Peripheral blood monocyte cytokine production and acute phase response in inflammatory bowel disease.

Cytokines released from activated mononuclear leukocytes are involved in triggering the acute phase response and many of the inflammatory manifestations of ulcerative colitis and Crohn's disease. The ability of circulating monocytes from patients with ulcerative colitis and Crohn's disease to generate the cytokines interleukin 1 beta (IL 1 beta) and tumour necrosis factor alpha (TNF alpha), both spontaneously and in response to stimulation by lipopolysaccharide, was compared. IL 1 beta generation in response to lipopolysaccharide was significantly higher in Crohn's disease than in ulcerative colitis and normal controls, with a dramatic increase in patients with active disease. There was a significant reduction in lipopolysaccharide stimulated TNF alpha generation in ulcerative colitis patients compared with Crohn's disease and normal control subjects. IL 1 beta and TNF alpha release correlated significantly with serum C reactive protein and serum alpha 1 acid glycoprotein in Crohn's disease. The ability of conditioned medium from monocytes in Crohn's disease to enhance release of alpha 1 acid glycoprotein from the liver cell line HepG2 in culture was assessed. There was a significant positive correlation between TNF alpha and IL 1 beta presence in the supernatant and alpha 1 acid glycoprotein production. The differences in the cytokine profile in patients with Crohn's disease compared with ulcerative colitis suggest an intrinsic difference in the ability to produce cytokines in patients with these two forms of inflammatory bowel disease, and may explain features such as the enhanced ability to generate a brisk C reactive protein response in Crohn's disease.     

Intestinal immune reactivity to interleukin 2 differs among Crohn's disease, ulcerative colitis, and controls

When stimulated by the lymphokine interleukin 2, human intestinal mucosal mononuclear cells mediate lymphokine-activated killer cell activity. When supplied with optimal doses of exogenous interleukin 2, lamina propria mononuclear cells isolated from inflammatory bowel disease and control tissue display comparable levels of cytotoxicity in vitro. However, cultures of Crohn's disease- and ulcerative colitis-derived cells contain significantly decreased interleukin 2 activity, suggesting that in vivo the availability of interleukin 2 may be limited, perhaps resulting in impaired cytotoxic function. To test this hypothesis, lamina propria mononuclear cells from inflammatory bowel disease and control patients were stimulated to produce endogenous interleukin 2, which was then used to induce autologous lymphokine-activated killer cells. When tested against K562 and Daudi target cells, Crohn's disease cells, despite producing only one-third of the amount of interleukin 2 generated by control cells, exhibited comparable levels of cytotoxicity. In contrast, ulcerative colitis cells produced substantially less interleukin 2 and exhibited remarkably low lymphokine-activated killer cell activity. When the same cells were supplied with an amount of human recombinant interleukin 2 equivalent to the average titer found in control cultures, similar results were obtained, and Crohn's disease cells even showed a significantly greater cytolytic activity than controls. These results suggest that the observed differences in lymphokine-activated killer cell activity cannot be attributed to the level of interleukin 2 alone, and that response to this lymphokine is different among Crohn's disease, ulcerative colitis, and control intestine. In Crohn's disease, there is either an increased number of interleukin 2-responsive cells or an exacerbated reactivity to interleukin 2. In ulcerative colitis, a loss of interleukin 2-responsive cells, a hyporesponsiveness to interleukin 2, or both might be present. In conclusion, this study demonstrates that reactivity to interleukin 2 distinguishes inflammatory bowel disease from control intestinal mononuclear cells, and, under appropriate experimental conditions, it can be used to uncover abnormalities of intestinal immunity.     

T lymphocyte subsets in inflammatory bowel disease: peripheral blood

Peripheral blood T lymphocytes and T lymphocyte subsets have been quantified in 28 patients with ulcerative colitis and 26 with Crohn's disease by an indirect immunofluorescence technique using monoclonal antibodies: OKT3, which detects all peripheral blood T lymphocytes; OKT4 (T cells of helper phenotype); and OKT8 (T cells of supressor-cytotoxic phenotype). Eighteen normal subjects and 16 patients with a variety of non-inflammatory gastrointestinal disorders were studied as controls. No significant differences were found between patient and control groups in the proportions of circulating T lymphocytes or their subsets. When compared with normal subjects, absolute numbers of T lymphocytes were reduced in patients with active ulcerative colitis or Crohn's disease (p less than 0.05). OKT4+ T cell numbers were reduced in ulcerative colitis, whether active (p less than 0.02) or inactive (p less than 0.05) and in active Crohn's disease (p less than 0.05) Numbers of OKT8+ T cells were reduced in active Crohn's disease (p less than 0.01). There were no differences in T lymphocyte numbers between the patient groups and the disease control subjects. The OKT4+:OKT8+ ratio in patients with inflammatory bowel disease did not differ from that in controls. No relation was found between any of the parameters studied and disease activity, site, or extent of disease, or treatment with sulphasalazine or corticosteroids. The presence of Ia-like, HLA-DR antigens on T cells was detected using a double marker immunofluorescence technique. In control subjects up to 7% of OKT3+ cells were HLA-DR+. In only three patients was the proportion of HLA-DR+ cells greater than in controls. These results indicate that the pathogenesis of ulcerative colitis or Crohn's disease does not depend upon an alteration in the proportion of circulating T lymphocytes nor upon an imbalance of T lymphocyte subsets as defined by monoclonal antibodies. The reduction in T lymphocyte numbers may result from mucosal infiltration. The findings also suggest that circulating T lymphocytes are not activated.     

Soluble interleukin 2 and CD8 and CD4 receptors in inflammatory bowel disease.

Serum levels of soluble interleukin 2 receptor (sIL-2R) have been proposed as a clinical marker of inflammatory bowel disease. The source of sIL-2R in patients with Crohn's disease and ulcerative colitis is unknown, and other soluble receptors have not been investigated. In the present study, sIL-2R and soluble CD8 and CD4 levels were measured in plasma and culture supernatants of peripheral blood and intestinal mucosal mononuclear cells from patients with inflammatory bowel disease, surgical controls, and healthy subjects. Level of plasma sIL-2R was significantly higher in patients with Crohn's disease and ulcerative colitis than in healthy volunteers. Intestinal cells always produced more sIL-2R than peripheral cells. Spontaneous sIL-2R production by mucosal cells was significantly elevated in Crohn's disease but not in ulcerative colitis supernatants compared with levels of surgical controls. Soluble CD8 and CD4 were poor indicators of systemic or mucosal immunity. A positive correlation was found between plasma sIL-2R and spontaneous production by intestinal cells of patients with Crohn's disease and surgical control patients, whereas ulcerative colitis plasma sIL-2R correlated with spontaneous production by peripheral cells. The association of plasma or spontaneous sIL-2R levels with the degree of intestinal inflammation was weak, and there was a wide overlap with control values. Therefore, caution should be used before considering sIL-2R an accurate marker of inflammatory bowel disease activity.     

Role of interleukin 1 in inflammatory bowel disease--enhanced production during active disease.

Interleukin 1 is a polypeptide cytokine produced by various cell types and has been shown to have a major role in inflammatory and immunological responses. In experimental colitis it proved to be a dominant mediator and a reliable marker of inflammation. The aim of the present study was to determine in vitro the extent of production and release of interleukin 1 from colonic mucosa of patients with active untreated inflammatory bowel disease. Colonic mucosal biopsy specimens were obtained during colonoscopy from 17 patients with ulcerative colitis, eight patients with Crohn's disease of the colon, and 16 normal control subjects. Interleukin 1 content was determined in fresh and 24 hour organ cultured mucosa as well as in cultured medium. Interleukin 1 content and release were significantly higher in the inflamed mucosa compared with that of control subjects. Prednisolone inhibited interleukin 1 release in a dose dependent fashion. We conclude that colonic mucosal interleukin 1 content and production is significantly raised in active inflammatory bowel disease and may have a role in the pathogenesis of the inflammatory response. Pharmacological suppression of tissue interleukin 1 production may have a beneficial therapeutic effect.     

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.     

Ornithine decarboxylase in colonic mucosa from patients with moderate or severe Crohn's disease and ulcerative colitis.

Polyamines, as well as ornithine decarboxylase (ODC), the enzyme involved in their synthesis, were reported to be closely related to cell proliferation. In Crohn's disease and ulcerative colitis, cell destruction and proliferation increase in the active stage. The aim of the present study was to determine the ODC in both involved and uninvolved areas of the colonic mucosa of active Crohn's disease and ulcerative colitis patients. The patients were divided in two groups, owing to the different level of activity (severe or moderate), by means of clinical endoscopy, laboratory, and histology evaluations. Subjects with suspected disease, but endoscopically unconfirmed, were used as controls. In all ulcerative colitis and Crohn's disease patients the ODC values both in involved and uninvolved mucosa were significantly lower than in controls. In severe Crohn's disease ODC was significantly reduced versus moderate Crohn's disease only in affected tissues. In all ulcerative colitis patients (moderate or severe) the ODC was significantly decreased in involved mucosa compared with uninvolved mucosa. Severe ulcerative colitis showed the significantly lowest ODC. We suggest that the significant decrease of ODC in the bowel mucosa is closely related to the severity of the disease. The highest decrease of ODC in ulcerative colitis patients would be due both to the enhanced cell destruction, and to the feed-back from exogenous increased polyamine production (bowel bacteria, cell desquamation). Therefore ODC would be considered a sensitive index of the inflammatory derangement of the mucosa, especially in acute ulcerative colitis. We conclude that this behaviour may result in an enhanced risk of neoplasia.     

Non-invasive evaluation of activity in inflammatory bowel disease by power Doppler sonography

BACKGROUND: To study the vascularization in the diseased bowel wall by power Doppler sonography in patients with inflammatory bowel disease. PATIENTS AND METHODS: The diseased bowel wall was investigated in 99 patients with inflammatory bowel disease (60 patients with Crohn's disease and 39 patients with ulcerative colitis) either with active disease or in remission by B-mode and power Doppler sonography. Disease activity was determined by clinical indices. Twenty healthy age and sex matched individuals served as controls. RESULTS: Bowel wall was thickened in active Crohn's disease (mean 7 mm, range 4-14) and ulcerative colitis (mean 5 mm, range 2-15) as compared to healthy controls (mean 2 mm, range 1-3), p < 0.001. In contrast to healthy controls blood vessels were detected in the bowel wall in 100 % of patients with active Crohn's disease and 91 % with active ulcerative colitis. Vascularization was significant decreased in patients with quiescent versus active disease in ulcerative colitis (p < 0.05), while in Crohn's disease there was no significance between active and remission phase. CONCLUSIONS: Thickened and hypervascularized bowel wall are characteristic findings in inflammatory bowel disease. A combination of B-mode and power Doppler sonography offers an additional noninvasive procedure for the determination of activity in patients with inflammatory bowel disease.     

Detection of mRNAs for macrophage products in inflammatory bowel disease by in situ hybridisation.

In situ hybridisation has been used to detect mRNAs to the macrophage secretory products, lysozyme, interleukin 1 beta and tumour necrosis factor-alpha. Sections of paraformaldehyde fixed, frozen colonoscopic biopsies from patients with ulcerative colitis, Crohn's disease or normal controls were hybridised with specific radiolabelled probes and the signal detected by autoradiography. Lysozyme mRNA expression was more common in ulcerative colitis (22/27) and Crohn's disease (eight of eight) compared with controls (17/27). Positive cells were found mainly in the subepithelial region in normal colon, while in inflammatory bowel disease they also appeared in the deeper lamina propria. Immunocytochemistry in parallel sections showed that lysozyme mRNA was expressed only in macrophages or in metaplastic Paneth cells in longstanding inflammatory bowel disease. Tissue neutrophils did not express the lysozyme mRNA, though they have large stores of the protein. Tumour necrosis factor mRNA was detected in four of nine controls compared with 11/15 inflammatory bowel disease patients. For interleukin 1 beta, three of eight controls were positive compared with 10/13 with ulcerative colitis. The tumour necrosis factor signal was located mainly in the deeper lamina propria whereas the interleukin 1 beta was seen in subepithelial macrophages. These results confirm increased macrophage activation in inflammatory bowel disease and suggest functional heterogeneity within the intestinal macrophage population.     

Interrelations between interleukin-6, interleukin-1 beta, plasma C-reactive protein values, and in vitro C-reactive protein generation in patients with inflammatory bowel disease.

Acute phase proteins are released from the liver in response to cytokines, and measurement of serum concentrations offers a valuable means of assessing inflammatory bowel disease. C-reactive protein (CRP) is a participating prominent component of the acute phase response in active Crohn's disease. This study aimed at determining the comparative role of the cytokines interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6), in driving CRP production in inflammatory bowel disease, and to test the hypothesis that there is a difference in the profile of cytokines generated in these two conditions. Serum CRP, the release of the cytokines IL-1 beta and IL-6 from monocytes, and the ability of monocyte conditioned medium to stimulate CRP synthesis by hepatocytes in an in vitro system was measured in patients with ulcerative colitis and Crohn's disease. Monocytes from patients with Crohn's disease produced more 1L beta-1 than monocytes from patients with ulcerative colitis or normal controls. There was no increased tendency for monocytes from Crohn's disease patients to produce more 1L-6, so the greater circulating values of IL-6 reported by a number of authors in Crohn's disease may reflect the participation of a larger number of cells of the monocyte-macrophage series, or production of IL-6 by other cell types. Correlation of cytokine production by monocytes with in vitro CRP release from cultured hepatocytes in response to monocyte conditioned medium showed that, in that system, IL-1 beta was the stronger stimulus to CRP production. Some of the differences in the inflammatory processes of ulcerative colitis and Crohn's disease may reflect differences in the amount of IL-1beta and IL-6 generated from macrophages and monocytes.     

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.     

Loss of interleukin-2-producing intestinal CD4+ T cells in inflammatory bowel disease.

Interleukin-2 activity of intestinal lamina propria mononuclear cells is decreased in Crohn's disease and ulcerative colitis patients compared with control patients with noninflammatory bowel disease. Factors that might be responsible for this phenomenon were investigated. Most interleukin-2 activity was produced by helper (CD4+) T cells. These were present in comparable numbers in both inflammatory bowel disease and control cultures, but the frequency of interleukin-2-producing cells was significantly (3-4 times) lower among Crohn's disease and ulcerative colitis than control cells. In agreement with this finding, levels of interleukin-2 messenger RNA were substantially decreased in both forms of inflammatory bowel disease compared with controls. Mucosal CD8+ T cells and plastic-adherent cells were unable to suppress interleukin-2 activity by autologous or allogeneic CD4+ T cells. The rate of interleukin-2 absorption was similar for inflammatory bowel disease and control cells. Induction of interleukin-2 by different stimuli (phorbol ester, phytohemagglutinin, or anti-CD3 monoclonal antibody) before or after incubation under basal conditions ("resting") failed to normalize the capacity to generate interleukin-2 by Crohn's disease and ulcerative colitis cells. Prostanoids (prostaglandin E2 and 6-keto-prostaglandin F1 alpha) were produced in large amounts in cultures of inflammatory bowel disease cells, but inhibition by indomethacin failed to restore interleukin-2 activity to control levels. Finally, supernatants from Crohn's disease and ulcerative colitis cell cultures failed to suppress interleukin-2 production by control CD4+ T cells. Our results show that the low interleukin-2 activity detected in inflammatory bowel disease mucosa is not caused by activated suppressor cells, excessive lymphokine utilization or immune stimulation, a defective response to activation signals, or production of inhibitory substances. Rather, the low interleukin-2 activity appears to be related to a loss of interleukin-2-producing mucosal CD4+ T cells. It is concluded that abnormalities of intestinal CD4+ T-cell function are associated with the immunopathogenesis of Crohn's disease and ulcerative colitis.     

Function of exudative neutrophilic granulocytes in patients with Crohn's disease or ulcerative colitis

Chemotactic, phagocytic, and oxidative metabolic activity of exudative leukocytes was measured in patients with Crohn's disease (n = 20) and with ulcerative colitis (n = 20). Unstimulated and casein-stimulated migration in Boyden chambers did not differ from that of healthy controls (n = 21). Patients with Crohn's disease had reduced serum-independent phagocytosis compared with healthy controls (p less than 0.01) and patients with ulcerative colitis (p less than 0.01). Serum-dependent phagocytosis by leukocytes from patients with Crohn's disease did not differ from that in controls but was slightly increased in patients with ulcerative colitis (p less than 0.02). Unstimulated leukocytes showed increased oxidative metabolic activity in both patient groups compared with controls (p less than 0.01), which was negatively correlated with the disease activity in Crohn's disease (p less than 0.02). The study shows that mobilized leukocytes from patients with Crohn's disease differ from those mobilized in ulcerative colitis and supports the concept of an abnormal inflammatory reaction in Crohn's disease.     

Virulence properties of Escherichia coli strains isolated from patients with inflammatory bowel disease.

Escherichia coli strains cultured from 74 patients with inflammatory bowel disease at different stages of disease activity (Crohn's disease (40), ulcerative colitis (34)) and 18 healthy controls were studied in relation to haemolysin and verotoxin production and enteroadherence. Disease activity was assessed by standard clinical and laboratory tests. Haemolytic E coli were isolated from 18% of patients with Crohn's disease, 24% with ulcerative colitis, and 11% of healthy controls. None of these differences was significant. No verotoxin producing strains were detected among the 216 E coli isolates examined but the extract from five strains (Crohn's (4), ulcerative colitis (1) produced a distinctive cytopathic effort on Vero cell monolayers which was later shown not to be due to verotoxin. The adhesion indices of E coli isolates cultured were: mean (SEM) 42.2 (6.4) for Crohn's disease, 43.3 (6.2) for ulcerative colitis, and 11.3 (2.0) for normal controls (p less than or equal to 0.0001). Adhesive E coli were isolated from 62% of patients with Crohn's disease and 68% with ulcerative colitis but from only 6% of normal controls (p less than or equal to 0.0002). Neither haemolysin production nor enteroadherence was dependent upon disease activity, disease location, sulphasalazine treatment, or previous intestinal resection. These results indicate that only enteroadherent E coli were frequently associated with inflammatory bowel disease; their relation to the pathogenesis of these conditions, however, remains uncertain.     

In vitro effects of oxpentifylline on inflammatory cytokine release in patients with inflammatory bowel disease.

BACKGROUND: Inflammatory cytokines, including tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1 beta, have been implicated as primary mediators of intestinal inflammation in inflammatory bowel disease. AIM: To investigate the in vitro effects of oxpentifylline (pentoxifylline; PTX; a phosphodiesterase inhibitor) on inflammatory cytokine production (1) by peripheral mononuclear cells (PBMCs) and (2) by inflamed intestinal mucosa cultures from patients with Crohn's disease and patients with ulcerative colitis. METHODS: PBMCs and mucosal biopsy specimens were cultured for 24 hours in the absence or presence of PTX (up to 100 micrograms/ml), and the secretion of TNF-alpha, IL-1 beta, IL-6, and IL-8 determined by enzyme linked immunosorbent assays (ELISAs). RESULTS: PTX inhibited the release of TNF-alpha by PBMCs from patients with inflammatory bowel disease and the secretion of TNF-alpha and IL-1 beta by organ cultures of inflamed mucosa from the same patients. Secretion of TNF-alpha by PBMCs was inhibited by about 50% at a PTX concentration of 25 micrograms/ml (IC50). PTX was equally potent in cultures from controls, patients with Crohn's disease, and those with ulcerative colitis. The concentrations of IL-6 and IL-8 were not significantly modified in PBMCs, but IL-6 increased slightly in organ culture supernatants. CONCLUSIONS: PTX or more potent related compounds may represent a new family of cytokine inhibitors, potentially interesting for treatment of inflammatory bowel disease.     

炎症性肠病患者CD27-CD70共刺激途径的激活研究

目的 探讨CD27-CD70共刺激途径在炎症性肠病患者外周循环和肠黏膜中的表达,比较炎症性肠病患者CD27-CD70表达与正常对照者间的差异.方法 共纳入62例克罗恩病(CD)、64例溃疡性结肠炎(UC)患者和56名正常对照者.应用酶联免疫吸附试验分析炎症性肠病患者和正常对照者血浆中CD27-CD70蛋白的表达;SYBR-green实时PCR法分析炎症性肠病患者和正常对照者外周血单个核细胞中CD27-CD70 mRNA的表达;免疫组化法分析炎症性肠病患者和正常对照者肠黏膜组织CD27-CD70蛋白的表达.结果 CD和UC患者血浆中CD27-CD70的表达均显著高于正常对照者(P值均<0.05).ROC曲线的分析表明,CD27-CD70对区分CD患者和正常对照者以及区分UC患者和正常对照者具有显著的诊断价值(P值均<0.05).CD患者血浆中CD27和CD70水平与内镜下疾病活动性(EDAI)无关(r值分别=0.055和0.024,P值分别为0.673和0.852),且UC患者血浆中CD27和CD70水平与EDAI无关(r值分别=0.077和0.021,P值分别为0.547和0.869).CD患者和UC患者外周血单个核细胞CD27和CD70 mRNA表达均显著高于正常对照者外周血单个核细胞中mRNA的表达(P值均=0.000).免疫组化实验表明CD患者和UC患者肠黏膜组织CD27和CD70的表达均显著高于正常对照者(P值均=0.000).结论 炎症性肠病患者血浆、外周血单个核细胞和肠黏膜中均存在CD27-CD70途径的激活,但血浆中CD27-CD70的水平不能反映内镜下疾病活动程度.选择性干预CD27-CD70共刺激通路可能成为缓解或减轻炎症性肠病进程的有益尝试.     

Mean platelet volume: a useful marker of inflammatory bowel disease activity

OBJECTIVES: We investigated whether the mean platelet volume would be a useful marker in the evaluation of inflammatory bowel disease activity. METHODS: Complete blood count, C-reactive protein, erythrocyte sedimentation rate, serum thrombopoietin and erythropoietin, plasma beta-thromboglobulin, and platelet factor 4 were measured in 93 patients with ulcerative colitis, 66 patients with Crohn's disease, and 38 healthy blood donors. Disease activity was assessed by the Clinical Colitis Activity Index in patients with ulcerative colitis and by the Crohn's Disease Activity Index in patients with Crohn's disease. RESULTS: Mean platelet count was increased in patients with active compared to inactive ulcerative colitis (p < 0.05), and in patients with active compared to inactive Crohn's disease (p = 0.0002) or healthy controls (p < 0.0001). On the other hand, mean platelet volume was significantly decreased in patients with active compared to inactive ulcerative colitis (p = 0.02) or healthy controls (p < 0.0001), and in patients with active compared to inactive Crohn's disease (p = 0.0005) or healthy controls (p < 0.0001). Mean platelet volume was inversely correlated with the white blood cell count (r = -0.17, p = 0.02), C-reactive protein (r = -0.46, p = 0.009) and erythrocyte sedimentation rate (r = -0.28, p = 0.008). No significant correlations were found between mean platelet volume and serum thrombopoietin or erythropoietin levels; however, a strong negative correlation between mean platelet volume and beta-thromboglobulin (r = -0.34, p < 0.0001) and platelet factor 4 (r = -0.30, p = 0.0002) was observed. CONCLUSIONS: Mean platelet volume is significantly reduced in active inflammatory bowel disease and is negatively correlated with the known inflammatory bowel disease activity markers and the platelet activation products. We propose that mean platelet volume provides a useful marker of activity in inflammatory bowel disease.     

Increased production of vascular endothelial growth factor by peripheral blood mononuclear cells in patients with inflammatory bowel disease

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent angiogenic, vascular permeability-enhancing cytokine with overexpression in various pathological disorders, including tumour growth, chronic inflammation and tissue repair. Recent studies have shown significantly increased serum levels of VEGF in patients with inflammatory bowel disease. The origin of the circulating VEGF is still unknown. The present investigation examines the VEGF production by peripheral blood mononuclear cells (PBMCs) in patients with inflammatory bowel disease. METHODS: VEGF levels were measured in culture supernatants of unstimulated PBMCs of 27 patients with inflammatory bowel disease and 10 healthy volunteers using a solid phase ELISA. In addition, VEGF serum levels were determined. RESULTS: PBMCs of both active Crohn's disease patients (1142.6+/-483.9 pg/ml, P < 0.001, n = 12) and active ulcerative colitis patients (748.0+/-637.6 pg/ml, P = 0.006, n = 4) produced significantly higher amounts of VEGF compared with PBMCs of healthy volunteers (113.4+/-101.8 pg/ml, n = 10). In addition, there was a significantly increased VEGF production by PBMCs of patients with active disease compared with PBMCs of patients with quiescent Crohn's disease (261.6+/-254.8 pg/ml, P < 0.001, n = 7) and inactive ulcerative colitis (147.7+/-100.3 pg/ml, P = 0.02, n = 4). There was no significant difference in VEGF release between patients with inactive inflammatory bowel disease and healthy controls. CONCLUSIONS: Significantly increased VEGF production by PBMCs was found in patients with active Crohn's disease and active ulcerative colitis. The study helps to clarify one of the origins of the significantly enhanced VEGF serum levels in patients with active inflammatory bowel disease observed in recent studies.     

Plasma polyunsaturated fatty acid pattern in active inflammatory bowel disease.

Plasma fatty acid patterns were assessed by gas liquid chromatography in 73 patients with active inflammatory bowel disease and 107 healthy controls. The influence of the disease activity on fatty acid profile was also investigated. Plasma fatty acid patterns in patients with ulcerative colitis and Crohn's disease were similar. Plasma C18:3n3 and C22:6n3 were significantly higher in active ulcerative colitis (p = 0.0143 and p < 0.00001 respectively) and in Crohn's disease (p < 0.00001 for both) than in controls, whereas C20:3n6 was significantly lower in patients than in controls, both in ulcerative colitis (p = 0.0001) and in Crohn's disease (p = 0.0041). In more severe disease, plasma polyunsaturated fatty acid concentrations fell with a significant stepwise decrease in the desaturation index (p = 0.0031 in ulcerative colitis and p = 0.0355 in Crohn's disease). Even in patients with severe disease, however, plasma n3 fatty acids (C18:3n3 and C22:6n3) never fell below those of healthy controls. These findings suggest that in active inflammatory bowel disease, an increased biosynthesis might coexist with an increased consumption of polyunsaturated fatty acids. These observations may be of relevance in the pathogenesis of the disease as polyunsaturated fatty acids are involved in tissue eicosanoid synthesis and cellular membrane function, including that of immunocompetent cells. These results also question the rationale of using n3 polyunsaturated fatty acids in the treatment of inflammatory bowel disease.     

Circulating von Willebrand factor in inflammatory bowel disease.

Raised circulating von Willebrand factor is a recognised marker of vascular injury. To evaluate the role of vascular injury in the pathogenesis of inflammatory bowel disease, serum von Willebrand factor in Crohn's disease, ulcerative colitis, confirmed bacterial diarrhoea, and healthy subjects was measured. von Willebrand factor values were raised in 9/14 patients (p = 0.007) with active Crohn's disease, 15/28 (p = 0.0004) with inactive Crohn's disease, 16/23 (p = 0.0003) with active ulcerative colitis, 9/27 (p = 0.04) with inactive ulcerative colitis, and 15/17 (p = 0.0001) patients with bacterial diarrhoea. Serum von Willebrand factor was unrelated to disease activity in Crohn's disease but was significantly raised in active (p = 0.02) compared with inactive ulcerative colitis. In contrast to controls, the detection of von Willebrand factor from inflammatory bowel disease sera and that from fractured endothelial cells was significantly inhibited by the reducing agent, dithiothreitol, suggesting the presence of an additional dithiothreitol sensitive form of the molecule derived from injured endothelial cells in inflammatory bowel disease. That serum von Willebrand factor is raised in quiescent as well as active Crohn's disease is compatible with the proposal that vascular injury is a fundamental abnormality in this disorder. The raised von Willebrand factor values in active inflammatory bowel disease and bacterial diarrhoea could be caused by either vascular injury, occurring secondary to bowel inflammation, or to an acute phase response resulting from endothelial cell stimulation by mediators released during the inflammatory process. Raised circulating von Willebrand factor could contribute to the increased risk of thrombosis associated with active inflammatory bowel disease.