Cholesterol ester transfer protein inhibition by TA-8995 in patients with mild dyslipidaemia (TULIP): a randomised, double-blind, placebo-controlled phase 2 trial.

BACKGROUND: Dyslipidaemia remains a significant risk factor for cardiovascular disease and additional lipid-modifying treatments are warranted to further decrease the cardiovascular disease burden. We assessed the safety, tolerability and efficacy of a novel cholesterol esterase transfer protein (CETP) inhibitor TA-8995 in patients with mild dyslipidaemia. METHODS: In this randomised, double-blind, placebo-controlled, parallel-group phase 2 trial, we recruited patients (aged 18-75 years) from 17 sites (hospitals and independent clinical research organisations) in the Netherlands and Denmark with fasting LDL cholesterol levels between 2·5 mmol/L and 4·5 mmol/L, HDL cholesterol levels between 0·8 and 1·8 mmol/L and triglyceride levels below 4·5 mmol/L after washout of lipid-lowering treatments. Patients were randomly allocated (1:1) by a computer-generated randomisation schedule to receive one of the following nine treatments: a once a day dose of 1 mg, 2·5 mg, 5 mg, or 10 mg TA-8995 or matching placebo; 10 mg TA-8995 plus 20 mg atorvastatin; 10 mg TA-8995 plus 10 mg rosuvastatin or 20 mg atorvastatin or 10 mg rosuvastatin alone. We overencapsulated statins to achieve masking. The primary outcome was percentage change in LDL cholesterol and HDL cholesterol from baseline at week 12, analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01970215. FINDINGS: Between Aug 15, 2013, and Jan 10, 2014, 364 patients were enrolled. At week 12, LDL cholesterol levels were reduced by 27·4% in patients assigned to the 1 mg dose, 32·7% in patients given the 2·5 mg dose, 45·3% in those given the 5 mg dose, and 45·3% in those given the 10 mg dose (p<0·0001). LDL cholesterol levels were reduced by 68·2% in patients given 10 mg TA-8995 plus atorvastatin, and by 63·3% in patients given rosuvastatin plus 10 mg TA-8995 (p<0·0001). A daily dose of 1 mg TA-8995 increased HDL cholesterol levels by 75·8%, 2·5 mg by 124·3%, 5 mg by 157·1%, and 10 mg dose by 179·0% (p<0·0001). In patients receiving 10 mg TA-8995 and 20 mg atorvastatin HDL cholesterol levels increased by 152·1% and in patients receiving 10 mg TA-8995 and 10 mg rosuvastatin by 157·5%. We recorded no serious adverse events or signs of liver or muscle toxic effects. INTERPRETATION: TA-8995, a novel CETP inhibitor, is well tolerated and has beneficial effects on lipids and apolipoproteins in patients with mild dyslipidaemia. A cardiovascular disease outcome trial is needed to translate these effects into a reduction of cardiovascular disease events. FUNDING: Dezima.

Adenosine triphosphate-binding cassette transporter genes up-regulation in untreated hepatocellular carcinoma is mediated by cellular microRNAs.

UNLABELLED: Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are drug efflux pumps responsible for the multidrug resistance phenotype causing hepatocellular carcinoma (HCC) treatment failure. Here we studied the expression of 15 ABC transporters relevant for multidrug resistance in 19 paired HCC patient samples (16 untreated, 3 treated by chemotherapeutics). Twelve ABC transporters showed up-regulation in HCC compared with adjacent healthy liver. These include ABCA2, ABCB1, ABCB6, ABCC1, ABCC2, ABCC3, ABCC4, ABCC5, ABCC10, ABCC11, ABCC12, and ABCE1. The expression profile and function of some of these transporters have not been associated with HCC thus far. Because cellular microRNAs (miRNAs) are involved in posttranscriptional gene silencing, we hypothesized that regulation of ABC expression in HCC might be mediated by miRNAs. To study this, miRNAs were profiled and dysregulation of 90 miRNAs was shown in HCC compared with healthy liver, including up-regulation of 11 and down-regulation of 79. miRNA target sites in ABC genes were bioinformatically predicted and experimentally verified in vitro using luciferase reporter assays. In total, 13 cellular miRNAs were confirmed that target ABCA1, ABCC1, ABCC5, ABCC10, and ABCE1 genes and mediate changes in gene expression. Correlation analysis between ABC and miRNA expression in individual patients revealed an inverse relationship, providing an indication for miRNA regulation of ABC genes in HCC. CONCLUSION: Up-regulation of ABC transporters in HCC occurs prior to chemotherapeutic treatment and is associated with miRNA down-regulation. Up-regulation of five ABC genes appears to be mediated by 13 cellular miRNAs in HCC patient samples. miRNA-based gene therapy may be a novel and promising way to affect the ABC profile and overcome clinical multidrug resistance.

Indian Hedgehog is an antagonist of Wnt signaling in colonic epithelial cell differentiation.

Wnt signaling defines the colonic epithelial progenitor cell phenotype, and mutations in the gene adenomatous polyposis coli (APC) that activate the Wnt pathway cause the familial adenomatous polyposis coli (FAP) syndrome and most sporadic colon cancers. The mechanisms that regulate the transition of epithelial precursor cells into their differentiated derivatives are poorly characterized. We report that Indian hedgehog (Ihh) is expressed by mature colonocytes and regulates their differentiation in vitro and in vivo. Hedgehog (Hh) signaling restricts the expression of Wnt targets to the base of the colonic crypt in vivo, and transfection of Ihh into colon cancer cells leads to a downregulation of both components of the nuclear TCF4-beta-catenin complex and abrogates endogenous Wnt signaling in vitro. In turn, expression of Ihh is downregulated in polyps of individuals with FAP and expression of doxycycline-inducible dominant negative TCF4 (dnTCF4) restores Ihh expression in APC mutant DLD-1 colon cancer cells. These data identify a new Wnt-Hh axis in colonic epithelial renewal.

Induction of antigen-specific tolerance by oral administration of Lactococcus lactis delivered immunodominant DQ8-restricted gliadin peptide in sensitized nonobese diabetic Abo Dq8 transgenic mice.

Active delivery of recombinant autoantigens or allergens at the intestinal mucosa by genetically modified Lactococcus lactis (LL) provides a novel therapeutic approach for the induction of tolerance. Celiac disease is associated with either HLA-DQ2- or HLA-DQ8-restricted responses to specific antigenic epitopes of gliadin, and may be treated by induction of Ag-specific tolerance. We investigated whether oral administration of LL-delivered DQ8-specific gliadin epitope induces Ag-specific tolerance. LL was engineered to secrete a deamidated DQ8 gliadin epitope (LL-eDQ8d) and the induction of Ag-specific tolerance was studied in NOD AB degrees DQ8 transgenic mice. Tolerance was assessed by delayed-type hypersensitivity reaction, cytokine measurements, eDQ8d-specific proliferation, and regulatory T cell analysis. Oral administration of LL-eDQ8d induced suppression of local and systemic DQ8-restricted T cell responses in NOD AB degrees DQ8 transgenic mice. Treatment resulted in an Ag-specific decrease of the proliferative capacity of inguinal lymph node (ILN) cells and lamina propria cells. Production of IL-10 and TGF-beta and a significant induction of Foxp3(+) regulatory T cells were associated with the eDQ8d-specific suppression induced by LL-eDQ8d. These data provide support for the development of effective therapeutic approaches for gluten-sensitive disorders using orally administered Ag-secreting LL. Such treatments may be effective even in the setting of established hypersensitivity.

Longitudinal Assessment of Lipoprotein(a) Levels in Perinatally HIV-Infected Children and Adolescents.

HIV is an independent risk factor of cardiovascular disease (CVD); therefore, perinatally HIV-infected (PHIV) children potentially have a greater CVD risk at older age. Lipoprotein(a) (Lp(a)) is an established risk factor for CVD in the general population. To evaluate a potential increased CVD risk for PHIV children, we determined their lipid profiles including Lp(a). In the first substudy, we assessed the lipid profiles of 36 PHIV children visiting the outpatient clinic in Amsterdam between 2012 and 2020. In the second substudy, we enrolled 21 PHIV adolescents and 23 controls matched for age, sex and ethnic background on two occasions with a mean follow-up time of 4.6 years. We assessed trends of lipid profiles and their determinants, including patient and disease characteristics, using mixed models. In the first substudy, the majority of PHIV children were Black (92%) with a median age of 8.0y (5.7-10.8) at first assessment. Persistent elevated Lp(a) levels were present in 21/36 (58%) children (median: 374 mg/L (209-747); cut off = 300). In the second substudy, the median age of PHIV adolescents was 17.5y (15.5-20.7) and of matched controls 16.4y (15.8-19.5) at the second assessment. We found comparable lipid profiles between groups. In both studies, increases in LDL-cholesterol and total cholesterol were associated with higher Lp(a) levels. A majority of PHIV children and adolescents exhibited elevated Lp(a) levels, probably associated with ethnic background. Nonetheless, these elevated Lp(a) levels may additionally contribute to an increased CVD risk.

Bone morphogenetic protein signaling suppresses tumorigenesis at gastric epithelial transition zones in mice.

Bone morphogenetic protein (BMP) signaling is known to suppress oncogenesis in the small and large intestine of mice and humans. We examined the role of Bmpr1a signaling in the stomach. On conditional inactivation of Bmpr1a, mice developed neoplastic lesions specifically in the squamocolumnar and gastrointestinal transition zones. We hypothesized that the regulation of epithelial cell fate may be less well defined in these junctional zones than in the adjacent epithelium and found that the mucosa at the squamocolumnar junction in mice shows a lack of differentiated fundic gland cell types and that foveolar cells at the gastrointestinal junctional zone lack expression of the foveolar cell marker Muc5ac. Precursor cell proliferation in both transition zones was higher than in the surrounding epithelium. Our data show that BMP signaling through Bmpr1a suppresses tumorigenesis at gastric epithelial junctional zones that are distinct from the adjacent gastric epithelium in both cellular differentiation and proliferation.

Elevated Lipoprotein(a) in Perinatally HIV-Infected Children Compared With Healthy Ethnicity-Matched Controls.

BACKGROUND: HIV-associated cardiovascular disease (CVD) risk in combination antiretroviral therapy (cART)-treated perinatally HIV-infected patients (PHIV+) remains unknown due to the young age of this population. Lipoprotein(a) (Lp(a)) has been established as an independent causal risk factor for CVD in the general population but has not been well established in the population of PHIV+. METHODS: We cross-sectionally compared lipid profiles, including nonfasting Lp(a), together with total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides between 35 cART-treated PHIV+ children aged 8-18 years and 37 controls who were matched for age, sex, ethnicity, and socioeconomic status. We explored associations between Lp(a) and disease- and treatment-related factors (inflammation, monocyte activation, and vascular), biomarkers, and neuroimaging outcomes using linear regression models. RESULTS: PHIV+ children had significantly higher levels of Lp(a) compared with controls (median, 43.6 [21.6-82.4] vs 21.8 [16.8-46.6] mg/dL; P = .033). Other lipid levels were comparable between groups. Additional assessment of apolipoprotein B, apolipoprotein CIII, apolipoprotein E, and APOE genotype revealed no significant differences. Higher Lp(a) levels were associated with higher plasma apoB levels and with lower monocyte chemoattractant protein-1 and TG levels in PHIV+ children. Lp(a) was not associated with HIV- or cART-related variables or with neuroimaging outcomes. CONCLUSIONS: cART-treated PHIV+ children appear to have higher levels of Lp(a) compared with ethnicity-matched controls, which may implicate higher CVD risk in this population. Future research should focus on the association between Lp(a) and (sub)clinical CVD measurements in cART-treated PHIV+ patients. DUTCH TRIAL REGISTER NUMBER: NRT4074.

Alterations in lipoprotein homeostasis during human experimental endotoxemia and clinical sepsis.

Cell wall constituents of bacteria are potent endotoxins initiating inflammatory responses which may cause dramatic changes in lipid metabolism during the acute phase response. In this study, the sequential changes in lipoprotein composition and lipid transfer and binding proteins during clinical sepsis and during low-dose experimental endotoxemia were followed. In addition, the effect on (phospho)lipid homeostasis by administration of reconstituted HDL (rHDL) prior to low-dose LPS administration was investigated. Changes in (apo)lipoprotein concentrations typical of the acute phase response were observed during clinical sepsis and experimental endotoxemia with and without the rHDL intervention. During clinical sepsis negative correlations between the acute phase marker C-reactive protein (CRP) and lecithin:cholesterol acyltransferase (LCAT) and cholesterylester transfer protein (CETP) activities were seen, whereas positive correlations between plasma phospholipid transfer protein (PLTP) activity and acute phase markers such as CRP and LPS binding protein were observed. Plasma lipid changes upon rHDL/LPS infusion were comparable with the control group (low-dose LPS only). PLTP activity decreased upon LPS infusion and transiently increased during rHDL infusion, whereas LCAT activity slightly decreased upon both LPS infusion and LPS/rHDL infusion. However, long-lasting increases of circulating HDL cholesterol, apo A-I and a high initial processing of both phosphatidylcholine (PC) and lyso-PC, were indicative for extensive rHDL and LDL remodelling. Both sepsis and experimental endotoxemia lead to a disbalance of lipid homeostasis. Depending on the magnitude of the inflammatory stimulus, LCAT and PLTP activities reacted in divergent ways. rHDL infusion did not prevent the lipid alterations seen during the acute phase response. However profound changes in both HDL and LDL phospholipid composition occurred upon rHDL infusion. This may be explained, at least in part, by the fact that PLTP as a positive acute phase protein, can accelerate the alterations in (phospho)lipid homeostasis thereby playing a role in the attenuation of the acute phase response.

Arginine deficiency affects early B cell maturation and lymphoid organ development in transgenic mice.

Apart from its role in the synthesis of protein and nitric oxide (NO), and in ammonia detoxification, the amino acid arginine exerts an immunosupportive function. We have studied the role of arginine in immune defense mechanisms in the developing postnatal immune system. In suckling mice, arginine is produced in the small intestine. In F/A-2(+/+) transgenic mice, which overexpress arginase in their enterocytes, circulating and tissue arginine concentrations are reduced to 30-35% of controls. In these mice, the development and composition of the T cell compartment did not reveal abnormalities. However, in peripheral lymphoid organs and the small intestine, B cell cellularity and the number and size of Peyer's patches were drastically reduced, and serum IgM levels were significantly decreased. These phenotypes could be traced to an impaired transition from the pro- to pre-B cell stage in the bone marrow. Cytokine receptor levels in the bone marrow were normal. The development of the few peripheral B cells and their proliferative response after in vitro stimulation was normal. The disturbance in B cell maturation was dependent on decreased arginine levels, as this phenotype disappeared upon arginine supplementation and was not seen in NO synthase- or ornithine transcarbamoylase-deficient mice. We conclude that arginine deficiency impairs early B cell maturation.

An improved protocol for generation of immuno-potent dendritic cells through direct electroporation of CD14+ monocytes.

In this study we demonstrate a novel protocol showing that electroporation of CD14+ monocytes directly isolated from blood with green fluorescent protein (GFP) RNA results in a 3-fold higher yield of antigen presenting dendritic cells (DCs) when compared to conventional methods employing immature DCs for electroporation. We further show a stable electroporation efficacy resulting in 60% of GFP positive cells. Expression of co-stimulatory molecules and maturation markers such as CD80, CD86, CD83 as well of the chemokine receptor 7 (CCR7) was found in 90% of the mature DCs. Importantly, production of IL-12p70 was 10 times higher in cells electroporated at the monocyte stage compared to cells electroporated at the immature DC stage. Stimulation of autologous naïve lymphocytes by DCs electroporated at monocytes stage elicited proliferation of CD8+ T-cell with 7-fold increase in IFN-gamma release. Blocking of the MHC-Class I molecules significantly inhibited the IFN-gamma release, indicating that antigen presentation was MHC-Class I mediated. In summary, electroporation of CD14+ monocytes with RNA results in a high yield of antigen presenting DCs with high immuno-stimulatory capacity and antigen presentation on MHC-Class I molecules. This improved method may represent an attractive approach for RNA-based DC immunotherapy.

Comparative analysis of colonic gene expression of three experimental colitis models mimicking inflammatory bowel disease.

BACKGROUND: Mouse models of inflammatory bowel diseases (IBD) are used to unravel the pathophysiology of IBD and to study new treatment modalities, but their relationship to Crohn's disease (CD) or ulcerative colitis (UC) is speculative. METHODS: Using Agilent mouse TOX oligonucleotide microarrays, we analyzed colonic gene expression profiles in three widely used models of experimental colitis. In 2 of the models (TNBS and DSS-induced colitis), exogenous agents induce the colitis. In the third model the colitis is induced after transfer of a T-cell population (CD4(+)CD45RB(high) T cells) that lacks regulatory cells into an immunodeficient host. RESULTS: Compared with control mice, in DSS, TNBS, and the CD45RB transfer colitis mice, 387, 21, and 582 genes were more than 2-fold upregulated in the intestinal mucosa. Analyses of exclusively shared gene expression profiles between the different models revealed that DSS/transfer colitis share 69 concordantly upregulated genes, DSS/TNBS 6, and TNBS/transfer colitis 1. Seven genes were upregulated in all three models. The CD45RB transfer model expression profile included the most genes that are known to be upregulated in IBD. Of 32 genes that are known to change transcriptional activity in IBD (TNF, IFN-gamma, Ltbeta, IL-6, IL-16, IL-18R1, IL-22, CCR2, 7, CCL2, 3, 4, 5, 7, 11, 17, 20, CXCR3, CXCL1, 5, 10, Mmp3, 7,9, 14, Timp1, Reg3gamma, and Pap, S-100a8, S-100a9, Abcb1, and Ptgs2), 2/32 are upregulated in TNBS, 15/32 are upregulated or downregulated in DSS and 30/32 are upregulated or downregulated in the CD45RB transfer colitis. CONCLUSION: The pattern of gene expression in the CD45RB transfer model most closely reflects altered gene expression in IBD.

Infliximab use in children and adolescents with inflammatory bowel disease.

Infliximab is a chimeric monoclonal antibody (75% human, 25% murine) against tumor necrosis factor-alpha, a cytokine with a central role in the pathogenesis of inflammatory bowel disease. Large randomized controlled trials have shown the efficacy and safety of infliximab for the induction and maintenance of remission in adult patients with active Crohn disease (CD). In children and adolescents, mostly small, nonrandomized, non-placebo-controlled studies have supported the notion that infliximab is a potent drug in a population that does not respond to standard therapies. The safety of infliximab is of major concern, and the most frequent severe adverse events are related to severe infections and reactivation of tuberculosis. Non-life-threatening infusion reactions occur rather frequently and seem to be related to the formation of antibodies. The indications for infliximab treatment are therapy-resistant luminal CD (no efficacy or insufficient efficacy of conventional treatment) and therapy-resistant fistulas. An efficient remission induction strategy consists of 3 initial infliximab infusions at 0, 2, and 6 weeks in a dosage of 5 mg/kg to sustain remission. Patients needing maintenance therapy are subsequently treated with an infliximab infusion every 8 weeks. There are indications that the early stages of CD may be more susceptible to immunomodulation, and the natural history of CD may be altered by the introduction of infliximab early in the disease process instead of waiting until conventional therapy has failed. Major points of discussion are whether infliximab maintenance treatment should be episodic (on demand) or scheduled and when infliximab therapy can be discontinued.

Effects of the cholesteryl ester transfer protein inhibitor, TA-8995, on cholesterol efflux capacity and high-density lipoprotein particle subclasses.

BACKGROUND: TA-8995 is a potent inhibitor of cholesteryl ester transfer protein (CETP) with beneficial effects on lipids and lipoproteins. The effect of TA-8995 on cholesterol efflux capacity (CEC), a measure of high-density lipoprotein (HDL) function, and HDL subparticle distribution is largely unknown. OBJECTIVE: To assess the effect of the CETP inhibitor TA-8995 on ABCA1- and non-ABCA1-driven CEC and on HDL particle distribution. METHODS: Total, non-ABCA1-, and ABCA1-specific CEC from J774 cells and HDL subclass distribution assessed by two-dimensional gel electrophoresis were measured at baseline and after 12-week treatment in 187 mild-dyslipidemic patients randomized to placebo, 1 mg, 5 mg, 10 mg TA-8995, or 10 mg TA-8995 combined with 10 mg rosuvastatin (NCT01970215). RESULTS: Compared with placebo, total, non-ABCA1-, and ABCA1-specific CEC were increased dose dependently by up to 38%, 72%, and 28%, respectively, in patients randomized to 10 mg of TA-8995. PreBeta-1 HDL, the primary acceptor for ABCA1-driven cholesterol efflux, was increased by 36%. This increase in preBeta-1 HDL correlated significantly with the total and the ABCA1-driven CEC increase, whereas the high-density lipoprotein cholesterol (HDL-C) increase did not. CONCLUSION: TA-8995 dose dependently increased not only total and non-ABCA1-specific CEC but also ABCA1-specific CEC and preBeta-1 HDL particle levels. These findings suggest that TA-8995 not only increases HDL-C levels but also promotes functional properties of HDL particles. This CETP inhibitor-driven preBeta-1 HDL increase is an important predictor of both ABCA1 and total CEC increase, independent of HDL-C increase. Whether these changes in HDL particle composition and functionality have a beneficial effect on cardiovascular outcome requires formal testing in a cardiovascular outcome trial.

Dedicated pinhole SPECT of intestinal neutrophil recruitment in a mouse model of dextran sulfate sodium-induced colitis.

UNLABELLED: Evaluating the efficacy of therapy in experimental inflammatory bowel disease (IBD) requires information about inflammatory activity in bowel segments or leukocyte recruitment and about kinetics in the follow-up of treatment. This study evaluated a noninvasive scintigraphic technique able to assess neutrophil trafficking in a mouse model of dextran sulfate sodium (DSS)-induced colitis. METHODS: Groups of 4 BALB/c mice were assessed at baseline and after 1, 3, 5, and 8 d of treatment with DSS. Donor neutrophils were harvested by rinsing of the peritoneal cavity with phosphate-buffered saline 5 h after intraperitoneal injection of proteose peptone contained in phosphate-buffered saline and labeled with freshly prepared (99m)Tc-hexamethylpropylene amine oxime (HMPAO). Pinhole SPECT of the abdomen was performed 1 h after reinjection of 50 MBq of labeled neutrophils. In addition, the severity of inflammation was determined by histologic examination. The possibilities of the technique were illustrated by scintigraphic assessment of neutrophil trafficking with and without blocking of neutrophil migration by a CD97 monoclonal antibody in mice with DSS-induced colitis. RESULTS: Colonic uptake of (99m)Tc-HMPAO neutrophils was determined with dedicated animal pinhole SPECT in mice with DSS-induced colitis and correlated well with histologic findings (R = 0.81) and wet colon weight (R = 0.87) and moderately with clinical weight loss (R = 0.62). The neutrophil uptake ratio was reduced significantly (P < 0.01) by blocking of neutrophil migration capacity with the CD97 antibody. CONCLUSION: Animal pinhole SPECT can be used to study inflammatory activity and neutrophil recruitment in vivo in experimental colitis.

Dichotomy between Lactobacillus rhamnosus and Klebsiella pneumoniae on dendritic cell phenotype and function.

The reaction of the intestinal immune system to intestinal bacteria shows striking differences between various bacterial strains. Whereas Klebsiella pneumoniae induces a fierce proinflammatory reaction, the probiotic strain Lactobacillus rhamnosus has clear anti-inflammatory effect in gastrointestinal disease and allergy. The molecular basis for this dichotomy is poorly understood but is likely to involve different modulation of antigen-presenting dendritic cells (DC) by L. rhamnosus and K. pneumoniae. Hence we evaluated phenotypic and functional characteristics of DC matured in the presence of L. rhamnosus and K. pneumoniae. Monocyte-derived immature DC were cultured in the presence of live bacteria to obtain mature DC. Both micro-organisms induced maturation of immature DC as shown by CD83 and CD86 expression, but receptors involved in activation of Th1 cells were expressed predominantly on DC exposed to K. pneumoniae. In contrast to K. pneumoniae, maturation with L. rhamnosus resulted in lower TNF-alpha, IL-6, and IL-8 production by immature DC and lower IL-12 and IL-18 production by mature DC. Moreover, L. rhamnosus led to the development of T cells without a typical Th phenotype whereas K. pneumoniae induced a Th1 immune response, dependent mainly on IL-12 production. Thus our results strongly support the concept that differential modulation of DC explains the differences in the immune response to various bacterial strains and indicates that K. pneumoniae induces Th1 immune responses via DC.

Expression of CD45RB functionally distinguishes intestinal T lymphocytes in inflammatory bowel disease.

The importance of CD45RB expression on T cells was already shown in mice where CD45RB(high) expression determines pathogenic potential. In this study, we analyzed the expression of CD45RA, CD45RB, and CD45RO on CD4(+) T lymphocytes in the intestinal mucosa and in the circulation of patients with inflammatory bowel disease (IBD). In addition, we studied the cytokine profile of these cells. In the circulation, virtually all CD4(+)CD45RB(high) T cells expressed the naive marker CD45RA, and circulating CD4(+)CD45RB(low) cells expressed the memory marker CD45RO in IBD patients and a control patient population. In contrast, the intestinal CD4(+) CD45RB(high) T cells are in normal controls for 90% CD45RO(+). However, in IBD, 27.7% [Crohn's disease (CD)] and 49% [ulcerative colitis (UC)] of the intestinal CD4(+) CD45RB(high) T cells are CD45RA(+). This special CD4CD45RA(+) T cell in IBD can be found in the lamina propria as well as in lymphoid follicles (confocal laser-scanning microscopy). The CD4(+)CD45RB(high) T lymphocytes produce significantly less interleukin (IL)-10 and IL-4 and produce more tumor necrosis factor alpha than CD45RB(low) T lymphocytes in control patients. CD4(+)CD45RB(low) T cells from IBD patients produced less IL-10 than CD4(+)CD45RB(low) T lymphocytes of controls, and interferon-gamma production by both T lymphocyte subsets was decreased in IBD. These data indicate that CD and UC are characterized by an influx of CD4(+)CD45RB(high) T lymphocytes. These CD4(+)CD45RB(high) T lymphocytes seem to be important in the pathogenesis of IBD, as they produce more proinflammatory cytokines and less anti-inflammatory cytokines compared with CD4(+)CD45RB(low) T lymphocytes.

In vivo evaluation of 111In-labeled T-lymphocyte homing in experimental colitis.

UNLABELLED: Blockade of lymphocyte recruitment to the intestinal mucosa is considered a useful therapy for inflammatory bowel disease (IBD) and anti-alpha4 antibodies have clinical benefit in patients with active Crohn's disease. The aim of this study was to evaluate a scintigraphic technique to assess lymphocyte homing to the colon in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced experimental colitis (TNBS colitis) in vivo. METHODS: TNBS-sensitized and nonsensitized murine total lymphocytes or CD4+ lymphocytes were radiolabeled with 111In-oxinate. Cells were injected into control mice (n = 5) or mice with TNBS colitis (n = 5). Specific abdominal radioactive uptake was determined by SPECT using a dedicated pinhole system 48 h after cell transfer. Radioactive colon uptake was correlated with histology and colon weight as parameters of inflammation. RESULTS: The radioactive colon uptake was most evident in mice with TNBS colitis that received sensitized lymphocytes (uptake ratio [mean +/- SEM], 0.51 +/- 0.03 vs. 0.22 +/- 0.04; P = 0.004). The sensitized 111In-labeled lymphocytes exacerbated colitis compared with nonsensitized lymphocytes. The colon uptake correlated well with both colon weight and histologic score (R2 = 0.836 and 0.933, respectively). The use of purified 111In labeled CD4+ lymphocytes resulted in a similar scintigraphic pattern. Administration of an anti-alpha4 antibody decreased radioactivity colon uptake of the (111)In-labeled cells compared with the control antibody in mice with TNBS colitis (uptake ratio, 0.72 +/- 0.14 to 0.33 +/- 0.03; P = 0.012). CONCLUSION: Animal pinhole SPECT can be applied for temporal and spatial analysis of the lymphocyte homing process in experimental colitis. This technique makes possible the in vivo evaluation of therapeutic efficacy of new drugs that interfere with lymphocyte migration. Moreover, colon uptake of radioactivity can be used as a parameter of disease activity in experimental colitis.

CXC-chemokines KC and macrophage inflammatory protein-2 (MIP-2) synergistically induce leukocyte recruitment to the central nervous system in rats.

Intracisternal injection of the CXC-chemokines KC or macrophage inflammatory protein (MIP)-2 induced a pleocytosis in the cerebrospinal fluid (CSF) of rats in a dose dependent way. MIP-2 was much more potent than KC. The concurrent injection of both chemokines revealed a profound synergistic effect on leukocyte recruitment into CSF.

The pathogenicity of cytomegalovirus in inflammatory bowel disease: a systematic review and evidence-based recommendations for future research.

During recent years, a clear association between complicated courses of ulcerative colitis and the presence of cytomegalovirus (CMV) has been established. The exact pathogenic role of CMV in these patients remains unclear despite a great number of published reports. Therefore, we undertook a systematic review to appraise critically all available evidence in the literature on the role of CMV during inflammatory bowel disease. We identified and analyzed more than 30 case reports and 9 case series. Based on these results, we propose a model for viral replication during inflammation and provide recommendations for future research.

Infliximab treatment for Crohn's disease: one-year experience in a Dutch academic hospital.

The aim of this study was to report the 1-year clinical experience with infliximab treatment for Crohn's disease (CD) in the Netherlands. All 73 CD patients receiving infliximab infusions were prospectively followed during 1 year after the drugs' registration in the Netherlands. Clinical response and adverse events were assessed for both active luminal disease as well as fistulous disease. A total of 212 infusions were administered to 57 patients with active luminal CD and 16 patients with fistulous CD. The mean duration between infusions was 60 days. In 17% of patients, adverse events were recorded, of which one was serious. The response rate was 81% in active luminal CD and 87% in fistulous disease. Response rates were highest in patients receiving concomitant methotrexate as maintenance therapy. Steroids could successfully be tapered off in 73% of responding luminal CD patients and 100% of responding CD patients with fistulae. Eleven patients showed a loss of response to continuous infliximab readministration. Our clinical experience with infliximab for active luminal and fistulous CD showed that the administration is safe, effective, and has high steroid-sparing efficacy. Higher response rates were seen with methotrexate as concomitant medication.