Barbara Hermes

Upregulation of TNF-α and IL-3 expression in lesional and uninvolved skin in different types of urticaria

BACKGROUND Although mast cells are known to secrete a broad spectrum of proinflammatory and immunomodulatory cytokines, the role of these molecules in mast cell-dependent cutaneous inflammation is not clear. OBJECTIVE We decided to study biopsy specimens from lesional and nonlesional skin of patients with acute, chronic recurrent, delayed pressure, and cold urticaria; from fleeting wheals of prick test reactions to allergens; and from normal skin of nonallergic subjects. METHODS Cryostat sections were stained by immunohistochemistry with antibodies against IL-3, IL-8, TNF-alpha, and mast cell-specific tryptase. In serial sections with tryptase and each cytokine, reactivity of mast cells was studied as well. RESULTS Compared with normal skin and prick test reactions, immunoreactivity for TNF-alpha and IL-3 was significantly increased on endothelial and perivascular cells of the upper dermis in all urticaria lesions. In nonlesional skin comparable upregulation was noted on endothelial cells and for TNF-alpha on perivascular cells of patients with delayed pressure urticaria. In addition, TNF-alpha was expressed throughout the epidermis in lesional and nonlesional skin of patients with all types of urticaria, but not in normal control subjects. Sequential biopsy specimens from patients with cold urticaria showed upregulation of TNF-alpha and IL-3 on endothelial cells 30 minutes after elicitation of lesions with an ice cube. In contrast to these findings, epidermal immunoreactivity, as well as endothelial and perivascular cell expression of IL-8, were only slightly altered in urticaria compared with normal skin. In sequentially stained sections, few tryptase-positive mast cells reacted to TNF-alpha, few reacted to IL-3 in pressure urticaria only, and practically none stained for IL-8. CONCLUSION These findings suggest that the cytokines studied here are involved in the pathology of urticaria, possibly by inducing subthreshold inflammation in endothelial cells of uninvolved skin.

Human skin: source of and target organ for angiotensin II

Abstract:  The present study examined the expression of angiotensin receptors in human skin, the potential synthesis of angiotensin II (Ang II) in this location and looked for a first insight into physiological functions. AT1 and AT2 receptors were found within the epidermis and in dermal vessel walls. The same expression pattern was found for angiotensinogen, renin and angiotensin‐converting enzyme (ACE). All components could additionally be demonstrated at mRNA level in cultured primary keratinocytes, melanocytes, dermal fibroblasts and dermal microvascular endothelial cells, except for AT2 receptors in melanocytes. The ability of cutaneous cells to synthesize Ang II was proved by identifying the molecule in cultured keratinocytes. Furthermore, in artificially wounded keratinocyte monolayers, ACE‐mRNA expression was rapidly increased, and enhanced ACE expression was still found in cutaneous human scars 3 months after wounding. These findings suggest that the complete renin–angiotensin system is present in human skin and plays a role in normal cutaneous homeostasis as well as in human cutaneous wound healing.

Clusters of Perifollicular Macrophages in Normal Murine Skin: Physiological Degeneration of Selected Hair Follicles by Programmed Organ Deletion

In back skin sections from adolescent C57BL/6 mice, regularly distributed, perifollicular inflammatory cell clusters (PICC) were found located around the distal noncycling portion of about 2% of all hair follicles examined. The PICC and the affected hair follicles were characterized during spontaneously developed or induced hair cycle stages, using antibodies against MHC Class II,F4/80, ER-MP23, NLDC 145, CD4, CD8, γδTCR, IL-1 receptor, and ICAM-1. PICC consisted predominantly of macrophages (MAC), accompanied by a few CD4+ cells, whereas γδTCR+ and CD8+ cells were absent. During anagen and catagen, some of the PICC+ hair follicles showed variable degenerative phenomena reminiscent of scarring alopecia: thickened basement membrane, ectopic MHC II expression, MAC infiltration into the follicle epithelium, and signs of keratinocyte apoptosis. Loss of distal outer root sheath keratinocytes was detected in 10% of PICC+ hair follicles (0.2% of all hair follicles). Because PICC were located in the vicinity of the bulge region, MAC-dependent damage to follicle stem cells might eventually lead to follicle degeneration. These perifollicular MAC clusters around selected hair follicles may indicate the existence of a physiological program of MAC-dependent controlled follicle degeneration by which damaged or malfunctioning follicles are removed by programmed organ deletion (POD).

Mast cell chymase and tryptase during tissue turnover: analysis on in vitro mitogenesis of fibroblasts and keratinocytes and alterations in cutaneous scars

Abstract: In order to shed further light on the potential role of mast cells during tissue turnover, we have investigated the number of mast cells containing only tryptase and those storing both tryptase and chymase by enzyme histochemistry in normal versus healing skin. Furthermore, we have studied the in vitro effect of these enzymes on the mitogenesis of subconfluent quiescent fibroblast and HaCaT keratinocyte cultures, using flowcytometric DNA analysis. Chymase‐containing mast cell numbers were markedly decreased in scars (P<0.001), whereas the overall number of tryptase‐containing mast cells was not decreased, although these cells were smaller and stained more faintly in scars. Chymase (5 to 300 mU/ml) induced a marked, dose‐dependent in vitro mitogenic response in 3T3 fibroblasts, whereas the effects of tryptase, at up to 60 nM, were only moderate, compared to the known fibroblast mitogens EGF, TGF‐α, α‐thrombin and trypsin at optimal concentrations. Coincubation of either protease with EGF or α‐thrombin had additive effects. In contrast to fibroblasts, keratinocytes showed only minor mitogenic responses to tryptase and chymase, also in comparison to other known mitogenic stimuli, and responses to EGF and α‐thrombin were inhibited on costimulation of cells with the proteases. These findings document for the first time a potential role of mast cell chymase in connective tissue repair, with tryptase being less active on fibroblasts, and with inhibitory effects of both mast cell proteases on keratinocytes.

Expression of Bcl-2 and Bcl-xL in Cutaneous and Bone Marrow Lesions of Mastocytosis

Mastocytosis is a rare disease characterized by accumulation of mast cells in tissues. To investigate whether an altered regulation of mast cell apoptosis might be involved in the pathogenesis of mastocytosis, expression of the apoptosis-preventing molecules bcl-2 and bcl-xL was studied by immunohistochemistry in skin and bone marrow lesions of mastocytosis patients. In addition, reverse transcription-polymerase chain reaction was used to investigate levels of bcl-2 and bcl-xL mRNA in cutaneous mastocytosis lesions. Since activating mutations of c-kit are known to be associated with some forms of mastocytosis, human mast cell cultures were also stimulated via c-kit and the expression of bcl-2 and bcl-xL was assessed by immunoblotting. In patients with mastocytosis, the expression of bcl-2 protein but not bcl-xL in cutaneous mast cells was significantly enhanced, compared to healthy controls. Evaluating different subgroups of adult and pediatric mastocytosis patients, all groups were found to express significantly increased levels of bcl-2 protein, and none of the patient groups was found to overexpress bcl-xL, with the exception of solitary mastocytomas that showed a tendency for up-regulated bcl-xL protein. Furthermore, the expression of bcl-2 mRNA was significantly enhanced in cutaneous lesions of adult and pediatric patients, while bcl-xL mRNA levels were only slightly increased in pediatric, but not in adult patients with mastocytosis. In contrast to the skin lesions, bone marrow infiltrates of patients with systemic mastocytosis showed only low or absent immunoreactivity for bcl-2, but marked expression of bcl-xL. In vitro, stimulation of two different mast cell culture systems by activation of c-kit resulted in up-regulation of bcl-2 and also in an increase of bcl-xL, although less pronounced. Thus, overexpression of bcl-2 and bcl-xL leading to prolonged survival of mast cells may contribute to the pathogenesis of mastocytosis. Our findings may help to develop new strategies for the treatment of this disease.

„Vernarbende” Alopezien Anmerkungen zur Klassifikation, Differentialdiagnose und Pathobiologie

ZusammenfassungVernarbende Alopezien mit irreversiblem Follikeluntergang stellen den Endzustand zahlreicher unterschiedlicher Krankheiten dar. Gebräuchliche Klassifikationen können pathogenetische Kriterien nicht zufriedenstellend berücksichtigen, da bisher unklar ist, durch welche Mechanismen im einzelnen der bleibende Follikelverlust bedingt ist. Am Beispiel von Sonderformen (Lichen planopilaris, Pseudopelade) werden bisherige Bemühungen um nosologische Zuordnung, aber auch die Grenzen geltender Klassifikationen und diagnostischer Möglichkeiten kritisch gewürdigt. Eine neue Einteilung der „vernarbenden” Alopezien, bei denen jedoch Vernarbungszeichen keineswegs zwingend sind, wird gefordert, die auf jüngeren Erkenntnissen zur Biologie und Pathologie von Haarfollikel, Haarzyklus und Bindegewebe aufbaut. Wesentlich für das Überleben des Follikels nach Traumatisierung erscheinen Regenerations- und Funktionsfähigkeit sowohl der epithelialen Follikelstammzellen in Höhe des Haarwulstes als auch der hochspezialisierten Fibroblasten der dermalen Papille sowie die molekulare Kommunikation zwischen diesen beiden Zellpopulationen. Die Erforschung vernarbender Alopezien sollte eine Definition pathologischer Prozesse anstreben, die auf den genannten Ebenen zu einer irreversiblen Follikelschädigung führen, um Voraussetzungen für neue therapeutische Optionen (z.B. Stammzellprotektiva, -stimulanzien) zu schaffen.SummaryNumerous different diseases lead to scarring alopecia with irreversible follicular destruction as a common ending. Current classifications are based on clinical, histopathological or prognostic parameters, as well as on pathogenetic criteria which allow only a rough assessment because the precise mechanisms leading to scarring alopecia are still unknown. Inadequacies of the established classifications are obvious when regarding special forms of scarring alopecia like lichen planopilaris or pseudopelade Brocq. In order to develop more satisfying classifications, recent insights into biology and pathology of the hair follicle and follicular cycling have to be considered. The most important structures for the survival of the hair follicle are the epithelial stem cells which reside in the follicular bulge and the fibroblasts of the dermal papilla including the molecular communication between these two cell populations. Research in the field of scarring alopecia should aim at defining the pathological processes on any of the above mentioned levels which will lead to an irreversible damage of the hair follicle thus allowing the development of new therapeutic agents.

Morgellons in dermatology

Delusional parasitosis (DP) is the most frequent delusional disorder in dermatology. In DP there is a fixed belief of a usually skin‐related invasion or infestation by a number of alleged infectious species (usually parasites and bacteria), whose identity has varied over the decades. Since 2002 worldwide an increasing number of patients have complained of unverifiable fibers and filaments in or on the skin, associated with numerous nonspecific complaints (arthralgias, altered cognitive function and extreme fatigue). This entity has been named “Morgellons disease” by the patients themselves, although medical evidence for its existence is lacking. As an example, we discuss a 55‐year‐old woman who complained of Morgellons disease and was treated as if she had DP. Currently the delusional assumption of infestation with Morgellons should be considered as a new type of DP with some kind of inanimate material. We therefore recommend in case of DP including Morgellons the use of the broader term “delusional infestation”.

Erfolgreiche Behandlung des chronisch diskoiden Lupus erythematodes mittels Argon-Laser

ZusammenfassungWir berichten über eine Patientin mit chronisch diskoidem Lupus erythematodes (CDLE), bei der wir erstmals den Argon-Laser zur Lokaltherapie einsetzten. Die Patientin litt unter langjährigen Hautveränderungen, die sich nicht oder nur geringfügig durch etablierte Behandlungsstrategien beeinflussen ließen. Nach Anwendung des Argon-Lasers kam es im Bereich der therapierten Läsionen zu einer vollständigen und dauerhaften Abheilung. Histologische und immunhistologische Befunde sprechen dafür, daß gefäßmediierte Effekte des Argon-Lasers für die beobachtete Wirkung bei LE-bedingten diskoiden Läsionen von Bedeutung sind. Im Rahmen dieser Fallbeschreibungen wird erstmals die Wirksamkeit des Argon-Lasers bei der Behandlung von therapieresistenten diskoiden Hautläsionen beim Lupus erythematodes gezeigt.SummaryWe report on a patient with chronic discoid lupus erythematosus who was treated with argon-laser. The patient suffered from long-standing lesions and had been pretreated with various drugs, with no or slight improvement. After a few argon-laser applications, the treated skin lesions improved dramatically while the untreated lesional skin showed continuous disease activity. Histological and immunohistological investigations of biopsies from treated and untreated lesional skin suggest that endothelial mechanisms play a role in the generation and maintenance of discoid lesions in lupus erythematosus. This is the first reported case of successful treatment of chronic discoid skin lesions of a lupus erythematosus patient with argon-laser.

Diagnostics of autoimmune bullous diseases in German dermatology departments.

Background: No consistent data are available on the currently employed diagnostic tools for autoimmune bullous diseases in Germany. The aim of this survey was to describe currently performed diagnostic methods for bullous autoimmune diseases in German dermatology departments.

Evidence for altered mast cell proliferation and apoptosis in cutaneous mastocytosis

Background  Mastocytosis presents as a focal or generalized increase of mast cells, particularly in the skin, but also in other organs. Activating mutations of KIT (formerly c‐kit), the receptor of the mast cell growth factor stem cell factor (SCF), appear to play a key role in the pathogenesis of sporadic adult onset mastocytosis. However, these mutations are not present in childhood‐onset and familial mastocytosis and also fail to explain the heterogeneity of adult‐onset disease. Other factors such as prolonged survival of mast cells may therefore participate in causing and modulating the pathological increase of mast cells in mastocytosis.