RESUMO
BACKGROUND: In both ulcerative colitis (UC) and Crohn's disease (CD) there is a marked increase in mucosal IgG plasma cells (PC), although their precise role is not well established. In this study we isolated gut PCs from patients with IBD and normal controls and analyzed cytokine production, matrix metalloproteinase (MMP)-3 and tissue inhibitor of metalloproteinase (TIMP)-1 production, and PC longevity ex vivo. METHODS: Lamina propria mononuclear cells (LPMCs) were isolated from patients with CD (n = 19), UC (n = 27), and normal controls (n = 42). PCs were further selected by immunomagnetic isolation using CD138 microbeads. Cytokine, MMP-3, and TIMP-1 expression was investigated by Taqman polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), Western blotting, and confocal microscopy. PC lifespan in vitro was studied by ELISpot analysis. RESULTS: PCs from both controls and IBD patients contained high levels of transcripts for TGFbeta, whereas they did not contain significant transcripts for IL-4, IL-5, IL-10, IFNgamma, TNF, or IL-12p40. PCs from patients with CD and UC expressed significantly higher levels of MMP-3 protein and transcripts than controls (P < 0.0001). The vast majority of MMP-3-expressing PCs were IgG+ve. In culture, IgA PCs from both IBD patients and controls persisted for only a few days, but IgG PCs from IBD patients persisted for at least 3 weeks. CONCLUSIONS: We have demonstrated that IgG PCs from patients with IBD express large amounts of MMP-3 and that they appear to be long-lived. These results identify a new pathway by which IgG PCs may damage the gut.
Assuntos
Colite Ulcerativa/imunologia , Doença de Crohn/imunologia , Mucosa Intestinal/imunologia , Metaloproteinase 3 da Matriz/metabolismo , Plasmócitos/metabolismo , Estudos de Casos e Controles , Citocinas/metabolismo , Humanos , Imunoglobulina G , Mucosa Intestinal/patologia , Plasmócitos/imunologia , Inibidor Tecidual de Metaloproteinase-1/metabolismoRESUMO
CONTEXT: Current best evidence is in favour of early institution of enteral feeding in acute severe pancreatitis with promising results from trials in immunonutrition on other patient groups. OBJECTIVE: To identify which groups of patients and products are associated with benefit, we investigated immunonutrition in patients with predicted acute severe pancreatitis. DESIGN: A randomised trial of a study feed containing glutamine, arginine, tributyrin and antioxidants versus an isocaloric isonitrogenous control feed was undertaken. PATIENTS: Thirty-one patients with a diagnosis of acute pancreatitis predicted to develop severe disease: 15 study feeds and 16 control feeds. INTERVENTIONS: Enteral feeding via nasojejunal tube for 3 days. If patients required further feeding the study was continued up to 15 days. MAIN OUTCOME MEASURES: Reduction in C-reactive protein (CRP) by 40 mg/L after 3 days of enteral feeding was the primary endpoint. Carboxypeptidase B activation peptide (CAPAP) levels were taken at regular intervals. RESULTS: After 3 days of feeding, in the study group 2/15 (13%) of patients had reduced their CRP by 40 mg/L or more. In the control group 6/16 (38%) of patients had reduced their CRP by this amount. This difference was found to be near the statistical significant limit (P=0.220). CONCLUSIONS: The cause of the unexpectedly higher CRP values in the study group is unclear. The rise in CRP was without a commensurate rise in CAPAP or outcome measures so there was no evidence that this represented pancreatic necrosis. The contrast between the CRP and CAPAP results is of interest and we believe that specific pancreatic indices such as CAPAP should be considered in larger future studies.