Expression of Three Adipokines (Adiponectin, Leptin and Resistin) in Normal Canine Skin: a Pilot Study.

Adipokines are biologically active cytokines that are mainly produced in adipose tissue. There is evidence, in man and mice, that some adipokines may be secreted in other tissues including the vascular endothelium, epithelia and sebaceous glands. Moreover, modified serum levels of adipokines have been detected in people with acne vulgaris or psoriasis; it is suspected that adipokines could contribute to local and systemic inflammatory conditions. We aimed to evaluate the expression of three adipokines (i.e. leptin, adiponectin and resistin) in normal canine skin. Formalin-fixed, paraffin wax-embedded punch biopsy samples were obtained from the sparsely-haired skin of the caudal ventral abdomen of a single clinically healthy dog with no history of skin disease. Immunohistochemistry was applied, using rabbit polyclonal primary antibodies specific for leptin, adiponectin and resistin. Adipokines were not expressed in normal canine dermis or hypodermis. In contrast, they were detected in the keratinocytes of all epidermal layers and hair follicle segments, sebocytes, apocrine gland cells and in the vascular endothelium. This is the first report on the expression of adipokines in normal canine skin, a first step in studying their role in the skin physiology and inflammatory skin diseases of dogs.

Development of brain metastases in patients with metastatic melanoma while receiving ipilimumab.

UNLABELLED: Ipilimumab is a monoclonal antibody blocking the inhibitory molecule CTLA4 expressed by activated T lympocytes, used for the treatment of metastatic melanoma. Recent studies have shown its potential efficacy on brain metastases. OBJECTIVES: To assess the development of brain metastases under ipilimumab and identify clinical, histological or evolving criteria related to the appearance of these metastases. A retrospective study was conducted in 52 patients treated with 4 cycles of ipilimumab 3 mg/kg every 3 weeks for unresectable stage III or stage IV melanoma between January 2011 and July 2013 in a Department of Dermato-Oncology. As no data has been find in the literature, the results were compared to our other cohort of patients treated with vemurafenib during the same period. Ten patients (21.7 %) developed brain metastases under ipilimumab in a median time of 6.58 months after treatment initiation. The multivariate analysis showed a lower rate of brain metastases in patients with acral lentiginous melanoma and melanoma of unknown primary site. The median survival after diagnosis of brain metastases was of 2.5 months. There was no significant difference with vemurafenib-treated patients in terms of incidence rate of brain metastasis, time of development and survival after diagnosis of cerebral metastases. This was the first study focused on the development of brain metastases under treatment with ipilimumab 3 mg/kg. Although ipilimumab is used for the treatment of brain metastases, it paradoxically did not seem to reduce the risk of developing brain metastases.

Profile of vemurafenib-induced severe skin toxicities.

BACKGROUND: Vemurafenib, a BRAF inhibitor, is commonly associated with skin toxicity. The impact of severe forms is unknown. OBJECTIVE: To determine the rate of permanent vemurafenib discontinuation due to grade 3-4 skin toxicity, features of these toxicities, their recurrence rate after a switch to dabrafenib and their impact on overall survival. METHODS: Retrospective cohort study of 131 patients treated with vemurafenib for melanoma between November 2010 and December 2014. Data on skin toxicities, the need for vemurafenib adjustment and the impact of switching to dabrafenib were collected. Regarding survival analysis, a conditional landmark analysis was performed to correct lead-time bias. RESULTS: Among the 131 vemurafenib-treated patients, 26% developed grade 3-4 skin toxicity. Forty-four percent of them permanently discontinued their treatment, mainly due to rash and classic skin adverse reactions (Steven-Johnson syndrome, Drug Reaction with Eosinophilia and Systemic Symptoms). Conversely, photosensitivity and carcinomas rarely required treatment adjustment. Grade 3-4 rashes were associated with clinical or biological abnormalities in 94% of patients. Among the 10 patients who subsequently switched to dabrafenib, skin toxicity recurred only in one patient. Overall survival was significantly prolonged in case of severe skin toxicity emerging within the first 4 (P = 0.014) and 8 weeks (P = 0.038) on vemurafenib, with only a trend at 12 weeks (P = 0.052). Median overall survival was also prolonged in case of severe rash. CONCLUSION: In this study, vemurafenib was continued in 56% of patients with grade 3-4 skin toxicity, which was associated with prolonged overall survival when emerging within the first 4 and 8 weeks of treatment. While developing severe skin adverse reactions permanently contraindicates vemurafenib use, other rashes should lead to retreatment attempts with dose reduction. In case of recurrence, dabrafenib seems to be an interesting option. For other skin toxicities, including photosensitivity and cutaneous carcinoma, treatment adjustment is usually not needed.

Incidence and characteristics of melanoma brain metastases developing during treatment with vemurafenib.

Vemurafenib is indicated for the treatment of patients with BRAF (V600)-mutant metastatic melanoma. We studied for the first time the characteristics of brain metastases developed during treatment with vemurafenib in real-life conditions. We included all patients treated over 3 years with vemurafenib in our department for metastatic melanoma without initial brain involvement. Our primary endpoint was to assess the incidence of brain metastases in these patients. Our secondary endpoints were to identify the risk factors for metastases occurrence and their characteristics and course. In our retrospective cohort of 86 patients, 20% had developed brain metastases on average 5.3 months after vemurafenib initiation. The median follow-up was 9 months (1-26 months). Radiological examinations revealed multiple brain metastases in 41% of patients. The only risk factor for metastasis occurrence identified was a high number of metastatic sites when initiating vemurafenib (p = 0.045). Metastasis development was associated with a trend toward a decrease in overall survival from 12.8 to 8.5 months (p = 0.07) and a significant decrease in progression-free survival from 7 to 5 months (p = 0.04). Among the patients who developed brain metastases, 82% died, of whom 64% within 3 months, versus 58% of patients without brain metastases over the same period. The extra-cerebral disease was well controlled in 59% of patients during brain progression. In vemurafenib-treated melanoma patients, brain metastases are frequent and associated with a particularly poor prognosis. Because of their high frequency in patients with controlled extra-cerebral disease, brain explorations should be systematically performed during treatment.

Optimization of an immunohistochemical method to assess distribution of tight junction proteins in canine epidermis and adnexae.

Epidermal tight junctions (TJs) have been well characterized in human medicine. Abnormality of these structures is involved in skin diseases such as atopic dermatitis. There is little information about the expression and distribution of TJ proteins in the canine skin. The aim of this study was to develop an optimal immunohistochemical method for assessment of the expression of TJ proteins in the skin of healthy dogs. Formalin-fixed and paraffin wax-embedded skin biopsy samples from healthy human and canine patients were used. Canine skin samples were from the inguinal region and the nasal planum. Immunohistochemistry was used to study the expression of zonula occludens-1 (ZO-1), occludin and claudin-1, -4 and -7. Heat-induced antigen retrieval with EDTA (pH 9.0) yielded the best labelling of TJ proteins. ZO-1 and occludin were expressed in the cytoplasm and along the keratinocyte membrane, while claudin-1 and -4 were mainly membrane in distribution. ZO-1, occludin and claudin-1 were detected in all epidermal layers with the exception of the stratum corneum, while claudin-4 expression was restricted to the stratum granulosum. Expression of claudin-7 was difficult to evaluate. There was no difference in labelling pattern between inguinal and nasal planum skin.

[Lymphomatoid granulomatosis revealed by cutaneous lesions]. / Granulomatose lymphomatoïde de révélation cutanée.

BACKGROUND: Lymphomatoid granulomatosis is a rare Epstein Barr virus (EBV)-related lymphoproliferative disorder. It most frequently involves the lungs, skin and central nervous system and arises preferentially in patients with immune disorders. Here we report a case revealed by cutaneous lesions in an immunocompetent patient. CASE REPORT: A 56-year-old man consulted for erythematous nodules of the trunk associated with malaise and marked weight loss (14kg). In a few days the nodules became necrotic. Two weeks later a cough appeared and the chest computerized tomography showed multiple poorly defined nodular opacities with a peribronchovascular distribution. Cutaneous and pulmonary biopsies showed an infiltrate composed of medium-sized atypical lymphocytes T and B. EBV was present in the infiltrate (in situ hybridization) with a high EBV load in plasma. All of these data helped confirm the diagnosis of lymphoid granulomatosis. Despite aggressive treatment with polychemotherapy, the patient died after 2 months. DISCUSSION: Lymphomatoid granulomatosis represents a diagnostic challenge. In most cases, the presenting symptoms are not specific: malaise, weight loss, fever and cough. Moreover histology is difficult because of the T-cell-rich background. It is essential to consider this diagnosis in cases of cutaneous and pulmonary symptoms.

Anti-inflammatory properties of a new undecyl-rhamnoside (APRC11) against P. acnes.

Acne vulgaris is a skin disease affecting pilosebaceous glands in which Propionibacterium acnes (P. acnes) induced inflammation plays a central role. In order to develop new therapies against the inflammatory events, we evaluated the modulating effect of a new undecyl-rhamnoside, APRC11, on different markers of the inflammation. For this purpose, normal human keratinocytes taken from five healthy donors were pre-incubated for 24 h with APRC11 or Zinc Gluconate (Zn) which was used as reference molecule for its anti-inflammatory properties. Then, keratinocytes were stimulated with P. acnes Membrane Fraction for 6 h, in the presence of either APRC11 or Zn. Different markers were evaluated at mRNA level using a Luminex-based Quantigene array system and at protein level using an ELISA test and a Luminex array system. Results showed that P. acnes significantly increased the expression of IL-1α, IL-1RA, IL-8 and MMP-9. A 24-h treatment with APRC11 prior to the P. acnes stimulation down-regulated the P. acnes-induced cytokines over expression (IL-1α, IL-8 and MMP-9) and up-regulated IL-1RA level in a similar manner than Zn. These regulations were noted at both protein and mRNA levels. In conclusion, the new undecyl-rhamnoside APRC11 is able to down-regulate the expression of molecules implicated in cutaneous inflammation and whose expression is induced by P. acnes, confirming its potential interest in inflammatory acne.

Comparison of three culture media for the establishment of melanoma cell lines.

Melanoma cell lines are useful tools for the analysis of tumor-specific lymphocytes which are injected to patients treated by adoptive immunotherapy. So they have been established previously (with an efficacy of 47%) in Roswell Park Memorial Institute (RPMI) medium enriched with fetal calf serum (FCS). In order to improve the probability of establishing melanoma cell lines, we compared two FCS-free media with the original FCS medium. Ten melanoma-invaded lymph nodes were tested for their ability to grow in three different culture media: RPMI with FCS; RPMI with human serum (HS); serum-free X-vivo 15 (X15). For each medium, we compared the following criteria: percentage of lines obtained; period of establishment; cell morphology; expression of melanoma-associated antigens and surface molecules. More cell lines were obtained with HS and X15 media compared to FCS medium (7/10, 5/10 and 4/10, respectively). The time period to establish a stable line was similar for the three media. No morphological differences were observed in cells derived from the same tumor sample in the different media. With the X15 medium, cells generally expressed lower levels of melanocytic differentiation antigens and surface molecules. The growth of melanoma cell lines in FCS-free culture media appears possible and advantageous, with an increased probability of obtaining autologous tumor cell lines. Furthermore the cells obtained could be used as multiple antigenic sources in active or adoptive immunotherapy protocols.

Toll-like receptors 2, 4 and 9 expression in cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome).

The aim of this work was to study Toll-like receptors (TLRs) 2, 4 and 9 expression patterns in parapsoriasis and in cutaneous T-cell lymphoma (CTCL): Mycosis fungoides (MF) and Sézary syndrome (SS) at different stages of the illness. The expression of TLRs was examined by immunohistochemistry on paraffin-embedded biopsies. Normal skin, atopic dermatitis and psoriasis, were used as controls. In cutaneous lesions of inflammatory diseases (atopic dermatitis, psoriasis) the expression of TLR2, TLR4 and TLR9 was low compared to normal skin. In parapsoriasis the expression of the three TLRs was similar to control. By contrast, in MF skin we observed a strong intensity of labelling with the three TLRs in the epidermis. Concerning SS, the expression of TLR2, TLR4 and TLR9 was intermediate between inflammatory lesions and MF. Thus, the development of skin lesions in MF appears associated with an increase of TLR2, TLR4 and TLR9 expression by keratinocytes in cutaneous lesions, which could play a role in the chronic activation of T lymphocytes in the skin.

Induction of toll-like receptors by Propionibacterium acnes.

BACKGROUND: The bacterium Propionibacterium acnes is involved in the induction and maintenance of the inflammatory phase of acne. Recent studies have found that keratinocytes express toll-like receptors (TLRs) implicated in immediate immunity. No studies have, to date, been carried out on the action of P. acnes upon TLR activation in keratinocytes. OBJECTIVES: Focusing on the inflammatory phase of acne, to clarify the role of P. acnes in immediate immunity by inducing expression of TLR-2 and TLR-4 by keratinocytes. We also studied how the secretion and expression of matrix metalloproteinase (MMP)-9 is induced by P. acnes. METHODS: The work was carried out on two levels: in vivo with the study of the expression of TLR-2 and TLR-4 proteins in biopsies of acne lesions and in vitro on cultured keratinocyte monolayers to study the modulating effects of P. acnes on the expression of TLR-2 and TLR-4 and also on the expression and secretion of MMP-9. RESULTS: Our findings reveal that in vivo TLR-2 and TLR-4 expression is increased in the epidermis of acne lesions. In vitro, an increase in TLR-2 and TLR-4 expression by human keratinocytes occurred in the first hours of incubation with bacterial fractions as well as an increase of the expression and secretion by the keratinocytes of MMP-9, which plays a role in inflammation. CONCLUSIONS: This work demonstrates that P. acnes induces TLR expression and that this mechanism could play an essential role in acne-linked inflammation. These receptors could be involved notably in acute acne.

Pathogenetic mechanisms of vitiligo in a patient with Sézary syndrome.

Patients exhibiting association between vitiligo and cutaneous T-cell lymphoma (CTCL) remain rare and it is not known whether some T-cell subpopulations of CTCL in the skin are able to recognize specific melanocytic epitopes and thus induce vitiligo. The aim of our study was to determine whether T cells specific to melanocyte differentiation antigens were detectable among tumour-infiltrating lymphocytes (TIL) in the hypopigmented skin of a patient with Sézary syndrome (SS). A 71-year-old patient presented with SS and developed vitiligo during the course of her disease. Immunohistochemical studies showed staining with HMB45 and MelanA antibodies in the pigmented skin biopsy, whereas no staining was observed in the hypopigmented skin biopsy. To analyse responses to melanocyte differentiation antigens, we used a transient COS transfection assay that permits an estimation of CD8 T-cell responses against a large number of HLA/antigen combinations. This technique allowed the detection of melanocyte differentiation antigen-specific T lymphocytes, directed mainly against Melan-A/MART1 antigen in the HLA-A*23 context. Our study supports the concept that vitiligo that has developed during the evolution of a CTCL is related to the presence of a T-lymphocyte subpopulation reactive against melanocyte differentiation antigens (mainly Melan-A/MART1) present in skin lesions. The role of interferon in the induction of this T-lymphocyte subpopulation is discussed.

The infragluteal skin flap: a new option for reconstruction in the perineogenital area.

Use of a local flap is often needed for closure of a defect in the perineogenital area. For this we have applied a pedicled skin flap raised in the infragluteal fold, the technical details and surgical results of which are presented in this paper. From 1985 until 1995, this infragluteal flap has been used to widen the vaginal introitus in 6 patients, to reconstruct the labia majora in 5, to close a rectovaginal fistula in 4, and to reconstruct the perineal body in 1. In all 16 patients the flap survived without signs of impaired circulation. The donor scar is inconspicuously located in the natural infragluteal plica, not violating any anatomic unit. The infragluteal skin flap adds to the surgical armamentarium for perineal and genital repair.