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Thomas Bieber

Publications and source records attributed to Thomas Bieber.

At least 19 recordsLinked to original sources

Mechanism of HBD-3 deficiency in atopic dermatitis.

Extrinsic atopic dermatitis (EAD) and intrinsic atopic dermatitis (IAD) patients suffer from recurrent bacterial and viral infections. In this study, we demonstrate significantly decreased expression of human beta defensin (HBD)-3, a potent antimicrobial peptide (AMP), in lesional skin of both IAD (p<0.01) and EAD patients (p<0.01), as compared to psoriasis patients. Using primary keratinocytes from EAD and IAD patients, we determined that the deficiency in HBD-3 expression is an acquired rather than a constitutive defect. Furthermore, we demonstrate the down-regulatory effect of IL-4, IL-10, and IL-13 - which are over-expressed in the skin of AD patients - on HBD-3 expression in keratinocytes. Additionally, treatment of EAD skin explants with antibodies against IL-4, IL-10, and IL-13 augmented the expression of HBD-3. These studies suggest that neutralizing the Th2 cytokine milieu in AD skin may augment the innate immune response against bacterial and viral pathogens.

Adult↗

Enhanced expression levels of IL-31 correlate with IL-4 and IL-13 in atopic and allergic contact dermatitis.

BACKGROUND: IL-31 is produced by activated T lymphocytes, preferentially by TH2 cells. Transgenic mice overexpressing IL-31 have a phenotype resembling allergic dermatitis in human subjects. OBJECTIVE: We sought to evaluate the potential importance of IL-31 in the pathogenesis of human T cell-mediated skin diseases. METHODS: We analyzed total RNA taken from 149 skin biopsy specimens from patients with atopic dermatitis (AD), allergic contact dermatitis (ACD), or psoriasis in comparison with specimens taken from patients with healthy skin (n = 13) by using quantitative real-time PCR for the expression of TH1/TH2 cytokines. RESULTS: We found statistically increased mRNA levels of IL-31 in biopsy specimens taken from patients with AD, irrespective of the severity of the disease and serum IgE levels. Moreover, IL-31 mRNA levels were strongly increased in many biopsy specimens taken from patients with ACD. However, no increased transcription of IL-31 could be detected in biopsy specimens taken from psoriatic plaques. A comparison of mRNA levels of IL-31 with TH1 or TH2 cytokines demonstrates a correlation of the expression of IL-31 with IL-4 and IL-13 but not with IFN-gamma. No significant increase of IL-31 receptor mRNA could be detected in any disease, whereas the second receptor subunit of IL-31, the oncostatin M receptor, seems to be enhanced transcribed in patients with psoriasis. CONCLUSION: IL-31 expression is not only increased in patients with AD but also in those with ACD, 2 pruritic skin disorders. In both types of eczema, expression of IL-31 is associated with the expression of the TH2 cytokines IL-4 and IL-13. CLINICAL IMPLICATIONS: IL-31 might contribute not only to the development of AD but also to ACD-provoked skin inflammation.

Dermatitis, Allergic Contact↗

Diagnostic performance of whole body dual modality 18F-FDG PET/CT imaging for N- and M-staging of malignant melanoma: experience with 250 consecutive patients.

PURPOSE: To assess the diagnostic performance of positron emission tomography/computed tomography (PET/CT) using (18)F-fluorodeoxyglucose (FDG) for N- and M-staging of cutaneous melanoma. PATIENTS AND METHODS: This is a retrospective and blinded study of 250 consecutive patients (105 women, 145 men; age 58 +/- 16 years) who underwent FDG-PET/CT for staging of cutaneous melanoma at different time points in the course of disease. Whole-body FDG-PET/CT was performed 101 +/- 21 minutes postinjection of 371 +/- 41 MBq FDG. Diagnostic accuracy for N- and M-staging was determined for CT alone, PET alone, and PET/CT. RESULTS: PET/CT detected significantly more visceral and nonvisceral metastases than PET alone and CT alone (98.7%, 88.8%, and 69.7%, respectively). PET/CT imaging thus provided significantly more accurate interpretations regarding overall N- and M-staging than PET alone and CT alone. Overall N- and M-stage was correctly determined by PET/CT in 243 of 250 patients (97.2%; 95% CI, 95.2% to 99.4%) compared with 232 patients (92.8%; 95% CI, 89.6% to 96.0%) by PET, and 197 patients (78.8%; 95% CI, 73.7% to 83.9%) by CT. All differences were significant. Accuracy of PET/CT was significantly higher than that of PET and CT for M-staging (0.98 v 0.93 and 0.84) and significantly higher than that of CT for N-Staging (0.98 v 0.86). Change of treatment according to PET/CT findings occurred in 121 patients (48.4%). CONCLUSION: The diagnostic performance of FDG-PET/CT for N- and M-staging of melanoma patients suggests its use for whole-body tumor staging, especially for detection or exclusion of distant metastases.

Adult↗

Diagnosis and treatment of atopic dermatitis in children and adults: European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Report.

There are remarkable differences in the diagnostic and therapeutic management of atopic dermatitis practiced by dermatologists and pediatricians in different countries. Therefore, the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology nominated expert teams who were given the task of finding a consensus to serve as a guideline for clinical practice in Europe as well as in North America. The consensus report is part of the PRACTALL initiative, which is endorsed by both academies.

Adult↗

Tumor necrosis factor-alpha- and IL-4-independent development of Langerhans cell-like dendritic cells from M-CSF-conditioned precursors.

GM-CSF and transforming growth factor beta (TGFbeta ) are required for the generation of Langerhans cells (LC), members of the dendritic cell (DC) family. Tumor necrosis factor alpha (TNFalpha) and IL-4 can enhance LC differentiation from human monocytes or CD34(+) progenitors. Here, we show that M-CSF-cultured DC precursors derived from CD34(+) progenitors resemble dermal CD14(+) cells and readily convert to LC-like DC in GM-CSF/TGFbeta. The cells express Langerin, CD1a, and CCR6, migrate in response to CCR6 ligand CCL20, and contain Birbeck granules. TNFalpha and IL-4, added separately or together, have an inhibitory effect on LC differentiation. Cells differentiated in the presence of IL-4 and TNFalpha express low levels of CCR7. This suggests that M-CSF-conditioned DC precursors retain the capacity to efficiently undergo a differentiation program, giving rise to LC-like DC solely through the effect of GM-CSF and TGFbeta.

Antigens, CD↗

0.3% Tacrolimus gel and 0.5% Tacrolimus cream show efficacy in mild to moderate plaque psoriasis: Results of a randomized, open-label, observer-blinded study.

The efficacy and safety of 0.3% tacrolimus gel and 0.5% tacrolimus cream compared with calcipotriol ointment were evaluated in adults (n = 124) with mild to moderate plaque psoriasis. Treatment was twice daily for a maximum of 12 weeks. Clinical efficacy was assessed by the percentage change in the local psoriasis severity index of a target lesion between baseline and week 12. By week 12, the median percentage changes in local psoriasis severity index of the target lesions in the tacrolimus gel, tacrolimus cream and calcipotriol groups were 55.6%, 50.0% and 58.6%, respectively (no statistically significant differences). Clinical improvement was observed after one week and increased throughout the study. Tacrolimus-treated patients experienced more application site skin burning (tacrolimus gel and cream both 31.0% versus 7.5% for calcipotriol; p = 0.011). Skin burning was mostly mild in intensity and decreased substantially after 1 week of treatment. There were no differences in the nature and incidence of infections and no clinically relevant changes in laboratory values.

Administration, Topical↗

Long-term survival benefit after adjuvant treatment of cutaneous melanoma with dacarbazine and low dose natural interferon alpha: A controlled, randomised multicentre trial.

In a prospective, controlled, randomised, multicentre study 252 patients with totally resected cutaneous melanoma (248 in stage II-III and 4 in stage IV) were either treated with two doses of dacarbazine (DTIC) followed by a 6-month treatment with 3 MU thrice weekly of highly purified natural interferon-alpha (n = 128; arm A) or received no adjuvant treatment (n = 124; arm B). Treatment was well tolerated. After a median follow-up of 8.5 years ITT analysis showed that the difference in survival was statistically significant with respect to melanoma-related deaths (HR = 0.65, CI = 0.46-0.97, p = 0.022) and close to significance with respect to overall survival (HR 0.71, CI 0.49-1.00, p = 0.052). The risk reduction of melanoma-associated death, calculated by Cox proportional hazards modelling, after adjusting for identified predictive variables, was almost 50% (p = 0.002). The overall efficacy of the treatment appeared to be mainly attributable to effects observed in patients with deep and/or metastasizing tumours (HR 0.60, CI 0.40-0.90, p = 0.013).

Adult↗

Type I interferon-associated cytotoxic inflammation in lichen planus.

INTRODUCTION: Lichen planus (LP) is an inflammatory autoimmune skin disease of unknown origin. Evidence has accumulated that autoreactive cytotoxic CD8(+) T lymphocytes cause destruction of keratinocytes. Recent studies suggested that type I interferons (IFNs) play a central role in cytotoxic skin inflammation by increasing the expression of IP10/CXCR10 and recruiting effector cells via CXCR3. Here, we investigated whether type I IFNs are also involved in the pathogenesis of LP. PATIENTS AND METHODS: Skin biopsies of altogether 17 donors (seven LP and 10 healthy controls) were analyzed by immunohistochemistry using monoclonal antibodies against CD3, CD4, CD8, CD20, CD68, CXCR3, granzyme B, IP10/CXCL10, CD123, and the MxA protein, which is specifically induced by type I IFNs. RESULTS: Our analysis revealed a significant expression of the MxA protein in all LP skin biopsies, indicating involvement of type I IFNs. Expression of MxA was closely associated with the recruitment of CXCR3(+) and granzyme B(+) lymphocytes, indicating a Th1-biased cytotoxic immune response. Strong expression of the CXCR3 ligand, the interferon-inducible protein IP10/CXCL10, links type I IFN expression and recruitment of CXCR3(+) lymphocytes. Plasmacytoid dendritic cells (pDCs) appear to be a major source of type I IFNs in LP. DISCUSSION: Our observations support the hypothesis that lesional type I IFNs produced by pDCs plays an important role in chronic cytotoxic inflammation of LP by recruiting cytotoxic effector lymphocytes via IP10/CXCR3 interactions.

Adolescent↗

Biologicals dramatic advances in the treatment of psoriasis.

Innovations in biotechnology have made possible the development of several new systemic therapies for psoriasis - the "biologicals", a new group of compounds including monoclonal antibodies, fusion proteins and recombinant proteins. These novel biotechnological advances potentially offer designer drugs, which interfere with specific targets in the pathophysiological network of psoriasis and are thus much safer. The therapeutic strategy of biologicals is based on the knowledge derived from pathogenetic studies, which have focused on targeting disease relevant T-cell- or mediator-systems. Important targets include inactivation of soluble mediators such as tumor-necrosis-factor-alpha, the blockade of receptors for cytokines, adhesion molecules and the interference with T-cell activation by antigen-presenting cells. In addition, recombinant cytokines are able to modulate the immunological balance of this chronic inflammatory skin disease. Currently, up to forty agents are under investigation for the treatment of psoriasis. Four of these agents, alefacept, efalizumab, etanercept and infliximab have already impacted on routine clinical practice. Current developments in the treatment of psoriasis with biologicals are reviewed.

Anti-Inflammatory Agents↗

Skin homing of Langerhans cell precursors: adhesion, chemotaxis, and migration.

Langerhans cells (LCs) are epidermal antigen-presenting dendritic cells. They contain unique granules, known as Birbeck granules, which are substructures of the endosomal recycling compartment. LCs migrate from the epidermis to the regional lymph nodes for presentation of antigenic peptides to T cells. There LCs either initiate a primary immune response or induce antigen-specific tolerance. The replenishment of the LC pool in the epidermis is the topic of this review. Chemokines produced by epidermal keratinocytes and by dermal fibroblasts guide the arrest of LC precursors on endothelial cells of dermal venules, followed by their transmigration through endothelium and dermis toward the epidermis. One necessary prerequisite for this is the coordinated expression of adhesion receptors and counter-receptors on LC precursors and on endothelial and dermal cells. LC precursors attach to and degrade basement membrane proteins to penetrate the dermal matrix and the basement membrane of the dermal-epidermal junction. LC migration depends on the activity of matrix metalloproteinases, which are proteolytic endopeptidases cleaving matrix components. Matrix metalloproteinases also execute an important role in modulating inflammatory and immune responses by processing chemokines, which turns them into dual players for the immigration of LC precursors into the epidermis.

Animals↗

CD83 localization in a recycling compartment of immature human monocyte-derived dendritic cells.

Dendritic cells (DC) change their phenotype and functional properties during maturation. CD83 cell surface expression is induced on mature DC (mDC). In this study, we investigated intracellular CD83 localization and transport in human monocyte-derived DC. The enhanced level of CD83 cell surface expression in mDC resulted predominantly from increased protein synthesis, and in addition from regulated intracellular transport of CD83 protein. An internal pool of CD83 protein is present in immature DC (iDC). Although CD83 protein in iDC and in mDC was localized in the Golgi compartment and in recycling endosomes, only in mature cells did CD83 co-localize with MHC class II molecules in endocytic vesicles. CD83 cell surface expression on iDC was induced by inhibition of endocytosis. This result could be explained by CD83 cycling between endosomes and the cell surface in iDC. The mDC also rapidly internalized membrane-bound CD83 protein. Furthermore, a thiol protease inhibitor and specific cathepsin inhibitors impaired CD83 up-regulation in DC, indicating a role of endosomal proteases in the maturation-induced exposure of CD83 on the plasma membrane.

Antigens, CD↗

Enhanced type I interferon signalling promotes Th1-biased inflammation in cutaneous lupus erythematosus.

Recent studies have suggested that type I interferons (IFN) play a role in the pathogenesis of lupus erythematosus (LE), an autoimmune disease of unknown aetiology. Natural interferon-producing plasmacytoid cells have been demonstrated in cutaneous LE (CLE) lesions, along with elevated levels of IFN-alpha mRNA. The hypothesis in the current study was that local production of type I IFNs in CLE induces Th1-biased inflammation via induction of IFN-inducible chemokines such as IP10/CXCL10 leading to the recruitment of chemokine receptor CXCR3 expressing T-cells into skin lesions. Skin biopsies from 21 patients suffering from different types of active cutaneous LE were analysed for the expression of MxA, a protein specifically induced by type I interferons, the IFN-inducible protein IP10/CXCL10, and the chemokine receptor CXCR3, characteristic for Th1 cells, by immunohistochemistry. Additionally, peripheral CD4+ and CD8+ T-cells were investigated for the expression of MxA and CXCR3 by flow cytometry. Cutaneous LE lesions were characterized by strong expression of MxA indicating the induction of localized type I IFN signalling in the skin. Large numbers of infiltrating CXCR3 positive lymphocytes were detected in CLE skin lesions, and correlated closely with lesional MxA expression (epidermis: Spearman's rho = 0.56, p < 0.001; dermis: rho = 0.82, p < 0.001). Intracellular MxA levels of circulating CD4+ and CD8+ T-cells were significantly enhanced in patients with active CLE lesions. The percentage of peripheral T-cells expressing CXCR3 was significantly decreased in specific CLE subtypes. Expression of IP10/CXCL10 in the epidermis links type I IFN signalling and recruitment of CXCR3+ T cells. These results suggest an important role for type I interferon signalling in the pathogenesis of cutaneous lupus erythematosus. It is proposed that type I IFNs induce a Th1-biased inflammatory immune response, with recruitment of CXCR3-expressing T-lymphocytes into the skin.

CD8-Positive T-Lymphocytes↗

The role of dendritic cell subtypes in the pathophysiology of atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is an inflammatory, immunologically mediated skin disease characterized by a T helper type 2 cell-predominant phenotype initially with additional acquisition of T helper type 1 cell phenotype during the chronic eczematous phase. Compelling evidence presented here suggests that two types of dendritic cells (DC), myeloid DC (mDC) and plasmacytoid DC (pDC), are important in the pathogenesis of AD. METHODS: We reviewed the current literature and summarized key information about the role of mDC and pDC in the pathogenesis of AD. RESULTS: Langerhans cells and inflammatory dendritic epidermal cells, which bear the high-affinity receptor for immunoglobulin E on their cell surface, are hypothesized to contribute to the pathogenesis of AD. pDC, Which play an important role in the defence against viral infections, have also been shown to express high-affinity receptor for immunoglobulin E. CONCLUSION: Immunoglobulin E receptor-bearing mDC and pDC subtypes in the blood and the skin of patients with AD are of critical immunologic importance in the complex pathophysiologic network of AD. Targeting mDC and pDC subtypes may lead to effective new therapies for the management of AD.

Chemokines↗

The role of cytotoxic skin-homing CD8+ lymphocytes in cutaneous cytotoxic T-cell lymphoma and pityriasis lichenoides.

BACKGROUND: Pityriasis lichenoides (PL) is a rare cutaneous lymphoproliferative disorder of unknown origin. Malignant transitions of PL have been described, but are very rare. We recently observed the fatal course of a 26-year-old patient who presented with a clinical picture resembling PL but had cytotoxic CD8+ T-cell lymphoma of the skin (CxCTL). This case prompted us to reinvestigate the role of cytotoxic T lymphocytes in PL and its relationship to antiviral immunity. METHODS: Skin biopsy specimens of 11 patients with PL and two biopsy specimens of CxCTL were included. In all, 5 biopsy specimens taken from healthy skin and 5 samples of varicella-zoster virus (VZV) skin lesions were analyzed for control purposes. The inflammatory infiltrate was characterized by immunohistochemistry using monoclonal antibodies against CD3, CD4, CD8, CD20, cutaneous lymphocyte-associated antigen (CLA), CCR4, CXCR3, Granzyme B, Tia-1, and MxA. Flow cytometry was used to analyze the expression of chemokine receptors on peripheral blood mononuclear cells in CxCTL. RESULTS: The CxCTL skin lesions were dominated by a dense infiltration of CD8+ cytotoxic lymphocytes with a skin-homing CLA+ CCR4+ phenotype. PL and VZV skin lesions were also characterized by a predominantly CD8+ T cellular infiltrate with strong expression of the cytotoxic molecules Granzyme B and Tia-1 and the skin-homing molecules CLA and CCR4. Coexpression analyses confirmed that skin CLA+ CD8+ cytotoxic T cells are present in CxCTL, VZV, and PL skin lesions. Strong lesional production of the antiviral protein MxA, which is specifically induced by type I interferons, could be found in all investigated disorders. The study was based on histologic, immunohistologic, and flow cytometric analyses in a limited number of patients, because of the rareness of the investigated diseases. CONCLUSION: Our results revealed a striking similarity between the immunohistologic picture of malignant CxCTL, benign PL, and VZV skin lesions. Strong expression of the antiviral protein MxA in all disorders supports the view that a common antiviral immune response pattern leads to aberrant skin recruitment of CLA+ CCR4+ cytotoxic T lymphocytes in PL and CxCTL.

Adult↗

Single nucleotide polymorphisms of the IL18 gene are associated with atopic eczema.

BACKGROUND: Human IL-18 is an inflammatory cytokine that plays a role in atopic diseases, such as atopic eczema (AE), by enhancing IL-4 and IL-13 production and stimulating the synthesis of IgE. OBJECTIVE: To evaluate associations of polymorphisms in the IL18 gene on chromosome 11q22 with AE, we performed genotyping for single nucleotide polymorphisms (SNPs) in the IL18 gene in 225 patients with AE and 175 healthy control volunteers. METHODS: Genotyping was performed by means of restriction fragment length polymorphism analysis. RESULTS: Analyses revealed significant associations of SNPs +113[t/g] and +127[c/t] in exon 1, -137[g/c] in promoter region 1, and -133[c/g] in promoter region 2 with AE. These associations were not directly dependent on a specific subtype of AE or the concomitant manifestation of allergic rhinitis or asthma. On the functional level, the amount of IL-18 in the supernatants of PBMCs of patients with AE stimulated with Staphylococcus aureus enterotoxin B was significantly higher than that in healthy control subjects. In parallel, the amount of active IL-18 in the sera of patients with AE was enhanced at the exacerbation of their disease. CONCLUSION: In conclusion, our data suggest that SNPs in the IL18 gene might be involved in the development of AE by contributing to a functional dysregulation of the IL-18 production in vivo .

Adult↗