Györgyi Muzes

Comparison of the effects of 1,25 dihydroxyvitamin D and 25 hydroxyvitamin D on bone pathology and disease activity in Crohn's disease patients

Background: Vitamin D is essential for osteopenia therapy in Crohns disease (CD). The active form of vitamin‐D (aVD) is the 1,25(OH)2D. There are no data available whether aVD or plain vitamin‐D (pVD) has any advantage in managing osteoporosis in CD or has any effect on the activity of the disease itself. Our work is a prospective study to compare the effects of aVD and pVD on bone metabolism and the clinical course of CD. Methods: In all, 37 inactive CD patients were involved in the study and divided into 2 age‐, gender‐, and t‐score‐matched groups. Group A was treated with aVD while group B received pVD. Osteocalcin, beta‐CrossLaps, osteoprotegerin, and receptor activator nuclear factor kappa‐B ligand concentrations were estimated at the start of the study and at 6 weeks and 3 and 12 months. The activity of CD was also measured clinically and by laboratory parameters. Results: At week 6 the Crohns Disease Activity Index (CDAI) scores and concentration of C‐reactive protein decreased (69.44 ± 58.6 versus 57.0 ± 54.89 and 15.8 ± 23.57 mmol/L versus 7.81 ± 3.91 mmol/L, respectively, P < 0.05) parallel with markers of bone turnover (beta‐CrossLaps: 0.46 ± 0.21 ng/mL versus 0.40 ± 0.25 ng/mL, and osteocalcin: 32.29 ± 15.3 ng/mL versus 29.98 ± 14.14 ng/mL, P < 0.05); however, osteoprotegerin concentration (marker of osteoblast activity) increased (3.96 ± 2.1 pg/mL versus 4.58 ± 2.19 pg/mL) in group A, but did not change in group B. Osteocalcin and beta‐CrossLaps concentrations changed more significantly by the 3rd month; however, these changes disappeared by the 12th month. Conclusions: According to our study, aVD has a more prominent short‐term beneficial effect on bone metabolism and disease activity in CD compared with pVD. (Inflamm Bowel Dis 2009)

Antinucleosome Antibodies and Decreased Deoxyribonuclease Activity in Sera of Patients with Systemic Lupus Erythematosus

ABSTRACT Nucleosomes are the dominant autoantigens in patients with systemic lupus erythematosus (SLE), and immune complexes involving nucleosomes are the major cause of tissue damage. The activity of DNase I, the enzyme responsible for nucleosome degradation, has been found to be decreased in patients with SLE. However, it is not known whether DNase activity is a clinically useful parameter. The aim of our study was to assess DNase activity in a prospective study of 113 patients with SLE in relation to disease activity and organ involvement. We included two control groups: 9 patients with undifferentiated connective tissue disease (UCTD) and 14 healthy individuals. DNase activity was found to be lower in patients with SLE (63.75% ± 12.1%) than in the controls (81.3% ± 9.25%) (P < 0.001). DNase activity in patients with UCTD (64.9% ± 18.2%; P = 0.854) did not differ from that in patients with SLE. Patients with SLE had higher antinucleosome antibody titers (356.3 ± 851) than the controls (1.44 ± 2.77; P < 0.01) or UCTD patients (39.9 ± 57.7; P < 0.01). In addition, samples positive for antinucleosome antibodies displayed low levels of DNase activity. Within the SLE group, the presence of renal disease had no impact on DNase activity or antinucleosome antibody titers. Also, the SLE disease activity index showed no correlation with DNase activity. In a longitudinal study of six SLE patients, DNase activity did not follow disease activity or autoantibody titers. Our results confirm that serum DNase activity is decreased in patients with SLE, but we conclude that it is not a clinically useful parameter for the prediction of flare-ups of disease or renal involvement.

Effect of silibinin and vitamin E on restoration of cellular immune response after partial hepatectomy

Our aim was to study the antioxidant and immunomodulatory effect of silibinin and vitamin E on the early postoperative course in rats that had undergone a partial hepatectomy (PHX). Male Wistar rats that were treated with silibinin (50 mg/b.w.kg i.p.) and/or vitamin E (500 mg/b.w.kg p.o.) were randomised to undergo 70% PHX. At 72 h after operation, Concanavalin A (Con-A) induced lymphocyte proliferation, and lipopolysaccharide (LPS) induced interleukin-1 (IL-1) mitogenicity and tumour necrosis factor-alpha (TNF-alpha) cytotoxicity were measured in the spleen. In addition, total free radical scavenger capacity of the liver was analysed. In PHX animals, Con-A induced lymphocyte proliferation was significantly decreased, and both LPS induced IL-1 and TNF-alpha activity were significantly increased as compared to Sham treated animals. Treatment with silibinin and vitamin E synergistically restored both lymphocyte proliferation (P<0.01) and cytokine activity (P<0.001) in PHX animals. In addition, silibinin and vitamin E synergistically (P<0.001) restored total hepatic free radical scavenger capacity as well as serum levels of AST and gammaGT, that were all markedly decreased in PHX animals. Our results suggest that preoperative treatment with silibinin and/or vitamin E modulates the cellular immunoresponse and restores impaired liver function following PHX, presumably through their antioxidant capacity. This may explain their beneficial effects on the postoperative course of liver repair.

Infliximab Therapy Improves the Bone Metabolism in Fistulizing Crohn’s Disease

Background: Tumor necrosis factor-α (TNF-α) plays a pivotal role in the pathogenesis of inflammatory bowel diseases and bone resorption as well. Limited data exist about the effect of anti-TNF-α infliximab on bone metabolism in inflammatory-type Crohn’s disease (CD). Aim: Our aim was to evaluate the effect of infliximab treatment on rapid changes of bone metabolism in fistulizing CD patients. Methods: 27 patients with fistulizing CD were treated with three series of infliximab. Serum osteocalcin (OC) and β-CrossLaps (bCL) were measured before administration of each infliximab infusion. 54 patients with inactive CD were controls. Results: In treated patients, there were significant differences in bCL concentrations on days 0 and 14 (p < 0.01) and days 0 and 42 (p < 0.05). OC levels increased significantly between day 0 and 42 (p < 0.05). The values of bCL and OC of control groups differed from serum levels in active patients before the treatment, but not on day 42. Bone markers improved significantly in responder patients, but not in non-responders. Conclusion: The beneficial effect of infliximab to the bone metabolism is more expressive in patients whose fistulizing disease improves with this therapy. Our results suggest that TNF-α has an important role in the alteration of bone metabolism in fistulizing CD patients.

Isolated lymphoid follicles in colon: Switch points between inflammation and colorectal cancer?

Gut-associated lymphoid tissue is supposed to play a central role in both the organization of colonic repair mechanisms and colorectal carcinogenesis. In inflammatory conditions, the number, diameter and density of isolated lymphoid follicles (ILFs) increases. They are not only involved in immune surveillance, but their presence is also indispensable in normal mucosal regeneration of the colon. In carcinogenesis, ILFs may play a dual role. On the one hand they may support tumor growth and the metastatic process by vascular endothelial growth factor receptor signaling and producing a specific cytokine and cellular milieu, but on the other hand their presence is sometimes associated with a better prognosis. The relation of ILFs to bone marrow derived stem cells, follicular dendritic cells, subepithelial myofibroblasts or crypt formation, which are all involved in mucosal repair and carcinogenesis, has not been directly studied. Data about the putative organizer role of ILFs is scattered in scientific literature.

Regeneration associated growth factor receptor and epithelial marker expression in lymphoid aggregates of ulcerative colitis

Abstract Objective. Mesenchymal-epithelial transition may have crucial role in mucosal regeneration, hence we assayed epithelial growth factor receptor (EGFR), insulin-like growth factor receptor-1 (IGF1R), hepatocyte-derived growth factor receptor (HGFR), CDX2 and cytokeratin (CK) expression in lymphoid aggregates (LA) of ulcerative colitis (UC). Material and methods. Tissue microarrays (TMAs) made of biopsy samples from 20 mildly, 20 moderately and 20 severely active UC, 12 non-specific colitis (NSC) and 20 healthy colon were prepared, and immunolabelled with anti-EGFR, -IGF1R, -HGFR, -CDX2, -CK antibodies. After virtual microscopic evaluation, one-way ANOVA and correlation analysis were performed. For validation, TaqMan real-time RT-PCR was performed by using RNA from laser microdissected LA from 10 healthy colon and 10 endoscopically active UC biopsies. Results. The number of LA was in tight positive correlation with the severity of inflammation (r=0.9). The number of EGFR/HGFR positive subepithelial cells was found to be significantly elevated in severe (21.6±2.1%/21.3±1.9%), moderate (14.3±1.7%/14.6±1.6%) and mild (7.2±1.6%/7.4±1.3%) inflammation compared to healthy colon mucosa (2.6±1.4%/2.4±1.03%) (p < 0.005). Some alterations were found between UC and NSC samples regarding EGFR and HGFR expression. IGF1R immunoreactive cells were only found in a trace number in all cases. Increasing trend of CDX2 and CK positive subepithelial cells was found in active UC, but it was not in significant correlation with the severity of inflammation. Conclusion. EGFR and HGFR positive subepithelial cells in LA may be involved in the induction of the regenerative mucosal processes. The presence of CDX2/CK positive subepithelial cells suggests that mesenchymal-to-epithelial transition may be located to lymphoid aggregates.

Inflammasome, Inflammation and Cancer: An Interrelated Pathobiological Triad

Cancer represents a major health problem worldwide, therefore on the basis of current research results constantly more effective therapeutic strategies are expected. Chronic, unchecked inflammation has widely been suggested to trigger carcinogenesis. The innate immune system ensures a first line host defense in which the inflammasome is essential maintaining a delicate balance betweeen pro- and anti-inflammatory signals in order to generate an appropriate immune response without harming the host. Studies have revealed a remarkable, but contradictory link of host inflammatory responses to tumorigenesis. Indeed, activation of the multiprotein complex inflammasome by danger signals seems to play diverse and sometimes conflicting, suppressive or stimulatory role in cancer development and progression with a significant context-dependency. The pleitropic inflammasomes may act at cell-autonomous level to eliminate malignant cells via the programmed cell death type of inflammatory pyroptosis, but on the contrary, may favor the production of gowth and trophic factors for tumor cells and their microenvironment. Further, upon caspase-1 activation the inflammasome can provoke sterile inflammation, and thus facilitate carcinogenesis, though in antigen-presenting cells it can elicit anti-tumor immune responses. Clarifying the exact, context-specific impact of inflammasomes on tumorigenesis represents a new research area with the potential to introduce promising novel targets for cancer therapeutics.

Connexin 43 Communication Channels in Follicular Dendritic Cell Development and in Follicular Lymphomas

Follicular dendritic cells (FDC) show homo- and heterocellular metabolic coupling through connexin 43 (Cx43) gap junctions and support B cell selection and maturation in germinal centers. In follicular lymphomas B cells escape apoptosis while FDC develop abnormally. Here we tested Cx43 channels in reactive FDC development and follicular lymphomas. In culture, the treatment of FDC-B cell clusters (resembling to “ex vivo” germinal centers) with Gap27 peptide, mimicking the 2nd extracellular loop of Cx43 protein, significantly impaired FDC-B cell cluster formation and cell survival. In untreated cultures of intact clusters, cell proliferation showed a moderate reduction. In tissues, Cx43 protein levels run parallel with the density of FDC both in reactive germinal centers and in malformed follicles of follicular lymphomas and showed strong upregulation in newly generated and/or degrading bi-/multinuclear FDC of rudimentary processes. However, the inverse correlation between Cx43 expression and B cell proliferation seen in reactive germinal centers was not detected in follicular lymphomas. Furthermore, Cx43 levels were not associated with either lymphoma grade or bone marrow involvement. Our results suggest that Cx43 channels are critical in FDC and “ex vivo” germinal center development and in the persistence of FDC in follicular lymphomas but do not affect tumor progression.

Interaction of Autophagy and Toll-Like Receptors: A Regulatory Cross- Talk - Even in Cancer Cells?

Accumulating evidence indicates that the aberrantly altered process of autophagy is definitely involved in carcinogenesis. Nonetheless, Toll-like receptors (TLRs) sensing cell-derived pattern/danger-associated molecules also have the capacity to promote tumor development and immune escape. TLRs are usually expressed in immunocompetent cells, though several types of cancer cells have also been reported to display these innate immune receptors. On the other hand, however, both TLR- and autophagy-related signals may exert tumor suppressor mechanisms mainly in a cell-specific and context-dependent manner. The role of autophagy has been radically expanded, and now this machinery is considered as a fundamental eukaryotic cellular homeostatic process and integral component of the immune system influencing infection, inflammation and immunity. Recent studies have documented that TLRs and autophagy are interrelated in response to danger signals, furthermore there is a controling cross-talk among them to avoid deficient or excessive immunological effects. Although the potential interaction of autophagy and TLRs in cancer cells has not yet been clarified, it seems to be a critical aspect of cancer development and progression. Upon translation of basic knowledge into practice it is reasonable to speculate that modulation of the TLR-autophagy regulatory loop might be relevant for cancer treatment by providing further possible therapeutic targets.

[Whipple's disease: current problems].

Whipples disease is a rare multisystemic infectious disease of bacterial origin characterized by variable clinical manifestations, and an insidious and chronic relapsing course. Untreated disease can be even fatal. The presence of the characteristic (though not specific) triad of weight loss, chronic diarrhea and arthralgias may raise its suspicion. When chronic intermittent fever and lymphadenopathy are associated, the suspicion is substantial. Recognition of the causative agent, Tropheryma whippelii with unique characteristics was essential. Despite the presumed ubiquitous presence of the bacteria the disease probably occurs only in cases of immunological host susceptibility. Presence of the bacteria living and multiplying especially in macrophages has suggested alterations of the mononuclear-phagocytic system. (Whipples disease is commonly mentioned as a macrophage disorder.) Clinical manifestations are quite diverse. While it has traditionally been regarded as a gastrointestinal disease, currently is considered to be a systemic disorder. In cases of suspected infection the approach of first choice is upper gastrointestinal endoscopy. Small, whitish-yellow diffusely distributed plaques alternating with an erythematous, erosive, friable mucosa in the postbulbar region of the duodenum or in the jejunum can appear. Histological samples indicate tissue infiltration of macrophages with intracellular bacterial invasion. The hallmark of Whipples disease is the presence of PAS positive macrophages in the lamina propria of duodenal biopsy specimens, still the diagnosis needs to be confirmed with the detection of bacteria by PCR. The selection of antibiotics and duration of treatment still remains largely empiric.