Expression of adhesion molecules and HLA-DR by macrophages and dendritic cells in aphthoid lesions of Crohn's disease: an immunocytochemical study

The phenotypes and ultrastructure of macrophages and dendritic cells in aphthoid lesions of the colon were immunocytochemically observed in patients with Crohn's disease. Biopsy specimens were endoscopically obtained from both aphthoid and advanced lesions in Crohn's disease patients. Biopsy specimens obtained from patients with infectious colitis and from normal individuals served as controls. Aphthoid lesions contained densely aggregated CD68+ macrophages, which were surrounded by numerous ID-1+ dendritic cells. In the normal controls and infectious colitis patients, however, a few scattered CD68+ macrophages and ID-1+ dendritic cells were noted beneath the surface epithelium. CD3+ lymphocytes were significantly increased in both aphthoid and advanced lesions of Crohn's disease, but the CD4/CD8 ratio was similar in all groups studied. The double immunoperoxidase staining method revealed that both CD68+ macrophages and ID-1+ dendritic cells in the aphthoid lesions simultaneously expressed ICAM-1 and HLA-DR antigens. Electronmicroscopic observation revealed that CD68+ macrophages had numerous vesicles and lysosomal granules and few projections, and that ID-1+ dendritic cells had appreciable cytoplasmic protrusions with a few vacuoles. These findings suggested that the colonic mucosa in Crohn's disease contained two types of macrophage/dendritic cells in the same lineage that expressed intercellular adhesion molecules and class-II MHC antigens. It also appeared that the aphthoid lesions of Crohn's disease featured an increase in macrophages and dendritic cells consistent with immunological activation.     

Antineutrophil cytoplasmic antibodies in Estonian patients with inflammatory bowel disease. Prevalence and diagnostic role

BACKGROUND/AIMS: In Estonia, the incidence of ulcerative colitis and especially Crohn's disease appears to be rare. Antineutrophil cytoplasmic antibodies (ANCA) are frequently found in ulcerative colitis but less frequently in Crohn's disease, their pathophysiological significance is still unclear. METHODOLOGY: Fifty-nine serum samples from patients with ulcerative colitis, 17 with Crohn's disease, 25 with irritable bowel syndrome, and 86 healthy persons were studied. Sera were analyzed for the presence of ANCA by indirect immunofluorescence, and enzyme-linked immunosorbent assay for specific ANCA using different antigens was performed. RESULTS: ANCA were detected in 29 of 59 (49%) patients with ulcerative colitis, 4 of 17 (24%) patients with Crohn's disease, and in 4 of 111 (4%) controls. The immunofluorescence staining was mostly perinuclear (pANCA). There was no correlation between ANCA and the duration or extent of the inflammatory bowel disease. In specific enzyme-linked immunosorbent assays, only 14 sera elicited binding above the normal range. CONCLUSIONS: Although the prevalence of ulcerative colitis and Crohn's disease in Estonia is much lower than in European countries, there seem to be no differences in the presence of ANCA.     

The majority of myeloid-antigen-positive (My+) childhood B-cell precursor acute lymphoblastic leukaemias express TEL-AML1 fusion transcripts

BACKGROUND & AIMS: Crohn's disease and ulcerative colitis show a familial aggregation. In both diseases, anti-goblet cell autoantibodies (GABs) have been described. The aim of this study was to define the role of GABs in the pathogenesis of inflammatory bowel disease. METHODS: The study population comprised 61 patients with ulcerative colitis, 76 patients with Crohn's disease, 101 first-degree relatives of patients with ulcerative colitis, and 105 first-degree relatives of patients with Crohn's disease. Thirty-five patients with infectious enterocolitis and 56 healthy unrelated subjects served as controls. Autoantibodies were detected by indirect immunofluorescence. RESULTS: Thirty-nine percent of patients with ulcerative colitis (24 of 61) and 30% of patients with Crohn's disease (23 of 76) were positive for GABs. GABs were detected in 21% (21 of 101) of first-degree relatives of patients with ulcerative colitis and in 19% (20 of 105) of first-degree relatives of patients with Crohn's disease. In patients with infectious enterocolitis and in healthy controls, GABs were seen in 3% (1 of 35) and 2% (1 of 56), respectively. The differences between control groups and both groups of patients or their first-degree relatives were significant. CONCLUSIONS: The high prevalence in first-degree relatives suggests that GABs may represent a marker characterizing susceptibility to inflammatory bowel disease.     

Alterations in classical cadherins associated with progression in ulcerative and Crohn's colitis

Human colitis is a condition associated with a spectrum of altered morphologic changes and cellular adhesion. The role of cadherins, which are powerful morphoregulatory cell adhesion molecules, in colitis is provocative and as yet unknown. Herein, we present results that suggest a strong correlation between the deregulation of two cadherin molecules, E- and P-cadherins, and the progression of human colitis. We examined the expression and structural integrity of E- and P-cadherins in inflamed, dysplastic, or neoplastic human ulcerative colitis (UC) (n=58), human Crohn's colitis (n = 30), and normal tissue (n = 20) to assess cadherin function in normal and abnormal epithelium. E-cadherin is strongly expressed in normal colorectal epithelium, whereas in left-sided UC it is either down-regulated or has a single-base pair mutation in exon 4 resulting in an amino acid alteration (6 of 58 UC cases). By contrast, P-cadherin is dramatically up-regulated in both Crohn's disease and ulcerative colitis and especially in dysplastic ulcerative tissue. In vitro transfected SW-480 colorectal cells containing E-cadherin mutations identical to those in vivo were associated with increased spontaneous disaggregation compared with cells transfected with wild-type E-cadherin. Based on this evidence, we hypothesize that a small subset of colorectal cells expressing mutant E-cadherin are associated with widespread ulceration, whereas those expressing P-cadherin are associated with a rapidly dividing immature phenotype that includes dysplasia. The differential expression of mutated and wild-type cadherins examined herein are associated with a broad spectrum of abnormal epithelial phenotypes, lymphocyte integrin binding, and resistance to denudation, as is seen in the colitis adenocarcinoma sequence.     

Prevalence of upper gastrointestinal lesions and Helicobacter pylori infection in Crohn's disease

Crohn's disease can affect the upper gut with reported variable frequency, although concurrent Helicobacter pylori infection has been reported to be low. We prospectively investigated the prevalence of esophageal, gastric, and duodenal lesions and Helicobacter pylori infection in 67 Crohn's disease, 41 ulcerative colitis patients, and 43 controls. Symptoms, esophagogastroduodenoscopy, and multiple biopsies were performed on all patients consecutively. Endoscopic lesions were found in 63% of Crohn's disease patients, with a Helicobacter pylori prevalence of 28%. Granulomas were found in three patients. Twenty-two percent of the ulcerative colitis patients had lesions, with a 29% prevalence of Helicobacter pylori infection. Half of the controls had pathological endoscopy, and Helicobacter pylori was positive in 40% of the cases. Subjective symptoms did not predict the presence of endoscopic lesions or Helicobacter pylori infection in inflammatory bowel disease patients. Chronic gastritis and duodenitis are common in Crohn's disease patients, and the majority are not associated with Helicobacter pylori infection.     

Increased expression of costimulatory molecules on peripheral blood monocytes in patients with Crohn's disease

BACKGROUND: Activation of T lymphocytes and monocytes/macrophages has been implicated in the pathogenesis of Crohn's disease (CD). Costimulatory molecules play important roles in optimal T-cell activation. METHODS: With flow cytometric analysis we have investigated the expression of the costimulatory molecules B7-1 (CD80), B7-2 (CD86), and CD18 and the intercellular adhesion molecule-1 (ICAM-1) on peripheral blood monocytes and the expression of the activation markers HLA-DR and IL-2R (CD25) on peripheral blood T lymphocytes from 31 CD patients, 17 ulcerative colitis (UC) patients, and 10 healthy controls. RESULTS: In CD patients the percentage of activated T cells (CD3+ HLA-DR+ and CD3+ IL-2R+) was significantly increased compared with those of controls and UC patients (P < 0.05). Most monocytes from all three groups expressed B7-2, CD18, and ICAM-1 molecules (all > 79%), but only a few positive cells expressed B7-1 molecules (< 5%). No significant differences were detected in the percentage positivity of all costimulatory molecules tested among CD, UC, and controls. The mean fluorescence intensity (MFI) of B7-1 in all three groups was very weak and not significantly different. However, in CD patients there was a significantly increased MFI of B7-2, CD18, and ICAM-1 molecules compared with UC and controls (P < 0.05). On the other hand, both the percentage positivity and MFI of HLA-DR molecules on monocytes of UC patients were significantly lower than those of CD patients and controls (P < 0.05). CONCLUSIONS: Expression of the costimulatory molecules B7-2, CD18, and ICAM-1 on peripheral blood monocytes of CD patients is increased. In CD patients activation of peripheral T lymphocytes may correlate with increased expression of these costimulatory molecules on peripheral blood monocytes.     

Prothrombin fragment 1 + 2 and thrombin-antithrombin III complex as markers of activation of blood coagulation in inflammatory bowel diseases

OBJECTIVES AND METHODS: The aims of the present work were to assess the presence of thrombin generation in Crohn's disease and in ulcerative colitis by using the prothrombin fragment 1 + 2 and the thrombin-antithrombin III complex assays and to study the possible relationships between these markers and disease activity. RESULTS: Prothrombin fragment 1 + 2 and thrombin-antithrombin III complex were significantly raised in patients with Crohn's disease (n = 69) and with ulcerative colitis (n = 25) as compared with healthy controls (n = 50). In Crohn's disease these two markers of thrombin generation were correlated with the Van Hees index (P < 0.05 and P < 0.001, respectively); values were significantly different from controls even in the patient group displaying the lowest disease activity (P < 0.001). No correlation was found with tumour necrosis factor alpha and C-reactive protein; nevertheless patients with C-reactive protein less than or equal to 10 mg/l had significant lower values of prothrombin fragment 1 + 2 (P < 0.03). In ulcerative colitis prothrombin fragment 1 + 2 and thrombin-antithrombin III complex were significantly increased by comparison with controls, were higher in patients with pancolitis and correlated with C-reactive protein (P < 0.002 and P < 0.009, respectively). CONCLUSION: These data show that prothrombin fragment 1 + 2 and thrombin-antithrombin III complex are increased in inflammatory bowel diseases and suggest that thrombin generation might be an early event in their pathogenesis.     

Systemic recombinant human interferon-beta treatment of relapsing-remitting multiple sclerosis: pilot study analysis and six-year follow-up

The role of the spleen in patients with ulcerative colitis and Crohn's disease was assessed by counting pitted erythrocytes with differential interference microscopy and by splenic ultrasound. The findings were compared with those from age- and sex-matched controls and a group of splenectomized patients. The incidence of hyposplenism was lower than previously reported, being found in six of 29 patients with ulcerative colitis (of whom five had relapsed pancolitis and one had quiescent pancolitis) and two of 21 patients with Crohn's disease. Pitted erythrocyte counts were significantly higher in patients with ulcerative colitis compared with age- and sex-matched controls (p < 0.001), but there was no difference in counts between patients with Crohn's disease and controls. Patients with relapsed but not quiescent ulcerative colitis had significantly smaller spleens than controls. Patients with the highest pitted erythrocyte counts had the smallest spleens on ultrasound. More effective medical and surgical therapy may account for the lower incidence of functional hyposplenism observed in this study. Nonetheless, patients may show marked hyposplenism and remain at risk of overwhelming infection and operative complications. Differential interference microscopy is a simple technique that can be used to assess splenic function in patients thought to be susceptible to infection.     

Peripheral cell-mediated immune response to mycobacterial antigens in inflammatory bowel disease

A mycobacterial etiology has been proposed in Crohn's disease (CD). We have sought evidence of increased or modified T lymphocyte immune responses to Mycobacterium tuberculosis and Myco, paratuberculosis in patients with CD (n = 13), compared with ulcerative colitis (UC; n = 17) and controls (n = 17). Peripheral blood cells were cultured with phytohaemagglutinin (positive mitogen control), mycobacterial purified protein derivative (PPD) preparations, lysates, column fractions and whole, heat-killed bacteria. Responses of T cells and T cell subsets were assessed by expression of activation markers (CD25, CD69), coupled with blastogenesis assays (3H-thymidine uptake) and estimates of proliferation. Virtually all patients responded to Myco. paratuberculosis and Myco. tuberculosis antigens. There were no significant differences between patient groups, although there was a very high overall correlation (r = 0.95; P < 0.0001) between responses to the two mycobacterial species. Most of the activation and proliferative responses resided in the CD4+ (T helper) subset. Although up to 15% of CD8+ (suppressor/cytotoxic) cells also became activated, the CD8+ cells did not proliferate subsequently. Cells expressing the alternate gamma delta form of the T cell receptor (TCR gamma delta+) did not activate or proliferate in response to mycobacterial antigens. There were no differences in any of these parameters between patient groups. We conclude that there is no specific increase or alteration in cell-mediated anti-mycobacterial immunity in inflammatory bowel disease (IBD). Thus our data do not support a mycobacterial etiopathology of Crohn's disease.     

Measurement of rectal blood flow by laser Doppler flowmetry in inflammatory bowel disease

BACKGROUND/AIMS: Vascular alterations have been suggested as pathogenic factors in inflammatory bowel disease, particularly Crohn's disease. The aim of our study was to assess rectal blood flow in patients with active inflammatory bowel disease involving the rectum. METHODOLOGY: Endoscopic measurement of rectal blood flow was performed by laser Doppler flowmetry in 45 subjects divided into three groups: healthy controls, ulcerative colitis and rectal Crohn's disease. RESULTS: Rectal perfusion was found to be significantly impaired in patients with ulcerative colitis, but not in those with Crohn's colitis. CONCLUSIONS: Our results confirm the role of local ischemia in ulcerative colitis, but do not support the theory that vascular factors play a key role in the pathogenesis of Crohn's disease.     

Anti-neutrophil cytoplasmic antibodies in inflammatory bowel disease with special attention for IgA-class antibodies

Perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) of the IgG class have been reported in inflammatory bowel disease, mainly in ulcerative colitis. Since this disease affects the gastrointestinal tract, we determined whether IgA class ANCA were present in inflammatory bowel disease. We used an indirect immunofluorescence assay for IgG and IgA ANCA testing. Sera from 34 patients with Crohn's disease and 29 patients with ulcerative colitis were collected together with clinical and laboratory data. We found IgA class ANCA of a perinuclear type in 52% of patients with ulcerative colitis and in 9% of Crohn's disease patients. There was a significant association between the presence of IgA ANCA and the occurrence of blood in the feces in the ulcerative colitis group (P = 0.03). IgG ANCA was found in 56% of patients with ulcerative colitis and in 7% of patients with Crohn's disease. Because of partial overlap between IgG and IgA ANCA positivity, the sensitivity of ANCA testing in ulcerative colitis increased from 56% up to 78% by combining IgG and IgA assays. In conclusion, IgA ANCA occurs with a high prevalence in ulcerative colitis. Moreover there is a possible relationship between IgA ANCA and disease activity in ulcerative colitis.     

Antineutrophil cytoplasmic antibodies in inflammatory bowel disease: diagnostic tool or research procedure?

Antineutrophil cytoplasmic antibodies, initially detected in the sera of patients with Wegener's granulomatosis and other forms of systemic vasculitides, have also been observed in patients with inflammatory bowel disease, with a higher prevalence in ulcerative colitis. In this study, we investigated the prevalence of these antibodies in the sera of 42 patients with ulcerative colitis and 48 patients with Crohn's disease, and the possible correlations with disease activity and extent, extraintestinal complications, and therapy. Antineutrophil cytoplasmic antibodies were found in 30 out of the 42 patients with ulcerative colitis (71.4%); only 16 out of the 48 patients (33.3%) with Crohn's disease were positive (p < 0.001), and the prevalent pattern was perinuclear. No correlations with disease activity and extent, extraintestinal complications, or surgical or medical treatment were found. Our data indicate that in the case of inflammatory bowel disease, the search for antineutrophil cytoplasmic antibodies still remains a research procedure and cannot be used for clinical diagnosis.     

Risk indicators for inflammatory bowel disease

We investigated the association between different risk indicators and inflammatory bowel disease in a case-control study based on the population of Stockholm County during 1980-1984. Information on physical activity, oral contraceptives, some previous diseases and childhood characteristics was collected using a postal questionnaire for 152 cases of Crohn's disease, 145 cases of ulcerative colitis, and 305 controls. The relative risk (RR) of Crohn's disease was inversely related to regular physical activity and estimated at 0.6 (95% CI: 0.4-0.9) and 0.5 (95% CI: 0.3-0.9) for weekly and daily exercise, respectively. Having psoriasis prior to the inflammatory bowel disease was associated with an increased relative risk of Crohn's disease (RR = 2.9, 95% CI: 1.1-7.9). Use of oral contraceptives was associated with an increased RR of 1.7 for both Crohn's disease and ulcerative colitis. Crohn's disease confined to the colon and total ulcerative colitis at diagnosis were most strongly associated with oral contraceptives.     

Cultured astrocytes express functional receptors for galanin

OBJECTIVE: Inflammatory bowel disease (IBD) is characterized by T cell activation. Activated T cells shed interleukin-2 receptors (IL-2R) in a soluble form. A positive correlation between sIL-2Ralpha (CD25) and disease activity is well documented in IBD, whereas IL-2Rgamma (CD132) has not been investigated in this respect. Sera from 42 patients with ulcerative colitis (UC), 34 with Crohn's disease (CD), 31 healthy volunteers, and 12 patients with infectious enterocolitis were obtained. METHODS: Disease activity was scored according to a semiquantitative score for UC and CD. sIL-2R alpha chain and gamma chain were assessed by sandwich ELISA techniques using monoclonal antibodies specific for CD25 and CD132, respectively. RESULTS: The concentration of IL-2Ralpha chain (CD25) was found to be median 3.8 ng/ml in healthy volunteers versus 7.0 ng/ml in UC patients (p < 0.001), and 9.6 ng/ml in CD patients (p < 0.001). With respect to IL-2Rgamma (CD132), significantly higher amounts were found in CD patients: 6.6 ng/ml as compared with healthy controls <1.0 ng/ml (p < 0.004). A Kruskal-Wallis test revealed a significant correlation between alpha chain and disease activity in CD (p < 0.001), and further significantly higher gamma chain levels were found in active CD (p = 0.03). For UC patients, a statistically significant increase of the alpha chain with increasing disease activity (p < 0.01) was observed, whereas no significant changes of the gamma chain levels were found (p > 0.05). A difference of gamma chain levels were found between CD and UC in moderate and severe disease activity (p < 0.05). Further analyses revealed that mesalazine did not influence the IL-2Ralpha or -gamma concentration either in UC or in CD patients. CONCLUSION: An increased circulating level of the soluble common gamma chain (CD132) seems to be found in CD, and an overlap exists between CD and UC.     

Interleukin-1 receptor antagonist in differential diagnosis of inflammatory bowel diseases

BACKGROUND: Immunoregulatory properties of cytokines may mediate disordered inflammatory events in inflammatory bowel diseases (IBDs). On the basis of data obtained in experimental colitis, the hypothesis has been advanced that in IBD the balance between interleukin-1 (IL-1) and the naturally occurring IL-1 receptor antagonist (IL-1ra) might influence disease expression. OBJECTIVE: We studied the profiles of IL-1ra and acute phase proteins produced by activated macrophages to determine whether the level of IL-1ra in peripheral blood is a marker of disease activity in IBD and a possible differential diagnostic marker. PATIENTS AND METHODS: Levels of IL-1ra, serum neopterin, urinary neopterin, alpha 1-glycoprotein and C-reactive protein (CRP) were measured in 80 patients with ulcerative colitis, Crohn's disease or infectious colitis. RESULTS: Levels of IL-1ra were markedly increased in patients with active ulcerative colitis or active Crohn's disease compared with those in patients with infectious colitis. Patients with active Crohn's disease had significantly higher serum IL-1ra levels than patients with active ulcerative colitis. Moreover, a positive correlation was found between levels of C-reactive protein, alpha 1-glycoprotein, and serum neopterin and the level of IL-1ra in active Crohn's disease but not in active ulcerative colitis, strongly suggesting that the pathogenesis of the two conditions differs. CONCLUSION: Levels of IL-1ra in the peripheral blood of patients with IBD are of clinical relevance, representing a potent marker of disease activity and a possible differential diagnostic marker.     

Abnormal mucosal glycoprotein synthesis in inflammatory bowel diseases is not related to cigarette smoking

Patients with ulcerative colitis are usually non- or ex-smokers in contrast to Crohn's disease where smoking is common. Abnormalities of quantity and quality of intestinal mucus have been postulated in the pathogenesis of these diseases. It is possible that smoking habit may exert its effects via changes in mucus in inflammatory bowel disease. We have therefore studied incorporation of N-acetylglucosamine into synthesized colonic mucin in explants from 85 controls with normal colonoscopic appearances and histology, including 27 smokers and 58 nonsmokers, 36 patients with ulcerative colitis and 19 with ileocolonic Crohn's disease over 24 h in tissue culture. Incorporation of N-acetylglucosamine into normal explants was 31.3 +/- (SD) 7.1 dpm/microgram biopsy protein, incorporation was increased in patients with active Crohn's disease (mean 41.2 +/- (SD) 10.4 dpm/microgram biopsy protein, p = 0.003), decreased in inactive ulcerative colitis (mean 24.1 +/- 7.8 dpm/microgram biopsy protein, p = 0.0006) but normal in active ulcerative colitis (mean 35.0 +/- 13.8 dpm/microgram biopsy protein, p = 0.44). No significant relationship was found between cigarette smoking habits and mucus synthesis in controls with normal mucosa (nonsmokers, n = 58, mean 31.0 +/- (SD) 7.52 dpm/microgram biopsy protein; smokers, n = 27, mean 31.8 +/- (SD) 6.1 dpm/microgram biopsy protein, p = 0.9). This study shows that mucus glycoprotein synthesis is reduced in inactive ulcerative colitis, rising to normal levels in active disease and that synthesis is increased in Crohn's disease. There is no effect of smoking on mucus synthesis by control biopsies suggesting that the differences seen in inflammatory bowel disease are not related to cigarette smoking.     

Two cases of adult Still''s disease with atypical rash

Previous studies on baseline pulmonary function testing (PFT) abnormalities in patients with inflammatory bowel disease (IBD) are conflicting because most of them have incorporated patients suffering from both ulcerative colitis (UC) and Crohn's disease (CD). The aim of the study is to investigate whether any PFT abnormalities could be detected in a large group of IBD patients and whether there are differences between the two IBD entities. A total of 132 patients, 47 with CD (mean age 35 years) and 85 with UC (mean age 40 years) were studied. Pulmonary function tests (PFTs), lung transfer factor for carbon monoxide (TLCO) were examined and compared with those of 36 healthy controls. No significant difference of mean values of spirometric indices, TLCO and ABG was found between the two groups of patients and controls, or between patients with CD and UC. However, nine (19%) patients with CD and 15 (17.6%) with UC had a reduction in TLCO, a percentage significantly higher than in controls (P < 0.05). The majority of the patients with TLCO reduction were in an active phase of disease (P < 0.05). Our results suggest that there is no difference in routine PFTs between UC and CD patients, as well as between both these groups and normal controls. However, TLCO abnormalities related to the degree of disease activity are found in patients with both UC and CD.     

Incidence of inflammatory bowel diseases in the department of Puy-de-D?me in 1993 and 1994. EPIMICI. Epidémiologie des Maladies Inflammatoires Cryptogenetiques de l'Intestin group

The aim of this prospective epidemiological study was to investigate the incidence of Inflammatory Bowel Disease in the Puy-de-D?me county using the same methodology as EPIMAD's registry. METHODS: From 01/01/93 to 31/12/94, each gastroenterologist (n = 22) collected patients consulting for the first time with clinical symptoms compatible with inflammatory bowel disease. Data were reported on a questionnaire by an interviewer practitioner. The final diagnosis of Crohn's disease and ulcerative colitis was made in a blind manner by two expert gastroenterologists and recorded according to the Calkin's criteria as definite, probable, or possible diagnosis, or unclassifiable chronic colitis or acute colitis. RESULTS: 167 new cases were identified: 112 (67.1%) inflammatory bowel disease for the combined group of definite and probable cases with 79 Crohn's disease (70.5%), 29 ulcerative colitis (25.9%) of which 11 ulcerative proctitis (37.9%), 4 unclassifiable chronic colitis (3.6%) and 55 acute colitis (32.9%). The crude and age-adjusted incidence (per 10(5)/year) was respectively 6.6 and 5.7 for Crohn's disease and 2.4 and 1.9 for ulcerative colitis. The highest age-specific incidence rate for Crohn's disease was between 40-49 years (14.1) and for ulcerative colitis between 80-89 years (6.8). The female/male ratio was 0.8 for Crohn's disease and 1.1 for ulcerative colitis. The median age at the time of diagnosis was 42.6 years for Crohn's disease and 35.3 years for ulcerative colitis. CONCLUSIONS: These preliminary findings revealed a high incidence of Crohn's disease and low of ulcerative colitis in this county. However, these results must be managed carefully because these data were recorded only on two years and the inflammatory bowel disease classified possible and acute colitis require a follow-up.     

Incidence of inflammatory bowel disease in northern France (1988-1990)

There were no data concerning the incidence of inflammatory bowel disease (IBD) in France. The aim of this study was to investigate the incidence of Crohn's disease and ulcerative colitis in northern France. This prospective population based study was realised through the gastroenterologists of the region Nord-Pas de Calais and the Somme Department. Each gastroenterologist referred patients consulting for the first time with clinical symptoms compatible with IBD. Data were collected by an interviewer practitioner present at the gastroenterologist's consulting room. Two independent expert gastroenterologists assessed each case in a blind manner and made a final diagnosis of Crohn's disease, ulcerative colitis, ulcerative proctitis, or unclassifiable chronic colitis. From 1988 to 1990, 1291 cases of IBD were recorded: 674 (52%) Crohn's disease, 466 (36%) ulcerative colitis including 162 proctitis (35%), and 151 (12%) unclassifiable chronic colitis. The mean annual incidence was 4.9 per 100,000 for Crohn's disease and 3.2 for ulcerative colitis. The sex ratio F/M was 1.3 for Crohn's disease and 0.8 for ulcerative colitis. The highest age specific incidence rate for Crohn's disease was between 20 and 29 years: 13.1 for women and 9.8 for men. The highest age specific incidence rate for ulcerative colitis was between 20 and 39 years: 5.5 for women and 6.5 for men. This first French prospective study has shown an incidence rate for Crohn's disease comparable with that seen in north European studies but lower than that seen for ulcerative colitis. These results could be related to the different environmental factors or the genetic background of the population studied, or both.     

An increased risk of Crohn's disease in individuals who inherit the HLA class II DRB3*0301 allele

The role of inflammatory T cells in Crohn's disease suggests that inherited variations in major histocompatibility complex (MHC) class II genes may be of pathogenetic importance in inflammatory bowel disease. The absence of consistent and strong associations with MHC class II genes in Caucasian patients with inflammatory bowel disease probably reflects the use of less precise typing approaches and the failure to type certain loci by any means. A PCR-sequence-specific oligonucleotide-based approach was used to type individual alleles of the HLA class II DRB1, DRB3, DRB4, and DRB5 loci in 40 patients with ulcerative colitis, 42 Crohn's disease patients, and 93 ethnically matched healthy controls. Detailed molecular typing of the above alleles has previously not been reported in patients with inflammatory bowel disease. A highly significant positive association with the HLA-DRB3*0301 allele was observed in patients with Crohn's disease (P = 0.0004) but not in patients with ulcerative colitis. The relative risk for this association was 7.04. Other less significant HLA class II associations were also noted in patients with Crohn's disease. One of these associations involved the HLA-DRB1*1302 allele, which is known to be in linkage disequilibrium with HLA-DRB3*0301. These data suggest that a single allele of an infrequently typed HLA class II locus is strongly associated with Crohn's disease and that MHC class II molecules may be important in its pathogenesis.