CD28/CTLA-4/B7 costimulatory pathway blockade affects regulatory T-cell function in autoimmunity.

Naïve T cells require B7/CD28 costimulation in order to be fully activated. Attempts to block this pathway have been effective in preventing unwanted immune reactions. As B7 blockade might also affect Treg cells and interfere with negative signaling through membrane CTLA-4 on effector T (Teff) cells, its immune-modulatory effects are potentially more complex. Here, we used the mouse model of multiple sclerosis (MS), EAE, to study the effect of B7 blockade. An effective therapy for MS patients has to interfere with ongoing inflammation, and therefore we injected CTLA-4Ig at day 7 and 9 after immunization, when myelin-reactive T cells have been primed and start migrating toward the CNS. Surprisingly, B7 blockade exacerbated disease signs and resulted in more severe CNS inflammation and demyelination, and was associated with an enhanced production of the inflammatory cytokines IL-17 and IFN-γ. Importantly, CTLA-4Ig treatment resulted in a transient reduction of Ki67 and CTLA-4 expression and function of peripheral Treg cells. Taken together, B7 blockade at a particular stage of the autoimmune response can result in the suppression of Treg cells, leading to a more severe disease.

Airway inflammation in patients with chronic non-asthmatic cough.

INTRODUCTION: Chronic non-asthmatic cough (CC) is a clinical challenge and underlying pathophysiological mechanisms remain still not completely understood. One of the most common comorbidities in CC is gastro-oesophageal reflux disease (GORD). Airway epithelium damage can contribute to airway inflammation in CC. AIMS: We studied airway inflammation in patients with CC compared to healthy controls. Patients with GORD were treated with proton pump inhibitors (PPI) and cough response to PPI was evaluated. PATIENTS AND METHODS: Sputum was induced in 41 adults with CC and 20 healthy non-smokers who were age and sex matched. We compared sputum differential cell count by cytospin and cytokine and chemokine production at the mRNA and/or protein levels by real-time (RT)-PCR and cytokine bead array (CBA), between patients with CC and healthy subjects. Furthermore we studied airway inflammation in patients with different comorbidities. RESULTS: No differences in sputum differential cell counts were observed between patients with CC and healthy subjects. Sputum monocyte chemoattractant protein-1 (MCP-1) protein levels were significantly higher in patients when compared to controls. Thymic stromal lymphopoietin (TSLP) mRNA was significantly more often expressed in sputum of patients with CC than from healthy controls. Sputum transforming growth factor (TGF)-ß levels did not differ between patients and controls, but were significantly lower in the PPI responders compared to the non-responders; p=0.047. There is no evidence for impaired T helper cell (Th)1/Th2/Th17 balance in CC. Patients with reflux oesophagitis (RO) have significantly more sputum eosinophils than patients without RO. CONCLUSIONS: CC is a condition presenting with different disease phenotypes. High sputum MCP-1 levels are present in a large group of patients with CC and a majority of these patients with CC have increased sputum TSLP levels, most likely produced by damaged airway epithelial cells.

Haptoglobin deficiency facilitates the development of autoimmune inflammation.

Haptoglobin (HP) is an acute phase protein synthesized by liver cells in response to IL-6. HP has been demonstrated to modulate the immune response and to have anti-inflammatory activities. To analyze HP's effect on autoimmune inflammation, we here studied the course of EAE induced by immunization of Hp knockout (Hp(-/-)) and syngeneic WT mice with myelin oligodendrocyte glycoprotein peptide (MOG(35-55)). Hp(-/-)mice suffered from a more severe disease that was associated with increased expression of IL-17A, IL-6, and IFN-gamma mRNA in the CNS and with a denser cellular infiltrate in the spinal cord. During the recovery phase, a significantly higher number of myeloid DC, CD8+ cells, IL-17+ CD4+ and IFN-gamma+ CD4+ cells persisted in the CNS of Hp(-/-) mice. Absence of HP affected the priming and differentiation of T cells after MOG(35-55) immunization, as levels of Th2 cytokines produced in response to MOG stimulation by Hp(-/-) T cells were reduced. These results suggest that HP plays a modulatory and protective role on autoimmune inflammation of the CNS.

Etanercept improves linear growth and bone mass acquisition in MTX-resistant polyarticular-course juvenile idiopathic arthritis.

OBJECTIVES: Chronic inflammation in juvenile idiopathic arthritis interferes with linear growth and bone mass acquisition. We prospectively evaluated and compared linear growth and evolution of bone mass acquisition and body composition in MTX-resistant polyarticular-course JIA (polyJIA) patients started on etanercept and in recently diagnosed polyJIA patients started on MTX monotherapy. METHODS: Sixteen MTX-resistant polyJIA patients were given add-on etanercept, eight recently diagnosed polyJIA patients were started on MTX. Patients were evaluated at baseline and at 1, 6, 12 and 18 months with respect to disease activity, linear growth, BMD and body composition. RESULTS: Baseline patient and disease characteristics were similar in both groups. Clinical disease activity (Pediatric ACR30) was equally well controlled in both groups. Growth velocity increased significantly allowing catch-up growth in the etanercept + MTX group only. BMD (lumbar spine Z-score) improved significantly in both groups. A significant increase of bone mineral content and lean:fat mass ratio was seen in the etanercept + MTX group, but not in the MTX group. CONCLUSION: Clinical control of disease activity by etanercept in MTX-refractory polyJIA is associated with rapidly instituted catch-up growth and improvement of bone mineralization and body composition. In recently diagnosed polyJIA patients treated with MTX the relation between clinical response and these parameters was less evident. Preliminary data on serum IL-6 and osteoprotegerin levels indicate that the beneficial effects seen with etanercept therapy may be related to its control of systemic IL-6 production and enhancement of osteoblast activity.

Elevated expression of both mRNA and protein levels of IL-17A in sputum of stable Cystic Fibrosis patients.

BACKGROUND: T helper 17 (Th17) cells can recruit neutrophils to inflammatory sites through production of IL-17, which induces chemokine release. IL-23 is an important inducer of IL-17 and IL-22 production. Our aim was to study the role of Th17 cells in cystic fibrosis (CF) lung disease by measuring IL-17 protein and mRNA levels and IL-22 and IL-23 mRNA in sputum of clinically stable CF patients and by comparing these levels with healthy controls. METHODS: Sputum induction was performed in adult CF patients outside of an exacerbation and healthy control subjects. IL-17A protein levels were measured in supernatants with cytometric bead array (CBA) and RNA was isolated and quantitative RT-PCR was performed for IL-17A, IL-22 and IL-23. RESULTS: We found significantly higher levels of IL-17A protein and mRNA levels (both: p < 0.0001) and IL-23 mRNA levels (p < 0.0001) in the sputum of CF group as compared to controls. We found very low levels of IL-22 mRNA in the CF group. The levels of IL-17 and IL-23 mRNA were higher in patients chronically infected with Pseudomonas aeruginosa (P. aeruginosa) as compared to those who were not chronically infected with P. aeruginosa. The presence of Staphylococcus aureus (S. aureus) on sputum did not affect the IL-17 or IL-23 levels. There was no correlation between IL-17 or IL-23 levels and FEV1 nor sputum neutrophilia. CONCLUSION: The elevated levels of IL-17 and IL-23 might indicate that Th17 cells are implicated in the persistent neutrophil infiltration in CF lung disease and chronic infection with P. aeruginosa.

Generation of antibody responses to pneumococcal capsular polysaccharides is independent of CD1 expression in mice.

Streptococcus pneumoniae is a bacterial microorganism that frequently causes serious infection, particularly in children and the elderly. Protection against infection with S. pneumoniae is based mainly on the generation of antibodies to the pneumococcal capsular polysaccharides (caps-PS), but the mechanisms responsible for the generation of anticapsular antibodies remain incompletely understood. The aim of the present study was to evaluate the role of CD1-restricted T cells in the antibody response to caps-PS. When immunized with Pneumo23, wild-type mice and CD1 knockout mice on BALB/c and C57BL/6 backgrounds generated immunoglobulin M (IgM) and IgG antibody responses to soluble caps-PS that were comparable. Similar results were obtained after immunization with heat-inactivated S. pneumoniae. The IgM and IgG antibody response of wild-type mice to Pneumo23 was not affected by an antagonizing monoclonal anti-CD1 antibody treatment. In summary, our data provide evidence that the antibody response to caps-PS is generated independently of CD1 expression.

ICOS deficiency results in exacerbated IL-17 mediated experimental autoimmune encephalomyelitis.

INTRODUCTION: Inducible costimulatory molecule (ICOS) is important for the effector function of T cells, especially for Th2 and T cell dependent B cell responses. However, it has been shown that ICOS is required for the differentiation of Th17 cells. Since IL-17 has been identified as a major cytokine involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), the enhanced severity of EAE in ICOS-deficient mice (ICOS(-/-)) mice is unexpected. METHODS: To better understand the role of ICOS and of IL-17 in EAE, we induced EAE in ICOS(-/-) by immunization with myelin oligodendrocyte glycoprotein peptide (MOG(35-55)) in complete Freund's adjuvant. RESULTS: As previously reported, we found that ICOS(-/-) mice developed more severe EAE. Upon restimulation with MOG(35-55,) splenocytes from ICOS(-/-) mice with EAE produced higher amounts of IL-17 and ICOS(-/-) mice had a higher expression of IL-17, IL-6, and TGF-beta mRNA in the spinal cords at the onset of the disease. Finally, the blockade of IL-17 strongly inhibited disease even in ICOS(-/-) mice, showing that IL-17 is playing a major role in the pathogenesis of EAE both in WT and ICOS(-/-) mice. CONCLUSION: In conclusion, MOG immunization induces MOG-specific Th17 cells also in ICOS(-/-) mice, and a higher expression of IL-17 and of Th17-driving cytokines IL-6 and TGF-beta in the central nervous system at the onset of EAE that correlates with their more severe disease.

Aprotinin reduces cardiac troponin I release and inhibits apoptosis of polymorphonuclear cells during off-pump coronary artery bypass surgery.

OBJECTIVES: In addition to blood-sparing effects, aprotinin may have cardioprotective and anti-inflammatory effects during cardiopulmonary bypass-assisted cardiac surgery. In this study, the authors examined whether aprotinin had cardioprotective and/or anti-inflammatory effects in patients undergoing off-pump coronary artery bypass grafting. DESIGN: A prospective randomized clinical trial. SETTING: University hospital. PARTICIPANTS: Fifty patients were randomized to control (n = 25) or aprotinin treatment (n = 25) groups. INTERVENTIONS: Aprotinin was given as a loading dose (2 x 10(6) KIU) followed by a continuous infusion at 5 x 10(5) KIU/h until skin closure. MEASUREMENTS AND MAIN RESULTS: Blood samples for cardiac troponin I; interleukin-6, interleukin-8, and interleukin-10; tumor necrosis factor alpha; and elastase were taken after anesthesia induction, completion of revascularization, and 6 hours, 12 hours, and 24 hours after revascularization. Blood samples were taken to assess for apoptosis in polymorphonuclear cells. Baseline plasma levels for cardiac troponin I did not differ between groups but were significantly lower in aprotinin-treated patients at the time of revascularization (p = 0.03) and 6 hours (p = 0.004) and 24 hours (p = 0.03) later. Aprotinin significantly reduced apoptosis in polymorphonuclear cells compared with control-treated patients (p = 0.04). There were no differences in plasma cytokine or elastase levels between groups. CONCLUSIONS: The authors conclude that aprotinin reduces perioperative cardiac troponin I release and attenuates apoptosis in polymorphonuclear cells but has no significant effects on plasma cytokine levels in patients undergoing off-pump coronary artery bypass graft surgery.

Immature and mature monocyte-derived dendritic cells in myelodysplastic syndromes of subtypes refractory anemia or refractory anemia with ringed sideroblasts display an altered cytokine profile.

Dendritic cells (DC) are pivotal for T cell-mediated immunity. We investigated the early and terminal maturation of monocyte-derived DC (MoDC) in myelodysplastic syndromes (FAB subtypes refractory anemia (MDS-RA) or refractory anemia with ringed sideroblasts (MDS-RARS)). Immature MoDC were obtained by culture of monocytes with GM-CSF and IL-4 for 8 days. To obtain mature MoDC, TNF-alpha was added during the final three culture days. T cell proliferation and T cell cytokine secretion in mixed lymphocyte reactions (MLR) unveiled a strong reduction of allostimulatory capacity of mature but also of immature MoDC from MDS patients. Immature MoDC from MDS patients exhibited an almost normal immunophenotype, but secreted substantially less IL-12 and more IL-10 in response to LPS/IFN-gamma than normal controls. Terminal addition of TNF-alpha to GM-CSF/IL-4 treated monocytes failed to extinguish cytokine production by MDS MoDC and failed to induce the expected membrane upregulation of costimulatory and other ligands as in normal controls. While our data provide further support for previous studies that have indicated an impaired differentiation of immature towards mature MoDC, they also clearly demonstrate a qualitatively and quantitatively altered cytokine secretion at the level of immature MoDC, which may in part explain the reduced allostimulatory capacity of these cells. These alterations may contribute to immune modulation of the clinical phenotype of marrow failure in MDS, and may have to be considered when designing DC-based immunotherapeutic strategies for MDS.

Anti-inflammatory activity of a pteridine derivative (4AZA2096) alleviates TNBS-induced colitis in mice.

Elevated production of tumor necrosis factor (TNF) plays a central role in the pathogenesis of many inflammatory diseases, such as rheumatoid arthritis and Crohn's disease. Naturally occurring pteridine analogs have been reported to have potent immunomodulatory activity, especially on TNF production. The aim of this study is to identify small molecule TNF inhibitiors derived from pteridine and to prove their in vivo efficacy in an inflammatory model. A focused chemical library based on the pteridine scaffold was screened in vitro on lipopolysaccharide (LPS)-induced TNF production in peripheral blood mononuclear cells (PBMC). One synthetic pteridine analog (4AZA2096), shown to have strong inhibitory activity, was selected and tested for its efficacy to treat trinitrobenzenesulfonate (TNBS)-induced colitis in mice, a model of Crohn's disease. Colitis was induced by rectal administration of 1 mg TNBS in 50% ethanol after presensitization via the skin. The synthetic pteridine analog 4AZA2096 was shown to potently inhibit LPS-induced TNF production in vitro. Colitic mice treated with 4AZA2096 orally (20 mg/kg/day) recovered more rapidly and, histologically, had a reduction of inflammatory lesions, less edema, a reduction of goblet cell loss, and reduced wall thickness. Cell infiltration in the colon, especially infiltration of neutrophils, as shown by myeloperoxidase (MPO) activity, was reduced in 4AZA2096-treated animals. Intralesional TNF production was lower in mice of the treated groups, whereas interleukin-18 (IL-18) and interferon-gamma (IFN-gamma) mRNA were not affected. Treatment had no effect on anti-TNBS antibody production, arguing against generalized immunosuppression. In conclusion, we identified a pteridine derivative, 4AZA2096, with strong inhibitory activity on TNF production and a remission- inducing effect in TNBS colitis, supporting further preclinical and clinical development of this novel TNF inhibitor for treatment of inflammatory diseases.

Blockade of CTLA-4 (CD152) enhances the murine antibody response to pneumococcal capsular polysaccharides.

The capsular polysaccharides (caps-PS) of Streptococcus pneumoniae are classified as thymus-independent antigens. Nevertheless, T lymphocytes can modulate the antibody response to caps-PS. In this study, we show that anticytotoxic T lymphocyte-associated antigen 4 (CTLA-4) treatment, along with administration of caps-PS to BALB/c mice, resulted in a dose-dependent generation of a strong caps-PS-specific antibody response. Anti-CTLA-4 treatment had no effect on the immunoglobulin G (IgG) antibody production in athymic nu/nu mice. Anti-CTLA-4 treatment stimulated the IgG antibody production in severe combined immunodeficiency (SCID)/SCID mice reconstituted with CTLA-4(-/-) B lymphocytes and wild-type T lymphocytes. This excluded the possibility that anti-CTLA-4 enhanced antibody production by direct interaction with B lymphocytes. Anti-CTLA-4 treatment enhanced the antibody production in SCID/SCID mice reconstituted with B lymphocytes and CD4(+) and CD8(+) T lymphocytes but not in SCID/SCID mice reconstituted with B lymphocytes in the absence of CD4(+) and/or CD8(+) cells. Administration of anti-CTLA-4 in BALB/c mice but not in nu/nu mice resulted in a markedly increased production of interleukin (IL)-2, IL-4, and interferon-gamma. Taken together, these data strongly suggest a role of T lymphocytes and CTLA-4 in the regulation of the antibody response to caps-PS.

Immunosuppressive parameters in serum of ovarian cancer patients change during the disease course.

Neoplastic cells can escape immune control leading to cancer growth. Regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC) and tumor-associated macrophages (TAM) are crucial in immune escape. TAM are divided based on their immune profile, M1 are immunostimulatory while M2 are immunosuppressive. Research so far has mainly focused on the intratumoral behavior of these cells. This study, on the other hand, explored the systemic changes of the key metabolites [IL-4 (interleukin), IL-13, arginase, IL-10, VEGF-A (vascular endothelial growth factor), CCL-2 (chemokine (C-C) motif ligand 2) and TGF-ß (transforming growth factor)] linked to Treg, MDSC and TAM during the course of the disease in ovarian and fallopian tube cancer patients. Serum samples were therefore analyzed at diagnosis, after (interval)-debulking surgery and after chemotherapy (paclitaxel-carboplatin). We also determined galectin-1 (gal-1), involved in angiogenesis and tumor-mediated immune evasion. We found significantly lower levels of IL-10, VEGF-A, TGF-ß and arginase and higher levels of gal-1 after chemotherapy compared to diagnosis. After debulking surgery, a decrease in IL-10 was significant. Gal-1 and CCL-2 appeared independent prognostic factors for progression-free and overall survival (OS) (multivariate analysis). These results will help us in the decision making of future therapies in order to further modulate the immune system in a positive way.

Acute shock induced by antigen vaccination in NOD mice.

Type 1 diabetes in NOD mice can be prevented through autoantigen vaccination by shifting lymphocyte differentiation toward a T-helper 2 (Th(2)) response. However, in other models of autoimmunity, this approach may be accompanied by unexpected triggering of Th(2)-dependent anaphylactic shock. To test the safety of vaccination therapy in the NOD mouse model, we evaluated the effects of immunization with a wide battery of antigens in NOD, BALB/c, and C57BL/6 mice. Surprisingly, a nondiabetogenic antigen, hen egg white lysozyme, induced severe shock exclusively in NOD mice (shock in 11 of 11 mice, lethal in 3 mice). Shock severity was further increased by a more pronounced Th(2) setting generated by 1alpha,25(OH)(2)D(3) administration (17 of 17 mice, lethal in 14 mice, P < 0.0001). Pretreatment with dexamethasone resulted in full rescue, indicating an immune-mediated mechanism. Serum IgE levels and Th(1)/Th(2) cytokine profile analysis showed that the shock phenomenon was paralleled by a Th(2) response. mRNA expression of platelet-activating factor receptor (PAF-R) was significantly higher in NOD mice (P < 0.01) and was further increased by 1alpha,25(OH)(2)D(3). Pretreatment with WEB2086 (PAF-R antagonist) again protected all mice from lethal shock, indicating PAF as an anaphylaxis effector. In conclusion, in NOD mice, vaccination leading to a Th(2) immune shift can result in a lethal anaphylactic reaction.

Low-grade systemic inflammation and the response to exercise training in patients with advanced COPD.

STUDY OBJECTIVE: Low-grade systemic inflammation may cause a chronic catabolic state that may affect trainability in patients with COPD as has been seen previously in healthy elderly. Therefore, the aim of the present study was to study the relationship between baseline circulating levels of inflammatory markers and the response to exercise training in clinically stable patients with COPD. DESIGN: An open prospective intervention study. SETTING: Tertiary care setting, University Hospital Gasthuisberg, Leuven, Belgium. PATIENTS: Seventy-eight clinically stable outpatients with COPD. INTERVENTION: A 12-week outpatient exercise-training program consisting of strengthening and endurance types of exercises. MEASUREMENTS AND RESULTS: Circulating levels of inflammatory markers were assessed at baseline. Moreover, lung function, quadriceps force (QF), peak and functional exercise capacity, and health-related quality of life were determined at baseline and after the intervention. Sixty-five of the 78 consecutive outpatients completed the study protocol. QF, peak and functional exercise capacity and health-related quality of life improved significantly compared to baseline. The absolute changes in health-related quality of life showed weak relationships with baseline circulating levels of interleukin-8 (CXCL8) in the whole group (n = 65; r= -0.26; p = 0.04). In addition, soluble tumor necrosis factor receptor p55 was strongly and positively related to the absolute changes in QF in the female patients only (n = 18; r = 0.81; p = 0.0001), while CXCL8 was inversely related to the absolute change in the total score of the Chronic Respiratory Disease Questionnaire (r= -0.65; p = 0.004). CONCLUSION: Baseline markers of low-grade systemic inflammation did not clearly explain the variances in absolute changes in QF, the distance walked in 6 min, peak external load, or health-related quality of life following a 12-week exercise-training program. Hence, they seem not very constructive in the characterization of patients with advanced COPD who do or do not respond to exercise training.

Inhibition of glycolipid biosynthesis by N-(5-adamantane-1-yl-methoxy-pentyl)-deoxynojirimycin protects against the inflammatory response in hapten-induced colitis.

Since glycolipid biosynthesis is potentially involved in immunological and inflammatory responses, we tested the effect of a novel inhibitor of intracellular glycolipid biosynthesis N-(5-adamantane-1-yl-methoxy-pentyl)-deoxynojirimycin (AMP-DNM) in two hapten-induced colitis models: trinitrobenzene sulphonic acid (TNBS)- and oxazolone (4-ethoxymethylene-2phenyl-2oxazoline-5-one; Oxa)-induced colitis. AMP-DNM was given either by intraperitoneal injection or orally via the diet. Mice treated with AMP-DNM had less severe colitis and a more rapid weight recovery, less edema and less wall thickness. Cellular infiltration, goblet cell loss and myeloperoxidase (MPO) activity were reduced in colons of AMP-DNM-treated animals. Intralesional IFN-gamma and IL-18 production were lower in mice of the AMP-DNM-treated groups. Furthermore, AMP-DNM treatment reduced the serum anti-TNBS and anti-Oxa antibody levels. Our findings show that the glycolipid biosynthesis inhibitor AMP-DNM has a strong anti-inflammatory and immune suppressive activity on both TNBS- and Oxa-induced colitis. The data also provide evidence that glycolipid biosynthesis is involved in the inflammatory cascade in these inflammatory bowel disease (IBD) models.

Pepsin and bile acids in induced sputum of chronic cough patients.

One of the theories which explain, why gastroesophageal reflux disease (GORD) may provoke cough, is the occurrence of aspiration of gastric content into the airways. The aim of the study was to assess the presence of aspiration markers: pepsin and bile acids (BA) in induced sputum in gastroesophageal reflux-related (GOR-related) chronic cough (CC) patients. Forty-one CC patients and 20 healthy controls were enrolled in the study. GORD as cause of CC was diagnosed by presence of GORD-related symptoms, gastroscopy and/or improvement of cough upon treatment with proton pump inhibitors (PPI). Patients were divided into two groups based on the response to PPI treatment. In all patients and healthy controls induced sputum was obtained and differential cell counts were calculated. Levels of pepsin and BA were measured in sputum supernatants. Pepsin was detectable in 48.8% samples in CC patients and in 60% healthy controls (p = NS). In pepsin positive samples no significant difference in pepsin concentration could be found between CC patients and control subjects. Pepsin levels in pepsin positive samples were significantly decreased in patients treated with PPI compared to non-treated patients. BA were detectable in 56% samples of CC patients and in 70% healthy controls (p = NS). BA concentration in BA positive samples in CC group was not different from healthy controls. There was also no difference when comparing patients who took PPI and those who did not. Patients characterized as PPI-responders and PPI-non-responders had similar pepsin and BA concentrations. Airway cellularity was not significantly different between groups of patients with or without pepsin or BA in induced sputum. Our results demonstrated the lack of differences in gastric content aspiration between patients with probable GOR-related CC and healthy control subjects. This might imply that the reflex cough theory may be more relevant than the reflux-associated aspiration theory in the pathophysiology of GORinduced chronic cough.

Murine bone marrow chimeras developing autoimmunity after CTLA-4-blockade show an expansion of T regulatory cells with an activated cytokine profile.

Autoimmune adverse events are a concern in patients treated with blocking anti-CTLA-4-mAb for solid and hematological tumors. Patient and mouse data on the contribution of a quantitative or qualitative defect of regulatory T cells (T(reg)) in this autoimmune phenomenon are conflicting. We have previously shown that a treatment course with blocking anti-CTLA-4-mAb in murine allogeneic bone marrow chimeras induces an antileukemic response in close association with systemic autoimmunity. Here, we used this model to investigate the effect of CTLA-4-blocking therapy on the kinetics of T(reg) frequency and function. As previously published, CTLA-4-blocking treatment, initiated on day 20 after bone marrow transplantation, led to overt autoimmunity by day 35. CD4(+)Foxp3(+) T(reg) frequency was determined (flowcytometry) on day 21, 23, 25 and 35: treated chimeras showed an expansion of CD4(+)Foxp3(+) T(reg) frequencies on day 25 and 35, without a prior frequency decrease. The T(reg) expansion occurred selectively in the recipient-derived CD4+ T-cell compartment. In vitro, purified CD4(+)CD25(+)FR4(high) T(reg) from 'day 35' autoimmune and control chimeras showed equal suppressive effects towards self-antigen-specific autoimmune T cells. Purified CD4(+)CD25(high)FR4(high) T(reg) from 'day 35' treated chimeras showed increased IL-10 and IFN-gamma mRNA-expression (RT-PCR) relative to control chimeras. In this model of CTLA-4-blockade-induced autoimmunity after allogeneic bone marrow transplantation, anti-CTLA-4-mAb gives rise to a progressive expansion - without a prior transient reduction - of T(reg) cells. T(reg) of autoimmune animals do not show a defect in in vitro suppressive function but show an in vivo activated cytokine profile, suggesting that the expansion occurs as a compensatory phenomenon to control autoimmunity.

Intravenous immunoglobulins in refractory childhood-onset epilepsy: effects on seizure frequency, EEG activity, and cerebrospinal fluid cytokine profile.

PURPOSE: Several studies have reported favorable effects of intravenous immunoglobulins (IVIG) in refractory epilepsy. Evidence substantiating an immunomodulatory action is scarce. In an open-label study, we prospectively investigated the effect of IVIG on clinical, EEG and serum/CSF immunological parameters in patients with refractory childhood-onset epilepsy. METHODS: Thirteen patients (median age 6.9 years; range 1.6-25.8) with refractory seizures despite 3-4 antiepileptic drug regimens were given IVIG (Sandoglobulin, ZLB-Behring, add-on, 4 x 400 mg/kg/3 weeks). Seizure frequency, 24-h video-EEG, and CSF/serum immunological parameters and cytokine profiles (IL-6/IL-8/IL-12/IL-10) were documented before and after completion of the course. RESULTS: Seizure frequency was reduced by > or = 50% in four, and by 25%-50% in three patients. In contrast, variation in automatically recorded spike counts (1-h-wake and -sleep) did not correlate with clinical improvement. Serum immunological parameters showed variable deviations in eight patients (e.g., IgG(2) deficiency) and CSF immunoblotting showed oligoclonal bands in two patients. Blood-brain barrier permeability was normal in 12 patients. IL-6 and IL-8 were clearly detectable in CSF of all patients; the levels were significantly higher than those in plasma but remained unaffected by IVIG treatment. CONCLUSIONS: Despite unchanged EEG spike counts, substantial reductions in seizure frequency occurred in 7 of 13 patients, suggesting that IVIG hinder progression of central epileptic activity into clinical seizures. Intrathecal presence of IL-8 and IL-6 was documented in all patients, but was unaffected by IVIG, suggesting that their production is directly related to electrical seizure activity and that IVIG may act through interference with immune pathways downstream to IL-6 and IL-8.

Acute inflammatory and anabolic systemic responses to peak and constant-work-rate exercise bout in hospitalized patients with COPD.

STUDY OBJECTIVES: To explore the acute systemic inflammatory and anabolic effects of cycling in hospital admitted patients with chronic obstructive pulmonary disease (COPD) and in patients with clinically stable disease. DESIGN: Cross-sectional comparative study. SETTING: University Hospital Gasthuisberg, a tertiary care setting. PATIENTS: 16 patients with clinically stable COPD (no acute exacerbation in the past 12 weeks; median age: 73 years (IQR: 60 to 75); median forced expiratory volume in the first second (FEV1): 45% predicted (IQR: 33 to 58)) and 14 patients who were admitted to a hospital due to an acute exacerbation of COPD (median age: 65 years (IQR: 59 to 74); median FEV1 on day 8 of hospital stay: 41% predicted (IQR: 33 to 54)). INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Circulating levels of C reactive protein, interleukin 6, interleukin 8 and insulin-like growth factor I were determined before, at the end and 2 and 30 minutes after a symptom-limited peak cycling test and before, at the end and 2 and 30 minutes after a symptom-limited constant-work-rate cycling test at 70% of the peak load. Non-significant changes in the circulating markers of inflammation and anabolism were found during or up to 30 minutes after ceasing the peak or constant-work-rate cycling exercise tests. The systemic responses of the hospitalized patients with COPD did not differ from those with clinically stable disease. CONCLUSIONS: High-intensity cycling exercises did not increase the circulating levels of inflammatory markers in patients with chronic obstructive pulmonary disease, irrespective of their clinical stability.