Multiple staging investigations may not change management in patients with high-grade dysplasia or early esophageal adenocarcinoma.

The clinical value of multiple staging investigations for high-grade dysplasia or early adenocarcinoma of the esophagus is unclear. A single-center prospective cohort of patients treated for early esophageal cancer between 2000 and 2019 was analyzed. This coincided with a transition period from esophagectomy to endoscopic mucosal resection (EMR) as the treatment of choice. Patients were staged with computed tomography (CT), endoscopic ultrasound (EUS) and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) positron emission tomography(PET)/CT. The aim of this study was to assess their accuracy and impact on clinical management. 297 patients with high-grade dysplasia or early adenocarcinoma were included (endoscopic therapy/EMR n = 184; esophagectomy n = 113 [of which a 'combined' group had surgery preceded by endoscopic therapy n = 23]). Staging accuracy was low (accurate staging EMR: CT 40.1%, EUS 29.6%, FDG-PET/CT 11.0%; Esophagectomy: CT 43.3%, EUS 59.7%, FDG-PET/CT 29.6%; Combined: CT 28.6%, EUS46.2%, FDG-PET/CT 30.0%). Staging inaccuracies across all groups that could have changed management by missing T2 disease were CT 12%, EUS 12% and FDG-PET/CT 1.6%. The sensitivity of all techniques for detecting nodal disease was low (CT 12.5%, EUS 12.5%, FDG-PET/CT0.0%). Overall, FDG-PET/CT and EUS changed decision-making in only 3.2% of patients with an early cancer on CT and low-risk histology. The accuracy of staging with EUS, CT and FDG-PET/CT in patients with high-grade dysplasia or early adenocarcinoma of the esophagus is low. EUS and FDG-PET/CT added relevant staging information over standard CT in very few cases, and therefore, these investigations should be used selectively. Factors predicting the need for esophagectomy are predominantly obtained from EMR histology rather than staging investigations.

Prediction of a positive circumferential resection margin at surgery following neoadjuvant chemotherapy for adenocarcinoma of the oesophagus.

Background: A positive circumferential resection margin (CRM) has been associated with higher rates of locoregional recurrence and worse survival in oesophageal cancer. The aim of this study was to establish if clinicopathological and radiological variables might predict CRM positivity in patients who received neoadjuvant chemotherapy before surgery for oesophageal adenocarcinoma. Methods: Multivariable analysis of clinicopathological and CT imaging characteristics considered potentially predictive of CRM was performed at initial staging and following neoadjuvant chemotherapy. Prediction models were constructed. The area under the curve (AUC) with 95% confidence intervals (c.i.) from 1000 bootstrapping was assessed. Results: A total of 223 patients were included in the study. Poor differentiation (odds ratio (OR) 2·84, 95 per cent c.i. 1·39 to 6·01) and advanced clinical tumour status (T3-4) (OR 2·93, 1·03 to 9·48) were independently associated with an increased CRM risk at diagnosis. CT-assessed lack of response (stable or progressive disease) following chemotherapy independently corresponded with an increased risk of CRM positivity (OR 3·38, 1·43 to 8·50). Additional CT evidence of local invasion and higher CT tumour volume (14 cm3) improved the performance of a prediction model, including all the above parameters, with an AUC (c-index) of 0·76 (0·67 to 0·83). Variables associated with significantly higher rates of locoregional recurrence were pN status (P = 0·020), lymphovascular invasion (P = 0·007) and poor response to chemotherapy (Mandard score 4-5) (P = 0·006). CRM positivity was associated with a higher locoregional recurrence rate, but this was not statistically significant (P = 0·092). Conclusion: The presence of advanced cT status, poor tumour differentiation, and CT-assessed lack of response to chemotherapy, higher tumour volume and local invasion can be used to identify patients at risk of a positive CRM following neoadjuvant chemotherapy.

Antecedentes: Un margen de resección circunferencial (circumferential resection margin, CRM) positivo se ha asociado con tasas más elevadas de recidiva locorregional y peor supervivencia en el cáncer de esófago. El objetivo de este estudio fue establecer si las variables clínico­patológicas y radiológicas podrían predecir la positividad del CRM en el adenocarcinoma de esófago tras quimioterapia neoadyuvante antes de la cirugía. Métodos: Se realizó un análisis multivariable de las características clínico­patológicas y de la tomografía computarizada (computed tomography, CT) que se consideraron potencialmente predictivas de CRM en la estadificación inicial y tras la quimioterapia neoadyuvante. Se construyeron modelos de predicción. Se evaluó el área bajo la curva (area under curve, AUC) con el i.c. del 95% a partir de 1.000 muestras bootstrap. Resultados: Se incluyeron 223 pacientes en el estudio. Una pobre diferenciación (razón de oportunidades, odds ratio, OR 2,84, i.c. del 95% 1,39­6,01) y un estadio clínico T avanzado (T3­4) (OR 2,93, i.c. del 95% 1,03­9,48) se asociaron de forma independiente con un riesgo aumentado de CRM en el diagnóstico. La falta de respuesta en la CT (estable o enfermedad en progresión) tras la quimioterapia se correspondía de forma independiente con un riesgo aumentado de CRM positivo (OR 3,38, i.c. del 95% 1,43­8,50). Además, la evidencia por CT de invasión local y un mayor volumen del tumor en CT (14 cm3) mejoraron el funcionamiento del modelo predictivo, incluyendo todos los parámetros previamente señalados; con AUC (índice c) de 0,76 (0,68­0,83). Las variables asociadas de forma significativa con tasas más elevadas de recidiva locorregional fueron el estado de los ganglios linfáticos patológicos (P = 0,002), la invasión linfovascular (P = 0,007) y la respuesta pobre a la quimioterapia (Mandard 4 y 5 (P = 0,006)). La positividad del CRM se asoció con una tasa de recidiva locorregional más elevada pero sin alcanzar significación estadística (P = 0,09). Conclusión: La presencia de un estadio clínico T avanzado, tumor pobremente diferenciado, falta de respuesta a la quimioterapia en la TC, mayor volumen del tumor en la TC e invasión local pueden ser utilizados para identificar pacientes en riesgo de un CRM positivo tras quimioterapia neoadyuvante.

Service provision and training for endoscopic ultrasound in the UK.

Endoscopic ultrasound (EUS) is a standard procedure that plays an important role in the management of both malignant and benign disease. The development of EUS services in the UK has been haphazard and training inconsistent. The British Society of Gastroenterology has charged a working group with the task of laying down a national framework for how such services might be commissioned, structured and regulated; with particular attention to defining how endoscopist skills might be acquired, assessed and maintained. This report lays out a map for this process and its future revision.

Defining the lymph node burden in a Northern European population without malignancy: the potential effect of geography in determining a need for FNA?

Data from the USA suggest that morphological specificity is insufficient to permit an assumption of malignancy in nodal staging with endoscopic ultrasound (EUS). This may not hold true elsewhere as the background lymph node burden may vary in different geographic regions. We aimed to assess the prevalence and features of mediastinal and abdominal lymph nodes at EUS in a Northern European population without malignant disease. A total of 129 consecutive patients without malignant disease referred for radial EUS were prospectively evaluated for the prevalence and echo features of lymph nodes in the mediastinum and upper abdomen. Sixty-two percent of patients had mediastinal lymph nodes and 17% had abdominal nodes at EUS. A mean of 1.4 (standard deviation 1.3, range 0-8) nodes were found per patient. No celiac nodes were seen. The majority of detected nodes were 0.5 cm or less in short axis, had oval shape, centrally echogenic pattern, and indistinct borders. The most common node locations were the subcarinal and paraesophageal areas, and the hepatoduodenal ligament. In multivariate analysis mediastinal lymphadenopathy was related to body mass index and abdominal lymphadenopathy to acute pancreatitis. The occurence of mediastinal lymphadenopathy is markedly lower in Northern Europeans than reported for US patients. Celiac nodes are extremely rare in patients without malignancy. The majority of nodes have a width of 0.5 cm or less, have oval shape, centrally echogenic pattern, and indistinct borders. The characterization of the background lymph node burden may improve the selection of lymph nodes for fine needle aspiration.

A large series, resection controlled study to assess the value of radial EUS in restaging gastroesophageal cancer following neoadjuvant chemotherapy.

The true value of endoscopic ultrasound (EUS) post-neoadjuvant chemotherapy for esophageal carcinoma is not established. Superior loco-regional detail may yield useful staging and prognostic information but information on its accuracy, as compared with computed tomography (CT), remains undefined and limited by small study size. We prospectively studied 109 patients with gastroesophageal cancer; 99 of whom were undergoing surgery. All had EUS and helical CT imaging before and after neoadjuvant chemotherapy and the results were compared with pathological staging of resected specimens. Tumor response was assessed by the reduction in maximal tumor depth at EUS and correlated with patient survival. There was no difference in T and N stage accuracies between EUS and CT following neoadjuvant chemotherapy. manova showed a reduction in maximal tumor depth by > 50% at EUS to be associated with longer survival (relative risk = 0.48, P < 0.05). EUS responders had a median survival of 38 months compared to 30 months for non-responders (P < 0.05). The identification of lymphadenopathy at radial EUS was not predictive of survival. This large series study demonstrates the staging accuracy of CT and non-biopsy EUS in the setting of neoadjuvant chemotherapy for gastroesophageal cancer to be equivalent and poor. An endosonography may contribute useful clinical information in respect of potential survival. It is questionable whether radial EUS should be included in protocols for restaging.

The preferred choice for radial endosonographic staging of esophageal cancer: standard echoendoscope or nonoptic esophagoprobe?

BACKGROUND: The nonoptic esophagoprobe has been reported to be comparable to the standard echoendoscope in esophageal cancer staging, with a superior advantage of traversing more stenotic tumors because of its smaller diameter. The aim of this study was to see whether its use in a general population of esophageal cancer patients confers any significant clinical benefit. METHODS: Five hundred seventy-seven consecutive patients referred for initial locoregional staging of esophageal cancer were analyzed retrospectively. Comparisons were made between the standard echoendoscope and the esophagoprobe. RESULTS: Complete staging (95.2% vs 77.5%; p < 0.001) was significantly higher in the esophagoprobe group compared with that of the standard echoendoscope group (315 and 262 patients, respectively). In 146 patients with histopathologic verification without prior chemotherapy or radiotherapy, the esophagoprobe was comparable in T-staging accuracy to the standard echoendoscope in those with traversable tumors (89.2% vs. 82.8%; p = 0.213). However, the presence of a nontraversable stricture significantly decreased standard echoendoscope T-staging accuracy compared with a traversable stricture (33.3% vs. 82.8%, respectively; p < 0.001). The esophagoprobe also picked more advanced tumors and distal nodes. CONCLUSIONS: The esophagoprobe is more accurate than the standard echoendoscope in the T staging of esophageal cancer because of its higher likelihood of traversing tumor stenosis. It can potentially reduce the necessity for dilation in stenotic tumors by four to five times. We propose using the esophagoprobe as the first choice for radial endoscopic ultrasound staging of esophageal cancer.

Endoscopic ultrasound-guided fine needle aspiration cytology of pancreatic neuroendocrine tumours: cytomorphological and immunocytochemical evaluation.

OBJECTIVES: Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) is increasingly used in preoperative localization and diagnosis of pancreatic neoplasms including neuroendocrine tumours (NETs). The objective of the present study was to identify the cytological features of pancreatic NETs obtained by EUS-FNA. METHODS: The study group consisted of nine cases of pancreatic tumours correctly diagnosed or strongly suggestive of NETs based on EUS-FNA. Cytological smears were retrospectively reviewed. The clinical data and immunocytochemical stains applied to the cell block preparations were also reviewed and examined. RESULTS: All cases except one showed characteristic cytomorphological features sufficient for their recognition and separation from pancreatic adenocarcinoma and other lesions. The most helpful cytological features that facilitated the cytological diagnosis of NET were a richly cellular aspirate with a monotonous, poorly cohesive population of small cells with a speckled or dusty chromatin pattern and plasmacytoid morphology. The neuroendocrine differentiation of these tumours was further confirmed by immunocytochemistry. CONCLUSION: EUS-FNA is a valuable method in the recognition of pancreatic NETs. By adherence to the characteristic cytomorphological criteria of pancreatic NET together with collection of suitable material for ancillary immunocytochemical stains, cytopathologists could reach a correct diagnosis in most instances.

Training in radial EUS: what is the best approach and is there a role for the nurse endoscopist?

BACKGROUND AND STUDY AIMS: The aim of this study was to determine the relative contribution of previous endoscopic experience, case observation, and hands-on experience to skill acquisition in radial EUS. METHODS: In EUS trainees, four senior gastroenterology fellows, and a nurse endoscopist, the ability to reproduce set views from the mediastinum, stomach, and duodenum was assessed. Points were ascribed to static and dynamic stations and to the use of console controls. RESULTS: Trainees observed 55 - 170 cases and conducted 25 - 124 examinations. Competence was demonstrated after performing approximately 25 examinations in the mediastinum, 35 examinations in the stomach, and 78 examinations in the duodenum. The number of previous examinations conducted correlated with the ability to scan the duodenum ( P < 0.01). Observation of 100 or more further procedures early in training did not accelerate learning. The nurse endoscopist showed a comparable degree of competence in mediastinal scanning to that of the other trainees after performing a similar number of examinations. CONCLUSIONS: Proficiency in radial endosonography is greatly influenced by the numbers of examinations performed. Observing large numbers of cases early in training does not appear to translate into competence. A background in advanced therapeutic endoscopy is not a prerequisite for acquiring endoscopic ultrasound skills. Nurse endoscopists may be expected to train successfully in mediastinal imaging at the same pace as senior gastroenterology fellows.

Thiopurine methyltransferase activity and the use of azathioprine in inflammatory bowel disease.

BACKGROUND: Azathioprine therapy is discontinued in one-third of patients with inflammatory bowel disease because of toxicity or a lack of clinical response. Patients with thiopurine methyltransferase (TPMT) deficiency are intolerant to azathioprine, whilst carriers are at increased risk of side-effects. AIM: To evaluate the importance of TPMT activity in the management of azathioprine therapy in inflammatory bowel disease. METHODS: Clinical response, adverse effects and haematological parameters were determined and correlated with TPMT enzyme activity and genotype in 106 patients with inflammatory bowel disease. RESULTS: Ninety-six patients had high TPMT activity, and 10 had intermediate activity. Nineteen patients (18%) were intolerant to azathioprine. Fifteen (16%) of those with high TPMT activity were intolerant, compared with five (50%) with intermediate activity [odds ratio (OR), 5.4; 95% confidence interval (CI), 1.5-19.8]. Complete remission was achieved in 63% of cases, and complete or partial remission in 79%. Interestingly, very high TPMT activity (> 14 units/mL red blood cells) was significantly associated with non-response, irrespective of the time on azathioprine (OR, 0.21; 95% CI, 0.07-0.68). TPMT gene mutations correlated with TPMT activity. CONCLUSIONS: Inflammatory bowel disease patients with intermediate TPMT activity have an increased risk of azathioprine toxicity. Conversely, very high TPMT activity predicts treatment failure. TPMT genotype predicted TPMT phenotype in this study.

Vancomycin and ceftazidime bioactivities persist for at least 2 weeks in the lumen in ports: simplifying treatment of port-associated bloodstream infections by using the antibiotic lock technique.

The residual antibiotic concentration of vancomycin (2 mg/ml)- or ceftazidime (2 mg/ml)-heparin solutions instilled in ports in pediatric hematology-oncology patients 1 to 34 days earlier was measured. Antibiotic concentrations of > or = 100 microg of either antibiotic per ml persisted for at least 21 days. For treatment of lumenal port infections, antibiotic-heparin dwell times of > or = 2 weeks may be appropriate.

Ferric trimaltol corrects iron deficiency anaemia in patients intolerant of iron.

BACKGROUND: Oral iron supplements, which are usually in the form of ferrous (Fe2+) salts, are toxic to the gastrointestinal mucosa, and so intolerance is common, resulting in poor compliance and failure of treatment. The sugar derivative maltol strongly chelates iron, rendering it available for absorption and stabilized in the less toxic ferric (Fe3+) form. AIM: To test whether ferric trimaltol could correct iron deficiency anaemia in patients intolerant of ferrous sulphate. METHODS: Twenty-three patients were recruited from gastroenterology clinics, of whom 1 5 had inflammatory bowel disease, a group often difficult to treat with oral iron. Patients with iron deficiency anaemia and documented intolerance to ferrous sulphate were given 3 months of treatment with ferric trimaltol. RESULTS: Nineteen of 23 patients completed the treatment and anaemia was fully corrected in 14 of these, mean haemoglobin increased from 106 +/- 15 to 126 +/- 16 g/L, and there was a particularly low incidence of side-effects. Of 11 patients with inflammatory bowel disease who completed the study, nine fully corrected their anaemia. CONCLUSION: The results demonstrate that in patients intolerant of ferrous compounds, ferric trimaltol corrects iron deficiency and has a low incidence of side-effects.

Variation in gut-homing CD27-negative lymphocytes in inflammatory colon disease.

Prolonged antigenic stimulation results in lymphocyte shedding of CD27, a member of the tumour necrosis factor receptor (TNFR) family, and transformation to a stable phenotype capable of synthesizing interleukin-4 (IL-4). Co-expression of alpha4beta7 identifies those cells with gut-homing potential. We have investigated these cell populations in patients with inflammatory colonic disease. Circulating and lamina propria mononuclear cells were isolated from patients with Crohn's disease (CD), ulcerative colitis (UC), non-inflammatory bowel disease (non-IBD) colonic inflammation and healthy controls. Double and triple colour flow cytometry for CD3, CD4, CD27, alpha4beta7 and intracellular cytokines was performed. Circulating CD4+ CD27- populations were increased in patients with CD (8.8 +/- 0.8%, P < 0.001), UC (12.2 +/- 1.9%, P < 0.001) and non-IBD colitis (10.5 +/- 1.3%, P < 0.01) as compared with controls (6.1 +/- 0.5%). CD4+ CD27- alpha4beta7+ cells were increased in CD (P < 0.01). Lamina propria CD4+ CD27- populations were depressed significantly in CD (P < 0.05), UC (P < 0.02) and non-IBD colitis (P < 0.03). Mucosal CD4+ CD27- cells synthesized IL-4 in preference to interferon-gamma. Thus, colonic inflammation is associated with alterations in gut-tropic circulating and mucosal populations of differentiated memory T cells with the phenotype of predominantly IL-4-synthesizing cells.

Anti-inflammatory effect of interleukin-10 in rabbit immune complex-induced colitis.

BACKGROUND: Interleukin-10 (IL-10) is an anti-inflammatory cytokine that downregulates the secretion of pro-inflammatory cytokines and additionally induces the secretion of anti-inflammatory cytokines, thus possibly leading to reduction of chronic inflammation in inflammatory bowel disease. In this study we evaluated the anti-inflammatory effect of IL-10 in a model of acute colitis in rabbits. METHODS: Colitis was induced by rectal instillation of formalin, 0.65%, followed by intravenous infusion of 0.85 ml heat-aggregated rabbit immunoglobulin. Rabbits were treated with an intravenous bolus of recombinant human IL-10 (SCH52000), 100 microg/kg (n=14) or 500 microg/kg (n=14), 1 h before induction of colitis (control group, n=12). RESULTS: High-dose IL-10 improved macroscopic scores of inflammation and decreased tissue myeloperoxidase levels and leukotriene B4 levels in dialysate fluid. Thromboxane B2 and prostaglandin E2 levels remained unaffected. CONCLUSION: IL-10 ameliorates acute colitis in this model. Consequently, this anti-inflammatory cytokine may have a role in the therapy of acute inflammatory bowel disease.

Phenotypical characterization of cells in the thoracic duct of patients with and without systemic inflammatory response syndrome and multiple organ failure.

The subset composition and recirculation properties of the migrating lymphocyte pool in humans is largely unknown. The present study was conducted in order to phenotypically characterize cells in human thoracic duct lymph of patients under non-inflammatory and inflammatory conditions. These data were compared with data from peripheral blood, with special emphasis on those cells homing to the gut. Thoracic duct lymph and peripheral blood contained comparable proportions of B and T lymphocytes and CD8+ cells. Thoracic duct lymph contained proportionally more CD4+ cells, more CD4+CD45RO+ that express alpha 4 beta 7 cells and more CD8+CD45RO+ that express alpha 4 beta 7, as compared to peripheral blood. These data suggest an equal recirculation rate of B and T lymphocytes; a more active recirculation of CD4+ cells compared to CD8+ cells; and a more active recirculation of memory cells to the gut as compared to other extra-lymphoid sites in patients under non-inflammatory conditions. Data were also obtained in patients with the system inflammatory response syndrome and multiple organ failure. Although it is generally assumed that granulocytes and monocytes do not recirculate, lymph of multiple organ failure patients contained significantly more granulocytes than monocytes, indicating that in severe generalized inflammatory states these cells re-enter the circulation through the thoracic duct. Furthermore, no increased activation of cells homing to the gut was found in these patients.

Epithelial cell folate depletion occurs in neoplastic but not adjacent normal colon mucosa.

BACKGROUND & AIMS: Restricted folate supply is associated with the development of carcinoma, and folate supplements have a protective effect in colorectal carcinoma. This effect may be mediated through correction of local folate deficiency. The aim of this study was to define the folate content of neoplastic colonic epithelial cells and its relation to that of adjacent normal tissue and circulating levels. METHODS: Epithelial cells were isolated from endoscopic biopsy specimens of normal, adenocarcinoma, adenoma, and adjacent normal colonic mucosa by ion chelation. Intracellular folate levels were determined by microbiological assay. RESULTS: Folate levels in carcinoma specimens were lower than in adjacent normal tissue (P < 0.02). Levels in adenoma epithelial cells were lower than in adjacent normal tissue, although this did not reach statistical significance (P < 0.06). Epithelial cells from normal tissue and mucosa adjacent to tumors and adenomata had similar folate contents. Blood folate and vitamin B12 indices for all groups were normal. CONCLUSIONS: Malignant colon epithelial cells show a relative localized folate deficiency. However, there is no evidence for the occurrence of generalized mucosal folate deficiency. This finding suggests that folate supplements do not inhibit carcinogenesis through correction of localized folate depletion.

Preferential expression of the mucosal homing receptor integrin alpha 4 beta 7 in gastrointestinal non-Hodgkin's lymphomas.

Recent studies have identified the integrin alpha 4 beta 7 as a mucosal homing receptor that mediates lymphocyte migration to the intestinal mucosa by binding to MAdCAM-1, a vascular recognition molecule (addressin) selectively expressed on mucosal endothelium. In the present study, we have assessed the expression of alpha 4 beta 7 on B- and T-cell non-Hodgkin's lymphomas of different primary localization and on related normal lymphocytes. Among B-lineage lymphomas, expression of alpha 4 beta 7 was present in the majority of cases of malignant lymphomatous polyposis of the intestine and low-grade lymphoma of the mucosa-associated lymphoid tissue/monocytoid B-cell lymphoma and in some cases of precursor B-cell lymphoma. CLL/small lymphocytic lymphoma, (nodal) mantle cell lymphoma, follicular center cell lymphoma, Burkitt's lymphoma, and diffuse large B-cell lymphoma were virtually always alpha 4 beta 7 negative, as was the case when localized in the mucosa-associated lymphoid tissue. The normal B cells of the follicle mantles and part of the B cells of the extrafollicular B-cell compartment of lymphoid tissues expressed moderate levels of alpha 4 beta 7. By contrast, follicular center cells were alpha 4 beta 7 negative. Among T-lineage lymphomas, expression of alpha 4 beta 7 was also strongly related to the primary localization; in mucosal, nodal, and cutaneous T cell lymphomas the percentage of positive cases was 56%, 17%, and 0%, respectively. All cases of precursor T-cell lymphoma were alpha 4 beta 7 negative. High expression of alpha 4 beta 7 was found on a subset of peripheral blood memory T cells as well as on lymphocytes in the intestinal mucosa. We conclude that non-Hodgkin's lymphomas that are related to mucosa-associated B- and T-lymphocyte populations selectively express the mucosal homing receptor alpha 4 beta 7. The presence of this receptor underscores their distinctive character and may play an important role in determining their characteristic mucosal dissemination pattern.

Altered expression of alpha 4 beta 7, a gut homing integrin, by circulating and mucosal T cells in colonic mucosal inflammation.

BACKGROUND AND AIMS: Expression of alpha 4 beta 7 on memory T lymphocytes identifies a cell population that preferentially migrates to the gut. Detection of alpha 4 beta 7 on circulating lymphocytes may permit the identification of specific subsets trafficking between the circulation and the gut in inflammatory bowel diseases. PATIENTS: Samples and clinical details were taken from patients with Crohn's disease (CD), ulcerative colitis (UC), diverticulitis/ infectious colitis, and healthy controls. METHODS: Peripheral blood and lamina propria mononuclear cells were isolated. Cells were labelled with CD3, CD4, CD25, CD45RO or alpha 4 beta 7. RESULTS: Median levels of circulating total memory T cells (CD4+CD45RO+) were increased in CD (p < 0.01) and UC (p < 0.05). However, the proportion of systemic gut homing T cells (CD4+CD45RO+ alpha 4 beta 7+) was decreased in CD (p < 0.05), UC (p < 0.002), and inflammatory controls (p < 0.05). Levels of activated gut homing T cells (CD4+CD25+ alpha 4 beta 7+) were increased in CD (p < 0.01) and UC (p < 0.05). For both CD4+CD45RO+ and CD4+CD25+ cells, the proportion of lymphocytes coexpressing alpha 4 beta 7 was decreased compared with controls. In small and large intestine lamina propria, expression of alpha 4 beta 7+ on CD3+ cells was extensive, although it was decreased in CD (p < 0.03), UC (p < 0.05), and inflammatory controls (p < 0.05). CONCLUSIONS: Circulating and mucosal gut homing lymphocyte populations are changed in patients with colonic inflammation. This may arise due to a dilution effect from recruited naive T cells, or from integrin down regulation. Changes in general CD4+ lymphocyte populations mask more subtle variations in those cells with gut homing potential.

Mediators of mucosal inflammation: implications for therapy.

Treatment of inflammatory bowel disease remains a challenge. The major shortcoming in the development of new therapeutic approaches is the fact that the cause of inflammatory bowel disease is still unknown. Recognition of the importance of the arachidonic acid cascade of inflammatory mediators presents the opportunity to specifically inhibit or antagonize leukotriene B4, thromboxane, platelet activating factor, or phospholipase. Interleukins and cytokines have more recently been defined as targets for specific therapy. The results of these specific immune modulating studies are not only important from a therapeutic point of view, but substantially contribute to our understanding of the pathogenic cascades in IBD. In this review, several targets for novel therapeutic intervention are discussed.