Increased CD8+ intraepithelial lymphocyte infiltration and reduced surface area to volume ratio in the duodenum of patients with ulcerative colitis.

OBJECTIVE: Recent evidence suggests the involvement of the upper gastrointestinal tract in ulcerative colitis (UC). By conducting a prospective controlled study, we explored the immunological abnormalities in the duodenal mucosa of UC patients. METHODS: Duodenal and colonic biopsies were collected from 24 corticosteroid-free UC patients and 21 controls. Colonization by Helicobacter pylori and positivity for anti-endomysial antibodies was an exclusion criteria. The severity of duodenal and colonic inflammation was determined by endoscopic and histologic scores. Morphometry was performed to measure the surface area to volume ratio (SV). Duodenal CD3(+) and CD8(+) intraepithelial lymphocytes (IELs) and lamina propria mononuclear cells (LPMCs) were detected by immunohistochemistry. RESULTS: Fifteen UC patients and 14 controls were Helicobacter pylori and anti-endomysial antibody negative and were thus included in the study. Microscopic duodenitis was reported in 4 of the 15 UC patients (26.6%), and in none of the controls. A significantly higher number of CD3(+) and CD8(+) IELs and LPMCs was found in UC patients than in controls. A significant positive correlation between the percentage of both CD3(+) and CD8(+) IELs and disease activity was found in UC patients. SV was significantly reduced in UC patients compared to controls, and inversely correlated with the percentage of CD8(+) IELs. CONCLUSIONS: The duodenum of UC patients is infiltrated by a higher number of CD8(+) IELs which correlates with the degree of villous flattening and disease activity, but not with extent of the colonic lesions. Further studies are needed to clarify whether the duodenum is a target organ in UC.

Prevalence and pathogenesis of anemia in inflammatory bowel disease. Influence of anti-tumor necrosis factor-alpha treatment.

BACKGROUND: Anemia is a common complication of inflammatory bowel disease, but its epidemiology may be changing due to earlier diagnosis and improved treatments. We investigated the prevalence and pathogenesis of anemia in patients with inflammatory bowel disease. DESIGN AND METHODS: In a cross-sectional study 263 out-patients with inflammatory bowel disease (165 with Crohn's disease, 98 with ulcerative colitis) were investigated. The influence of time from diagnosis, disease activity, inflammation and the status of iron and hematinic vitamins on the level of hemoglobin and prevalence of anemia were evaluated. In a second group of 27 patients with Crohn's disease, undergoing anti-tumor necrosis factor-alpha treatment with infliximab because of refractory or fistulizing disease, we determined the effects of infliximab on disease activity, hemoglobin, serum erythropoietin levels, iron status and inflammation. RESULTS: In all, 104 of the 263 patients with inflammatory bowel disease were anemic. Age, gender and azathioprine treatment had no influence on anemia. The prevalence of anemia was highest at diagnosis (65%), decreased during the first 4 years after disease onset, and was stable thereafter. Active disease was associated with higher rates of anemia. At diagnosis most anemic patients had anemia of chronic disease; during follow-up iron deficiency and multifactorial forms of anemia became more prevalent. Eighteen of 27 patients undergoing treatment with infliximab were anemic; most of them had anemia of chronic disease. Infliximab reduced disease activity and improved anemia in 12 patients. This was mediated by an increased production of erythropoietin for the degree of anemia. In vitro infliximab increased the growth of erythroid progenitors from the peripheral blood of patients with active disease. Conclusions Anemia is a common problem in out-patients with inflammatory bowel disease; the prevalence and severity of anemia are related to the activity of the bowel disorder. The pathogenesis of anemia changes during the course of the disease, with anemia of chronic disease having a major role at diagnosis and iron deficiency and multifactorial forms of anemia during follow-up. In patients requiring anti-tumor necrosis factor-alpha treatment, response to therapy improves erythropoiesis.

Splenic function and IgM-memory B cells in Crohn's disease patients treated with infliximab.

BACKGROUND: Under experimental chronic inflammation, tumor necrosis factor (TNF)-alpha plays a role in damaging spleen marginal zone. This latter has a crucial function in mounting B cell-dependent immune responses against infections by encapsulated bacteria. In Crohn's disease (CD), a chronic inflammatory disorder where TNF-alpha is centrally involved, impaired splenic function may increase the susceptibility to bacterial infections. On this basis, we aimed to investigate the influence of anti-TNF therapy on splenic function in CD patients. METHODS: Peripheral blood samples were obtained from 15 CD patients before and after treatment with infliximab administered at weeks 0, 2, and 6 at a dose of 5 mg/kg. Counting of erythrocytes with membrane abnormalities (pitted red cells) was used as an indicator of splenic function. Multicolor flow cytometry was performed to analyze circulating B cells. RESULTS: A substantial clinical improvement in 10 of the 15 CD patients was associated with a significant reduction of pitted red cells (from median 6.0% to 3.6%; P < 0.01) after 10 weeks of treatment. In responder patients the improvement of splenic function was accompanied by a parallel increase of circulating IgM-memory B cells (from median 6.9% to 13.3%; P < 0.005). Splenic function was not ameliorated in nonresponder patients. CONCLUSIONS: Splenic function improved in CD patients who responded to infliximab and was accompanied by a concomitant restoration of the IgM-memory B cell pool responsible for the protection against encapsulated bacteria. Restoration of splenic function after infliximab treatment is intriguing and requires further investigation.

Splenic hypofunction and the spectrum of autoimmune and malignant complications in celiac disease.

BACKGROUND & AIMS: We investigated the prevalence of functional hyposplenism in autoimmune disorder (AID)-associated and complicated celiac disease (CD). In addition, because the association between hyposplenism and overwhelming infections caused by Streptococcus pneumoniae in patients with CD is well known, we investigated whether immunoglobulin (Ig)M memory B cells, which are responsible for protection against infections by encapsulated bacteria and require the spleen for their generation and/or survival, mirror the reduced splenic function in CD. METHODS: Peripheral blood samples were collected from 73 adult CD patients (27 with AID, 36 without AID, and 10 with CD-related complications including enteropathy-associated T-cell lymphoma, refractory sprue, and ulcerative jejunoileitis). Thirty-four non-CD patients with AID, 35 healthy volunteers, and 29 splenectomized patients also were studied. Counting of erythrocytes with membrane abnormalities (pitted red cells) was used as an indicator of splenic function, and flow cytometry was performed to analyze peripheral blood B cells. RESULTS: A significantly higher risk for hyposplenism was found in AID-associated CD (59%) and complicated CD (80%) than in uncomplicated CD without AID (19%). In AID-associated CD, the degree of splenic function did not correlate to the duration of gluten-free diet. In AID-associated and complicated CD, the frequency of circulating IgM memory B cells was significantly lower than in CD patients without AID or healthy subjects. A significant inverse correlation between IgM memory B cells and pitted red cells was found in all 73 CD patients. CONCLUSIONS: The prevalence of splenic hypofunction is increased in CD with AID and in complicated CD, and is not related to the duration of gluten-free diet. IgM memory B cells are reduced in AID-associated and complicated CD. This defect, which is related to the impairment of splenic function, might predispose hyposplenic CD patients to infections by encapsulated bacteria.

Depletion of immunoglobulin M memory B cells is associated with splenic hypofunction in inflammatory bowel disease.

OBJECTIVES: IgM memory B cells that are responsible for the protection against infections by encapsulated bacteria, require the spleen for their generation and/or survival. Since the association between inflammatory bowel disease and functional hyposplenism is well described, our aim was to verify whether IgM memory B cells mirror the reduced splenic function in Crohn's disease and ulcerative colitis patients. METHODS: Peripheral blood samples were obtained from 32 Crohn's disease and 29 ulcerative colitis patients, 33 healthy controls, and 27 splenectomized patients. Perendoscopic intestinal biopsies were also collected from 15 of 32 Crohn's disease patients, 14 of 29 ulcerative colitis patients and 13 of 33 control subjects. Counting of erythrocytes with membrane abnormalities (pitted red cells) was used as an indicator of splenic function and flow cytometry was performed to analyze both peripheral and mucosal B cells. RESULTS: Twelve of 32 Crohn's disease patients and 13 of 29 ulcerative colitis patients had pitted red cell values >4% and were considered to be hyposplenic. In inflammatory bowel disease patients circulating IgM memory B cells were significantly lower than in control subjects. We observed a significant inverse correlation between the frequency of circulating IgM memory B cell and the pitted red cell values in inflammatory bowel disease patients with hyposplenism. To exclude the possibility that the reduction of circulating IgM memory B cells reflected their recruitment in the inflamed bowel mucosa, lamina propria B-cell populations were also characterized. We found that the frequency of IgM memory B cells was similar in the blood and in the lamina propria of the same patient. CONCLUSIONS: Our findings show that peripheral IgM memory B cells are reduced in inflammatory bowel disease patients and this defect seems to be related to the impairment of splenic function.

Serum bFGF and VEGF correlate respectively with bowel wall thickness and intramural blood flow in Crohn's disease.

Serum levels of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF)--two factors known to promote tissue repair, fibroblast proliferation, and angiogenesis--were measured in Crohn's disease patients and correlated with bowel wall thickness (BWT), measured by conventional grey scale ultrasonography, and with the ileal intramural vessel flow, measured by contrast-enhanced color Doppler imaging. Serum samples were obtained from 25 patients with active Crohn's disease and 22 healthy volunteers, all sex- and age-matched. Serum bFGF and VEGF levels were measured by ELISA assay. All the patients were examined with conventional transabdominal bowel sonography. Color Doppler of the intramural enteric vessels was then performed after the intravenous injection of Levovist, a galactose-based sonographic contrast agent. In Crohn's disease patients, serum bFGF and VEGF were significantly higher compared with healthy volunteers. A positive correlation between serum bFGF and BWT and between serum VEGF and color Doppler signal intensity was found. The raised serum bFGF levels in Crohn's disease patients with intestinal strictures compared with patients with other phenotypes (fistulizing, inflammatory), together with the correlation observed between serum bFGF and BWT, suggests a possible involvement of bFGF in the process of transmural fibrogenesis in Crohn's disease. The higher levels of VEGF in those patients with increased intramural blood flow suggests that VEGF may be considered a marker of angiogenesis in this condition.