Silica induced scleroderma--clinical and experimental aspects

Clinical and experimental data concerning silica induced systemic sclerosis (SSc) are discussed in comparison to current knowledge of the pathophysiology of idiopathic SSc. About 280 patients with SSc after longterm silica dust exposure, some with associated silicosis, have been reported; 111 of them were analyzed as the largest cohort in our department. Based on clinical and laboratory data, silica induced and idiopathic SSc show similar pathophysiology and similar markers of the disease including vascular involvement, immunological abnormalities, and dysregulation of extracellular matrix metabolism. Experimental studies show that silica dust is able to activate microvascular endothelial cells, mononuclear cells from peripheral blood, and dermal fibroblasts in vitro in a fashion in common with pathophysiological events known from idiopathic SSc.

[Progressive systemic scleroderma--prognosis determining involvement of internal organ systems]

Prognosis of systemic sclerosis (scleroderma, Ssc) is largely depending on involvement of internal organs. Abnormalities of the gastrointestinal tract are found most frequently (85%), especially decreased motility of the oesophagus, which has little impact on the longterm clinical course of Ssc. Pulmonary manifestations can be demonstrated in 40-90% of patients; one must distinguish between pulmonary hypertension or fibrotic lung disease. The heart is affected in 50% of cases. Patchy or diffuse myocardial fibrosis, as well as pericarditis and pericardial effusions can induce symptoms of arrhythmia or congestive heart failure. Renal involvement is associated with increased mortality and occurs in 45% of Ssc, producing proteinuria, hypertension, scleroderma renal crisis and renal failure. In conclusion, involvement of the lungs, heart and kidneys are determining factors for the longterm course of systemic sclerosis.

Pathophysiology of scleroderma: an update

OBJECTIVES

To review the pathophysiological background of systemic sclerosis in relation to the main components involved: microvascular system, immunological system and fibroblasts of the connective tissue.

BACKGROUND

Although many particular aspects of the pathophysiology of systemic sclerosis have been investigated in recent years, the complexity of the pathogenesis and the important links between the components involved remain unclear.

METHODS

Literature review.

RESULTS AND CONCLUSION

Scleroderma is a connective tissue disorder resulting in a progressive fibrosis of skin and internal organs. The genetic background is not clear. The microvascular system is one of the first targets involved (damage of capillaries, enhanced expression of adhesion molecules interacting with lymphocytes, perivascular infiltrates as starting points for tissue fibrosis). The immune system is unbalanced (selection of T-cell subpopulations, elevated serum levels of several cytokines, occurrence of autoantigens to topoisomerase I, centromeric proteins and RNA polymerases). As far as autoimmunity is concerned the triggering autoantigen is still unknown. Development of connective tissue fibrosis is prominent (subpopulations of fibroblasts with disturbed regulation of collagen turnover by TGF-beta, CTGF and collagen receptors (alpha1beta1, alpha2beta1)). Investigation of pathophysiology of scleroderma is effected by monitoring the serum levels for soluble mediators, by cell culture studies of affected and non-affected fibroblasts and EC, by studying environmentally induced forms of scleroderma and by studies using animal models.

The monoclonal antibody AS02 recognizes a protein on human fibroblasts being highly homologous to Thy-1

Recently, we described a novel fibroblast-restricted monoclonal antibody (mAb AS02) that recognizes a membrane-bound antigen. Characterization and isolation of the corresponding antigen showed that mAb AS02 recognized a protein on human fibroblasts that is highly homologous or identical to human Thy-1 antigen (CD90). Partial amino acid sequencing of the corresponding mAb AS02 antigen and comparison with known proteins revealed a 100% homology of the sequenced peptides to the human Thy-1 antigen. Cross-immunodepletion studies with mAb AS02 and an anti-Thy-1 antibody confirmed these results. Utilizing two-dimensional (2D) gel electrophoresis of fibroblast cell extracts and purified antigen, mAb AS02 and the anti-Thy-1-antibody recognized identical protein spots. Furthermore, we demonstrated many identical biochemical properties of the corresponding AS02 antigen and Thy-1 antigen, such as the molecular weight of the core protein and deglycosylation products and the detection of a GPI anchor. In functional assays, the attachment of fibroblasts to collagen I and fibronectin was increased after incubation of fibroblasts with mAb AS02. Therefore, the Thy-1 antigen appears to be involved in the regulation of the adherence of human dermal fibroblasts.

Squamous cell carcinoma of the skin--histopathological features and their significance for the clinical outcome

BACKGROUND

Owing to the rising incidence of tumours, the question of reliable risk classification is becoming increasingly significant.

OBJECTIVE

Participation in the multicentre carcinoma registry maintained by the Association of Operative and Oncological Dermatology of the German Dermatological Society requires, in addition to the parameters of clinical staging and grading already established by the International Union against Cancer, description of other histopathological criteria related to prognosis, with special attention to microstaging.

METHODS

One hundred and eighty-four patients with squamous cell carcinoma of the skin were examined. The histological parameters, carcinoma type, Breslow index, invasion level, growth form, grading and mitotic index were recorded and classified, and clinical staging was performed.

RESULTS

It was found that the clinical criterion of tumour diameter (T-category) determines the further course of the disease. The other parameters taken into account, namely pathohistological microstaging and grading, can increase the accuracy of prognosis evaluation, and in particular enable carcinomas of the T1-category to be classified as either high malignant or low malignant tumours. The desmoplastic squamous cell carcinoma subtype is a potential risk tumour. Endophytic tumours are more malignant in their development than exophytically-growing carcinomas, and the probability of recurrence and metastatic tumour spread further increases when ulceration can be detected by microscope. In order to distinguish metastatic and recurring carcinomas, in addition to determining the invasion levels after Clark, measuring the Breslow index proved to be an important criterion. Quoting the mitotic index augmented the grading system, which further improved the reliability of malignancy assessment.

CONCLUSIONS

The TNM categories currently applied to squamous cell carcinomas of the skin must be supplemented by additional histological parameters which, according to our findings, permit more accurate classification of high and low malignant tumours.

Serum levels of soluble Fas/APO-1 receptor are increased in systemic sclerosis

It has been suggested that rheumatic diseases may result from a deficit in Fas-mediated T-cell apoptosis. Recent studies have demonstrated increased soluble Fas in sera from lupus erythematosus patients. We were interested to determine whether elevated soluble Fas levels are associated with systemic sclerosis. Soluble Fas levels were retrospectively assayed using a sandwich enzyme-linked immunosorbent assay in serum from 30 patients with systemic sclerosis and 15 normal controls. Hospital medical records were retrospectively reviewed for clinical and laboratory characteristics of the patients. Soluble Fas levels were analysed in subsets of patients with limited (lcSSc) versus diffuse cutaneous systemic sclerosis (dcSSc) and correlated with inflammatory activity. In systemic sclerosis soluble Fas serum levels (lcSSc, 2.19 +/- 0.71 ng/ml, dcSSc 2.53 +/- 1.37 ng/ml) were significantly higher than in normal controls (1.26 +/- 0.36 ng/ml). However, there were no significant differences in soluble Fas levels between lcSSc and dcSSc and poor correlation between soluble Fas levels and inflammatory activity status. Detection of elevated soluble Fas might serve as a clinical marker for immunological dysregulation in systemic sclerosis, but not for inflammatory disease activity.

Cyclosporine A delays wound healing and apoptosis and suppresses activin beta-A expression in rats

Cyclosporine A is a powerful immunosuppressive agent which is widely used for the prevention of allograft rejection and for the treatment of autoimmune diseases. Clinical and experimental data show that it may also act on connective tissue. We investigated the influence of cyclosporine A on granulation tissue formation and wound healing. Using an in vitro approach, we followed the time course of rat dermal fibroblasts during wound repair. Granulation fibroblasts were compared to dermal fibroblasts flow cytometrically and by mRNA analysis with respect to the expression of procollagen alpha1(I), integrin beta1, interleukin-6, transforming growth factor beta1, keratinocyte growth factor and activin betaA. The most pronounced effect in cyclosporine-treated rats was the strong down-regulation of activin beta expression. In cryo-sections of granulation tissue from the same rats, the distribution and expression intensity of intercellular adhesion molecule and its receptors were investigated by immunohistology. Clearly, a time course was detectable. Tissue from CsA-treated animals showed a delay of three days compared to untreated animals. Apoptosis was also delayed in CsA-treated rats by around three days. Furthermore, we investigated the effect of CsA on the expression of collagen alpha1(I), fibronectin and matrix metalloprotease 1 genes in dermal fibroblasts from untreated donors. No changes in the mRNA steady state levels of these genes were revealed after direct addition of different doses of CsA to fibroblast cultures. Our data suggest that CsA may interfere with the complicated net of interactions between connective tissue and the immune system by down-regulation of the inflammatory phase by modulation of cytokines and a subsequent delay of tissue repair.

The fibroblast-specific MAb AS02: a novel tool for detection and elimination of human fibroblasts

The unwelcome presence of fibroblasts in many cell cultures prevents the long term cultivation of various cell types and work with pure populations. Recently, we described a novel fibroblast-specific monoclonal antibody (MAb AS02) that recognises a membrane-bound antigen. We have now developed a method using the fibroblast-specific MAb AS02 immobilised on goat-anti-mouse-magnetic beads to separate contaminating fibroblasts. An endothelial cell line experimentally contaminated with 5%-50% fibroblasts was successfully purified. Additionally, an endothelial cell line with an initial fibroblast contamination of 1.5% was prepared. A proportion of each preparation was cultured with no separation step being performed, whereas the remainder was cultured after purification with MAb AS02 to exclude the presence of a minor number of fibroblasts (<0.1%). The proportion of fibroblasts increased up to 38% in the fifth passage of culture without elimination of the low initial fibroblast contamination, whereas in the fraction with the separation step, no fibroblasts were detectable by flow cytometry, even after the fifth passage. We also used the antibody to detect the presence of naturally contaminating fibroblasts in thyrocyte cultures. After cultivation of thyrocyte cultures over five passages, the number of fibroblasts increased dramatically up to 50%-80% of the whole population. Subsequently, we successfully applied the method for complete elimination of naturally contaminating fibroblasts from freshly isolated thyrocyte cultures from enzymatically digested thyroid glands. Thus, MAb AS02 is a fibroblast-specific marker that is a useful tool for the detection and elimination of contaminating fibroblasts. The specificity of MAb AS02 permits the universal application of this antibody for human cell cultures of interest.

Combination of an island advancement flap and a composite graft for reconstruction of the nasolabial defect

BACKGROUND

The alar region is one of the most difficult areas of the face to reconstruct. Up until now, various methods have been demonstrated for achieving the best possible results in terms of cosmetic appearance and function. This report deals with a combination of a random pattern flap and a free composite graft, carried out in two stages.

OBJECTIVE

In order to reconstruct the alar region, an island advancement flap as well as a composite graft from the contralateral ear were used.

METHODS

The defect in the cheek-upper lip region was closed using an island advancement flap. In a second operation 2 weeks later, the reconstruction of the alar region was attempted using a composite graft from the right ear.

RESULTS

The reconstruction of the contour of the wing of the nose succeeded in a satisfactory manner. There are no functional restrictions on nose breathing.

CONCLUSIONS

The combination of an island advancement flap with a composite graft from the ear for the reconstruction of the alar region is essentially a less invasive operation that can be carried out under local anaesthesia and that represents an addition to the previously stated methods.

In situ expression and serum levels of tumor necrosis factor-alpha receptors in patients with early stages of systemic sclerosis

OBJECTIVE

Tumor necrosis factor-alpha (TNF-alpha) is an important cytokine in the early stage of systemic sclerosis (SSc), which is characterized by mononuclear cell infiltration and microvascular alterations. Most effects of TNF-alpha are mediated by its interaction with 2 types of TNF receptors and depend on their surface expression on individual cell subsets. Our purpose was to correlate the serum levels of soluble TNF receptors-TNF-RI(p55) and RII(p75)-with (1) their in situ expression and distribution in lesional skin and on peripheral blood mononuclear cells (PBMC), and (2) the clinical disease progression and inflammatory serum variables in patients with SSc.

METHODS

Serum samples of 32 patients with SSc and 36 healthy probands were examined by ELISA. We performed immunohistological stainings and in situ hybridization on cryostat sections of skin lesions, cytometric analysis on PBMC, and reverse transcriptase polymerase chain reactions using RNA from cultured skin fibroblasts in 17 of these 36 patients.

RESULTS

In contrast to healthy skin and chronic fibrotic SSc, TNF-RI is expressed on about 30% of mononuclear infiltrating cells in early skin lesions. Neither TNF-RI nor RII was detectable on fibroblasts by immunohistochemistry, but specific mRNA could be found on the transcriptional level. TNF-RII is found on most lymphocytes and on 30-50% of endothelial cells, especially in early SSc. Expression of both receptor types on PBMC in patients and controls was not significantly different. Serum levels of soluble TNF-RI and RII correlated well with their in situ expression and with clinical and laboratory signs of inflammation and disease progression in patients with SSc.

CONCLUSION

Our data provide evidence for a central role of the TNF-alpha/TNF-R system in the early pathological events of scleroderma with prominent inflammation and endothelial cell damage. Determination of TNF-R serum levels provides a useful diagnostic tool for characterization of the disease stage and progression, and to guide experimental therapy in patients with SSc.

Tinea corporis due to Trichophyton tonsurans Malmsten--report of a patient from Zaire

Trichophyton tonsurans is an anthropophilic dermatophyte that is predominantly responsible in man for tinea capitis. Although this fungus has a world-wide distribution, most reports of the occurrence of Trichophyton tonsurans infections originate from the USA, Latin America and some European countries. A 31-year-old African woman, formerly a resident of Zaire, with tinea corporis caused by Trichophyton tonsurans infection is described here.

Molecular analysis of different phases in human wound healing

Cultured granulation fibroblasts grown from punch biopsies of the same lower arm area, obtained 3, 6, 9 and 14 days after wounding, were used as a human wound healing model in comparison to quiescent fibroblasts. We investigated the expression of key extracellular matrix components at the protein level by flow cytometry and mRNA steady state levels by Northern blotting of the different fibroblasts and compared these data to the ability to migrate towards a chemotactic signal. Procollagen alpha 1 (I), fibronectin and matrix metalloprotease-1 synthesis was strongly up-regulated at the mRNA steady state level on days 3 and 14. Tissue inhibitor of metalloprotease-1 mRNA is only 20% down-regulated between day 3 and 14. Chemotaxis towards conditioned medium reflects a net effect of several factors and is distinctly different from chemotaxis towards platelet-derived growth factor, which peaks at day 3. Compared to the protein level, the enhanced expression of the corresponding PDGF receptor beta chain mRNA is delayed by 3 to 6 days. PDGF receptor alpha shows no regulatory changes during the observation period. This data further supports the idea that functionally divergent subpopulations of fibroblasts exist during wound healing.

[Longitudinal study of the excretion of 1-hydroxypyrene in urine after external treatment with coal tar]

In order to study the dermal uptake, time course, and urinary excretion of polycyclic aromatic hydrocarbons, the concentration of 1-hydroxypyrene in urine was determined by means of high performance liquid chromatography with fluorescence detection before, during, and after the topical treatment with coal tar in 19 patients suffering from prurigo simplex subacuta, microbial eczema, atopic dermatitis, eczematization after scabies, exanthematous lichen ruber, pityriasis lichenoides and cutaneous sarcoidosis. Beginning with a value of 6.04 +/- 2.06 micrograms 1-hydroxypyrene/g creatinine before treatment, the urinary excretion significantly increased during the therapy with coal tar (p < 0.0001 at 3rd, 5th, and 6th day of therapy). A maximum was reached at day 8 of topical treatment with a value of 584.35 +/- 191.96 micrograms 1-hydroxypyrene/g creatinine (p < 0.002). Already during treatment at day 10 there was a beginning decrease of 1-hydroxypyrene to 361.63 +/- 170.13 micrograms/g creatinine. After the end of treatment, the excretion further decreased reaching a value of 5.31 +/- 2.85 micrograms 1-hydroxypyrene/g creatinine at the 10th day after therapy. Skin carcinomas due to therapeutical use of coal tar occur extremely rarely and only after vergoten, non-controlled use. We suggest that the duration of exposure is the most important factor for the carcinogenic effect of coal tar.

[Bullous mastocytosis in a child]

We report a case of bullous mastocytosis in a 30-month-old girl, who developed disseminated pruritic urticarial and bullous lesions on the trunk accompanied by episodes of vomiting and generalized flushing. Her problems began at the age of 6 months. Her stool was repeatedly positive for occult blood. Histamine and 5-hydroxytryptamine were measured in the urine and serum; urine 5-hydroxytryptamine levels were elevated. In addition, trypsin and chymotrypsin levels were raised in the blister fluid. Metachromatic staining of the mast cells in a skin biopsy specimen confirmed the diagnosis. A combination of oral disodium cromoglycate and ketotifen produced a dramatic improvement of the cutaneous and gastrointestinal features.

In vitro susceptibility testing of Malassezia furfur against rilopirox

The in vitro antifungal activity of the new hydroxypyridone antimycotic rilopirox has been evaluated against 29 separate clinical isolates of Malassezia (M.) furfur obtained from patients with pityriasis versicolor, seborrhoeic dermatitis or dandruff. Minimum inhibitory concentrations (MICs) of rilopirox were measured by the agar dilution technique and, in comparison, by a recently described microdilution method with colorimetric detection of the MIC end points. Rilopirox was found to be able to inhibit growth of all clinical yeast isolates. For the investigated M. furfur strains MIC values from 12.5 to 50 micrograms ml-1 with a median of 25 micrograms ml-1 were determined by the agar dilution method. Using the microdilution technique, MIC values between 16 and 128 micrograms ml-1 (median 32 micrograms ml-1) were found for the M furfur isolates. It has to be taken into account that with a 0.3% solution concentrations of 300,000 micrograms ml-1 are applied to the skin. Furthermore, due to its extreme low penetration rilopirox is long-term available in the skin in inhibiting concentrations. In comparison with rilopirox, the in vitro susceptibility of M. furfur against the systemically applicable triazole antimycotic itraconazole and clotrimazole, an established topical antifungal, was tested. As expected, low MIC values for these azoles were found by the agar dilution method. The median of the MIC of M. furfur was 0.1 microgram ml-1 for itraconazole, and 6.25 micrograms ml-1 for clotrimazole. The inhibitory effectivity of rilopirox against clinical isolates of M. furfur seems to justify its therapeutic evaluation in clinical trials. This new antifungal may be a useful alternative not only in pityriasis versicolor but also in seborrhoeic dermatitis due to the growth inhibition of M. furfur.

Rare fatal simultaneous mould infection of the lung caused by Aspergillus flavus and the basidiomycete Coprinus sp. in a leukemic patient

The basidiomycete Coprinus sp. was isolated repeatedly from bronchial secretions and bronchoalveolar lavage of a 40-year-old woman suffering from a relapse of acute lymphoblastic leukemia 5 years after she underwent autologous bone marrow transplantation. Post-mortem microbiological investigation of lung tissue revealed simultaneously growing Coprinus sp. and Aspergillus flavus. Histopathological examination of the lung demonstrated septate hyphae characteristic of both Aspergillus and Coprinus. The basidiomycete Coprinus sp. should be considered as a potential opportunistic pathogen because of its excellent growth at 37 degrees C.

In vitro analysis of adhesion molecule expression and gel contraction of human granulation fibroblasts

The objective of this study was to determine whether human fibroblasts obtained at different times from normally healing wounds were phenotypically distinct with respect to cell-matrix interactions. We cultured human granulation fibroblasts obtained from repeated biopsies from the same punch area. On days 3, 6, 9, and 14 the expression of key adhesion molecules and extracellular matrix components at the protein level by flow cytometry analysis were compared with quiescent fibroblasts. Intercellular adhesion molecule-1 levels were significantly elevated only around day 3, which implies a phenotypic change during the early phase of wound healing. Homing cell adhesion molecule, as well as the alpha4 integrin subunit (CD49d), were essentially unaltered. The alpha5 integrin subunit (CD49e), which imparts the specificity of the fibronectin receptor and alphav (CD51), a vitronectin receptor component, are upregulated around days 3 and 6; the alpha2 and 3 integrin subunits (CD49b/c) were only increased on day 6. In granulation fibroblasts, at days 3 and 14, the level of the beta1 integrin subunit was enhanced. In addition, collagen gel contraction with granulation fibroblasts increases constantly from day 3 to day 14. These results show that human granulation fibroblasts differentially express cell surface adhesion molecules depending on the age of the healing wound. Further, changes in the ability of these cells to contract collagen gels indicate a synchronicity between wound bed contraction and different stages of wound healing.

Disseminated mycosis due to Scedosporium prolificans in an AIDS patient with Burkitt lymphoma

A case of fatal disseminated infection caused by the dematiaceous hyphomycete Scedosporium prolificans diagnosed post mortem is reported in a 60-year-old male patient with acquired immunodeficiency syndrome who additionally suffered from Burkitt's lymphoma. The patient was significantly granulocytopenic following aggressive chemotherapy and irradiation. He developed dyspnoea at rest and chest pain despite a normal chest radiograph. Fluconazole treatment was carried out empirically because no sign of a fungal infection was detected ante mortem, either by mycological cultivation or by serological investigation. First post-mortem examination revealed a disseminated fungal infection involving the central nervous system. Scedosporium prolificans was cultured from the kidney, spleen and myocardium. In vitro, the fungal isolate was found to be highly resistant to all available systemic antimycotics.

Tacalcitol ointment in the treatment of psoriasis vulgaris: a multicentre, placebo-controlled, double-blind study on efficacy and safety

Tacalcitol is a vitamin D analogue which ahs been developed for the therapy of psoriasis vulgaris. The treatment with a twice daily application of 2 micrograms/g ointment is efficacious and safe in Japanese patients. The objective of this randomized, placebo-controlled, intraindividual right-left comparison was to investigate the efficacy and safety of 8 weeks' therapy with a once daily application of a 4 micrograms/g tacalcitol ointment in Caucasian psoriatics. The data on 122 male and female patients were analysed. The score sum of erythema, infiltration and desquamation was influenced significantly more by tacalcitol ointment than by placebo (P < 0.0001) at every control point, starting from week 2. With regard to the individual symptoms of desquamation, infiltration and erythema, the treatment with tacalcitol was also superior to placebo treatment beginning at week 2. Qualitatively, the same results were obtained with the preference assessment of both treated body sides and also the global assessments of efficacy and benefit. Symptoms of local skin irritation which may be related to the active compound or the ointment base were reported by 12.3% of patients. In only one patient, irritation required discontinuation of tacalcitol treatment. Laboratory criteria, including serum calcium, serum phosphate and serum levels of calcitonin, parathormone, 1 alpha, 24-dihydroxyvitamin D3 and 25-hydroxyvitamin D3, did not reveal any changes of clinical relevance during or after treatment. Furthermore, the global assessment of tolerance was good or very good in more than 90% of cases. The results of this study demonstrate that the once daily application of a 4 micrograms/g tacalcitol ointment is an efficacious therapy for psoriasis vulgaris in Caucasian patients, and that its tolerance is good, wherever the lesion is located, including on the face.