Human intestinal epithelial cells respond to ß-glucans via Dectin-1 and Syk.

Intestinal epithelial cells (IECs) are the first to encounter luminal antigens and may be involved in intestinal immune responses. Fungi are important components of the intestinal microflora. The potential role of fungi, and in particular their cell wall component ß-glucan, in modulating human intestinal epithelial responses is still unclear. Here we examined whether human IECs are capable of recognizing and responding to ß-glucans, and the potential mechanisms of their activation. We show that human IECs freshly isolated from surgical specimens, and the human IEC lines HT-29 and SW480, express the ß-glucan receptor Dectin-1. The ß-glucan-consisting glycans curdlan and zymosan stimulated IL-8 and CCL2 secretion by IEC lines. This was significantly inhibited by a Dectin-1 blockade using its soluble antagonist laminarin. Spleen tyrosine kinase (Syk), a signaling mediator of Dectin-1 activation, is expressed in human IECs. ß-glucans and Candida albicans induced Syk phosphorylation, and Syk inhibition significantly decreased ß-glucan-induced chemokine secretion from IECs. Thus, IECs may respond to ß-glucans by the secretion of pro-inflammatory chemokines in a Dectin-1- and Syk-dependent pathway, via receptors and a signaling pathway described to date only for myeloid cells. These findings highlight the importance of fungi-IEC interactions in intestinal inflammation.

Differential stimulation of peripheral blood mononuclear cells in Crohn's disease by fungal glycans.

BACKGROUND AND AIM: Crohn's disease (CD) is characterized by loss of tolerance to intestinal microorganisms. This is reflected by serological responses to fungal glycans such as mannan and ß-glucans. Fungal glycans have various effects on immune cells. However, the evidence for their effects in CD is vague. This study aimed to assess the effects of fungal cell wall glycans on human peripheral blood mononuclear cells (PBMCs) from CD and control patients. METHODS: Human PBMCs from CD and control patients were stimulated by fungal cell wall glycans. Cytokine secretion was detected by ELISA and glycan receptor expression by flow cytometry. RESULTS: Mannan, ß-glucans (curdlan), chitosan, and zymosan induced the secretion of interleukin (IL)-1ß, IL-6, IL-23, IL-10, and tumor necrosis factor-α by PBMCs. Spleen tyrosin kinase and Src tyrosine kinase were involved in the response to mannan and ß-glucans. Mannan and whole yeast cells induced a significantly higher pro-inflammatory cytokine response in CD compared with control patients. CONCLUSIONS: The results may suggest that CD is characterized by hyperresponsiveness to fungal glycans. Thus, glycans may potentially be triggering or perpetuating inflammation.

Diagnostic and prognostic value of very high serum lactate dehydrogenase in admitted medical patients.

BACKGROUND: Serum lactate dehydrogenase (LDH) is elevated in various diseases. OBJECTIVES: To analyze serum LDH as a distinguishing clinical biomarker and as a predictor of in-hospital outcome in admitted medical patients. METHODS: We analyzed a cohort of all 158 patients with very high isolated LDH (LDH > or = 800 IU/ml without concomitant elevations of alanine aminotransferase and aspartate aminotransferase) admitted to our internal medicine department during a 3 year period. Epidemiologic and clinical data, as well as the final diagnosis and outcome were recorded and compared with those of a cohort of all 188 consecutive control patients. RESULTS: Very high isolated LDH was a distinguishing biomarker for the presence of cancer (27% vs. 4% in the LDH group and controls respectively, P < 0.0001), liver metastases (14% vs. 3%, P < 0.0001), hematologic malignancies (5% vs. 0%, P = 0.00019), and infection (57% vs. 28%, P < 0.0001). Very high isolated LDH was a marker for severe prognosis, associated with more admission days (9.3 vs. 4.1, P < 0.0001), significantly more in-hospital major complications, and high mortality rate (26.6% vs. 4.3%, P < 0.0001). Finally, very high isolated LDH was found in a multivariate regression analysis to be an independent predictor of mortality. CONCLUSIONS: The presence of very high isolated LDH warrants thorough investigation for the presence of severe underlying disease, mostly metastatic cancer, hematologic malignancies, and infection. Moreover, it is a marker for major in-hospital complications and is an independent predictor of mortality in admitted medical patients. lactate dehydrogenase (LDH), cancer, internal medicine

Antibodies against glycoprotein 2 are novel markers of intestinal inflammation in patients with an ileal pouch.

BACKGROUND AND AIMS: The Crohn's disease (CD)-specific pancreatic auto-antibodies (PAB), have been recently identified to target glycoprotein 2 (GP2). Pouchitis is an inflammation of the small bowel developing in up to 60% of ulcerative colitis patients undergoing proctocolectomy and ileal pouch anal anastomosis. Occurrence of CD-specific antibodies was reported to be a predictor of pouchitis. We aimed to assess the prevalence of anti-GP2 antibodies (anti-GP2) in the serum and feces of pouch patients and to correlate them with clinical parameters. Furthermore, we examined mucosal expression of the GP2 protein in the pouch. METHODS: Pouch patients were prospectively recruited and checked for clinical, endoscopic, and laboratory markers of inflammation. IgG and IgA anti-GP2 levels in serum and fecal samples were determined using ELISA. GP2 protein was assessed by immunohistochemistry. RESULTS: Anti-GP2 was elevated in both serum and fecal samples of patients with inflamed compared to those with non-inflamed pouches and patients with familial-adenomatous polyposis after surgery (p<0.05, respectively). Moreover, patients with CD-like complications exhibited significantly higher anti-GP2 titers than those without CD-like complications (p≤0.01). High levels of anti-GP2 correlated with more frequent bowel movements per day and with the presence of at least one anti-glycan antibody (p≤0.05). GP2 itself was more abundant in the mucosa of patients with chronic pouchitis. CONCLUSIONS: Anti-GP2 exists in the serum and feces of pouch patients and correlates with pouch inflammation, and presence of other serological markers. Thus, anti-GP2 may contribute to better stratification of pouchitis, more-so when the inflammation exhibits CD-like complications.

Diagnostic and prognostic value of thrombocytosis in admitted medical patients.

INTRODUCTION: Whether secondary thrombocytosis is a distinguishing clinical biomarker of various diseases, and whether it is an independent predictor of short-term outcome of admitted medical patients is unknown and has never been examined. METHODS: A cohort of all 138 patients with secondary thrombocytosis (platelets count ≥ 5 x 105/µL) admitted to the department of medicine during the last 2 years was analyzed. Epidemiological and clinical data, and the final diagnosis and outcome were recorded and compared with a cohort of 684 consecutive admitted patients without thrombocytosis. RESULTS: Thrombocytosis was not a non-specific marker of inflammation, because uncomplicated infections and most admission causes were not associated with thrombocytosis, except for inflammatory rheumatic diseases (6% versus 1%), along with anemia (9.4% versus 2.5%) and tumor comorbidity (25% versus 14%). In contrast, thrombocytosis was a distinguishing biomarker for severe pyogenic infections, especially empyema (5% vs. 0%), any abscesses (14% versus 3%), and soft tissue infections (7% versus 3%). Moreover, the thrombocytosis group had significantly more admission days, infections (45% versus 33%), sepsis (21% versus 6%), in-hospital major complications (15% versus 3%) and mortality (19% versus 5%). Finally, thrombocytosis was found to be an independent predictor of mortality, in a multivariate regression analysis. CONCLUSIONS: Thrombocytosis is not a simple marker of inflammation. Its presence warrants thorough investigation for the presence of severe underlying disease, mostly complicated pyogenic infections, inflammatory rheumatic diseases and malignancy. Moreover, thrombocytosis is a marker for major complications and is an independent predictor of mortality in admitted medical patients.

Significantly elevated C-reactive protein serum levels are associated with very high 30-day mortality rates in hospitalized medical patients.

BACKGROUND: There is insufficient data regarding the differential diagnosis and the prognostic value of significantly elevated serum levels of C-reactive protein (CRP) in hospitalized medical patients. DESIGN AND METHODS: A retrospective review of medical charts of patients admitted to a tertiary hospital's Internal Medicine ward during a period of 1 year who had at least one CRP serum level measurement of 200mg/L or more. RESULTS: Overall, 341 patients with a mean age of 69.8+/-1.0 years were included in the study. Acute infection was the most prevalent diagnosis (n=293; 85.9%) with community-acquired pneumonia being the most common acute infection (n=115; 33.7%). Non-infectious conditions accounted for 9.1% (n=31) of the diagnoses and included mainly malignant metastatic diseases (n=19; 5.6%). Overall, 70 (20.5%) patients died within 30 days of admission. Age and active malignancy, with metastasis or without metastasis, were independently associated with 30-day mortality. CONCLUSION: Significantly elevated CRP serum levels are associated with bacterial infections, malignant diseases, and very high rates of 30-day mortality in hospitalized medical patients.

First report of screening an asymptomatic population for cancer: the yield of an integrated cancer prevention center.

BACKGROUND: Cancer is a leading cause of mortality worldwide. The most effective way to combat cancer is by prevention and early detection. OBJECTIVES: To evaluate the outcome of screening an asymptomatic population for the presence of benign and neoplastic lesions. METHODS: Routine screening tests for prevention and/or early detection of 11 common cancers were conducted in 300 consecutive asymptomatic apparently healthy adults aged 25-77 years. Other tests were performed as indicated. RESULTS: Malignant and benign lesions were found in 3.3% and 5% of the screenees, respectively, compared to 1.7% in the general population. The most common lesions were in the gastrointestinal tract followed by skin, urogenital tract and breast. Advanced age and a family history of a malignancy were associated with increased risk for cancer with an odds ratio of 9 and 3.5, respectively (95% confidence interval 1.1-71 and 0.9-13, respectively). Moreover, high serum C-reactive protein levels and polymorphisms in the APC and CD24 genes indicated high cancer risk. When two of the polymorphisms existed in an individual, the risk for a malignant lesion was extremely high (23.1%; OR 14, 95% CI 2.5-78). CONCLUSIONS: Screening asymptomatic subjects identifies a significant number of neoplastic lesions at an early stage. Incorporating data on genetic polymorphisms in the APC and CD24 genes can further identify individuals who are at increased risk for cancer. Cancer can be prevented and/or diagnosed at an early stage using the screening facilities of a multidisciplinary outpatient clinic.

Prognostic significance of serum uric acid in patients admitted to the Department of Medicine.

BACKGROUND: Hyperuricemia has been linked to proatherogenic processes, including increased oxidative stress and leukocyte activation, and was shown to predict adverse prognosis in heart failure, renal failure, and hypertension. Recently, serum uric acid (SUA) was shown to be an independent predictor of long-term mortality in patients with cardiovascular diseases. However, the prognostic significance of SUA for the short-term outcome of admitted medical patients is unknown. METHODS: Initial SUA, together with epidemiological, clinical, and laboratory data, was analyzed for a prospective cohort of 650 consecutive adult patients admitted to the department of internal medicine during a 3-month period. RESULTS: The mean, median, and range of SUA at admission were 6.1 +/- 2.7, 5.6, and 1.2 to 24 mg/dL, respectively. Increased SUA was significantly correlated with age, gender, comorbidities (coronary heart disease, heart failure, hypertension, diabetes, renal failure, and gout), use of diuretics, and current admission for cardiovascular diseases but not with current diagnosis of infection, malignancy, or inflammatory diseases, nor with C-reactive protein. However, SUA significantly correlated with mortality (7.7 versus 6 mg/L, P < 0.025) and was an independent predictor of mortality in a multivariate regression analysis (odds ratio: 1.11; confidence interval: 1.003-1.218; P = 0.04), with a significant difference in mortality between normal SUA (<6 mg/dL) with 5% mortality and high SUA (>12 mg/dL) with 27% mortality. CONCLUSIONS: Initial SUA is an independent predictor of mortality in admitted medical patients. Whether significant asymptomatic hyperuricemia should be treated remains to be determined in further studies.

CXCL12 is a constitutive and inflammatory chemokine in the intestinal immune system.

BACKGROUND: Inflammatory bowel disease (IBD) is characterized by increased lymphocytic infiltrate to the lamina propria (LP) and upregulation of inflammatory chemokines and receptors. CXCL12 is a constitutive chemokine involved in lung, brain, and joint inflammation. We hypothesized that CXCL12 and its receptor, CXCR4, would have a constitutive and inflammatory role in the gut. METHODS: Intestinal epithelial cells (IECs) and T lymphocytes were isolated from intestinal mucosa of IBD and control patients undergoing bowel resection. Autologous T cells were isolated from peripheral blood (PB). CXCL12 and CXCR4 expression by IECs was assessed by polymerase chain reaction and immunohistochemistry, lymphocyte phenotype by flow cytometry, and migration by Transwells. RESULTS: IECs expressed CXCL12 and expression was increased and more diffuse in IBD compared to normal crypts (ulcerative colitis [UC] > Crohn's disease [CD], inflamed > noninflamed). CXCR4 was expressed by IECs, LP T cells (LPTs), and PB T cells (PBTs), and CXCR4+ cells were increased in IBD LP in situ. PBTs and LPTs from all patients had a high and comparable migration toward CXCL12 (P < 0.0001 and P < 0.05 vs. medium, respectively). Migration toward IBD-IEC-derived supernatant was significantly higher compared to normal. Antibodies against CXCR4 and CXCL12 blocked migration. CONCLUSIONS: CXCL12 is expressed by normal IECs and upregulated and differentially distributed in IBD IECs. CXCR4 is expressed by IECs and LPTs, and CXCR4+ cells are significantly increased in IBD LP. CXCL12 is chemotactic for both PBTs and LPTs. Thus, CXCL12 and CXCR4 have a constitutive and inflammatory role in the intestinal mucosa and their selective therapeutic manipulation may be considered in IBD management.

The effect of blockade of tumor necrosis factor alpha on VLA-1+ T-cells in rheumatoid arthritis patients.

The alpha1beta1 integrin, very late antigen (VLA)-1, characterizes collagen adherent interferon (IFN) gamma producing memory T cells in inflamed synovium. We now report that the mean percentage of VLA-1+ T cells is significantly lower among peripheral blood mononuclear cells of rheumatoid patients responsive to antitumor necrosis factor (TNF) alpha therapy than of those with active disease not receiving therapy. Neutralization of TNFalpha during in vitro polyclonal activation of VLA-1- T cells reduced differentiation to expression of VLA-1 and inhibited secretion of IFNgamma, but did not affect integrin expression on in vivo differentiated VLA-1+ T cells. Moreover, synovial fluids of patients relapsing during and after therapy were enriched in VLA-1+ T cells and lines derived from VLA-1+ T cells in peripheral blood of treated patients retained collagen binding and secreted IFN gamma. Thus, whereas therapy decreases VLA-1+ T cells in rheumatoid arthritis patients, a subset is resistant and contributes to residual and recurring inflammation.

Abnormal germinal center reactions in systemic lupus erythematosus demonstrated by blockade of CD154-CD40 interactions.

To determine the role of CD154-CD40 interactions in the B cell overactivity exhibited by patients with active systemic lupus erythematosus (SLE), CD19+ peripheral B cells were examined before and after treatment with humanized anti-CD154 mAb (BG9588, 5c8). Before treatment, SLE patients manifested activated B cells that expressed CD154, CD69, CD38, CD5, and CD27. Cells expressing CD38, CD5, or CD27 disappeared from the periphery during treatment with anti-CD154 mAb, and cells expressing CD69 and CD154 disappeared from the periphery during the post-treatment period. Before treatment, active-SLE patients had circulating CD38 (bright) Ig-secreting cells that were not found in normal individuals. Disappearance of this plasma cell subset during treatment was associated with decreases in anti-double-stranded DNA (anti-dsDNA) Ab levels, proteinuria, and SLE disease activity index. Consistent with this finding, peripheral B cells cultured in vitro spontaneously proliferated and secreted Ig in a manner that was inhibited by anti-CD154 mAb. Finally, the CD38(+/++)IgD(+), CD38(+++), and CD38(+)IgD(-) B cell subsets present in the peripheral blood also disappeared following treatment with humanized anti-CD154. Together, these results indicate that patients with active lupus nephritis exhibit abnormalities in the peripheral B cell compartment that are consistent with intensive germinal center activity, are driven via CD154-CD40 interactions, and may reflect or contribute to the propensity of these patients to produce autoantibodies.

Sternoclavicular infectious arthritis in previously healthy adults.

OBJECTIVE: To define characteristics of sternoclavicular infection (SCI) in previously healthy patients. METHODS: SCI in a previously healthy man is reported along with 4 similar cases found by surveying the hospital's database; 22 previously reported cases were culled from the literature and summarized. RESULTS: The frequency of SCI in healthy adults was 0.5% of all bone and joint infections admitted to the hospital. The clinical and bacteriologic features were similar to previous reports in nonselected SCI patients. Computerized tomography (CT) scan, arthrocenthesis, and biopsy were required for diagnosis. Complications included abscess formation, mediastinitis, and sepsis. The majority of patients were treated by surgical drainage and antibiotics. The final outcome was good, without mortality or long-term morbidity. CONCLUSIONS: Although SCI is a rare infection in healthy adults, it should be considered in the differential diagnosis of a painful sternoclavicular joint. Prompt diagnosis and appropriate treatment of SCI results in excellent outcome in most cases.