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Biomedical subjects

W H Boehncke

Publications and source records attributed to W H Boehncke.

At least 19 recordsLinked to original sources

[Tolerability of a selective cyclooxygenase-2-inhibitor (rofecoxib) in patients with intolerance reactions to nonsteroidal anti-inflammatory agents].

BACKGROUND AND OBJECTIVE: Pseudoallergic reactions triggered by nonsteroidal anti-inflammatory drugs (NSAIDs) are common and caused by inhibition of the enzyme cyclooxygenase-1, whereas their therapeutic effects are mediated by inhibition of cyclooxygenase-2. This study analyzed the tolerability of the selective cyclooxygenase-2-inhibitor rofecoxib in patients who encountered pseudoallergic reactions to NSAIDs. PATIENTS AND METHODS: 37 patients (12 males, 25 females, mean age 35 years [15-75 years]) with a history of pseudoallergic reactions to NSAIDs underwent standardized skin prick, scratch and patch tests along with oral placebo-controlled blinded exposure to rofecoxib (maximum single dose 12.5 mg, cumulative dose 25 mg). RESULTS: 23 patients had skin reactions, 4 times respiratory symptoms were documented, and in 10 cases cutaneous as well as respiratory symptoms were reported. Salicylic acid was identified as the most common trigger for a pseudoallergic reaction (n = 28). In 9 cases several non-steroidal antiphlogistics of different chemical groups caused symptoms. All skin tests showed negative results. Oral challenge with rofecoxib was tolerated by all 37 patients without adverse effects. CONCLUSION: Given the high incidence of pseudoallergic reactions to NSAIDs the use of selective cyclooxygenase-2-inhibitors represents a therapeutic alternative as well as a means of prevention of the described reactions.

Adolescent↗

Antibodies to desmogleins 1 and 3, but not to BP180, induce blisters in human skin grafted onto SCID mice.

Pemphigus and bullous pemphigoid (BP) are blistering skin diseases associated with IgG autoantibodies to desmosomal and hemidesmosomal components. When autoantibodies to desmogleins 1 and 3 from patients with pemphigus foliaceus (PF) and pemphigus vulgaris (PV) or rabbit antibodies against the murine hemidesmosomal component BP180 are passively transferred into neonatal mice, they induce blisters in the skin of the mice. To develop an animal model that would duplicate the findings in the skin of the patients more closely, full-thickness human skin from healthy volunteers was grafted onto SCID mice. Injection of the purified IgG fraction from the serum of PF and PV patients led to subcorneal and suprabasal splits in the human grafts and human IgG was deposited intercellularly in the upper and lower layers of the epidermis, respectively. Interestingly, anti-BP180 autoantibodies purified from the serum of BP patients and from a rabbit immunized with recombinant human BP180 strongly bound to the basement membrane zone of the grafts (n=32), fixed murine complement, led to the recruitment of neutrophils to the upper dermis of the graft, but did not induce subepidermal blisters. We report a novel experimental model for PF and PV which should greatly facilitate further studies to dissect the immunopathological mechanisms in these diseases. Specifically, this model can be used to identify pathogenically relevant epitopes on human desmogleins 1 and 3 and to develop novel strategies for the treatment of pemphigus.

Animals↗

The Western blot is a highly sensitive and efficient technique in diagnosing allergy to wasp venom.

BACKGROUND: Diagnosis of allergy to wasp venom and decision to perform immunotherapy are based on the patient's history, along with skin and in vitro tests. OBJECTIVE: Given the high prevalence of specific IgE also in non-allergic individuals, we evaluated the sensitivity and specificity of Western blots as a possible alternative to serum analyses of venom-specific IgE. METHODS: Skin prick and/or intracutaneous tests were performed in 30 patients with allergy to wasp venom (generalized reaction following sting) along with serum analysis of venom-specific IgE (AlaSTAT microplate) and Western blots. Western blots were subsequently scanned and evaluated qualitatively and semiquantitatively by means of densitometry. Bands were scored 'positive' in cases of signal intensities beyond the mean plus 3 standard deviations of control sera. Twenty newborns (age 2-7 days) and 30 adults without systemic or increased local reactions to hymenoptera stings served as controls. RESULTS: Western blot sensitivity reached 100% in the samples studied and was thus superior to the sensitivities of serum analysis of venom-specific IgE using AlaSTAT microplate assay (90%) and skin tests (87%). The sensitivity of detection of a phospholipase A1 and antigen 5-specific band was higher compared with a hyaluronidase-specific band (97%, 97% and 86%, respectively). Twenty-four out of twenty-nine (83%) patients exhibited specific IgE antibodies against at least three distinct allergens. With regard to the specificities, skin tests as well as AlaSTAT microplate assays were comparable (90% and 93%, respectively), whereas the specificity of the Western blots was 70% if the appearance of any single band was regarded as a positive result. However, when analysing the appearance of a specific band for antigen 5 or hyaluronidase the specificity and overall diagnostic value increased markedly, making it the most efficient test (specificity 97% and 100%, efficiency 96.8% and 93.2%, respectively). CONCLUSION: As allergy to wasp venom is a severe and potentially life threatening disease, false-negative test results need to be minimized. Therefore, the superiority of the Western blot with regard to sensitivity, specificity and overall efficiency makes this technique a valuable tool for its diagnosis.

Adolescent↗

Antagonistic effects of the staphylococcal enterotoxin a mutant, SEA(F47A/D227A), on psoriasis in the SCID-hu xenogeneic transplantation model.

Psoriasis is a T-cell-mediated immune dermatosis probably triggered by bacterial superantigens. This pathomechanism has been experimentally reproduced in a SCID-hu xenogeneic transplantation model. We analyzed the effects of different bacterial superantigens on the induction of psoriasis in this model. Staphylococcal enterotoxin B and exfoliative toxin triggered the onset of psoriasis when administered repetitively intracutaneously over a period of 2 wk, whereas staphylococcal enterotoxin A representing a distinct subfamily of staphylococcal enterotoxins only mimicked certain aspects of psoriasis. The biologic effects of staphylococcal enterotoxin A were more pronounced when a mutated form, SEA(H187A), of this superantigen with reduced affinity to major histocompatibility complex class II was coinjected. Another mutated variant, SEA(F47A/D227A), exhibiting no measurable major histocompatibility complex class II affinity blocked the effects triggered by wild-type staphylococcal enterotoxin A when injected in a 10-fold higher dose. Inhibition was specific as induction of psoriasiform epidermal changes by staphylococcal enterotoxin B could not be blocked. As staphylococcal enterotoxin A, in contrast to the other superantigens tested, is capable of inducing epidermal thickening but not the typical appearance of psoriasis, we conclude that bacterial superantigens may differ with regard to their effects on human nonlesional psoriatic skin. Staphylococcal-enterotoxin-A-mediated effects were blocked by a genetically engineered superantigen highlighting the potential therapeutic use of mutated superantigens.

Animals↗

Monitoring of phagocytic activity in histiocytic cytophagic panniculitis.

Histiocytic cytophagic panniculitis presents with subcutaneous panniculitis. Histologically, it is characterized by phagocytosis of blood cells in the subcutaneous tissue and bone marrow. One patient with histiocytic cytophagic panniculitis is described in whom hemophagocytosis macrophages and histiocytes was observed histologically and was confirmed in vitro measuring phagocytosis by peripheral blood monocytes by means of chemiluminescence. In vitro measurements of phagocytosis corresponded well with the clinical course. Chemiluminescence for measuring phagocytosis in vitro may be suitable for analyzing disease activity and for testing therapeutic compounds in vitro.

Adult↗

Calcipotriol solution for the treatment of scalp psoriasis: evaluation of efficacy, safety and acceptance in 3,396 patients.

BACKGROUND: Psoriasis of the scalp is a very common disease, cosmetically disturbing and therapeutically difficult to manage. OBJECTIVE: The aim of our study was to investigate the efficacy, safety and cosmetic acceptance of calcipotriol solution in a large number of patients with mild to moderate scalp psoriasis and to compare this treatment with previous therapies used. METHODS: In this multicentre prospective observational cohort study 3,396 patients were treated with calcipotriol solution (50 microg/ml) twice daily over an 8-week period either alone or in combination with other treatments. The psoriasis scalp severity index (PSSI) and investigator/patient global assessment were used for the evaluation of clinical response. RESULTS: All psoriasis severity parameters measured were reduced with a significant decrease in PSSI scores from 18.4 to 5.6 after 8 weeks of therapy (p < 0.001). About 80% of the patients showed very good or good clinical improvement. Combination of calcipotriol solution with other treatment modalities e.g. corticosteroids or salicylic acid, showed an increased treatment response. In only 2.4% of the patients side effects occurred (e.g. irritation). CONCLUSION: Calcipotriol solution is an effective, safe, well-tolerated and cosmetically acceptable treatment modality. By patients and physicians, this treatment was found to be a valuable supplement to previously available and established treatments for scalp psoriasis.

Adult↗

Mycophenolate mofetil is effective in the treatment of atopic dermatitis.

OBJECTIVE: To evaluate whether mycophenolate mofetil, a new immunosuppressive agent, is effective for treating moderate-severe atopic dermatitis (AD). DESIGN: In an open-label pilot study, mycophenolate mofetil, 1 g, was given orally twice daily for 4 weeks. At week 5, the dosage was reduced to 500 mg twice daily until study end (week 8). Patients were followed up for 20 weeks. SETTING: University hospital dermatology department. PATIENTS: Ten consecutive patients with moderate-severe AD nonresponsive to standard therapy. MAIN OUTCOME MEASURE: Severity of AD as measured using the subjective SCORAD [SCORing Atopic Dermatitis] index. RESULTS: Clinical efficacy was measured every 2 weeks using the subjective SCORAD index. Treatment with mycophenolate notably reduced the severity of AD within 4 weeks in all patients (P<.05), and after 8 weeks the mean +/- SD SCORAD index dropped from the pretreatment value of 49.2 +/- 13.8 to 21.9 +/- 26.5 (P<.01). One patient had to discontinue mycophenolate therapy after 4 weeks because of the development of herpes retinitis. Except for this event, mycophenolate was tolerated well in all patients. Six of 7 patients who had responded to mycophenolate monotherapy had no relapse of disease during 20-week follow-up. In the 7 patients who finished the study, the SCORAD index was reduced by 74%, from 44.0 +/- 7.8 before treatment to 11.4 +/- 5.9 at 20-week follow-up. CONCLUSIONS: Mycophenolate is a highly effective drug for treating moderate-severe AD, with no serious adverse effects occurring in any patients. Thus, mycophenolate might develop into a promising alternative in the therapy of moderate-severe AD.

Administration, Oral↗

Expression of the basal cell adhesion molecule (B-CAM) in normal and diseased human skin.

The basal cell adhesion molecule (B-CAM) is a 90-kD cell surface glycoprotein with a characteristic immunoglobulin domain structure. The pattern of B-CAM expression in cultured cells suggests that the molecule is associated with a substrate-adherent growth pattern in some lineages. We investigated the expression of B-CAM in normal and diseased human epidermis by means of immunohistochemistry employing a single batch of high-titer mouse monoclonal antibody G253. Snap-frozen biopsy material from normal skin (n = 8), psoriasis (n = 5), contact dermatitis (n = 6), basal cell carcinoma (n = 5) and fetal skin (n = 6) was studied. In normal human skin, B-CAM was found in varying degrees throughout the epidermis with a preference for suprabasal expression, hair follicles were regularly of a B-CAM-positive phenotype. There were no qualitative differences with regard to the B-CAM expression pattern in normal skin in comparison to psoriasis and contact dermatitis. In contrast, fetal skin (15th to 18th week of gestation) was characterized by B-CAM-positive cells in the basal layer of the epidermis as well as in the outer root sheath of hair follicles. Basal cell carcinomas also regularly expressed high levels of B-CAM. A strong B-CAM-positive phenotype can be found in the outer root sheath of hair follicles of adult and fetal human skin as well as in fetal basal keratinocytes.

Basal Cell Carcinoma↗

Is psoriasis a T-cell disease?

The etiology and pathogenesis of psoriasis--one of the most common chronic, inflammatory, hyperproliferative skin disorders of man--have long fascinated dermatologists, pathologists and biologists alike. Here, we have a model disease that offers to study neuroectodermal-mesenchymal interactions in the widest sense possible. Epithelial, endothelial, and hematopoietic cells as well as neurons projecting into the skin apparently all interact with each other to generate the characteristic psoriatic lesion. For decades, the ongoing controversy on the molecular nature, choreography and hierarchy of these complex interactions e.g. between epidermal keratinocytes, T cells, neurotrophils, endothelial cells and sensory nerves has served as a driving force propelling investigative dermatology to ever new horizons. This debate has not only been at the heart of our quest to develop more effective forms of therapy for this socially crippling disease, but it also has profoundly influenced how we view the skin as a whole: the numerous competing theories on the pathogenesis of psoriasis published so far also are reflections on the evolution of mainstream thought in skin biology over the last decades. These days, conventional wisdom infatuated with a T-cell-centered approach to inflammatory skin diseases-- portrays psoriasis as an autoimmune disease, where misguided T lymphocyte activities cause secondary epithelial abnormalities. And yet, as this CONTROVERSIES feature reminds us, some authoritative "pockets of academic resistance" are still quite alive, and interpret psoriasis e.g. as a genetically determined, abnormal epithelial response pattern to infectious and/or physicochemical skin insults. Weighing the corresponding lines of argumentation is not only an intriguing, clinically relevant intellectual exercise, but also serves as a wonderful instrument for questioning our own views of the skin universe and its patterns of deviation from a state of homeostasis.

Animals↗

Treatment of chronic plaque-stage psoriasis and psoriatic arthritis with mycophenolate mofetil.

Mycophenolate mofetil (MMF), a widely used immunosuppressant in organ transplantation, is a recent addition to the therapeutic armamentarium of autoimmune and inflammatory skin disorders in dermatology. We describe 5 patients with moderate to severe chronic plaque psoriasis and 6 patients with psoriatic arthritis that was refractory to conventional systemic and/or topical antipsoriatic treatment who were treated with MMF monotherapy (2 g/d) in a 10-week study. Although MMF was tolerated well in all patients, only patients with moderate psoriasis and psoriatic arthritis improved with therapy, whereas patients with severe psoriasis did not respond to MMF. Although MMF seems to be effective and safe for blistering autoimmune diseases and pyoderma gangrenosum, our data do not allow optimistic statements on the use of MMF in severe plaque-stage psoriasis. However, MMF may develop into an interesting therapeutic alternative for patients with psoriatic arthritis.

Adult↗

Selection of conserved TCR VDJ rearrangements in chronic psoriatic plaques indicates a common antigen in psoriasis vulgaris.

Psoriasis vulgaris is a common HLA-associated inflammatory skin disease. Although its etiology is still unknown, it is thought to involve T cell-mediated inflammatory mechanisms. In examining the lesional psoriatic TCR beta chain (TCRB) usage in a pair of identical twins concordant for psoriasis, we observed repetitive TCR VDJ rearrangements which indicated antigen-specific oligoclonal T cell expansion. Several of these TCRB rearrangements were identical or highly homologous in the amino acid composition of the complementarity determining region 3 (CDR3), suggesting that T cells with these TCR might be important for disease manifestation. This conclusion was strengthened by TCR analysis of other psoriasis patients. Several repetitive lesional TCRB rearrangements were found that were similar to the conserved CDR3 seen in the twins. Since TCR antigen specificity is largely determined by the beta chain CDR3, selection of T cells with conserved TCRB CDR3 motifs could indicate the presence of a common antigen as a major target of the lesional psoriatic immune response.

Amino Acid Sequence↗

[The role of bacterial superantigens in pathophysiology of the skin].

In contrast to conventional antigens, bacterial superantigens activate a large percentage of an organism's total T-cell repertoire. This has clinical implications particularly in the case of infections with Gram-positive bacteria. Unravelling the molecular mechanisms of superantigen-mediated T-cell activation has yielded new insights in the pathogenesis of a number of diseases, in the field of dermatology namely atopic dermatitis and psoriasis. Moreover, therapeutic applications of superantigens have begun to emerge.

Dermatitis, Atopic↗

Ablative techniques in Psoriasis vulgaris resistant to conventional therapies.

BACKGROUND: Treatment of patients with psoriasis vulgaris exhibiting only solitary plaque-stage lesions might become difficult since topical treatments often fail and systemic therapies seem inappropriate. OBJECTIVE: We evaluated the feasibility of ablative techniques in this clinical setting comparing dermatome shaving to the application of an Er:YAG laser. METHODS: Six patients were treated by means of dermatome shaving; in four of these patients additional lesions were ablated utilizing an Er:YAG laser (2 J, 10 Hz, 5 mm spot size). RESULTS: Four of six patients experienced complete clearance of the lesions treated, three of the four patients receiving additional Er:YAG treatment also showed a complete clinical response. CONCLUSION: Our observations document that removal of epidermis and the papillary dermis is effective in treating recalcitrant psoriatic plaques. The Er:YAG laser represents a state-of-the-art device for performing this task. The beneficial effect on skin might be due to clearance of the putative autoantigen along with a considerable part of the potential effector cell population.

Debridement↗