Impact of toll-like-receptor-9 (TLR9) deficiency on visceral adipose tissue adipokine expression during chronic DSS-induced colitis in mice.

BACKGROUND: Studies postulate an involvement of adipokines in inflammatory gastrointestinal diseases. Leptin-deficient ob/ob mice as well as TLR9-deficient mice have a more moderate course of chronic DSS-induced colitis (DSS-CC) and adipocytes do express functional TLR9 molecules. MATERIAL AND METHODS: Adipokine mRNA expression in visceral adipose tissue of mice before and after the induction of DSS-CC was investigated. Experiments were performed in both TLR9(wt/wt) and TLR9(-/-) mice. In vitro, the effect of TLR9 blocking peptide on leptin and visfatin protein secretion was studied in 3T3-L1 adipocytes. RESULTS: Induction of DSS-CC led to an upregulation of leptin mRNA expression in TLR9(wt/wt) mice, while TLR9(-/-) animals showed a significant reduction of leptin expression even below baseline. While visfatin expression remained unchanged in TLR9(wt/wt) animals, TLR9(-/-) mice exhibited a significant induction during DSS-CC. CTRP-3 expression was reduced after colitis induction only in TLR9(-/-) animals. Of note, IL-6 expression levels remained unchanged, while CXCL1/KC and cyclophilin A expression was reduced in DSS-CC. Inhibition of TLR9 signaling by using TLR9 blocking peptide led to reduced leptin protein secretion into cell culture supernatants in 3T3-L1 adipocytes, while visfatin protein secretion was enhanced. CONCLUSIONS: DSS-CC leads to differential adipokine expression profiles in the visceral fat pad in TLR9(wt/wt) vs. TLR9(-/-) mice. In vitro, inhibition of TLR9 signaling induces visfatin secretion while inhibiting leptin secretion in adipocytes. Thus, visceral adipokines are regulated by intact TLR9 signaling pathway and a specific interplay between the leptin- and the TLR9-pathways might be of pathophysiological importance in chronic intestinal inflammation.

Systemic metabolic signaling in acute and chronic gastrointestinal inflammation of inflammatory bowel diseases.

Acute and chronic intestinal inflammation stimulates innate and adaptive immune systems, thereby increasing energy demand of activated immune cells. Energy regulation by systemically released mediators is of critical importance for homeostasis. We wanted to find out how systemic metabolic mediators are affected during intestinal inflammation. A total of 123 patients suffering from Crohn's disease (CD), 76 patients with ulcerative colitis (UC), and 21 healthy controls were recruited. Patients receiving systemic steroids or therapy regimens including biologicals (anti-TNF) were excluded from the study. Serum levels of IL-6, CRP, insulin, glucose, free fatty acid, and RBP-4 were measured by ELISA and RIA. Intestinal inflammation was accompanied by elevated systemic inflammatory para-meters such as IL-6 and CRP in UC and CD and, concomitantly, with elevated insulin levels and increased insulin/glucose ratio in patients with UC. This indicates insulin resistance in liver, muscle, and fat. In addition, intestinal inflammation was associated with elevated levels of circulating free fatty acids in UC and CD, indicating an activation of the organism's appeal for energy-rich substrates (energy appeal reaction). RBP-4 serum levels were also high in acute and chronic intestinal inflammation in UC and CD, which can support insulin resistance. The organism's "energy appeal reaction" in response to acute and chronic inflammation provides free energy in the circulation, which is needed by inflammatory cells. A major mechanism of the redirection program is insulin resistance. New therapeutic strategies might be developed in the future, directly impacting on the storage and utilization of energy-rich fuels.

Downregulation of the ubiquitin-proteasome system in normal colonic macrophages and reinduction in inflammatory bowel disease.

BACKGROUND: In normal mucosa, intestinal lamina propria macrophages (IMACs) maintain tolerance against food antigens and the commensal bacterial flora. Several mechanisms have been identified that mediate tolerance. The ubiquitin-proteasome system (UPS) is a large multiprotein complex that degrades cellular proteins. As the UPS may modulate immune functions of IMACs, we performed a detailed investigation of UPS expression and function under normal conditions and in cells derived from patients suffering from inflammatory bowel disease (IBD). METHODS: IMACs were isolated from intestinal mucosa. mRNA expression of macrophages differentiated in vitro (i.v. MACs) and IMACs was compared by Affymetrix® oligonucleotide arrays. Quantitative Taqman-PCR was performed on five exemplary proteasomal and five ubiquitinylation genes each. Proteins were analyzed by immunohistochemistry and Western blotting. Proteasome function was assessed by a fluorimetric test. RESULTS: Affymetrix analysis showed downregulation of mRNA expression of almost all represented proteasomal and of 22 ubiquitination-associated genes in IMACs as compared to i.v. MACs and monocytes. By quantitative PCR, up to tenfold higher mRNA expression of 10 exemplary genes of the UPS (UBE2A, UBE2D2, UBE2L6, USP14, UBB and ATPase2, ß2, ß5, ß2i/MECL-1, ß5i/LMP7) was demonstrated in i.v. MACs as compared to IMACs. Immunohistochemistry and Western blots confirmed these findings in intestinal mucosa of controls and patients suffering from diverticulitis. In contrast, a significant increase in protein amounts was found in mucosa of patients with IBD. CONCLUSION: Reduced expression of subunits of the UPS in IMACs of normal mucosa supports the concept of the presence of a nonreactive, anergic macrophage phenotype in the gut under normal conditions. Reinduction in IMACs of IBD mucosa reflects activated IMACs which can present antigenic peptides and thus support inflammation.

Clinical relevance of IgG antibodies against food antigens in Crohn's disease: a double-blind cross-over diet intervention study.

BACKGROUND: Environmental factors are thought to play an important role in the development of Crohn's disease (CD). Immune responses against auto-antigens or food antigens may be a reason for the perpetuation of inflammation. METHODS: In a pilot study, 79 CD patients and 20 healthy controls were examined for food immunoglobulin G (IgG). Thereafter, the clinical relevance of these food IgG antibodies was assessed in a double-blind cross-over study with 40 patients. Based on the IgG antibodies, a nutritional intervention was planned. The interferon (IFN)gamma secretion of T cells was measured. Eosinophil-derived neurotoxin was quantified in stool. RESULTS: The pilot study resulted in a significant difference of IgG antibodies in serum between CD patients and healthy controls. In 84 and 83% of the patients, respectively, IgG antibodies against processed cheese and yeast were detected. The daily stool frequency significantly decreased by 11% during a specific diet compared with a sham diet. Abdominal pain reduced and general well-being improved. IFNgamma secretion of T cells increased. No difference for eosinophil-derived neurotoxin in stool was detected. CONCLUSION: A nutritional intervention based on circulating IgG antibodies against food antigens showed effects with respect to stool frequency. The mechanisms by which IgG antibodies might contribute to disease activity remain to be elucidated.

Recipient NOD2/CARD15 status affects cellular infiltrates in human intestinal graft-versus-host disease.

Nucleotide-binding oligomerization domain 2/caspase recruitment domain 15 (NOD2/CARD15) polymorphisms have been identified as risk factors of both Crohn's disease and graft-versus-host disease (GVHD) following allogeneic stem cell transplantation. However, the role of these receptors of innate immunity in the pathophysiology of gastrointestinal GVHD is still poorly defined. Immunohistological features of intestinal GVHD were analysed in gastrointestinal biopsies from 58 patients obtained at the time of first onset of intestinal symptoms. The observed changes were correlated with concomitant risk factors and the presence of polymorphisms within the pathogen recognition receptor gene NOD2/CARD15. Intestinal GVHD was associated with a stage-dependent decrease in CD4 T cell infiltrates and an increase in CD8 T cells in the lamina propria; CD8 infiltrates correlated with extent of apoptosis and consecutive epithelial proliferation. The presence of NOD2/CARD15 variants in the recipient was associated with a significant loss of CD4 T cells: in a semiquantitative analysis, the median CD4 score for patients with wild-type NOD2/CARD15 was 1.1 (range 3), but only 0.4 (range 2) for patients with variants (P = 0.002). This observation was independent from severity of GVHD in multivariate analyses and could not be explained by the loss of forkhead box P3(+) T cells. Our results suggest a loss of protective CD4 T cells in intestinal GVHD which is enhanced further by the presence of NOD2/CARD15 variants. Our study might help to identify more selective therapeutic strategies in the future.

CpG-oligodeoxynucleotides stimulate immunoglobulin A secretion in intestinal mucosal B cells.

Bacterial DNA motifs (such as CpG-oligodeoxynucleotides: CpG-ODN) induce innate immune responses via binding to Toll-like-receptor-9 (TLR-9). In murine intestinal mucosa treatment with CpG-ODN worsens chronic intestinal inflammation, whereas it prevents or ameliorates colitis when given in a prophylactic setting. In tonsils B cells have been reported to express TLR-9, especially after activation. Whether B cells in the human intestinal mucosa also express TLR-9 and whether their function can be influenced by CpG-ODN is, so far, unknown. Mucosal B cells were isolated according to a new protocol from surgical specimens of patients with inflammatory bowel disease and from controls by collagenase digestion followed by magnetic cell sorting using anti-CD19 antibody armed magnetic beads. TLR-9 mRNA and protein expression were quantified by real-time polymerase chain reaction (PCR) and Western blot, respectively. Immunoglobulin A (IgA) secretion was measured by enzyme-linked immunosorbent assay after stimulation of isolated B cells with CpG-ODN, control GpC-ODN or lipopolysaccharide (LPS). Flow cytometric analysis of the isolated lamina propria mononuclear cells showed a purification of 73% (+/-22%) CD19(+) cells. By quantitative reverse transcription-PCR and by Western blot TLR-9 expression in this cell population was evident. IgA secretion was increased significantly by CpG-ODN incubation compared with GpC-ODN and LPS. Compared with unstimulated controls, CpG-ODN up-regulated IgA secretion to 139% (+/-21%). These data demonstrate that CD19(+) mucosal B cells express TLR-9 and secrete increased levels of IgA upon stimulation with CpG-ODN, indicating an additional link between adaptive and innate intestinal immune responses.

[Partial splenic artery embolization for the treatment of a patient with hypersplenism due to liver cirrhosis]. / Partielle Milzarterienembolisation zur Behandlung eines Hypersplenismus bei Leberzirrhose.

HISTORY AND CLINICAL FINDINGS: A 52-year-old man with liver cirrhosis and ascites, hepatorenal syndrome and severe pancytopenia was admitted to hospital for treatment and consideration for future liver transplantation. INVESTIGATIONS: Laboratory tests revealed severe leukocytopenia and thrombocytopenia, which had persisted after otherwise successful treatment of spontaneous bacterial peritonitis and a hepatorenal syndrome. There was no evidence of a toxic cause such as drugs or alcohol nor of an underlying haematologic disease. The most likely diagnosis was hypersplenism. DIAGNOSIS, THERAPY AND CLINICAL COURSE: Because of the high risk of a splenectomy it was decided to perform a partial splenic arterial embolization. Both leukocyte and thrombocyte counts rose after the intervention and continued to stay within normal range. This made it possible to discharge the patient from inpatient treatment until he was admitted again for a subsequently successful liver transplantation. CONCLUSIONS: Partial splenic artery embolization can be successfully used to treat severe leukocytopenia and thrombocytopenia in patients with liver cirrhosis and hypersplenism.

Anti-inflammatory role of sympathetic nerves in chronic intestinal inflammation.

BACKGROUND: Substance P (SP) is a pro-inflammatory neuropeptide in colitis, whereas sympathetic neurotransmitters are anti-inflammatory at high concentrations. AIM AND METHODS: In all layers of the colon, nerve fibre densities of SP(+) and sympathetic nerve fibres were investigated (22 Crohn's disease, six diverticulitis, and 22 controls). In addition, the nerve fibre repellent factor semaphorin 3C (SEMA3C) was studied. The functional role of the sympathetic nervous system was tested in dextran sodium sulfate (DSS) and Il10(-/-) colitis. RESULTS: In all layers, Crohn's disease patients demonstrated a loss of sympathetic nerve fibres. Sprouting of SP(+) nerve fibres was particularly observed in the mucosa and muscular layer in Crohn's disease. SEMA3C was detected in epithelial cells, and there was a marked increase of SEMA3C-positive crypts in the mucosa of Crohn's disease patients compared to controls. In Crohn's disease, the number of SEMA3C-positive crypts was negatively related to the density of mucosal sympathetic nerve fibres. Sympathectomy reduced acute DSS colitis but increased chronic DSS colitis. Sympathectomy also increased chronic colitis in Il10(-/-) mice. CONCLUSIONS: This study demonstrated a loss of sympathetic and an increase of SP(+) nerve fibres in Crohn's disease. SEMA3C, a sympathetic nerve repellent factor, is highly expressed in the epithelium of Crohn's disease patients. In chronic experimental colitis, the sympathetic nervous system confers an anti-inflammatory influence. Thus, the loss of sympathetic nerve fibres in the chronic phase of the disease is most probably a pro-inflammatory signal, which might be related to repulsion of these fibres by SEMA3C and other repellents.

Regulation of galectin-3 function in mucosal fibroblasts: potential role in mucosal inflammation.

Recently we identified galectin-3 (gal-3), which is secreted by colonic epithelial cells (CEC), to be a strong activator of colonic lamina propria fibroblasts (CLPF). Modulation of CLPF function may play a role during stricture and fistula formation in inflammatory bowel disease (IBD). Therefore, we investigated further the expression of gal-3 and effects on CLPF. The aim of this study is to perform a direct comparison of gal-3 between tissue from healthy controls and from patients with either Crohn's disease (CD) or ulcerative colitis (UC). CEC, CLPF and intestinal macrophages (IMAC) were isolated from control and IBD colonic tissue. Interleukin-8 secretion as a readout of CLPF activation was quantified by enzyme-linked immunosorbent assay. Gal-3 in cell cultures and tissue samples was evaluated by Western blot, immunofluorescence and immunohistochemistry. CLPF-migration was assayed in the 48-well modified Boyden chamber. Gal-3 expression was found in all segments of the colon. In the terminal ileum, less gal-3 was found compared with the colon. Immunohistochemistry and immunofluorescence revealed a homogenous distribution of gal-3 in CEC and IMAC of control mucosa and UC. However, significantly less gal-3 was found in IMAC from CD patients. In CD fistulae and stenoses, gal-3 expression was reduced significantly and barely detectable. In co-incubation studies lactose reduced significantly the CLPF-stimulatory potential of gal-3, indicating that the C-terminal domain of gal-3 is responsible for CLPF activation. Gal-3 stimulated CLPF migration in CLPF derived from fistulae. In conclusion, gal-3 expression is down-regulated in CD-fistulae and stenoses as well as in IMAC in CD patients. Gal-3 induces migration of CLPF derived from fistulae. Its role for stricture and fistula formation warrants further investigation.

In vivo treatment with the herbal phenylethanoid acteoside ameliorates intestinal inflammation in dextran sulphate sodium-induced colitis.

Recently we demonstrated that in inflammatory bowel disease (IBD) macrophage-oxidative burst activity is increased and NADPH oxidase mRNA is induced. The herbal phenylethanoid acteoside isolated from Plantago lanceolata L. was shown to exhibit anti-oxidative potential. Using the dextran sulphate sodium (DSS)-induced colitis model, in this study we have assessed whether systemic application of acteoside affects colitis. Colitis was induced by DSS in Balb/c mice. Treatment with acteoside (120, 600 microg/mouse/day) was performed intraperitoneally. The colon lengths were determined. Colonic tissue was scored histologically (max. score 8) by a blinded investigator. T cells isolated from mesenteric lymph nodes (MLN) were stimulated with anti-CD3 antibody in the presence of interleukin (IL)-2 (final concentration 10 U/ml). After incubation for 24 h, IL-1beta, IL-6, IL-12 tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma levels in supernatants were analysed by the beadlyte cytokine detection system. Histological scoring of colonic tissue revealed that application of acteoside was followed by a significantly improved histological score. In acute colitis the histological score was 3.2 with acteoside versus 5.2 with phosphate-buffered saline (PBS) (P < 0.02). In chronic colitis both 120 microg (3.3 versus 5.2) or 600 microg acteoside (3.0 versus 5.2) significantly ameliorated colitis (both P < 0.02). Stimulated MLN from mice with chronic DSS-induced colitis treated with acteoside showed a significant down-regulation of IFN-gamma secretion (195 pg/ml with 600 microg acteoside versus 612 pg/ml with PBS, P < 0.02). Inhibition of oxidative burst activity with acteoside reduced mucosal tissue damage in DSS colitis and could be a therapeutic alternative for IBD treatment. Further studies of this agent are warranted.

Adrenal insufficiency and colonic inflammation after a novel chronic psycho-social stress paradigm in mice: implications and mechanisms.

We investigated chronic psycho-social stress effects on stress-related parameters and on pathohistological changes in the murine colon. Moreover, we aimed to reveal the involvement of adrenal glucocorticoids in chronic stress effects. Chronic subordinate colony housing (CSC, 19 d) resulted in reduced body weight gain, thymus atrophy, adrenal hypertrophy, increased plasma norepinephrine, and increased anxiety. With respect to the time course of CSC effects, CRH mRNA in the hypothalamic paraventricular nucleus, light phase corticosterone and tyrosine hydroxylase expression in colonic tissue were found to be increased, whereas tyrosine hydroxylase expression in the locus coeruleus was found to be decreased on d 2 of CSC; these parameters returned to control levels thereafter. Nevertheless, after 19 d of CSC exposure, the adrenal corticosterone responses in vivo and in vitro, and glucocorticoid sensitivity of isolated splenic cells were found to be decreased. Importantly, in CSC mice a significant histological damage of the colon was found beginning on d 14 of CSC exposure. Additionally, pro- and antiinflammatory cytokine secretion by mesenteric lymph node cells was increased after CSC exposure. Adrenalectomy before CSC at least partially prevented these chronic stress effects as reflected by less increase in proinflammatory cytokine secretion and an equal histological damage score in adrenalectomized compared with sham-operated CSC mice. In conclusion, chronic exposure to CSC alters relevant neuronal, neuroendocrine and immune functions that could be directly or indirectly involved in the damage of the histological integrity of the colon comparable with that seen during the development of colitis.

Cathepsins B, L and D in inflammatory bowel disease macrophages and potential therapeutic effects of cathepsin inhibition in vivo.

The cathepsins D (CTSD), B (CTSB) and L (CTSL) are important for the intracellular degradation of proteins. Increased cathepsin expression is associated with inflammatory diseases. We have shown previously an induction of CTSD expression in intestinal macrophages (IMAC) in inflamed mucosa of patients with inflammatory bowel disease (IBD). Here we investigated the regulation of CTSB and CTSL in IMAC during IBD and effects of CTSD and CTSB/CTSL inhibition in vivo. Human IMAC were isolated from normal and inflamed mucosa. Reverse transcription-polymerase chain reaction (RT-PCR) was performed for CTSB and CTSL mRNA. Immunostaining was used to confirm PCR results. Cathepsin inhibition was investigated in the dextran-sulphate-sodium (DSS) colitis model in mice with application of pepstatin A (CTSD inhibitor), CA-074 (CTSB inhibitor) and Z-Phe-Tyr-aldehyde (CTSL inhibitor). CTSL mRNA was significantly up-regulated in IMAC isolated from IBD mucosa. Up-regulated protein expression was found mainly in areas of mucosal damage by immunostaining. Inhibition of CTSD in mouse DSS colitis was followed by an amelioration of the disease. Inhibitor-treated mice showed a significant lower histological score (HS) and less colon reduction in comparison to controls. Similarly, simultaneous inhibition of CTSB/CTSL was followed by a significant amelioration of colitis. Expression of tissue-degrading cathepsins is increased in IMAC in IBD. Inhibition of CTSD as well as CTSB/CTSL is followed by an amelioration of experimental colitis. The prevention of mucosal damage by cathepsin inhibition could represent a new approach for the therapy of IBD.

Hepatitis C - contamination of toothbrushes: myth or reality?

Chronic hepatitis C patients are advised not to share toothbrushes, razors, nail-scissors or other personal articles that potentially may have been in contact with blood, with others. This study examines the contamination of toothbrushes in patients with chronic hepatitis C as a model for a possible unconventional way of transmission. In 30 patients with chronic hepatitis C, 2 mL of saliva (before and after toothbrushing) and the toothbrush rinsing water after toothbrushing were tested for HCV-RNA. Saliva before and after toothbrushing was positive for HCV-RNA in nine (30%) and 11 patients (36.7%), respectively. Twelve of the toothbrush rinsing water specimens (40%) tested HCV-RNA-positive. In six of these 12 patients, the 'native' saliva had been negative for HCV-RNA. Patients with HCV-RNA-positive toothbrush rinsing water showed no significant differences from those with negative rinsing water with respect to certain clinical, biochemical and virological parameters. In conclusion, our study demonstrates a contamination with HCV-RNA of a considerable portion of toothbrushes used by hepatitis C patients, suggesting at least a theoretical risk of infection by sharing these objects and strengthening the recommendations to take care of a clear separation of these personal care objects between patients and their household members.

Chronic intermittent psychosocial stress (social defeat/overcrowding) in mice increases the severity of an acute DSS-induced colitis and impairs regeneration.

Ulcerative colitis is a multifactorial disease, with immunological, genetic, and environmental factors playing an important role in its pathogenesis. Here we investigated the consequences of exposure to chronic psychosocial stress on the severity of a dextran sulfate sodium (DSS)-induced colitis in male C57BL/6 mice. Chronic stress was induced by repeated exposure to social defeat (SD, 2 h) and overcrowding (OC, 24 h) during 19 consecutive days. SD/OC mice showed a diminished body weight gain, thymus-atrophy, and adrenal hypertrophy, but similar light-phase plasma corticosterone concentrations, compared with unstressed mice. In contrast, the rise in dark-phase corticosterone concentration was significantly attenuated in SD/OC mice, whereas plasma ACTH concentrations and hypothalamic CRH mRNA expression did not differ between stressed and nonstressed groups. Additionally, adrenal cells from SD/OC mice showed a decreased in vitro response to ACTH stimulation. Subsequent treatment with 1% DSS for 7 d resulted in a more severe intestinal inflammation in SD/OC mice, as reflected by an increase in body weight loss, histological damage scores, and secretion of IL-6, TNFalpha, and interferon-gamma from mesenteric lymph node cells and by decreased colon length. The impaired health status of stressed mice was also reflected by a significantly lower survival rate after termination of the DSS treatment. In conclusion, the present findings demonstrate that chronic intermittent exposure to a psychosocial stressor before the induction of acute DSS-colitis results in adrenal insufficiency, increases in the severity of the acute inflammation, and impairs the healing phase.

Comparison of low and high frequency transducers in the detection of liver metastases.

BACKGROUND AND AIMS: To evaluate the benefit of the additional use of a high frequency ultrasound probe (7.5 MHz) in finding suspicious liver lesions compared to the examination using a 3.5-MHz transducer only. PATIENTS AND METHODS: One hundred and fifty-seven patients with underlying malignant disease were examined with both transducers using one of three ultrasound machines (Siemens Sonoline Elegra, GE Healthcare Logic 9, or Hitachi EUB-8500). Findings on hepatic lesions were collected on a standardised documentation sheet and evaluated by descriptive statistics. RESULTS: Ninety-three patients (59.2% of all patients) showed no evident liver lesion on conventional ultrasound with the 3.5 MHz probe. In 29 patients (18.5%) new suspicious liver lesions were found by using the high frequency transducer. Thirteen of these 29 patients (44.8%) were suspected to suffer from diffuse infiltration of the liver with malignant lesions or at least 10 additional visible lesions. In 14 patients, no liver lesion had been known before high frequency ultrasound examination. The size of newly described liver lesions ranged from 2 mm to 1.5 cm. Time needed for the additional examination with the high frequency transducer ranged between 1 and 15 min with an average of 4.0 min. CONCLUSION: The additional use of a high frequency transducer in patients with underlying malignant disease slightly extends the examination time, but reveals new, potentially malignant hepatic lesions in almost every fifth patient.

Vasculitis of the aortic arch and cardiac valves as the cause of relapsing fever of unknown origin in an elderly, white man.

Here, we report the case of fever of unknown origin (FUO) in a 77-year-old white man. The patient presented with a 3-week history of fever (between 38.5 and 39 degrees C) and general malaise. These symptoms had occurred about five to seven times during the past 30 years, and despite repeated hospitalizations, no diagnosis was made. Physical examination did not reveal any specific signs of infection nor did the patient fulfill the criteria for any rheumatic disease including vasculitides. Blood chemistry showed a greatly elevated C-reactive protein (CRP; 158.2 mg/l) and an erythrocyte sedimentation rate >100 mm, indicating an active inflammatory process, and leukocytes were significantly elevated (20,000/mul). Rheumatological parameters showed only nonspecific changes. Finally, a 2-[(18)F]-fluoro-2-deoxy-D: -glucose-positron emission tomography was performed, revealing a markedly enhanced glucose uptake in the ascending aorta and the cardiac valves, indicating vasculitis as the cause of FUO in this patient. Based on this finding, treatment was started with corticosteroids, and 2 days after the initiation of treatment, the patient had normal body temperature, and after 5 days, CRP values had returned to normal. After tapering and final complete removal of steroid treatment, the patient was still free of symptoms, hence no disease-modifying antirheumatic drug therapy was necessary.

Influence of intestinal bacteria on induction of regulatory T cells: lessons from a transfer model of colitis.

BACKGROUND: The resident flora plays a critical role in initiation and perpetuation of intestinal inflammation, as demonstrated in experimental models of colitis where animals fail to develop disease under germ free conditions. However, the importance of exposure to commensal bacteria before the onset of colitis is unclear. Our aim was to investigate the influence of previous exposure of donor animals to bacterial antigens on colitis development using a transfer model. METHODS: Clinical course and histology were evaluated after transfer of CD4(+)CD62L(+) lymphocytes from germ free and conventionally housed donor mice into SCID recipients. Cotransfer of CD4(+)CD62L(+) cells with CD4(+)CD62L(- )lymphocytes from both groups of mice was initiated. Lymphocytes were analysed by FACS, polarisation potential of cells determined, and cytokines measured within the supernatant by enzyme linked immunosorbent assay. RESULTS: Animals that received cells from germ free donors developed an earlier onset of colitis compared with mice reconstituted with lymphocytes from conventionally housed animals. Additionally, CD4(+)CD62L(- )cells from germ free mice were not able to abrogate colitis induced by cotransfer with CD4(+)CD62L(+) lymphocytes whereas CD4(+)CD62L(- )T cells from normal mice ameliorated disease. The higher percentage of CD4(+)GITR(+) expressing lymphocytes and the production of interleukin 10 after priming by dendritic cells suggests the presence of T(reg) cells within the CD4(+)CD62L(+) lymphocyte subset derived from conventional housed mice and assumes a lack of T(reg) cells within germ free mice. CONCLUSION: The results indicate that bacterial antigens are crucial for the generation and/or expansion of T(reg) cells in a healthy individual. Therefore, bacterial colonisation is of great importance in maintaining the immunological balance.

Analysis of intestinal haem-oxygenase-1 (HO-1) in clinical and experimental colitis.

Haem-oxygenase-1 (HO-1) has been shown to exert anti-inflammatory, anti-apoptotic and anti-proliferative effects. We investigated HO-1 expression in patients with inflammatory bowel disease (IBD) and could demonstrate a scattered expression of HO-1 in the intestinal epithelium of severely inflamed colonic mucosa of patients with IBD compared to control specimens such as diverticulitis, suggesting dysregulated expression in IBD. To further analyse potential mechanisms of HO-1 induction in the intestine we employed an in vitro epithelial cell apoptosis model and an experimental colitis model. In vitro induction of HO-1 by the HO-1 inducer cobalt protoporphyrin (CoPP) resulted in a dose-dependent down-regulation of caspase-3 activation in HT-29 cells, indicating an anti-apoptotic function of HO-1 in the intestine. In vivo, preventive HO-1 induction by CoPP in acute dextran sodium sulphate (DSS)-induced colitis led to a significant down-regulation of colonic inflammation (P < 0.01) with a concomitant reduction in interferon (IFN)-gamma - but unaffected interleukin (IL)-10-secretion by isolated mesenteric lymph nodes (P < 0.01). Additionally, TUNEL staining of colonic sections demonstrated fewer apoptotic epithelial cells in the colon of CoPP treated animals. No beneficial effects were observed if HO-1 was induced by CoPP after the onset of acute colitis or in chronic DSS-induced colitis. In conclusion, the data suggest a protective role of HO-1 if it is induced before the onset of inflammation. However, as shown by the lack of effects in established acute or in chronic colitis, the induction of HO-1 may not be a promising approach for the treatment of IBD.