Single-cell RNA sequencing profiling in a patient with discordant primary cutaneous B-cell and T-cell lymphoma reveals micromilieu-driven immune skewing.

BACKGROUND: Primary cutaneous lymphomas comprise a heterogeneous group of B-cell and T-cell malignancies which often show an indolent course, but can progress to aggressive disease in a subset of patients. Diagnosis is often delayed owing to clinical and histopathological similarities with benign inflammatory conditions. Especially during early disease, cancer cells are present at relatively low percentages compared with the inflammatory infiltrate, an interplay that is currently only insufficiently understood. OBJECTIVES: To improve diagnostics and perform molecular characterization of a complex type of primary cutaneous lymphoma. METHODS: Single-cell RNA sequencing (scRNA-seq) was performed and combined with T-cell and B-cell receptor sequencing. RESULTS: We were able to diagnose a patient with concurrent mycosis fungoides (MF) and primary cutaneous follicle centre lymphoma (PCFCL), appearing in mutually exclusive skin lesions. Profiling of tumour cells and the tissue microenvironment revealed a type-2 immune skewing in MF, most likely guided by the expanded clone that also harboured upregulation of numerous pro-oncogenic genes. By contrast, PCFCL lesions exhibited a more type-1 immune phenotype, consistent with its indolent behaviour. CONCLUSIONS: These data not only illustrate the diagnostic potential of scRNA-seq, but also allow the characterization of specific clonal populations that shape the unique tissue microenvironment in clinically distinct types of lymphoma skin lesions.

Biologic drug survival rates in the era of anti-interleukin-17 antibodies: a time-period-adjusted registry analysis.

BACKGROUND: Drug survival rates reflect efficacy and safety and may be influenced by the availability of alternative treatment options. Little is known about time-dependent drug survival in psoriasis and the effect of increasing numbers of biologic treatment options. OBJECTIVES: To determine whether drug survival is influenced by the availability of treatment options and by factors such as gender, psoriatic arthritis or previous biologic treatment. METHODS: This observational, retrospective, multicentre cohort study analysed data from patients registered in the Austrian Psoriasis Registry (PsoRA) who were treated with biologics between 1 January 2015 and 30 November 2019. RESULTS: A total of 1572 patients who received 1848 treatment cycles were included in this analysis. The highest long-term Psoriasis Area and Severity Index improvement was observed after treatment with ixekizumab, followed by ustekinumab and secukinumab, adalimumab and etanercept. Overall, ustekinumab surpassed all other biologics in drug survival up to 48 months. However, when adjusted for biologic naïvety, its superiority vanished and drug survival rates were similar for ixekizumab (91·6%), secukinumab (90·2%) and ustekinumab (92·8%), all of them superior to adalimumab (76·5%) and etanercept (71·9%) at 12 months and beyond. Besides biologic non-naïvety (2·10, P < 0·001), the introduction of a new drug such as secukinumab or ixekizumab (relative hazard ratio 1·6, P = 0·001) and female gender (1·50, P = 0·019) increased the risk of treatment discontinuation overall, whereas psoriatic arthritis did not (1·12, P = 0·21). CONCLUSIONS: The time-dependent availability of drugs should be considered when analysing and comparing drug survival. Previous biologic exposure significantly influences drug survival. Women are more likely to stop treatment.

[Chronic leg ulcers in older patients]. / Ulcus cruris beim alten Patienten.

Chronic ulcers of the lower extremities are one of the most common medical problems encountered in western societies. The prevalence of leg ulcers is estimated to be 0.5-1.0% of the German population and is clearly associated with age. Therefore, in an aging society chronic leg ulcers are an important health issue with respect to increased morbidity and healthcare costs. The most frequent causes of leg ulcers are chronic venous insufficiency, peripheral arterial occlusive disease and diabetes mellitus. Efficient treatment necessitates an exact diagnosis and a close interdisciplinary collaboration. Affected patients often require instructions regarding self-help and support for competent nursing and prophylaxis. Therapeutic strategies, especially in the geriatric setting, aim to maintain the quality of life through preservation of patient mobility and autonomy.

Frequency of primary cutaneous lymphoma variants in Austria: retrospective data from a dermatology referral centre between 2006 and 2013.

BACKGROUND: Primary cutaneous lymphomas (PCL) are a heterogenous group of rare lymphoid neoplasms with incomplete information on global and regional prevalence. The recently introduced lymphoma classifications define distinctive clinicopathological disease entities that should allow for more accurate epidemiological assessment. OBJECTIVE: The aim of this study was to evaluate the prevalence and clinical spectrum of PCL diagnosed and treated at the Department of Dermatology and Venereology in St. Pölten, Lower Austria, a dermatology referral centre providing secondary and tertiary care for a population of about 600 000. METHODS: In this retrospective study pathology reports, electronically archived between 2006 and 2013, were screened for the terms lymphoma, mycosis fungoides (MF) and lymphomatoid papulosis (LyP). Patients were diagnosed according to the current WHO-EORTC classification for cutaneous lymphomas and results were compared with data from European, US and Asian centres. RESULTS: Among 86 patients with PCL (age 58.3 ± 17.35 years, mean ± SD; women 38%, n = 33; men 62%, n = 53) 83% (n = 71) were classified as cutaneous T-cell lymphomas (CTCL) and 17% (n = 15) as cutaneous B-cell lymphomas (CBCL). Nine patients with CTCL showed associated haematological disorders and malignomas. Among 47 MF patients following variants were observed: pilotropic MF (n = 2), follicular mucinosis (n = 1), unilesional MF (n = 1), large-cell transformation (n = 3), erythrodermic MF (n = 1), poikilodermatous MF (n = 2) and posttransplant lymphoproliferative disorder (CD8(+) MF with gamma/delta phenotype after renal transplantation) (n = 1). One patient had MF concurrent with lymphomatoid papulosis. The group of CBCL comprised six cases (40%) of PCMZL and PCFCL each, 20% (n = 3) were classified as PCLBCL, LT. CONCLUSION: This study for the first time provides data on the distribution of PCL clinicopathologic variants and stages according to the latest classification and staging systems in an Austrian referral centre.

Prevalence of actinic keratosis among dermatology outpatients in Austria.

BACKGROUND: Actinic keratoses (AKs) are common precursors of squamous cell carcinomas (SCCs) of the skin making them an important public health issue with information on their prevalence widely lacking. OBJECTIVES: To define the prevalence of AK in dermatology outpatients in Austria and to identify more accurately the target population for AK screening, treatment and prevention. METHODS: Each of the 48 randomly selected Austrian office-based dermatologists simultaneously screened 100 consecutive patients (aged ≥ 30 years) for the presence of AK. RESULTS: In total, 4449 evaluable patients showed an overall AK prevalence of 31·0%, which was higher in men (39·2%) than in women (24·3%) and increased with age in both sexes. AK distribution among sun-exposed body sites and extent of disease varied with sex and region. CONCLUSIONS: In Austria, AKs are common among dermatology outpatients, who have access to professional education and treatment. Investigations regarding the efficacy of routine AK screening in dermatology outpatients for the prevention of invasive SCC is warranted.

A simple and rapid quantitative sweat test based on cobalt chloride color change.

BACKGROUND: Existing sweat tests are either cumbersome, require dedicated technical equipment and/or do not give reliable quantitative results. The present study was performed to develop and describe a rapid and simple test for a practical and quantitative evaluation of sweating. METHODS: Cobalt chloride patches were used to collect sweat during exercise and after application of aluminum hydrochloride. Color change from blue to red was recorded and quantified, and the amount of sweat was calculated from a standard curve. RESULTS: Cobalt-chloride-containing patches evaluated with standard office equipment provide a rapid, simple and highly sensitive method for the quantitative measurement of sweating. CONCLUSIONS: Possible applications that need to be evaluated in further studies are the diagnosis and monitoring of diseases associated with disordered sweat production and the evaluation of antiperspirants.

Dermal infiltrates of cutaneous T-cell lymphomas with epidermotropism but not other cutaneous lymphomas are abundant with langerin⁺ dendritic cells.

BACKGROUND: The Langerhans cell (LC) hypothesis suggests that cutaneous T-cell lymphomas (CTCL) are diseases of chronic T-cell stimulation by LC-mediated antigen presentation. OBJECTIVE: To investigate a broad panel of CTCL and cutaneous B-cell lymphomas (CBCL) for the spatial association of langerin(+) dendritic cells (DC) with T and B cells in the skin, respectively. METHODS: Fifty-five specimens of CTCL and 10 of CBCL were double-stained with monoclonal antibodies against langerin and CD3 or CD20, respectively, and evaluated by confocal laser scan microscopy. RESULTS: Dermal infiltrates in mycosis fungoides (n = 38), primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoma (n = 3) and primary cutaneous peripheral T-cell lymphoma, unspecified (n = 3) were characterized by a high frequency of dermal langerin(+) DCs. These cells were exclusively present in the malignant infiltrates. No direct co-localization of CD3 and langerin could be resolved. Dermal langerin(+) cells were detected only in one of six primary cutaneous anaplastic large cell lymphomas (C-ALCL), characterized by epidermotropism. In other C-ALCL cases (five of six), in lymphomatoid papulosis (n = 3), subcutaneous panniculitis-like T-cell lymphoma (n = 2), and all variants of CBCL no dermal langerin(+) DCs could be found. CONCLUSIONS: Langerin(+) DCs are abundant in the dermal infiltrates of T-cell lymphomas with specific involvement of the epidermis. This might indicate that immature LC and neoplastic T cells interact and gives rise to further studies to characterize the phenotype of the langerin(+) cell population described here and its role in the pathology of CTCL.

Somatostatin receptor scintigraphy in primary cutaneous T- and B-cell lymphomas.

BACKGROUND: Monitoring and repeated staging is of substantial importance in many patients with primary cutaneous T-cell lymphomas (CTCL). For primary cutaneous B-cell lymphomas (CBCL), extensive initial staging is the mainstay for correct diagnosis. AIM: To evaluate the value of somatostatin receptor scintigraphy using the radiolabeled somatostatin analog (111)In-pentetreotide in comparison to conventional imaging methods for the staging of patients with primary CTCL and primary CBCL. METHODS: Twenty-two patients (15 patients with histologically verified CTCL and 7 patients with histologically verified CBCL) were included. Stage of disease was established by physical examination, laboratory screening, skin inspection, palpation of superficial lymph nodes, sonography and computed tomography (CT) in patients with advanced clinical stage. Focally elevated tracer uptake of (111)In-pentetreotide was compared to common imaging modalities, physical aspect and digital photographs of the respective skin lesions. RESULTS: Of the 15 patients with CTCL, only 4 (27%) showed positive scintigraphic results, but not in all sites of lymphomatous involvement. None of the five patients with mycosis fungoides in stage I, nor any of the four patients with Sézary syndrome, had a positive (111)In- pentetreotide scan. Of the seven patients with CBCL three positive scintigraphic results (43%) could be obtained: in two patients with a follicular center lymphoma and one patient with a diffuse large B-cell lymphoma - leg type, but again not in all apparent sites of lymphoma. CONCLUSIONS: Based on our results, we do not recommend the use of somatostatin receptor scintigraphy for routine staging of patients with CTCL and CBCL. As our series includes only 22 patients, and the number of patients with rarer variants of CTCL was rather small, it might be too premature to abandon SST-R in the staging of patients with cutaneous lymphomas.

Rituximab monotherapy for primary cutaneous B-cell lymphoma: response and follow-up in 16 patients.

BACKGROUND: We have carried out a retrospective analysis to evaluate the therapeutic value of the anti-CD20 antibody rituximab in 16 consecutive patients with primary cutaneous CD20+ B-cell lymphomas. PATIENTS AND METHODS: Sixteen patients (4 females, 12 males) with a median age of 54 years received systemic therapy with rituximab 375 mg/m(2) once weekly for four or six consecutive weeks. Eleven patients had primary cutaneous follicle center cell lymphoma and five patients had a primary cutaneous marginal zone B-cell lymphoma. RESULTS: Of the 16 patients with PCBCL, 14 patients (87.5%) achieved complete remission (CR). In two patients, partial remission was obtained and additional focal radiotherapy was applied, which resulted in final CR. Five to 14 (35%) patients with CR relapsed, in an interval between 6 and 37 months. There were no severe side-effects. CONCLUSIONS: On the basis of our results, single-agent treatment with i.v. rituximab appears to be feasible and safe and results in a high rate of durable remissions. Judging from our data, it appears to be an attractive treatment option and should be directly compared with local radiotherapy.

Proopiomelanocortin-derived peptides are synthesized and released by human keratinocytes.

Proopiomelanocortin (POMC), the precursor for melanotropic, corticotropic, and opioid peptides such as alpha-melanocyte-stimulating hormone (alpha MSH), ACTH, and other related peptides, was originally identified as a product of the pituitary gland. However, recent evidence shows that POMC products can also be produced by nonpituitary tissues. Because keratinocytes, the major constituent of the epidermis exhibit the capacity to release a variety of proinflammatory and immunomodulatory mediators, the present study was performed to investigate whether human keratinocytes are able to produce POMC-derived peptides. Supernatants of human normal keratinocytes and an epidermal carcinoma cell line (A431) contained significant levels of immunoreactive alpha MSH and ACTH. Upon immuneprecipitation and size-exclusion chromatography, keratinocyte-derived alpha MSH exhibited a molecular mass of approximately 1 kD and was biologically active as demonstrated in a tyrosinase bioassay. Northern blot analysis revealed the expression of POMC-specific transcripts (1.3 kb) in both normal keratinocytes and A431 cells. The production of alpha MSH and ACTH could be significantly upregulated both at the protein and mRNA level upon treatment with phorbol myristate acetate, ultraviolet light, or interleukin 1. These data provide first evidence that human keratinocytes produce POMC-derived peptides such as alpha MSH and ACTH. Because POMC-derived peptides recently have been recognized as potent immunomodulatory mediators, their presence in the epidermis may have a major impact on the skin immune system.

Heat shock proteins in the skin.

Heat shock proteins (hsp) are expressed in all cells and organisms. Their expression is induced by heat shock (temperatures above 42 degrees C) and other forms of pathophysiological stress. Elevated levels of hsp protect cells from further stress exposure. Hsp are expressed intracellularly. They are highly conserved throughout evolution indicating hsp being necessary for survival under potentially harmful environmental conditions. Hsp are divided into families according to their molecular weight. The majority of hsp function as molecular chaperones. Chaperone function is characterized by binding to other proteins and mediating their folding, transport and interaction with other molecules. In human epidermis hsp are abundantly expressed and have been linked with functions in cell differentiation and photobiology. Recent research has mainly focused on the 27 and 72 kD hsp that are constitutively expressed in human keratinocytes. ultraviolet radiation (UV)-induced cell death and sunburn cell formation can be inhibited by previous heat shock exposure and UV itself can induce hsp expression. The expression of the 27 kD hsp (hsp27) in epidermal keratinocytes in situ and in culture correlates with differentiation. Expression of hsp27 increases simultaneously with keratinocyte differentiation. For that reason, hsp27 is described as a marker of epidermal differentiation. Changes in the expression and inducibility of hsp have been linked with ageing. In the skin, recent data indicate that hsp72 expression remains remarkably stable with intrinsic ageing. In contrast, levels of hsp27 have been found to be elevated in sun-protected aged skin indicating a link between hsp27 expression and age-dependent epidermal alterations. Regulation of hsp can be modified by pharmacological intervention and the development of safe topical and systemic treatments for the prevention of skin damage and disorders of keratinocyte differentiation can be expected for the future.

Selective release of tumor necrosis factor binding protein II by malignant human epidermal cells reveals protection from tumor necrosis factor alpha-mediated cytotoxicity.

Most tumor cells produce both tumor necrosis factor (TNF) receptors, the M(r) 55,000 TNFRI and the M(r) 75,000 TNFRII, but they are mostly resistant to TNF-alpha-induced cytotoxicity. To gain further insight into the escape mechanisms of tumor cells from the harmful effect of TNF-alpha, we investigated the production of TNF-binding proteins (TNF-BPI, TNF-BPII, both M(r) 30,000) by malignant and normal epidermal cells and studied their functional role in TNF-alpha-induced cytotoxicity. Malignant human keratinocytes (A431, KB, HaCaT) and malignant human melanoma cells (KRFM) produced significant levels of both TNF-BPI and TNF-BPII on stimulation with phorbol myristate acetate. In contrast, normal human keratinocytes (HNK) and normal human melanocytes (HNM) released TNF-BPI but not TNF-BPII. The specific production of TNF-BPII in concert with TNF-BPI by the malignant cell lines revealed an inhibitory effect of supernatants on recombinant human TNF-alpha-mediated cytotoxicity of the TNF-dependent murine cell line L929, while supernatants of normal epidermal cells had no effect. Preincubation of supernatants with anti-TNF-BPI monoclonal antibody htr-9 or anti-TNF-BPII monoclonal antibody utr-1 reversed this inhibitory effect additively, indicating that the production of both TNF-BPs is necessary to protect cells from TNF-alpha-mediated cytotoxicity. A TNF-alpha scavanging effect of TNF-BPs resulting in subsequent inhibition of TNF-alpha binding to L929 cells could be demonstrated by ligand blotting and fluorescence-activated cell sorting analysis. Thus the production of TNF-BPII by epidermal tumor cells in concert with TNF-BPI appears to demonstrate a specific mechanism by which malignant epithelial cells escape from TNF-alpha-mediated cytotoxicity.

Variable frequencies of MALT lymphoma-associated genetic aberrations in MALT lymphomas of different sites.

Although several recurrent genetic aberrations are known to occur in MALT lymphoma, no comprehensive study on the most prevalent MALT lymphoma-associated genetic aberrations is available. We therefore screened 252 primary MALT lymphomas for translocations t(11;18)(q21;q21), t(14;18)(q32;q21), and t(1;14)(p22;q32), and trisomies 3 and 18. The above-listed translocations occurred mutually exclusively and were detected overall in 13.5, 10.8, and 1.6% of the cases; trisomy 3 and/or 18 occurred in 42.1%. The frequency at which the translocations occurred varied markedly with the primary site of disease. The t(11;18)(q21;q21) was mainly detected in pulmonary and gastric tumors, whereas the t(14;18)(q32;q21) was most commonly found in lesions of the ocular adnexa/orbit, skin, and salivary glands. Trisomies 3 and 18 each occurred most frequently in intestinal and salivary gland MALT lymphomas. Our results demonstrate that the three translocations and trisomies 3 and 18 occur at markedly variable frequencies in MALT lymphoma of different sites.

Respiratory burst capability of polymorphonuclear neutrophils and TNF-alpha serum levels in relationship to the development of septic syndrome in critically ill patients.

Activated polymorphonuclear neutrophils (PMN) and neutrophil activating mediators such as tumor necrosis factor-alpha (TNF-alpha) are thought to be involved in the pathophysiology of sepsis and multiple organ failure syndrome (MOFS). In critically ill patients at high risk for the development of septic syndrome (n = 17) peripheral blood PMN were assayed for O2- and H2O2 production after stimulation with phorbol myristate acetate (PMA, 40 nM). Serum TNF-alpha levels were determined by ELISA. At the time of admission to the intensive care unit we found significant higher levels of TNF-alpha (P = 0.0001) in the serum of patients finally developing sepsis correlating to higher respiratory burst capability in comparison to nonseptic patients. Additionally we were able to demonstrate a significant (P = 0.0016) lower dismutation rate of O2- to H2O2 in deceased patients in comparison to survivors. These results give further evidence that elevated levels of circulating TNF-alpha and activated PMN play a significant role in the pathogenesis of septic syndrome in critically ill patients.

Treatment of peripheral blood mononuclear cells with 8-methoxypsoralen plus ultraviolet A radiation induces a shift in cytokine expression from a Th1 to a Th2 response.

Treatment with 8-methoxypsoralen plus ultraviolet A radiation and extracorporeal photochemotherapy (photopheresis) are widely used for the treatment of psoriasis and other inflammatory skin diseases, graft-versus-host disease, and mycosis fungoides. As the ratio of Th1 and Th2 cells appears to be critical for pathogenesis and progression of these disorders the effect of psoralen plus ultraviolet A on Th1 and Th2 cytokine production by CD4+ lymphocytes was investigated. Human peripheral blood lymphocytes were incubated in the presence of anti-CD3, rh-IL2, and rh-IL4 for 48 h. After subsequent stimulation with rh-IL2 and rh-IL4 for 72 h cells were treated with 8-methoxypsoralen (100, 500, 1000 ng per ml) plus ultraviolet A (2 J per cm2) and incubated for a further period of 5 h in the presence of ionomycine, phorbol-12-myristate acetate and monensin. Fluorescence-activated cell sorter analysis revealed a significant reduction of interleukin-2- and interferon-gamma-producing CD4+ cells upon psoralen plus ultraviolet A treatment depending on the concentration of 8-methoxypsoralen. In contrast, interleukin-4-producing CD4+ cells were increased, indicating a shift from Th1 to a Th2 cell cytokine profile upon psoralen plus ultraviolet A treatment. These results indicate that 8-methoxypsoralen photochemotherapy of lymphocytes is able to modulate their Th1/Th2 distribution. Inhibition of Th1 cytokine expression by psoralen plus ultraviolet A might help to explain its beneficial effects in the treatment of Th1 dominated skin diseases.

Pentoxifylline suppresses irritant and contact hypersensitivity reactions.

Pharmacologic suppression of the effector phase of contact hypersensitivity appears to have major relevance with regard to treatment of type IV reactions like contact dermatitis. Recently, tumor necrosis factor alpha has been shown to be a critical mediator in hapten-induced irritant and contact hypersensitivity reactions, thus offering new possibilities, for therapeutic intervention. Pentoxifylline, a methylxanthine derivative used in the treatment of vascular disorders, currently has been found to suppress the production of tumor necrosis factor alpha by human and murine leukocytes. Therefore, the effect of pentoxifylline on the elicitation phase of contact hypersensitivity was studied. Intraperitoneal injection of pentoxifylline into sensitized Balb/c and C3H/HeN mice before application of the challenging hapten dose resulted in a significant reduction of the outcome of the contact hypersensitivity reaction. The suppressive effect of pentoxifylline was dose dependent and maximally pronounced upon injection 3 h before hapten application. In contrast to the effector phase of contact hypersensitivity, induction of contact hypersensitivity was not affected by pentoxifylline when injected into naive mice before performance of sensitization. In addition, irritant dermatitis induced by 1% croton oil or 5% benzalkonium chloride was suppressed by pentoxifylline as well. These data suggest a potential pharmacologic intervention, with pentoxifylline as a means to treat contact dermatitis.

Human keratinocytes in vivo and in vitro constitutively express the 72-kD heat shock protein.

Exposure of cells to elevated temperatures induces a physiologic response characterized by the synthesis of a specific set of proteins (heat shock or stress proteins, HSPs) mediating repair mechanisms and protection from cellular damage. In the present study upon immunohistochemistry using a specific monoclonal antibody, the constitutive and heat-induced expression of the 72-kD HSP (HSP72) in normal human skin and in human epidermal cell lines (KB, A431) was investigated. Normal (unstressed) epidermis and adnexal structures of normal human skin were found to constitutively express HSP72. In contrast, a substantial HSP72 expression could not be observed in the dermal cellular compartment. In vitro heat treatment of punch biopsies from normal skin (42 degrees C, 4 h) resulted in a further increase of epidermal HSP72 expression. In addition, dermal cells were found to be induced to express HSP72. To further evaluate the spontaneous HSP72 expression of epidermal cells two epidermoid carcinoma cell lines (A431, KB) were investigated. Upon immunohistochemistry and Western blot analysis a significant HSP72 expression could be detected in unstressed KB and A431 cells. In contrast, a human fibrosarcoma cell line (HT1080) was negative for HSP72 at 37 degrees C but upon heat treatment a strong induction was observed. Furthermore, Northern blot analysis using a cDNA probe specific for human HSP72 revealed a constitutive expression of HSP72 mRNA in both epidermal cell lines. These findings demonstrate a significant expression of the stress-inducible HSP72 in unstressed human skin as well as in epidermal cell lines, suggesting that HSP72 may inherently be involved in the protective function of normal human skin.

72-kD heat shock protein is a mediator of resistance to ultraviolet B light.

We have shown previously that human epidermal keratinocytes in situ and in vitro constitutively express high levels of the 72-kD heat shock protein (hsp72) and that hsp72 expression in these cells can be further induced with heat treatment. In the present study, we continue our investigation of the ultraviolet (UV) B protective effect of hyperthermic treatment and ask whether hsp72 is a mediator of heat-shock-induced UVB resistance. The results of our experiments demonstrate that heat treatment (42 degrees C for 4 h) before UVB exposure is able to increase significantly the UVB resistance of the epidermal carcinoma cell line A431. Heat-induced UVB resistance was most pronounced if the cells were exposed to UVB immediately after heat treatment. The protective effect was not detectable beyond a recovery period of 12 h. To investigate the role of hsp72 in hyperthermia-induced UVB resistance, we inhibited the expression of this protein using either a specific antisense oligodeoxynucleotide or quercetin, a flavonoid that has been shown to down-regulate hsp expression. Treatment with the oligomer as well as with quercetin significantly increased the susceptibility of A431 to UVB-induced damage and nullified the protective effect of heat preconditioning. A noncomplementary control oligodeoxynucleotide had no significant effect. These results indicate that heat treatment is able to induce a state of increased resistance to the deleterious effects of UVB in human keratinocytes in vitro. hsp72 is a molecular mediator of this protective effect, and its constitutive expression in human epidermal keratinocytes may be an important mechanism for the protection of human epidermis from UVB-induced damage.

Long-term adjuvant therapy of high-risk malignant melanoma with interferon alpha 2b.

Fifty-three high-risk melanoma patients in stage I and 15 patients in stage II were treated after standard surgical intervention with adjuvant therapy with recombinant interferon alpha-2b (rIFN alpha 2b) therapy for a total period of 20 months. Concomitant patients (stage I, n = 82; stage II, n = 33) with identical stages and prognostic factors without adjuvant therapy were used to evaluate the efficacy of rIFN alpha 2b therapy. No difference in 5-year relapse incidence and overall survival rates could be detected. However, it appears that patients of both stage I and stage II benefit from long-term adjuvant rIFN alpha 2b therapy, because during the treatment period (20 months), the incidence of relapses was lower in comparison to controls. After stopping treatment the incidence of relapse is equal in treated and control groups. According to the results of our study, we suggest using continuous low-dose rIFN alpha 2b therapy for adjuvant treatment of malignant melanoma.