Faecal sulphatase in health and in inflammatory bowel disease.

Histochemical studies have shown a relative depletion of colonic sulphated mucins (sulphomucins) in active ulcerative colitis. One possible explanation for this could be desulphation by bacterial sulphatases. Studies have therefore been done to determine whether normal faeces contain sulphatase and if so to determine whether this activity is increased in ulcerative colitis. Using a fluorimetric assay considerable sulphatase activity (greater than 0.3 IU/g pellet weight) was found in bacteria free filtrates of the homogenates of nine of 17 faecal samples from healthy controls. This sulphatase activity had an alkaline pH optimum (pH 8.5-9.5). A similar range of faecal sulphatase activity with a similar pH optimum was found in samples from patients with ulcerative colitis (n = 39) and Crohn's disease (n = 17) and there was no correlation with disease activity in either disease. This faecal sulphatase activity may be involved in the degradation of colonic mucus and merits further study but these findings do not explain the relative depletion of colonic mucosal sulphomucins in ulcerative colitis.     

A study of histochemical changes in mucus from patients with ulcerative colitis,Crohn's disease,and diverticular disease of the colon

The colonic mucosa produces a protective and lubricating layer of mucus. In certain conditions, the quantity and quality of this mucus is impaired. This study assessed the histochemical changes in mucus in inflammatory bowel disease compared with the severity and extent of the condition. Biopsy specimens were taken from 62 patients (32 with ulcerative colitis; ten with colonic Crohn's disease; ten with diverticular disease; ten with normal controls) and sections stained with high iron diamine-alcian blue to distinguish sulphated mucins from sialomucins. Normal subjects showed a predominance of sulphated mucins. The patients with Crohn's and diverticular disease also demonstrated this normal pattern. Of the 20 patients with ulcerative colitis, and without demonstrable dysplastic changes, only one showed a moderate increase in sialomucins. However, of the 12 patients with extensive colitis and dysplastic changes, ten had an increase in sialomucins. Thus, the predominant sialomucin pattern was seen mainly in patients with dysplasia. It may, therefore, indicate patients at high risk of malignancy.     

Increased production of vascular endothelial growth factor by intestinal mucosa of patients with inflammatory bowel disease.

BACKGROUND/AIMS: Vascular endothelial growth factor (VEGF) is a heparin-binding glycoprotein with potent angiogenic, mitogenic and vascular permeability-enhancing activities specific for endothelial cells. Recent studies have shown significantly increased VEGF serum levels in patients with active Crohn's disease and ulcerative colitis. The origin of the circulating VEGF is not yet completely described. The present investigation examines the VEGF production of colonic mucosa in consideration of mucosal disease activity in patients with inflammatory bowel disease. METHODOLOGY: Fifteen patients with inflammatory bowel disease were studied, 9 patients with Crohn's disease and 6 patients with ulcerative colitis. Biopsies were taken from endoscopically inflamed and non-inflamed colonic mucosa. Therefore, an analysis of the spontaneous VEGF production of cultured biopsies without stimulus and of the histological grade of inflammation scored on a scale of 0-3 (normal mucosa--severe chronic colitis) were performed. Eight patients with irritable bowel syndrome served as controls. VEGF levels in the supernatant of cultured mucosal biopsies were measured using an enzyme linked immunosorbent assay. RESULTS: VEGF production is expressed as pg/mg wet weight of the biopsies. Inflamed mucosa of patients with active ulcerative colitis (16.27 +/- 10.39, p = 0.003, n = 6) and active Crohn's disease (9.88 +/- 5.98, p < 0.012, n = 9) showed a significantly higher spontaneous production of VEGF by colonic mucosa than normal mucosa of controls (3.16 +/- 1.63, n = 8). In addition, there was an increased unstimulated VEGF production by cultured inflamed mucosa of patients with Crohn's disease compared with non-inflamed mucosa (3.88 +/- 3.66, p < 0.015, n = 9). In both Crohn's disease and ulcerative colitis, there was no significant difference between VEGF production by non-inflamed mucosa and normal mucosa of controls. CONCLUSIONS: The present study identifies the intestinal mucosa as one of the origins of the elevated VEGF serum levels in patients with active inflammatory bowel disease and verifies the findings of recent studies about the importance of VEGF in Crohn's disease and ulcerative colitis.     

Altered lectin binding by colonic epithelial glycoconjugates in ulcerative colitis and Crohn's disease

Evidence is accumulating that colonic mucin glycoconjugates are altered in ulcerative colitis. In order to investigate this further, the lectin-binding properties of rectal glycoconjugates have been studied in ulcerative colitis, Crohn's disease, and controls using lectin-peroxidase histochemistry. Ten lectins were used including peanut agglutinin (PNA) which is known to bind to malignant and adenomatous but not normal colonic mucins. Eight of 21 ulcerative colitis rectal biopsies and 10 of 17 Crohn's disease rectal biopsies showed PNA positivity, particularly in the supranuclear region of surface epithelial cells. There was no correlation between PNA positivity and duration of disease or inflammation, and none of the biopsies showed evidence of dysplasia. This abnormality in epithelial cell glycoconjugates seems to be commonly present in nondysplastic mucosa and occurs in both ulcerative colitis and Crohn's disease. It may reflect a fundamental abnormality in mucus glycoprotein synthesis in inflammatory bowel disease.     

Faecal mucus degrading glycosidases in ulcerative colitis and Crohn's disease.

Because the normal faecal flora includes bacteria which can produce mucus-digesting glycosidases, it follows that increased digestion of colonic mucus by these bacterial enzymes could be important in the pathogenesis of ulcerative colitis. Faecal activities of potential mucus-degrading glycosidases have therefore been assayed in samples from patients with inflammatory bowel disease and normal controls. The enzymes alpha-D-galactosidase, beta-D-galactosidase, beta-NAc-D-glucosaminidase alpha-L-fucosidase and neuraminidase were assayed. Considerable glycosidase activity was present in most faecal samples. Similar activities of all the enzymes assayed were found in faeces from patients with ulcerative colitis, Crohn's disease and normal controls and there was no significant correlation with disease activity. These results imply that relapse of ulcerative colitis is not initiated by increased degradation of colonic mucus by faecal glycosidases but do not exclude a role for bacterial mucus degradation in the pathogenesis of ulcerative colitis.     

Mucin secretion in inflammatory bowel disease: correlation with disease activity and dysplasia.

When rectal biopsies from 65 patients with ulcerative colitis and 20 patients with Crohn's disease was stained for mucins, an abnormal pattern (excess of sialomucins) was seen in about half of them. This is in contrast with 65 cases of non-specific proctitis where the mucin pattern of rectal biopsies was normal in all except one case. The abnormal mucin secretion in patients with ulcerative colitis was apparently related to the activity, duration, and extent of the disease. All biopsies with dysplasia showed predominant sialomucin staining except one. All biopsies showing sialomucins during remission also had dysplasia, while during active disease a number of biopsies had increased sialomucins without the evidence of dysplasia. It is not known if such cases will subsequently develop morphological atypia.     

Reduced mucosal antimicrobial activity in Crohn's disease of the colon

OBJECTIVES: In order to maintain the mucosal barrier against luminal microorganisms the intestinal epithelial cells synthesise various broad-spectrum antimicrobial peptides including defensins and cathelicidins. Recent studies indicate that both may be deficient in Crohn's disease. To elucidate the possible functional consequences of this deficiency antimicrobial activity in colonic mucosa from patients with inflammatory bowel disease and healthy controls was investigated. METHODS: A flow cytometric assay was established to quantitate bacterial killing and test the antibacterial activity of cationic peptide extracts from colonic biopsies taken from patients with active or inactive ileocolonic or colonic Crohn's disease (n = 22), ulcerative colitis (n = 29) and controls (n = 13) against clinical isolates of Bacteroides vulgatus and Enterococcus faecalis or the reference strains Escherichia coli American Type Culture Collection (ATCC) 25922 and Staphylococcus aureus ATCC 25923. RESULTS: Compared with controls and ulcerative colitis there was a reduced antimicrobial effect in Crohn's disease extracts that was most evident against B. vulgatus. The antimicrobial effect against E. coli and E. faecalis was significantly lower in Crohn's disease compared with ulcerative colitis. Activity against S. aureus disclosed a similar pattern, but was less pronounced. The differences were independent of the inflammation status or concurrent steroid treatment. Bacteria incubated with biopsy extracts from ulcerative colitis patients frequently showed a characteristic change in cell size and granularity, compatible with more extensive membrane disintegration, compared with bacteria incubated with extracts from controls or Crohn's disease. CONCLUSION: Crohn's disease of the colon is characterized by a diminished functional antimicrobial activity that is consistent with the reported low antibacterial peptide expression.     

Immunohistochemical localization of vascular endothelial growth factor in colonic mucosa of patients with inflammatory bowel disease

BACKGROUND/AIMS: Significantly enhanced serum levels of VEGF (vascular endothelial growth factor) were found in patients with inflammatory bowel disease. Peripheral blood mononuclear cells have been identified as one of the origins of the circulating VEGF. The present investigation examines the localization of VEGF at the site of inflammation in colonic mucosa of patients with Crohn's disease and ulcerative colitis. METHODOLOGY: Immunohistochemical localization of VEGF and immunostaining for leukocytes were performed in colonic mucosal biopsies of 41 patients with Crohn's disease, 26 patients with ulcerative colitis and normal mucosal specimens of 5 patients with irritable bowel syndrome. Measurement of immunohistochemical staining for VEGF and for leukocytes within the epithelium and the lamina propria was performed separately by area morphometry using a computerized cell analysis system. RESULTS: In both patients with Crohn's disease and ulcerative colitis immunohistochemical staining for VEGF within the lamina propria of inflamed colonic mucosa was significantly higher compared with noninflamed mucosa (Crohn's disease: 4.26% vs. 0.07%, P < 0.001; ulcerative colitis: 3.68% vs. 0.32%, P = 0.001). There was a significant correlation between immunostaining for leukocytes and VEGF within the lamina propria in both patients with Crohn's disease (r = 0.73, P < 0.05)) and ulcerative colitis (r = 0.67, P < 0.05). In Crohn's disease immunostaining for VEGF within the epithelium was significantly higher in inflamed mucosa compared with noninflamed mucosa (9.85% vs. 0.63%, P < 0.001). In contrast, strong immunostaining for VEGF has been observed in the epithelium of noninflamed mucosa (7.60%, P < 0.003), as well as in inflamed mucosa of patients with active ulcerative colitis (9.68%, P < 0.002) compared with noninflamed mucosa of patients with inactive ulcerative colitis (1.39%). CONCLUSIONS: The present data indicate, that the increased VEGF expression within the epithelium and the interstitial accumulation of VEGF-producing leukocytes in inflamed mucosa may play an important role in the inflammatory mechanisms of Crohn's disease and ulcerative colitis.     

Increased faecal mucin sulphatase activity in ulcerative colitis: a potential target for treatment.

Colonic mucin is heavily sulphated and it has been shown that enzymatic desulphation by faecal bacterial sulphatases greatly increases its susceptibility to degradation by faecal glycosidases. A possible role for faecal mucin sulphatase in the pathogenesis of inflammatory bowel disease has therefore been explored. Faecal mucin sulphatase activity assayed using 35S mucin as substrate was increased in ulcerative colitis (median 80.2 units/g pellet weight (range 6.9-1063; 95% confidence intervals (CI): 45.2 to 293.8, n = 22) compared with 11.3 units/g (range 3.0-53.5; 95% CI: 8.7 to 29.8, n = 17) in healthy controls (p < 0.01), where one unit released 1000 dpm free sulphate/hour from 35S mucin (1680 dpm/microgram). Patients with active ulcerative colitis had higher sulphatase activity (median 146; 95% CI: 98 to 253 units/g, n = 10) than those with inactive ulcerative colitis (median 42.2; CI: 22.5 to 81.6 units/g, n = 12) (p < 0.05). Longitudinal studies in patients with ulcerative colitis show fluctuations of faecal mucin sulphatase activity corresponding to clinical disease activity in six of seven patients. Faecal mucin sulphatase activity was not significantly increased in Crohn's disease (median 36.6, range 5.7-106.6; 95% CI: 22.9 to 65.3 units/g, n = 14). The bismuth salts, bismuth subcitrate and bismuth subsalicylate were found to inhibit faecal mucin sulphatase activity at concentrations achievable therapeutically. The increased faecal mucin sulphatase activity in ulcerative colitis could be the result of greater intraluminal substrate (mucin) availability leading to bacterial enzyme induction, but would probably result in more rapid degradation of secreted mucin and represents a potential target for treatment.     

Thiol methyltransferase activity in inflammatory bowel disease

BACKGROUND: Luminal anionic sulphide may contribute to epithelial damage in ulcerative colitis. Thiol methyltransferase (TMT) governs sulphide detoxification by the colonic mucosa and circulating erythrocytes. AIMS: To measure levels of TMT activity in erythrocytes of surgically treated cases of colitis or in rectal biopsies of defined groups of colitis. PATIENTS: Venepuncture blood was obtained from 37 blood donors and 27 subjects who had previously undergone a proctocolectomy for colitis: 18 for ulcerative colitis and nine for Crohn's colitis. Rectal biopsies from 122 cases were obtained: 47 without mucosal disease, 33 post-colon resection for cancer, 14 with moderate to severe ulcerative colitis, 15 with quiescent ulcerative colitis, seven with acute Crohn's colitis, and six with radiation proctitis. METHODS: TMT activity was measured by high performance liquid chromatography with radioactive detection to measure (14)C methylmercaptoethanol formation, the reaction product of cell extracts incubated with mercaptoethanol and (14)C S-adenosylmethionine. RESULTS: Erythrocyte TMT activity of surgically treated cases of colitis was significantly elevated (p<0. 001) compared with control cases. TMT activity of rectal biopsies was significantly decreased (p<0.02) in acute but not quiescent ulcerative colitis, Crohn's colitis, or radiation colitis. CONCLUSIONS: Erythrocyte TMT activity was persistently elevated after proctocolectomy for Crohn's disease and ulcerative colitis. No primary defect of TMT activity was found in any case of unoperated colitis but mucosal activity was diminished with disease progression of ulcerative colitis. Studies of genetic control of TMT activity of erythrocytes in inflammatory bowel disease appear worthwhile.     

Immunoglobulin containing cells in inflammatory bowel disease of the colon: a morphometric and immunohistochemical study.

Immunoglobulin containing cells in rectal and sigmoid colonic mucosa in endoscopically obtained biopsies from 10 patients with ulcerative colitis and 10 patients with Crohn's disease were studied, using an indirect immunoperoxidase technique. These findings were compared with the immunoglobulin containing cell number in colonic biopsies from 10 control patients with no evidence of colitis. In biopsies from the 20 patients with inflammatory bowel disease a marked increase in area of the lamina propria per millimetre mucosa length was found. In ulcerative colitis a marked increase in number of IgG containing cells was observed. In Crohn's disease the increase in IgG containing cell number is dependent on the degree of activity of inflammation. In quiescent of active Crohn's disease of the colon we found a significant increase of the IgM containing cells. The number of IgM containing cells per millimetre mucosa length will differentiate the pathology of Crohn's disease from ulcerative colitis.     

Identification of a prodromal period in Crohn's disease but not ulcerative colitis

OBJECTIVES: Irritable bowel syndrome, a common gastrointestinal diagnosis, has not been clearly studied in inflammatory bowel disease. Some of the residual symptoms in subjects treated with Crohn's disease and ulcerative colitis are thought to be related to irritable bowel syndrome. The aims of this study were 1) to describe the duration and nature of complaints before the diagnosis of Crohn's disease and ulcerative colitis (prodromal period), and 2) to determine the role of IBS in this prodromal period. METHODS: A total of 66 patients with confirmed inflammatory bowel disease were enrolled in the study. The subjects received a questionnaire to ascertain the nature and duration of symptoms preceding the diagnosis of Crohn's disease or ulcerative colitis, including features described under the Rome criteria for irritable bowel syndrome. RESULTS: Of the 66 subjects analyzed, 45 had Crohn's disease and 21 had ulcerative colitis. The prodromal period was 7.7 +/- 10.7 yr for Crohn's disease and 1.2 +/- 1.8 yr for ulcerative colitis (p < 0.05). Once patients meeting the Rome criteria for irritable bowel syndrome during the prodrome were excluded, the duration of the prodromal period (non-IBS) for ulcerative colitis dropped to 0.8 +/- 1.3 yr compared to 6.9 +/- 9.8 yr in the Crohn's disease group (p < 0.05). The symptoms of the non-IBS prodrome in subjects with Crohn's disease were bloating, diarrhea, stomach pain, heartburn, fever, weight loss, and fatigue. Further analysis demonstrated that subjects whose Crohn's disease initially began as colonic disease had a longer prodrome than with small bowel. In the non-IBS Crohn's group, there was also a correlation between the age at the time of diagnosis and the duration of prodrome (r = 0.67, p < 0.0001). CONCLUSIONS: There is a significant prodromal period before the time of diagnosis of Crohn's disease that is not found in ulcerative colitis even after exclusion of subjects with IBS.     

111Indium autologous granulocytes in the detection of inflammatory bowel disease.

Indium leucocyte scanning and measurement of faecal Indium leucocyte excretion are techniques which have recently been introduced for assessing patients with inflammatory bowel disease. The methodology has recently been made more specific for acute inflammation by labelling pure granulocytes rather than the mixed leucocyte preparation. To determine the accuracy of this modified technique in detecting inflammatory bowel disease, we have prospectively compared Indium granulocyte scanning and faecal In granulocyte excretion with rectal histology and contrast bowel radiology as screening procedures in 100 patients with suspected inflammatory bowel disease. Thirty three patients were shown to have inflammatory bowel disease - 24 with Crohn's disease and nine with ulcerative colitis or indeterminate colitis. Overall the respective sensitivities for detecting inflammatory bowel disease were 97% for faecal Indium granulocyte excretion, 94% for Indium granulocyte scanning, 79% for radiology and 70% for rectal histology. The superiority of In granulocytes over radiology and rectal histology in detecting inflammatory bowel disease was, in the main, due to the difficulty in diagnosing Crohn's with conventional techniques. Although three of the patients with ulcerative colitis and indeterminate colitis had normal sigmoidoscopic appearances - all had abnormal rectal histology. No patient with a non-inflammatory bowel disorder had a positive In granulocyte scan or a raised faecal excretion. These results show that investigations using In granulocytes are accurate in identifying inflammatory bowel disease and offer important advantages over conventional procedures for detecting Crohn's disease.     

Macrophage heterogeneity in normal colonic mucosa and in inflammatory bowel disease

Immunohistological techniques using monoclonal antibodies were employed to study the morphology and phenotypic expression of macrophage like cells in ulcerative colitis, Crohn's colitis and histologically normal colonic mucosa. The antibody RFD1 identifies interdigitating (antigen presenting) cells whereas RFD7 binds to mature tissue macrophages. In normal colonic mucosa, the majority of cells recognised by these reagents were positive for Class II antigen expression and a median 87% (range 80-95%) were positive for both RFD1 and RFD7, with 6.5% (ranges 1-14%) positive for either antibody alone. There was much greater macrophage heterogeneity in the ulcerative colitis and Crohn's colitis biopsies than in normal mucosa. Clusters of RFD9+ cells (epithelioid cells) were found in Crohn's colitis and, to a lesser extent, in ulcerative colitis. Some Crohn's colitis sections showed replacement of the normal colonic macrophage phenotype with RFD1-RFD7+ cells (classical scavenger macrophages). The degree of this replacement correlated with the histological severity of the disease. By contrast, large numbers of RFD1+ RFD7- cells, with long dendritic processes, were found in intimate association with the lymphoid infiltrates in the lamina propria of the ulcerative colitis sections. Future studies of the factors controlling macrophage differentiation in tissues may help to explain the greater macrophage heterogeneity in inflammatory bowel disease and the differences between ulcerative colitis and Crohn's colitis observed in this study.     

Expression of vascular adhesion molecules in inflammatory bowel disease.

The expression of the vascular adhesion molecules ELAM-1 (endothelial leukocyte adhesion molecule 1) and VCAM-1 (vascular cell adhesion molecule 1) was evaluated in colonic mucosa of patients with inflammatory bowel disease and normal controls by immunocytochemistry. VCAM-1 was found to be constitutively expressed in lymphoid aggregates in normal colonic mucosa and was not significantly enhanced or altered in distribution in mucosa of patients with inflammatory bowel disease regardless of the activity of the inflammatory process. In contrast, ELAM-1 was not detected by these techniques in normal colonic mucosa (n = 11) or in colonic mucosa of patients with inflammatory bowel disease which was either uninvolved or quiescent (n = 30). However, high levels of ELAM-1 were consistently found on endothelial surfaces in association with active inflammation in affected areas of colonic mucosa in patients with either ulcerative colitis (n = 27) or Crohn's colitis (n = 9). In addition, ELAM-1 appeared to be present within neutrophils which had migrated into crypt abscesses in affected mucosa. Similar analysis was carried out in the cotton-top tamarin (CTT), a primate that experiences an idiopathic chronic diffuse colitis resembling human ulcerative colitis. Although anti-human VCAM-1 antibodies did not react with the CTT, anti-human ELAM-1 stained endothelial surfaces in mucosal biopsies from CTT with active colitis. No ELAM-1 was identified in mucosa of CTT in which colitis activity was quiescent. Thus ELAM-1 is expressed on colonic endothelial surfaces in association with inflammation and may play an important role in facilitating leukocyte migration into sites of active IBD involvement.     

Prolyl hydroxylase activity in serum and rectal mucosa in inflammatory bowel disease.

Prolyl hydroxylase activity in rectal mucosa was found to be significantly greater in 11 patients with Crohn's disease than in 11 control subjects with the irritable bowel syndrome and 16 patients with ulcerative colitis (P less than 0.005). Seven of the patients with Crohn's disease had a histologically normal rectum. This abnormality in apparently normal mucosa supports the concept that Crohn's disease is a 'continuous' disease of the gastrointestinal tract. Although there was no significant difference in prolyl hydroxylase activity between control subjects and patients with ulcerative colitis, those patients with quiescent disease tended to have lower values than those with active mucosal inflammation. Prolyl hydroxylase activity could not, however, be detected in the sera of either healthy control subjects or patients with inflammatory bowel disease.     

Faecal mucinase activity assessed in inflammatory bowel disease using 14C threonine labelled mucin substrate.

Previous studies have shown the presence in faeces of sulphatases, sialidases, glycosidases, and proteases relevant to mucus degradation, but the relative role of these enzymes in the degradation of colonic mucus has been unclear. A total mucinase assay using 14C threonine biologically labelled human colonic mucin as substrate was therefore developed in this study. Faecal mucinase activity of a pooled normal faecal filtrate was capable of removing 80% of the 14C threonine label from mucin within eight hours incubation, but 20% remained intact despite prolonged incubation. The pH profile of mucinase activity is broad (pH 4.5-9.5) suggesting contribution from multiple enzymes. Mucinase activity was reduced by preincubation with 100 micrograms/ml chymostatin (82.8%), 0.5 mg/ml EDTA (91.6%), and 4 g/l bismuth subsalicylate (72.0%). All 55 faecal samples studied contained detectable mucinase activity, measured as dpm release/micrograms protein/hour, which was greater in samples from patients with ulcerative colitis (n = 17, median 52.7, interquartile range 32.9-66.9), than controls (n = 26, 34.4, 26.8-40.4, p < 0.02) or patients with Crohn's disease (n = 12, 35.5, 17.5-55.7, p < 0.05). There was, however, no significant difference in faecal mucinase activity between inactive and active ulcerative colitis. These results suggest that faecal mucinase activity is one factor contributing to the thin mucus layer in ulcerative colitis and represents a potential target for drug treatment.     

Different distribution of mast cells and macrophages in colonic mucosa of patients with collagenous colitis and inflammatory bowel disease

BACKGROUND/AIMS: Chronic inflammatory cells in colonic mucosa is a histopathologic feature in patients with collagenous colitis and inflammatory bowel disease. The aim of this study was to compare the distribution of mast cells and macrophages in the colonic mucosa of patients with collagenous colitis, Crohn's disease, and ulcerative colitis. METHODOLOGY: Patients with histologically confirmed collagenous colitis (n = 13), Crohn's disease (n = 20) or ulcerative colitis (n = 20) and normal control patients (n = 20) were included in this study. Biopsy specimens were obtained from the sigmoid colon of each patient, and immunostained using antibodies to tryptase (AA1) and CD68. The number of mast cells and macrophages located in upper and lower part of the lamina propria was determined. RESULTS: The number of mast cells in the upper part of lamina propria in patients with collagenous colitis (286 +/- 89/mm2, mean +/- SD), Crohn's disease (330 +/- 84/mm2) and ulcerative colitis (355 +/- 90/mm2), was higher than normal controls (201 +/- 44/mm2). The number of mast cells in the lower part of lamina propria in patients with Crohn's disease (345 +/- 87/mm2) and ulcerative colitis (363 +/- 86/mm2) was higher than collagenous colitis (266 +/- 63/mm2) and normal controls (309 +/- 60/mm2). The number of macrophages in the lower part of lamina propria in patients with Crohn's disease (330 +/- 63/mm2) and ulcerative colitis (301 +/- 60/mm2) was higher than in collagenous colitis (247 +/- 46/mm2) and normal controls (242 +/- 52/mm2), although there were no significant differences in the number of macrophages present in the upper part of the lamina propria among the four groups. CONCLUSIONS: Our data showed the presence of a different distribution of mast cells and macrophages in collagenous colitis and inflammatory bowel disease, and these suggest that because mucosal mast cells have been implicated in the development of Th2 response collagenous colitis is more of a Th2 type reaction rather than Th1.