IP-10 differentiates between active and latent tuberculosis irrespective of HIV status and declines during therapy.

OBJECTIVES: Biomarkers for diagnosis and therapy efficacy in tuberculosis (TB) are requested. We have studied biomarkers that may differentiate between active and latent TB infection (LTBI), the influence of HIV infection and changes during anti-TB chemotherapy. METHODS: Thirty-eight plasma cytokines, assessed by multiplex and enzyme immunoassays, were analyzed in patients with active TB before and during 24 weeks of anti-TB chemotherapy (n = 65), from individuals with LTBI (n = 34) and from QuantiFERON-TB (QFT) negative controls (n = 65). The study participants were grouped according to HIV status. RESULTS: Plasma levels of the CXC chemokine IP-10 and soluble TNF receptor type 2 (sTNFr2) significantly differentiated active TB from the LTBI group, irrespective of HIV status. In the HIV-infected group the sensitivity and specificity was 100% for IP-10 with a cut-off of 2547 pg/mL. Plasma IP-10 declined gradually during anti-TB chemotherapy (12-24 weeks, p = 0.002) to a level comparable to LTBI and QFT negative control groups. sTNFr2 fluctuated throughout therapy, but was decreased after 12-24 weeks (p = 0.006). CONCLUSIONS: IP-10 distinguished with high accuracy active TB from LTBI irrespective of HIV infection and declined during anti-TB chemotherapy. Plasma IP-10 may serve as a diagnostic biomarker to differentiate between the stages of TB infection and for monitoring therapy efficacy.

Prior statin use and 90-day mortality in Gram-negative and Gram-positive bloodstream infection: a prospective observational study.

In several studies on patients with bloodstream infection (BSI), prior use of statins has been associated with improved survival. Gram-positive and Gram-negative bacteria alert the innate immune system in different ways. We, therefore, studied whether the relation between prior statin use and 90-day total mortality differed between Gram-positive and Gram-negative BSI. We conducted a prospective observational cohort study of 1,408 adults with BSI admitted to Levanger Hospital between January 1, 2002, and December 31, 2011. Data on the use of statins and other medications at admission, comorbidities, functional status, treatment, and outcome were obtained from the patients' hospital records. The relation of statin use with 90-day mortality differed between Gram-negative and Gram-positive BSI (p-value for interaction 0.01). Among patients with Gram-negative BSI, statin users had significantly lower 90-day total mortality [odds ratio (OR) 0.42, 95 % confidence interval (CI) 0.23-0.75, p = 0.003]. The association remained essentially unchanged after adjusting for the effect of sex, age, functional status before the infection, and underlying diseases that were considered confounders (adjusted OR 0.38, 95 % CI 0.20-0.72, p = 0.003). A similar analysis of patients with Gram-positive BSI showed no association of statin use with mortality (adjusted OR 1.22, 95 % CI 0.69-2.17, p = 0.49). The present study suggests that prior statin use is associated with a lower 90-day total mortality in Gram-negative BSI, but not in Gram-positive BSI.

Expression of Toll-like receptor-3 is enhanced in active inflammatory bowel disease and mediates the excessive release of lipocalin 2.

Anti-microbial peptides might influence the pathogenesis and course of inflammatory bowel disease (IBD). We sought to clarify the role of the anti-microbial glycoprotein lipocalin 2 (LCN2) in the colon by determining its localization and regulation in IBD. Following a microarray gene expression study of colonic biopsies from a large IBD population (n = 133), LCN2 was localized using immunohistochemistry and in-situ hybridization. Moreover, we examined the regulation of LCN2 in HT-29 cells with a panel of pattern recognition receptors (PRRs) and sought evidence by immunohistochemistry that the most relevant PRR, the Toll-like receptor (TLR)-3, was indeed expressed in colonic epithelium in IBD. LCN2 was among the 10 most up-regulated genes in both active ulcerative colitis (UCa) and active Crohn's disease (CDa) versus healthy controls. LCN2 protein was found in both epithelial cells and infiltrating neutrophils, while mRNA synthesis was located solely to epithelial cells, indicating that de-novo synthesis and thus regulation of LCN2 as measured in the gene expression analysis takes place in the mucosal epithelial cells. LCN2 is a putative biomarker in faeces for intestinal inflammation, different from calprotectin due to its epithelial site of synthesis. LCN2 release from the colonic epithelial cell line HT-29 was enhanced by both interleukin (IL)-1ß and the TLR-3 ligand poly(I:C), and TLR-3 was shown to be expressed constitutively in colonic epithelial cells and markedly increased during inflammation.

Enhanced levels of CCL19 in patients with advanced acquired immune deficiency syndrome (AIDS).

Based on the ability to recruit lymphocytes and dendritic cells to lymphoid tissue and to promote inflammation, we hypothesized a role for dysregulated CCL19 and CCL21 levels in human immunodeficiency virus (HIV)-infected patients with advanced immunodeficiency, and in particular in those with accompanying Mycobacterium avium complex (MAC) infection. The hypothesis was explored by studies in HIV-infected patients with and without MAC infection, as well as in vitro, examining the ability of proteins from MAC to promote CCL19 and CCL21 responses in peripheral blood mononuclear cells (PBMC) during highly active anti-retroviral therapy (HAART). Our main findings were: (i) raised serum levels of CCL19 in HIV-infected patients with CD4(+) T cell count <50 cells/µl compared with HIV-infected patients with CD4(+) T cell count >500 cells/µl and healthy controls, with particularly high levels in those with MAC infection; (ii) elevated plasma levels of CCL19 predicted a higher mortality in acquired immune deficiency syndrome (AIDS)-patients, independent of ongoing MAC infection; and (iii) marked production of CCL19 in MAC-stimulated peripheral blood mononuclear cells (PBMC) and pronounced disturbances in MAC-induced CCL19 production in PBMC from HIV patients that was partly reversed during HAART. Our findings suggest the involvement of CCL19 in AIDS patients with advanced immunodeficiency, potentially mediating both adaptive and maladaptive responses.

Body composition and plasma levels of inflammatory biomarkers in COPD.

Previous studies suggest a relationship between systemic inflammation and body composition in chronic obstructive pulmonary disease (COPD). We examined the relationships between body composition (fat free mass index (FFMI) kg·m(-2) and fat mass index (FMI) kg·m(-2)) and three plasma inflammatory markers C-reactive Protein (CRP), soluble tumour necrosis factor receptor 1 (sTNF-R1) and osteoprotegerin (OPG) in 409 stable COPD patients (aged 40-75 yrs, Global Initiative for Obstructive Chronic Lung Disease (GOLD) categories II-IV, 249 male) from the Bergen COPD Cohort Study in Norway. FFMI and FMI were measured by bioelectrical impedance. Plasma CRP (µg·mL(-1)), sTNF-R1 (pg·mL(-1)) and OPG (ng·mL(-1)) were determined by enzyme immunoassays. Correlations and Kruskal-Wallis tests were used for bivariate analyses. Linear regression models were fitted for each of the three markers, CRP, sTNF-R1 and OPG, with FFMI and FMI as explanatory variables including sex, age, smoking habits, GOLD category, hypoxaemia, Charlson Comorbidity Index and inhaled steroid use as potential confounders. CRP and sTNF-R1 levels correlated positively with both FFMI and FMI. The adjusted regression coefficients for an increase in logCRP per unit increase in FFMI was 1.23 (1.14-1.33) kg·m(-2) and 24.9 (11.8-38.1) kg·m(-2) for sTNF-R1. Higher FMI was associated with a lower OPG, with adjusted regression coefficient -0.14 (-0.23- -0.04), whereas FFMI was unrelated to OPG. In conclusion, COPD patients with low FFMI had lower not higher plasma levels of CRP and sTNF-R1, whereas higher fat mass was associated with higher CRP and sTNF-R1 and lower OPG.

Systemic inflammatory markers in COPD: results from the Bergen COPD Cohort Study.

Chronic obstructive pulmonary disease (COPD) is considered an inflammatory pulmonary disorder with systemic inflammatory manifestations. The aim of this study was to assess the systemic levels of six inflammatory mediators in a large cohort of COPD patients and controls. 409 COPD patients and 231 healthy subjects, aged 40-75 yrs, were included from the first phase of the Bergen COPD Cohort Study. All COPD patients were clinically diagnosed by a physician, and had a forced expiratory volume in 1 s/forced vital capacity ratio less than 0.7 and a smoking history of >10 pack-yrs. The plasma levels of C-reactive protein (CRP), soluble tumour necrosis factor receptor (sTNFR)-1, osteoprotegrin, neutrophil activating peptide-2, CXCL16 and monocyte chemoattractant protein-4 were determined by ELISA. After adjustment for all known confounders, COPD patients had significantly lower levels of osteoprotegrin than subjects without COPD (p<0.05), and higher levels of CRP (p<0.01). Among COPD patients, CRP was elevated in patients with frequent exacerbations (p<0.05). sTNFR-1 and osteoprotegrin were both related to Global Initiative for Chronic Obstructive Lung Disease stage and frequency of exacerbations in the last 12 months (p<0.05). In addition, sTNFR-1 was significantly associated with important comorbidities such as hypertension and depression (p<0.05). The present study confirms that certain circulating inflammatory mediators are an important phenotypic feature of COPD.

Chemokines and common variable immunodeficiency; possible contribution of CCL19, CCL21 and CCR7 to immune dysregulation.

Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by defective immunoglobulin production and high frequency of bacterial infections, autoimmunity and manifestations of chronic inflammation. The homeostatic chemokines CCL19 and CCL21 and their receptor CCR7 are associated with modulation of inflammatory responses. CVID patients have decreased proportions of CCR7(+) T cells in peripheral blood and we hypothesized a further dysregulation of CCL19/CCL21/CCR7 in CVID. Serum levels of CCL19 and CCL21 were compared in CVID patients and controls. T cell expression of CCR7 was related to clinical characteristics in CVID patients. Spleens extirpated from CVID patients were analysed for expression of CCL19, CCL21 and CCR7. Peripheral blood mononuclear cells (PBMC) from CVID patients and controls were analysed for cytokine response on stimulation with CCL19 and CCL21. The main findings were: (i) CVID patients have raised serum levels of CCL19 and CCL21 independently of features of chronic inflammation; (ii) CCL19 and CCR7 have similar expression in spleens from CVID patients and controls, while CCL21 is variably down-regulated in spleens from patients; (iii) T cell expression of CCR7 is particularly low in patients characterized by chronic inflammation in vivo; and (iv) PBMC from CVID patients had attenuated cytokine response to stimulation with CCL19 and CCL21. CVID patients have raised circulatory levels of CCL19 and CCL21, and an attenuated cytokine response to stimulation with these chemokines. Because CCR7, CCL19 and CCL21 are key mediators balancing immunity and tolerance in the immune system, the abnormalities of these mediators might contribute to the profound immune dysregulation seen in CVID.

CXCL16 in HIV infection - a link between inflammation and viral replication.

BACKGROUND: While some chemokines are thought to be protective in HIV-infected individuals by their ability to block HIV entry into T cells and macrophages, chemokines could also have harmful effects in HIV infection through their ability to promote inflammation. Here, we examined the regulation and the effects of CXCL16, a newly discovered chemokine of the CXC family, in HIV-infected patients. MATERIALS AND METHODS: We examined serum levels of CXCL16 in clinically well-defined subgroups of HIV-infected individuals both before (n = 62) and during HAART (n = 40) as well as in age- and sex-matched healthy controls (n = 30). We also examined the effects of CXCL16 on inflammatory and anti-inflammatory cytokines and HIV replication in peripheral blood mononuclear cells (PBMC). RESULTS: Our main and novel findings were: (i) HIV-infected patients had significant raised CXCL16 levels according to disease severity and progression. (ii) During HAART, the immunological improvement was accompanied by a modest increase in CXCL16 level. (iii) While soluble CXCL16 promoted an anti-inflammatory response in PBMC from those on successful HAART, it induced an inflammatory response and enhanced HIV replication in PBMC from those with high viral load irrespectively of ongoing HAART. (iv) Recombinant HIV-tat protein significantly increased CXCL16 release in THP-1 macrophages. CONCLUSIONS: Our findings suggest a complex interaction between CXCL16 and HIV, promoting both inflammatory and anti-inflammatory effects as well as HIV replication, partly dependent on accompanying HIV replication.

Homeostatic chemokines CCL19 and CCL21 promote inflammation in human immunodeficiency virus-infected patients with ongoing viral replication.

CCL19 and CCL21 and their receptor CCR7 are expressed constitutively within lymphoid organs, regulating lymphocyte homing. Recent studies suggest that these chemokines may have inflammatory properties. We hypothesized a role of CCL19/CCL21 in human immunodeficiency virus (HIV) infection by promoting inflammation. We examined the expression of CCL19 and CCL21 in mononuclear cells from peripheral blood mononuclear cells (PBMC) and bone marrow mononuclear cells (BMMC) in HIV-infected patients before and during highly active anti-retroviral therapy (HAART). We also examined the ability of CCL19/CCL21 to promote inflammatory responses in these patients. PBMC from untreated HIV-infected patients (n = 29) released enhanced levels of CCL19 spontaneously compared with cells from controls (n = 20), particularly in those with symptomatic disease (n = 15, P < 0.01 versus controls). During HAART (n = 9), there was a decrease in the spontaneous CCL19 release and an increase in the phytohaemagglutinin-stimulated CCL19 release in both PBMC (P < 0.01) and BMMC (P < 0.05). In patients with enhanced HIV replication there was an increased proportion of inflammatory CD8(+)CCR7(-)CD45RA(-) T cells in peripheral blood [P < 0.01 and P < 0.05 versus controls, untreated (n = 9) and treatment failure (n = 8), respectively]. In vitro, CCL19/CCL21 promoted an inflammatory response in PBMC when accompanied by high viral load, irrespective of HAART. The HIV-tat protein significantly boosted the inflammatory effect of CCL19/CCL21 in PBMC. These findings link a dysregulated CCL19/CCL21/CCR7 system in HIV-infected patients to persistent inflammation and HIV replication, not only in untreated HIV infection, but also in treatment failure during HAART.

Decreased serum lipocalin-2 levels in human immunodeficiency virus-infected patients: increase during highly active anti-retroviral therapy.

Although neutrophil gelatinase-associated lipocalin (NGAL) may play a pivotal role in the innate immune response, there are currently no data on NGAL levels in human immunodeficiency virus (HIV)-infected patients. In this study we aimed to examine the regulation of NGAL in HIV infection. The regulation of NGAL in HIV infection was examined by different experimental approaches, including studies in peripheral blood and mononuclear cells (MNC) from bone marrow aspirates before and during highly active anti-retroviral therapy (HAART). We found that: before initiating HAART, HIV-infected patients (n = 37) had significantly decreased serum NGAL levels compared with healthy controls (n = 26); (ii) during HAART, there was a gradual and significant increase in NGAL concentrations reaching levels comparable to those in healthy controls after 12 months; (iii) this increase was seen primarily in virological responders to HAART (HIV RNA level <200 copies/ml after 24 months); (iv) phytohaemagglutinin-stimulated NGAL release in MNC cells from bone marrow aspirates was decreased in untreated HIV-infected patients compared with healthy controls, but increased after 26 weeks on HAART; and (v) there was a significant positive correlation between neutrophil counts and NGAL levels at all time-points during HAART. We have shown decreased NGAL levels in HIV-infected patients, potentially reflecting decreased number and function of neutrophils as well as impaired bone marrow myelopoiesis. These abnormalities were reversed by successful HAART. Our findings underscore further the involvement of neutrophils and innate immunity in HIV-related immunodeficiency.

Clopidogrel increases expression of chemokines in peripheral blood mononuclear cells in patients with coronary artery disease: results of a double-blind placebo-controlled study.

BACKGROUND: Chemokines and platelet activation are both important in atherogenesis. Platelet inhibitors are widely used in coronary artery disease (CAD), and we hypothesized that the platelet inhibitor clopidogrel could modify chemokines in CAD patients. OBJECTIVES: We sought to investigate the effect of clopidogrel on the expression of chemokines and chemokine receptors in peripheral blood mononuclear cells (PBMC) in CAD patients. PATIENTS/METHODS: Thirty-seven patients with stable angina were randomized to clopidogrel (n = 18) or placebo (n = 19). PBMC, blood platelets and plasma were collected at baseline and after 7-10 days in the patients, and in 10 healthy controls. mRNA levels of chemokines and chemokine receptors in PBMC were analyzed by ribonuclease protection assays and real-time reverse transcriptase polymerase chain reaction. Platelet activation was studied by flow cytometry. RESULTS: (i) At baseline, the gene expression of the regulated on activation normally T-cell expressed and secreted (RANTES) chemokines and macrophage inflammatory peptide (MIP)-1beta in PBMC, the expression of CD62P and CD63 on platelets and the levels of platelet-derived microparticles (PMP) were elevated in angina patients comparing healthy controls; (ii) markers of platelet activation were either reduced (CD63) or unchanged (CD62P, PMP, beta-thromboglobulin) during clopidogrel therapy; (iii) in contrast, clopidogrel significantly up-regulated the gene expression of RANTES and MIP-1beta in PBMC, while no changes were found in the placebo group; (iv) a stable adenosine 5'-diphosphate metabolite attenuated the release of MIP-1beta, but not of RANTES, from activated PBMC in vitro. CONCLUSIONS: Even if we do not argue against a beneficial role for clopidogrel in CAD, our findings may suggest potential inflammatory effects of clopidogrel in CAD.

The tumor necrosis factor superfamily in heart failure.

Numerous clinical studies have established that tumor necrosis factor (TNF)-alpha may play a pathogenic role in the development and progression of heart failure (HF). Recent reports suggest that other ligands in the TNF superfamily could also play a pathogenic role in chronic HF. TNF superfamily ligands are expressed predominantly by cells in the immune system, while the TNF receptor superfamily are expressed by a wide variety of cells, including myocardial cells. Several pathways are activated by ligand-receptor interactions, but of particular importance is the nuclear factor (NF)-kappaB pathway which is activated in the failing human heart. All ligands in the TNF superfamily have the potential to activate NF-kappaB, leading to transcription of genes involved in apoptosis, cell survival, proliferation, inflammation and hypertrophic signaling in cardiomyocytes. Among several TNF superfamily members that are activated in HF, the authors' have recentlyshown that CD40L-CD40 and OPG-RANK-RANKL interactions may be implicated in the pathogenesis of HF through different mechanisms, possibly representing new targets for therapy in this disorder.

Common variable immunodeficiency and the complement system; low mannose-binding lectin levels are associated with bronchiectasis.

The importance of the innate immune system, including mannose-binding lectin and the complement system, in common variable immunodeficiency is unclear. The objective of this study was to evaluate mannose-binding lectin and the complement system in relation to clinical and immunological parameters in patients with common variable immunodeficiency. Circulating levels of mannose-binding lectin, complement components, complement activation products and functional capacity of complement pathways were correlated to clinical features within 71 patients and compared with 30 healthy controls. The main findings were; the patients had signs of increased complement activation significantly associated with signs of autoimmunity and immunological hyperactivity; there were no signs of deficiencies of the classical and alternative complement pathways in the patient group; the prevalence of lectin pathway deficiency was the same in patients and controls, but patients with increased frequency of lower respiratory tract infections or bronchiectasis had lower capacity of the lectin pathway than patients without these features (P = 0.002 and 0.004, respectively); the serum concentration of mannose-binding lectin was inversely correlated to the frequency of lower respiratory tract infections (P = 0.002) and bronchiectasis (P = 0.01). We conclude that patients with common variable immunodeficiency have no increased frequency of complement deficiencies but signs of increased complement activation. Our findings suggest that mannose-binding lectin and the lectin complement pathway may protect against lower respiratory tract infection and bronhiectasis in patients with common variable immunodeficiency.

Expression of matrix metalloproteinases in patients with Wegener's granulomatosis.

BACKGROUND: Enhanced activity of matrix metalloproteinases (MMPs) has been reported to have a pathogenic role in several diseases such as cancer and cardiovascular disorders, and seems also to play a part in certain autoimmune diseases. OBJECTIVE: To examine whether enhanced MMP activity may also have a role in the pathogenesis of Wegener's granulomatosis (WG). METHODS: In a study group of 15 patients with WG and 15 controls, plasma levels and gene expression were measured in freshly isolated peripheral blood mononuclear cells (PBMCs) of several MMPs and their endogenous inhibitors (that is, tissue inhibitors of metalloproteinases (TIMPs)) by enzyme immunoassays and RNase protection assay, respectively. RESULTS: Whereas patients with WG in remission had enhanced gene expression of several MMPs and TIMPs in PBMCs, those with active disease had a selective up regulation of MMP-2 and MMP-8 compared with healthy controls, and a down regulation of TIMP-1 and TIMP-3 compared with other patients with WG. Moreover, plasma levels of TIMP-1 and MMP-8 correlated significantly with C reactive protein levels, further supporting an association between activation of the MMP/TIMP system and disease activity in WG. Finally, these changes in MMP/TIMP expression in WG were accompanied by increased total MMP activity in PBMC supernatants, particularly in those with active disease, suggesting a matrix degrading net effect. CONCLUSION: These findings suggest that disturbed MMP and TIMP activity has a role in the pathogenesis of WG.

Stimulation of toll-like receptor 2 in mononuclear cells from HIV-infected patients induces chemokine responses: possible pathogenic consequences.

Toll-like receptor 2 (TLR2) stimulation in monocytes may contribute to enhanced inflammation and viral replication in HIV infection. In the present study we examined if TLR2 stimulation could modulate chemokine responses in peripheral blood mononuclear cells (PBMC) from HIV-infected patients and healthy controls. Our main findings were, with similar qualitative patterns in both healthy controls and HIV-infected patients: (1) TLR2 stimulation induced up-regulation of several chemokines at the mRNA level as well as increased protein levels of macrophage inflammatory protein (MIP)-1alpha, interleukin (IL)-8 and regulated on activation, normal T cell expressed and secreted (RANTES); (2) TLR2 stimulation induced enhanced protein expression of CCR5 (a receptor for MIP-1alpha and RANTES) on monocytes; (3) In vitro stimulation with RANTES induced release of MIP-1alpha, MCP-1, IL-8 and interferon-gamma from PBMC. While increased levels of beta-chemokines possibly have antiviral effects, TLR2 stimulation may also promote a chemokine-driven inflammatory loop, potentially contributing to the immunopathogenesis of HIV infection.

8-isoprostane increases scavenger receptor A and matrix metalloproteinase activity in THP-1 macrophages, resulting in long-lived foam cells.

BACKGROUND: Oxidative stress is a key factor in atherogenesis, in which it is closely associated with the inflammation and formation of bioactive lipids. Although 8-isoprostane is regarded as a reliable marker of oxidative stress in vivo, the pathogenic role of this F(2)-isoprostane in atherogenesis is far from clear. Based on the important role of foam cells in the initiation and progression of atherosclerosis we hereby examined the ability of 8-isoprostane to modulate oxidized (ox)LDL-induced foam cell formation and the function of these cells, particularly focusing on the effect on matrix degradation. METHODS AND RESULTS: 8-isoprostane (10 micro M) augmented the oxLDL-induced (20 micro g mL(-1)) lipid accumulation of THP-1 macrophages evaluated by Oil-Red-O staining and lipid mass quantification (colourimetric assay). Additionally, 8-isoprostane induced the expression of the scavenger receptor A type 1 (MSR-1) [mRNA and protein level], assessed by RT-PCR and Western blotting, respectively. Moreover, 8-isoprostane counteracted the oxLDL-induced apoptosis of these cells, involving both mitochondrial-protective and caspase-suppressive mechanisms. Along with these changes, 8-isoprostane increased the oxLDL-induced gene expression of matrix metalloproteinase (MMP)-9 and its endogenous inhibitor [i.e. tissue inhibitor of MMP (TIMP)-1] accompanied by enhanced total MMP activity. CONCLUSIONS: We show that 8-isoprostane increases foam cell formation at least partly by enhancing MSR-1 expression and by inhibiting apoptosis of these cells, inducing long-lived foam cells with enhanced matrix degrading capacity. Our findings further support a role for 8-isoprostane not only as a marker of oxidative stress in patients with atherosclerotic disorders, but also as a mediator in atherogenesis and plaque destabilization.

CXC-chemokines in coronary artery disease: possible pathogenic role of interactions between oxidized low-density lipoprotein, platelets and peripheral blood mononuclear cells.

CXC-chemokines may be involved in atherogenesis. Herein we examined the possible role of CXC-chemokines in the inflammatory interactions between oxidized (ox-) low-density lipoprotein (LDL), platelets and peripheral blood mononuclear cells (PBMC) in 15 patients with coronary artery disease (CAD) without 'traditional' risk factors and 15 carefully matched controls. Our main findings were: (a) ox-LDL stimulated the release of the CXC-chemokines interleukin (IL)-8, ENA-78 and GRO-alpha from PBMC, particularly in CAD. (b) In platelets, ox-LDL induced release of ENA-78 and, when combined with SFLLRN, also of GRO-alpha, with significantly higher response in CAD. (c) Platelet-rich plasma, especially when costimulated with ox-LDL, enhanced the release of IL-8 from PBMC, particularly in CAD patients. (d) Freshly isolated PBMC showed markedly increased IL-8 mRNA expression in CAD patients. Our findings suggest enhanced inflammatory interactions between ox-LDL, platelets and PBMC in CAD patients involving CXC-chemokine related mechanisms, possible contributing to atherogenesis in these and other CAD patients.

Raised serum levels of interleukin-18 is associated with disease progression and may contribute to virological treatment failure in HIV-1-infected patients.

To gain further insight into the possible role of interleukin (IL)-18 in HIV-1 infection we examined serum levels of IL-18 in various clinical and immunological stages of HIV-1 infection during cross-sectional (n = 41) and longitudinal testing (n = 20) and during HAART (n = 21, 24 months follow-up). Our main findings were that HIV-1-infected patients had significantly raised IL-18 levels comparing healthy controls, particularly in those with advanced disease, that while HAART induced a marked decline in IL-18, virological treatment failure was associated with persistently raised IL-18 levels during such therapy and that our in vitro experiments showed an IL-18-mediated up-regulation of the HIV-1 coreceptor CXCR4 and the pro-apoptotic mediator TRAIL in PBMC from HIV-1-infected patients receiving HAART. HIV-1 infection appears to be characterized by persistently raised IL-18 levels and during HAART, such a pattern was associated with virological treatment failure, possibly contributing to immunodeficiency and HIV-1 replication in these patients.

Immunomodulating effects of 3-thia fatty acids in activated peripheral blood mononuclear cells.

BACKGROUND: 3-thia fatty acids such as tetradecylthioacetic acid (TTA) are modified fatty acids that have been suggested to change the plasma profile from atherogenic to cardio protective. Because of its interaction with peroxisome proliferator activated receptor (PPAR) we hypothesized that TTA also could have immunomodulatory properties. Based on the suggested role of inflammation in atherogenesis, any immunomodulating effects of TTA would be of particular interest for the potential use of this fatty acid in atherosclerotic disorders. MATERIALS AND METHODS: We examined if TTA could modulate proliferation and the release of cytokines from peripheral mononuclear cells (PBMCs) taken from five healthy blood donors. RESULTS: Our main findings were: (i) TTA had several effects on cytokine release from activated PBMCs with a marked increase in interleukin (IL)-10 accompanied by a reduction in IL-2 possibly favouring anti-inflammatory net effects. (ii) These cytokine-modifying effects were found in both T cells and monocytes when cultured separately. (iii) Tetradecylthioacetic acid increased the cytokine stimulating effects of tumour necrosis factor alpha with a particularly enhancing effect on IL-10. (iv) Tetradecylthioacetic acid significantly suppressed PBMC proliferation, and this antiproliferative property did not involve enhanced apoptosis or necrosis. (v) These immunomodulatory effects of TTA were accompanied by a marked down-regulation of PPARoad mRNA expression, the most abundant PPAR subtype in PBMCs. CONCLUSIONS: Our findings show potent immunomodulatory effects of TTA in activated PBMCs, possibly involving PPAR-related mechanisms.

Inflammatory imbalance between IL-10 and TNFalpha in unstable angina potential plaque stabilizing effects of IL-10.

BACKGROUND: The pathogenesis of atherosclerosis and acute coronary syndromes involves inflammation and immunological mechanisms. We hypothesized that patients with unstable angina may have an imbalance between inflammatory and anti-inflammatory cytokines. DESIGN: Plasma levels of tumour necrosis factor (TNF)alpha and interleukin (IL)-10 were analyzed in 44 patients with stable angina, 29 patients with unstable angina and 20 controls. mRNA levels of these cytokines were analyzed in peripheral blood mononuclear cells (PBMC). We also studied the in vitro effects of IL-10 in PBMC from unstable angina patients. RESULTS: Our main findings were: (1) the angina patients and particularly those with unstable disease had significantly raised TNFalpha in comparison with the controls, both at the protein and mRNA level; (2) in contrast, the levels of IL-10 were not different in the angina patients in comparison with the healthy controls, resulting in a markedly enhanced TNFalpha:IL-10 ratio, particularly in the unstable angina patients; (3) while exogenously added IL-10 markedly inhibited the release of TNFalpha, IL-8 and tissue factor as well as impairing the gelatinolytic activity and mRNA production of matrix metalloproteinase-9, it enhanced the tissue inhibitor of this metalloproteinase (i.e. TIMP-1) in PBMC from the unstable angina patients. CONCLUSION: Patients with unstable angina appear to have an imbalance between TNFalpha and IL-10, possibly favouring inflammatory net effects. IL-10 may have beneficial effects on mechanisms that are important in plaque rupture and thrombus formation.