, respectively. On the other hand, mucosal protective PGE values remained constant or slightly increased during SC-53228 treatment (pre: 6.9 (2.2) ng/ml; day 28: 6.7 (1.4) ng/ml; day 56: 9.9 (1.6) ng/ml). Furthermore, assessment of a panel of 35 clinical chemistry and haematology parameters throughout the treatment showed there were no significant untoward effects of drug treatment. Six CCTs finished the eight week treatment and five of six gained weight (ranging from 27-121 grams each) while one CTT lost weight (50 g). Stool condition improved in five of six animals while one of six remained unchanged. All CCTs showed dramatic improvement histologically, with no or only minimally active colitis after treatment. The histological changes plus significant weight gains and improvement of stool condition (quality of life parameters) after eight weeks of SC-53228 treatment were remarkable. Furthermore, in follow up biopsies seven months after treatment ceased, three of six CTTs had no active colitis. This is the first time afflicted CTTs have not had recurring colitic exacerbations after a treatment regimen was stopped. It is concluded that in colitic CTTs, SC-53228 has shown both an immediate and a long acting anticolitic activity. It is also concluded that reduced LTB4 concentrations during treatment inhibited neutrophil infiltration of the colonic tissue and this, coupled with the maintenance of mucosal protective prostaglandins, contributed to the dramatic anticolitic efficacy. The treatment was safe over eight weeks. A compound such as SC-53228 may be useful in the medical treatment of human inflammatory bowel disease.

Expression of a unique protein on colon cancer cells that reacts with a novel monoclonal antibody and ulcerative colitis serum

We earlier developed a MoAb, 7E12H12 (IgM isotype), against a protein present in normal colonic epithelial cells. To examine if 7E12H12-reactive protein is expressed in colon cancer cells and is recognized by ulcerative colitis (UC)-associated autoantibody, we investigated several colon cancer cell lines. 7E12H12 reactivity against the cells was examined by indirect immunofluorescence assay and whole cell ELISA against six colon cancer cell lines HT-29, LoVo, COLO 205, DLD-1, LS 180 and SW 1116. A competitive ELISA was developed using 7E12H12 MoAb and patients' serum to examine the cross-reactive antibodies in the serum. Among the six colon cancer cell lines only LS 180, DLD-1 and SW 1116 reacted with 7E12H12 MoAb, while others did not. The mean (+/- s.e.m.) inhibition of the binding of 7E12H12 MoAb to LS 180 cells by UC serum (n = 51) was 42 +/- 2.1%, whereas in normal subjects (n = 17) it was 14 +/- 2.6%, in Crohn's disease (n = 19) it was 15.3 +/- 2.5%, in infectious diarrhoea (n = 10) it was 11% +/- 3%, and in systemic lupus erythematosus (n = 10) it was 2% +/- 0.6%. The inhibition by the UC group was significantly (P < 0.001 - < 0.0001) higher than any of the non-UC groups, and this inhibition was mainly by IgG1 antibody. The protein in the specific colon cancer cells recognized by the 7E12H12 MoAb cross-reacts with UC-IgG1 antibody and may provide an in vitro system to examine the autoimmune mechanisms in UC.

Circulating immunoglobulin G1 antibody in patients with ulcerative colitis against the colonic epithelial protein detected by a novel monoclonal antibody

Autoimmunity has been implicated in the pathogenesis of ulcerative colitis (UC). Several studies have shown amplified immunoglobulin G1 (IgG1) antibody response in UC; however the immunoreactive antigen(s) is unknown. To study this antigen(s), mucosal colonic extract was prepared by sonication, ultracentrifugation followed by ion exchange chromatography in fast protein liquid chromatography. The fraction (enriched colonic peptide), that was most reactive to a novel monoclonal antibody, 7E12H12 (IgM isotype), was isolated and used to examine the immunoreactivity against the patients' serum samples. Two hundred and thirteen coded samples from 111 patients with UC (symptomatic and untreated (63), symptomatic and treated (26), remission (22)); 47 with Crohn's disease (CD) (40 were symptomatic and untreated, and 30 had colonic disease); 29 with acute diarrhoea caused by specific pathogen(s); 10 with systemic lupus erythematosus, and 16 normal subjects were examined against the enriched colonic peptide by IgG subtype specific enzyme linked immunosorbent assays (ELISAs). Total IgG antibody reactivity was significantly (p < 0.01) higher only in symptomatic and untreated UC patients compared with each of the non-UC group, but the sensitivity was only 50%. IgG2 and IgG3 reactivities were not different among various groups. The IgG1 antibody reactivity against the enriched colonic peptide, however, differentiated UC patients from CD and each of the other non-UC groups. Seventy nine per cent of the patients with UC, treated or untreated, symptomatic or in remission, had significantly (p < 0.0001) higher IgG1 antibody against the enriched colonic peptide when compared with each of the other non-UC groups. Only 12% of CD serum samples and none of the other control serum samples reacted. Using purified serum IgG1 and 7E12H12-IgM, by 7E12H12 reactive peptide indeed reacts with UC-IgG1 antibody but not with control IgG1.

Bone mineral density in coeliac disease

Patients with coeliac disease may have osteomalacia or osteoporosis, even in the absence of abdominal symptoms. Little is known about the effects of a gluten-free diet and villous restitution on the bone mineral density in adult patients with coeliac disease. Of the 288 patients with coeliac disease in our unit, 13 (5%) had persistent villous atrophy of the small bowel despite dietary recommendations over at least the previous 4 years. For each of these 13 patients, 1 or 2 controls with coeliac disease, matched for age, gender, menopausal state, and dermatitis herpetiformis, whose intestinal mucosa had normalized at least 4 years earlier, were identified (n = 17). Bone mineral density was measured in the forearm using single-photon absorptiometry and in the femoral neck and trochanter using dual-energy X-ray absorptiometry. Bone mineral density was reduced at all sites in patients with persistent villous atrophy compared with patients responsive to diet and healthy controls. Bone mineral density in patients responsive to diet did not differ from that in healthy controls. Persistent villous atrophy is associated with low bone mineral density, underlining the importance of keeping to a proper diet.

Ultrasound scanning

Inflammatory or neoplastic bowel pathology is associated with thickening of the bowel wall. Ultrasound appearances reflect the pathological changes in the bowel. Crohn's disease is a transluminal disease leading to fibrosis. This fibrosis is responsible for the formation of an echo-poor halo surrounding a central echogenic zone. In the earlier stages with transmural oedema and inflammation, the halo assumes a ground glass appearance. Ulcerative colitis is a mucosal disease and hence the halo is a less prominent feature. Severe oedema in the bowel wall in fulminant ulcerative colitis can be recognized by the marked reduction of the haustral and central lumen of the colon.

99mTc-HMPAO planar white cell scanning

The management of inflammatory bowel disease depends on knowledge of the site, extent and severity of inflammation. Early work showed that 111In-labelled white cells could fulfil this role. More recently. 99mTc-HMPAO white cell scanning was introduced. Several studies have shown that this test can reliably detect disease and can assess extent. Simple visual grading of uptake intensity can also be used to assess severity. The improved image resolution allows assessment of small bowel disease in addition with high sensitivity in the detection of ulcerating Crohn's disease. Other causes of bowel inflammation should be excluded. Complicating abscesses can be detected and the inflammatory component of strictures can be assessed. False positive activity can be avoided by imaging early at one hour, before such non-specific excretion occurs. Later images are also useful in order to help localize disease, but only in addition to the initial one hour scan. 99mTc-HMPAO white cell scanning, a simple non-invasive, highly informative test should be added to the armamentarium of every gastroenterologist.

Epithelial deposits of immunoglobulin G1 and activated complement colocalise with the M(r) 40 kD putative autoantigen in ulcerative colitis

The intestinal expression pattern and general tissue distribution of the M(r) 40 kD putative epithelial autoantigen in ulcerative colitis were re-examined by in situ two and three colour immunofluorescence staining including the murine monoclonal antibody 7E12H12. The intestinal distribution was also compared with the epithelial codeposition of IgG1 and activated complement (C3b and terminal complement complex) seen selectively in ulcerative colitis. The M(r) 40 kD antigen was found for the first time in goblet cells of normal terminal ileum and proximal colon but not in rectal goblet cells. By contrast, colonic enterocytes expressed this antigen apically with increasing intensity in a distal direction, expanding to intense cytoplasmic expression in rectal enterocytes. The antigen was also expressed by the epithelium of the fallopian tubes, major bile ducts, gall bladder, and epidermis but not by proximal gastrointestinal tract epithelium or 13 other extra-gastrointestinal organs. Activated complement and IgG1 often colocalised with the M, 40 kD antigen apically on the surface epithelium in active ulcerative colitis but not in Crohn's disease. Our results support the idea that an autoimmune response to this antigen, leading to complement activation mediated by IgG1, is a possible pathogenetic mechanism for epithelial damage and persistent inflammation in ulcerative colitis.

Gastroduodenal problems associated with non-steroidal, anti-inflammatory drugs (NSAIDs)

Non-steroidal, anti-inflammatory drugs (NSAIDs) inhibit gastric mucosal prostaglandins (PG) synthesis and thereby induce mucosal injury and ulceration, and possibly impair pain perception and ulcer healing. Dyspepsia is a poor guide to ulceration so a life threatening complication may be the first presentation and vigilance is important. Impaired healing can be overcome with more potent or prolonged ulcer healing therapy. For prophylaxis of high-risk patients (elderly women, past history, taking high doses, steroid co-therapy, first three months of treatment) the prescriber has to choose between the side effects of misoprostol or the more limited efficacy against gastric ulcers of ranitidine. Both drugs are highly effective in preventing duodenal ulcers.