Permissive expansion and homing of adoptively transferred T cells in tumor-bearing hosts.

Activated T cells expressing endogenous or transduced TCRs are two cell types currently used in clinical adoptive T-cell therapy. The ability of these cells to recognize their antigen, expand and traffic to the tumor site are the initial steps necessary for successful therapy. In this study, we used in vivo bioluminescent imaging (BLI) of Renilla luciferase (RLuc) expressing T cells to evaluate the ability of adoptively transferred T cells to survive, expand and home to tumor site in vivo. Using this method, termed RT-Rack (Rluc T cell tracking), we followed T-cell response against tumors in vivo. Expansion and homing of adoptively transferred T cells were antigen dependent, but independent of the host immune status. Moreover, we successfully detected T-cell response to small and large tumors, including autochthonous liver tumors. The adoptively transferred T cells were not ignorant or excluded in a partially tolerant host, which expressed low level of the target in the periphery. Using T cell receptor (TCR)-engineered T cells, we showed the ability of these cells to respond in tumor-bearing hosts by expanding and homing to the tumor site. In all these models, the host immune status, the nature of the tumor or of the antigen, the tumor size and the presence of the targeted antigen in the periphery did not prevent the adoptively transferred T cells from responding by expanding and homing to the tumor. However, T cells had higher expression of the inhibitory receptor PD1 and reduced functional activity when a self-antigen was targeted.

[Cutaneous Rosai-Dorfman syndrome. Successful therapy with intrralesional corticosteroids]. / Kutanes Rosai-Dorfman-Syndrom. Erfolgreiche Therapie mit intraläsional applizierten Steroiden.

BACKGROUND: Cutaneous Rosai-Dorfman disease is a rare disorder belonging to the spectrum of non-Langerhans cell histiocytoses. It is characterized by dermal and subcutaneous infiltrates of histiocytes as well as accompanying lymphocytes, plasma cells and granulocytes. Because it is so rare, standard therapies have not been established. CASE REPORT: A 27-year-old man showed an excellent response to intralesional corticosteroids after unsuccessful prior treatment with methotrexate, systemic steroids and surgery as well as laser therapy.

Mechanisms and rescue strategies of calcineurin inhibitor mediated tolerance abrogation induced by anti-CD4 mAb treatment.

To ensure safety tolerance induction protocols are accompanied by conventional immunosuppressive drugs (IS). But IS such as calcineurin inhibitors (CNI), for example, cyclosporin A (CsA), can interfere with tolerance induction. We investigated the effect of an additional transient CsA treatment on anti-CD4mAb-induced tolerance induction upon rat kidney transplantation. Additional CsA treatment induced deteriorated graft function, resulting in chronic rejection characterized by glomerulosclerosis, interstitial fibrosis, tubular atrophy and vascular changes. Microarray analysis revealed enhanced intragraft expression of the B cell attracting chemokine CXCL13 early during CsA treatment. Increase in CXCL13 expression is accompanied by enhanced B cell infiltration with local and systemic IgG production and C3d deposition as early as 5 days upon CsA withdrawal. Adding different CNIs to cultures of primary mesangial cells isolated from glomeruli resulted in a concentration-dependent increase in CXCL13 transcription. CsA in synergy with TNF-α can enhance the B cell attracting and activating potential of mesangial cells. Transient B cell depletion or transfer of splenocytes from tolerant recipients 3 weeks after transplantation could rescue tolerance induction and did inhibit intragraft B cell accumulation, alloantibody production and ameliorate chronic rejection.

UDCA slows down intestinal cell proliferation by inducing high and sustained ERK phosphorylation.

Ursodeoxycholic acid (UDCA) attenuates colon carcinogenesis in humans and in animal models by an unknown mechanism. We investigated UDCA effects on normal intestinal epithelium in vivo and in vitro to identify the potential chemopreventive mechanism. Feeding of mice with 0.4% UDCA reduced cell proliferation to 50% and suppressed several potential proproliferatory genes including insulin receptor substrate 1 (Irs-1). A similar transcriptional response was observed in the rat intestinal cell line IEC-6 which was then used as an in vitro model. UDCA slowed down the proliferation of IEC-6 cells and induced sustained hyperphosphorylation of ERK1/ERK2 kinases which completely inhibited the proproliferatory effects of EGF and IGF-1. The hyperphosphorylation of ERK1 led to a transcriptional suppression of the Irs-1 gene. Both, the hyperphosphorylation of ERK as well as the suppression of Irs-1 were sufficient to inhibit proliferation of IEC-6 cells. ERK1/ERK2 inhibition in vitro or ERK1 elimination in vitro or in vivo abrogated the antiproliferatory effects of UDCA. We show that UDCA inhibits proliferation of nontransformed intestinal epithelial cells by inducing a sustained hyperphosphorylation of ERK1 kinase which slows down the cell cycle and reduces expression of Irs-1 protein. These data extend our understanding of the physiological and potentially chemopreventive effects of UDCA and identify new targets for chemoprevention.

[Tropheryma whipplei infection. Colonization, self-limiting infection and Whipple's disease]. / Infektionen mit Tropheryma whipplei. Besiedlung, selbstlimitierte Infektion und Morbus Whipple.

Whipple's disease is a multisystemic infection caused by the ubiquitous bacterium Tropheryma whipplei. Immunological host factors enable classical Whipple's disease; however, T. whipplei can be found in three other clinical conditions: healthy colonization, self-limiting infections, and isolated endocarditis. The genetic predisposition of the host rather than the genotype of the bacterium influences the infection. Modern diagnostic methods elucidate the many facets of Whipple's disease. In particular, isolated T. whipplei-induced infective endocarditis can only be diagnosed after valve resection. The sole treatment of Whipple's disease evaluated prospectively comprises intravenous induction therapy with ceftriaxone or meropenem, followed by continuation therapy with oral TMP-SMX. In the case of Immune reconstitution inflammatory syndrome (IRIS) or inflammatory lesions of the CNS in the setting of Whipple's disease, additional treatment with corticosteroids should be considered to avoid severe tissue damage.

[Histopathology of graft-versus-host disease]. / Histopathologie der Graft-versus-Host-Erkrankung.

Graft-versus-host disease (GvHD) occurs as a major complication in 35%-50% of all patients undergoing allogeneic stem cell transplantation. A distinction is made between acute and chronic GvHD depending on the time of onset, type of clinical symptoms and histology. Both forms preferably show manifestations in the skin, mucosal membranes, gastrointestinal tract, liver and (less often) lung. As the clinical presentation is rather unspecific, particularly for the diagnosis of acute GvHD, histology is important to exclude infectious diseases or drug reactions. This review covers the diagnostic morphological criteria and differential diagnoses of GvHD in the skin, gastrointestinal tract and the liver.

Impairment of fat oxidation under high- vs. low-glycemic index diet occurs before the development of an obese phenotype.

Exposure to high vs. low glycemic index (GI) diets increases fat mass and insulin resistance in obesity-prone C57BL/6J mice. However, the longer-term effects and potentially involved mechanisms are largely unknown. We exposed four groups of male C57BL/6J mice (n = 10 per group) to long-term (20 wk) or short-term (6 wk) isoenergetic and macronutrient matched diets only differing in starch type and as such GI. Body composition, liver fat, molecular factors of lipid metabolism, and markers of insulin sensitivity and metabolic flexibility were investigated in all four groups of mice. Mice fed the high GI diet showed a rapid-onset (from week 5) marked increase in body fat mass and liver fat, a gene expression profile in liver consistent with elevated lipogenesis, and, after long-term exposure, significantly reduced glucose clearance following a glucose load. The long-term high-GI diet also led to a delayed switch to both carbohydrate and fat oxidation in the postprandial state, indicating reduced metabolic flexibility. In contrast, no difference in carbohydrate oxidation was observed after short-term high- vs. low-GI exposure. However, fatty acid oxidation was significantly blunted as early as 3 wk after beginning of the high-GI intervention, at a time where most measured phenotypic markers including body fat mass were comparable between groups. Thus long-term high-GI feeding resulted in an obese, insulin-resistant, and metabolically inflexible phenotype in obesity-prone C57BL/6J mice. Early onset and significantly impaired fatty acid oxidation preceded these changes, thereby indicating a potentially causal involvement.

Cellular senescence predicts treatment outcome in metastasised colorectal cancer.

BACKGROUND: Cellular senescence is a terminal cell-cycle arrest that occurs in response to activated oncogenes and DNA-damaging chemotherapy. Whether cancer cell senescence at diagnosis might be predictive for treatment outcome is unknown. METHODS: A senescence index (SI) was developed and used to retrospectively correlate the treatment outcome of 30 UICC stage IV colorectal cancer (CRC) patients with their SI at diagnosis. RESULTS: 5-Fluorouracil/leucovorin-treated CRC patients achieved a significantly longer progression-free survival when presenting with SI-positive tumours before therapy (median 12.0 vs 6.0 months; P=0.044). CONCLUSION: Cancer cell senescence predicts treatment outcome in metastasised CRC. Prospective analyses of larger patient cohorts are needed.

Lipocalin2 protects against airway inflammation and hyperresponsiveness in a murine model of allergic airway disease.

BACKGROUND: Allergen-induced bronchial asthma is a chronic airway disease that involves the interplay of various genes with environmental factors triggering different inflammatory pathways. OBJECTIVE: The aim of this study was to identify possible mediators of airway inflammation (AI) in a model of allergic AI via microarray comparisons and to analyse one of these mediators, Lipocalin2 (Lcn2), for its role in a murine model of allergic airway disease. METHODS: Gene microarrays were used to identify genes with at least a twofold increase in gene expression in the lungs of two separate mouse strains with high and low allergic susceptibility, respectively. Validation of mRNA data was obtained by Western blotting, followed by functional analysis of one of the identified genes, Lcn2, in mice with targeted disruption of specific gene expression. Epithelial cell cultures were undertaken to define induction requirements and possible mechanistic basis of the results observed in the Lcn2 knock-out mice. RESULTS: Lcn2 was up-regulated upon allergen sensitization and airway challenges in lung tissues of both mouse strains and retraced on the protein level in bronchoalveolar lavage fluids. Functional relevance was assessed in mice genetically deficient for Lcn2, which showed enhanced airway resistance and increased AI associated with decreased apoptosis of lung inflammatory cells, compared with wild-type controls. Similarly, application of Lcn2-blocking antibodies before airway challenges resulted in increased inflammation and reduced apoptosis. CONCLUSION: These data indicate a protective role for Lcn2 in allergic airway disease, suggesting a pro-apoptotic effect as the underlying mechanism.

Long-term reduction in local inflammation by a lipid raft molecule in atopic dermatitis.

BACKGROUND: The complex pathogenesis of atopic dermatitis (AD) is guided by cell surface receptor-mediated signal transduction regulated in lipid rafts. Miltefosine is a raft-modulating molecule targeting cell membranes. With this controlled clinical study, the clinical and immunomodulatory efficacy of miltefosine was investigated in patients with AD in comparison with a topical corticosteroid treatment. METHODS: Sixteen patients with AD were treated topically with miltefosine and hydrocortisone localized on representative AD target lesions for 3 weeks. To assess the clinical efficacy, the three item severity (TIS) score was evaluated before, during and after treatment as well as after 4-week-follow-up period. To study the anti-inflammatory effect of miltefosine on the cellular T cell pattern, skin biopsies were analysed before and after treatment. RESULTS: The TIS score dropped in both groups significantly after treatment. A carry-over effect was exclusively seen for miltefosine after discontinuing the treatment. These findings were substantiated by thermographic imaging with a significant decrease in the maximum temperature (T(max)) after miltefosine application (P = 0.034, DeltaT(max) = 1.7 degrees C [2.1-3.9]). Immunohistochemically, a reduction in lesional CD4(+)-infiltrating T cells was observed in both treatments. Moreover, increased FoxP3(+) cells were present in the skin after miltefosine treatment (before 5.4% [1.9-9.8], after 6.2% [3.5-9.5]). CONCLUSION: We demonstrate that miltefosine is locally active in patients with AD and led to a sustained clinical improvement in local skin inflammation. Moreover, the increased frequency of FoxP3(+) cells in the skin of patients with AD suggests its immunomodulatory properties.

Diagnostic value of confocal endomicroscopy in celiac disease.

BACKGROUND: Improved endoscopic screening with targeted biopsies might enhance diagnostic yield in celiac disease. Confocal endomicroscopy (CEM) allows high-resolution in vivo histological analysis. We compared the endomicroscopic findings during ongoing endoscopy with the histological findings graded according to the Marsh classification. METHODS: Twenty-four patients with celiac disease and six patients with celiac disease that was refractory on a gluten-free diet were examined using CEM. The duodenal mucosa was evaluated by CEM and by conventional histological analysis in respect of villous atrophy, crypt hyperplasia, and increased numbers of intraepithelial lymphocytes (IELs > 40 / 100 enterocytes). The CEM results were assessed as to sensitivity, specificity, and interobserver variability. A Marsh classification score determined by CEM was compared to that obtained by histology. Thirty patients undergoing routine upper gastrointestinal endoscopy were used as controls. RESULTS: Conventional histology showed villous atrophy and crypt hyperplasia in 23 and increased numbers of IELs in 27 of the 30 patients with celiac disease. With CEM, villous atrophy, crypt hyperplasia, and increased IELs were respectively identified in 17, 12, and 22 of the 30 patients. The agreement of the findings on CEM with those of conventional histology was good in relation to villous atrophy (sensitivity 74 %) and increased numbers of IELs (sensitivity 81 %), but inadequate in relation to crypt hyperplasia (sensitivity 52 %). The kappa values for determination of interobserver variability were 0.90 for villous atrophy, 1.00 for crypt hyperplasia, and 0.84 for IEL detection. In the 30 control patients, normal duodenal architecture was found by both histology and endomicroscopy, indicating an overall specificity of 100 %. CONCLUSION: The assessment of duodenal histology by CEM in patients with celiac disease is sensitive and specific in determining increased numbers of IELs and villous atrophy, but insufficient in respect of crypt hyperplasia. For routine use of CEM in patients with celiac disease, the technique would need to be improved.

[Primary ductal adenocarcinoma near the orbit]. / Primäres duktales Adenokarzinom im Bereich der Orbita.

The case of a 59-year-old patient is described who presented with a left-sided pressure sensation in the left orbit and exophthalmus with a proud bulbus. The limited bulbus motility led to double vision. A preoperative MRI showed a space-occupying lesion in the left medial orbit. The morphological and immunohistochemical findings led to the diagnosis of a primary ductal carcinoma resembling salivary duct carcinoma (SDC). The tumor could be removed without compromising the eye. The patient suffers no side-effects or recurrences 12 months later.

Structural and functional changes of the duodenum in human norovirus infection.

BACKGROUND: Norovirus infection is the most frequent cause of infectious diarrhoea in the western world. This study aimed to characterise functionally and histomorphologically the diseased duodenum in human biopsies. METHODS: Norovirus infection was diagnosed by the Kaplan criteria and confirmed by PCR of stool samples. Duodenal biopsies were obtained endoscopically. In miniaturised Ussing chambers, short circuit current, flux measurements and impedance spectroscopy were performed. Histological analysis including apoptosis staining and characterisation of intraepithelial lymphocytes was performed. Tight junction proteins were quantified by immunoblotting. RESULTS: In norovirus infection, epithelial resistance decreased from (mean (SEM)) 24 (2) Omega cm(2) in controls to 10 (1) Omega cm(2). Mannitol flux increased from 113 (24) nmol h(-1) cm(-2) in controls to 242 (29) nmol h(-1) cm(-2). Microdissection revealed a villus surface area reduced by 47% (6.6%). Intraepithelial lymphocytes were increased to 63 (7) per 100 enterocytes, with an increased rate of perforin-positive cytotoxic T cells. Expression of tight junctional proteins occludin, claudin-4 and claudin-5 was reduced. The epithelial apoptotic ratio was doubled in norovirus infection. Furthermore, the basal short circuit current was increased in norovirus infection and could be reduced by bumetanide and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB). CONCLUSIONS: Norovirus infection leads to epithelial barrier dysfunction paralleled by a reduction of sealing tight junctional proteins and an increase in epithelial apoptosis, which may partly be mediated by increased cytotoxic intraepithelial lymphocytes. Furthermore, active anion secretion is markedly stimulated. Thus, the diarrhoea in norovirus infection is driven by both a leak flux and a secretory component.

Impairment of the intestinal barrier is evident in untreated but absent in suppressively treated HIV-infected patients.

BACKGROUND AND AIMS: Impairment of the gastrointestinal mucosal barrier contributes to progression of HIV infection. The purpose of this study was to investigate the effect of highly active antiretroviral therapy (HAART) on the HIV-induced intestinal barrier defect and to identify underlying mechanisms. METHODS: Epithelial barrier function was characterised by impedance spectroscopy and [(3)H]mannitol fluxes in duodenal biopsies from 11 untreated and 8 suppressively treated HIV-infected patients, and 9 HIV-seronegative controls. The villus/crypt ratio was determined microscopically. Epithelial apoptoses were analysed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) and caspase-3 staining. Tight junction protein expression was quantified by densitometric analysis of immunoblots. Mucosal cytokine production was determined by cytometric bead array. RESULTS: Only in untreated but not in treated HIV-infected patients, epithelial resistance was reduced (13 (1) vs 23 (2) ohm cm(2), p<0.01) and mannitol permeability was increased compared with HIV-negative controls (19 (3) vs 9 (1) nm/s, p<0.05). As structural correlates, epithelial apoptoses and expression of the pore-forming claudin-2 were increased while expression of the sealing claudin-1 was reduced in untreated compared with treated patients and HIV-negative controls. Furthermore, villous atrophy was evident and mucosal production of interleukin 2 (IL2), IL4 and tumour necrosis factor alpha (TNFalpha) was increased in untreated but not in treated HIV-infected patients. Incubation with IL2, IL4, TNFalpha and IL13 reduced the transepithelial resistance of rat jejunal mucosa. CONCLUSIONS: Suppressive HAART abrogates HIV-induced intestinal barrier defect and villous atrophy. The HIV-induced barrier defect is due to altered tight junction protein composition and elevated epithelial apoptoses. Mucosal cytokines are mediators of the HIV-induced mucosal barrier defect and villous atrophy.

Comparative analysis of mononuclear cells isolated from mucosal lymphoid follicles of the human ileum and colon.

Studies of human mucosal lymphoid follicles are rare and have been limited to children's Peyer's patches, which are visible at endoscopy. We investigated lymphoid follicles in ileum biopsies of 87 patients and surgical colon specimens from 66 cancer patients, and examined phenotype and function of isolated follicular immune cells. Two (0-10) and 12 (0-117) follicles per patient were found in ileum and colon samples respectively (P < 0.001). The number of lymphoid follicles mononuclear cells (LFMC) that could be isolated per patient was higher from colon compared with ileum specimens [725 000 (0-23 Mio) versus 100 000 (0-1.3 Mio), P < 0.001]. T cells were predominant in both LFMC and lamina propria mononuclear cells (LPMC), but B cells were more and plasma cells less frequent in LFMC. T cells from mucosal follicles were more frequently CD4-positive and CD62L-positive, but less frequently CD8-positive, CD103-positive and CD69-positive than lamina propria T cells. LFMC from ileum compared with colon showed no differences in mononuclear cell composition. Anti-CD3/CD28 stimulation induced similar proliferation of LFMC and LPMC from ileum and colon, as well as secretion of high levels of interferon-gamma, tumour necrosis factor-alpha and interleukin (IL)-2, but lower levels of IL-4, IL-6 and IL-10. LFMC from colon secreted more IL-2 than those from ileum. Our study shows that mucosal lymphoid follicles can be identified clearly in adult human colon and yield viable immune cells sufficient for phenotypical and functional analysis. The cellular composition of LFMC from ileum and colon is similar, and both secrete predominantly T helper type 1 cytokines.

Gastrointestinal nematode infection interferes with experimental allergic airway inflammation but not atopic dermatitis.

BACKGROUND: Some helminth infections are negatively associated with the prevalence of allergic disorders, arguing for a modulation of allergic reactions by the parasites, depending on the worm species, intensity and phase of infection and the type of disease. OBJECTIVE: The aim of this study was to analyse the influence of a chronic infection with the gastrointestinal nematode Heligmosomoides polygyrus, in a murine model of allergic airway disease and of atopic dermatitis (AD), respectively. METHODS: Mice were infected with H. polygyrus and systemically sensitized with the model allergen ovalbumin. Subsequently, the animals were challenged with the allergen either via the airways for induction of airway disease, or via skin patches for induction of dermatitis. RESULTS: Mice concomitantly infected with H. polygyrus showed diminished eosinophil and lymphocyte recruitment into the lungs and decreased allergen-specific IgE levels when compared with sensitized and airway challenged controls. In addition, animals showed a trend towards reduced airway hyper-reactivity. In contrast, no significant differences in the severity of eczematous skin lesions were observed between infected and control animals in the AD model. Although H. polygyrus infection reduced CD8+ and CD4+ T-cell infiltration into the skin and production of allergen-specific IgE, mast cell recruitment was significantly increased in worm-infected mice in the dermatitis model. The worm infection was associated with significantly elevated numbers of Foxp3+ regulatory T cells (Treg) in peribronchial lymph nodes in H. polygyrus-infected sensitized and airway challenged mice. In contrast, Treg cells were basically absent in eczematous skin and their number was not increased in skin-draining lymph nodes of mice with experimental dermatitis. CONCLUSION: Infection with the gastrointestinal nematode used in our study leads to significant inhibition of mucosa-associated but not cutaneous allergic reactions, pointing to a site specificity of the immunomodulation exerted by helminths. This finding might be an important aspect for future considerations of helminths for treatment of allergic diseases.

Long-term clopidogrel administration following severe coronary injury reduces proliferation and inflammation via inhibition of nuclear factor-kappaB and activator protein 1 activation in pigs.

BACKGROUND: The optimal duration of clopidogrel treatment following percutaneous coronary intervention (PCI) and the patient population that would benefit most are still unknown. In a porcine coronary injury model, we tested two different durations of clopidogrel treatment on severely or moderately injured arteries and examined the arterial response to injury. To understand the molecular mechanism, we also investigated the effects on transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein 1 (AP-1). MATERIALS AND METHODS: In 24 cross-bred pigs, one coronary artery was only moderately injured by percutaneous transluminal coronary angioplasty (PTCA) and one coronary artery was severely injured by PTCA and subsequent beta-irradiation (Brachy group). Animals received 325 mg aspirin daily for 3 months and 75 mg clopidogrel daily for either 28 days [short-term (ST) clopidogrel group] or 3 months [long-term (LT) clopidogrel group]. RESULTS: After 3 months, the number of proliferating cells per cross-section differed significantly between ST and LT in both injury groups (PTCA(ST) 90.2 +/- 10.3 vs. PTCA(LT )19.2 +/- 4.7, P < 0.05; Brachy(ST) 35.8 +/- 8.4 vs. Brachy(LT) 7.5 +/- 2.0, P < 0.05). Similar results were seen for inflammatory cells (CD3(+) cells): PTCA(ST) 23.5 +/- 3.55 vs. PTCA(LT )4.67 +/- 0.92, P < 0.05; Brachy(ST) 83.17 +/- 11.17 vs. Brachy(LT) 20 +/- 4.82, P < 0.05). Long-term administration also reduced the activity of NF-kappaB and AP-1 by 62-64% and 42-58%, respectively. However, the effects of different durations of clopidogrel administration on artery dimensions were not statistically significant. CONCLUSIONS: Regarding inflammation and transcription factor activity at the PCI site, long-term clopidogrel administration is superior to short-term administration, especially in severely injured arteries. Transferring our results to the human situation, patients with more severely diseased arteries may benefit from a prolonged clopidogrel medication after PCI.

In vivo diagnosis of acute intestinal graft-versus-host disease by confocal endomicroscopy.

BACKGROUND AND STUDY AIMS: Conventional histology with hematoxylin and eosin (H&E) staining is the accepted standard for diagnosing acute intestinal graft-versus-host disease (GvHD). Confocal endomicroscopy (CEM) is a noninvasive method that allows in vivo histology to be performed during endoscopy. The aim of this study was to evaluate CEM for the diagnosis of acute intestinal GvHD. PATIENTS AND METHODS: This observational pilot study conducted between September 2006 and August 2008 included patients with acute diarrhea after stem cell transplantation, infectious diarrhea, or active ulcerative colitis. CEM (EC-3870CIFK, Pentax, Tokyo, Japan) was performed after intravenous injection of fluorescein 10% and topical application of acriflavine 0.05%. RESULTS: A total of 35 patients with acute diarrhea after stem cell transplantation were examined. In 16 patients, CEM and histology showed no evidence of GvHD. In 14/19 patients with histologically confirmed GvHD, the diagnosis could already be established by CEM during ongoing endoscopy. In GvHD grade IV, near complete destruction of the colonic crypts ("flat mucosa") was visible. Control patients with infectious colitis (N = 15) or ulcerative colitis (N = 15) displayed inflammatory changes but no evidence of GvHD. Altogether, sensitivity of CEM was 74% and specificity was 100 %. CONCLUSIONS: CEM improves rapid diagnosis of acute intestinal GvHD with high accuracy while performing endoscopy. Platelet transfusions and unnecessary biopsy acquisition can be avoided once acute intestinal GvHD has been diagnosed in vivo.

Rheumatoid arthritis and ankylosing spondylitis - pathology of acute inflammation.

Histomorphological analysis of inflammatory lesions in rheumatoid arthritis (RA) and ankylosing spondylitis (AS) display similarities but also major differences. Ankylosing spondylitis is characterised by two key pathological findings: sacroiliac joint and spinal inflammation and new bone formation with the possible consequence of bone fusion, usually in the axial skeleton. In AS the primary site of inflammation is located at the enthesis or subchondral bone marrow with bone marrow oedema, lymphocytic infiltrates, increased osteoclast density and increased microvessel density are typical findings in acute inflammation. In RA joint inflammation has its origin in the synovial membrane of peripheral joints. Osteitis in the subchondral bone marrow reveals similar findings compared to AS and it is suggested to occur secondary to inflammation in the synovial membrane. Structural damage defines the outcome in both diseases. However, in AS it is defined by new bone formation and in RA by the destruction of cortical bone.