Hidradenitis suppurativa/acne inversa (HS) is a chronic, inflammatory, recurrent, debilitating skin disease of the hair follicle that usually presents after puberty with painful, deep-seated, inflamed lesions in the apocrine gland-bearing areas of the body, most commonly the axillae, inguinal and anogenital regions. A mean disease incidence of 6.0 per 100,000 person-years and an average prevalence of 1% has been reported in Europe. HS has the highest impact on patients' quality of life among all assessed dermatological diseases. HS is associated with a variety of concomitant and secondary diseases, such as obesity, metabolic syndrome, inflammatory bowel disease, e.g. Crohn's disease, spondyloarthropathy, follicular occlusion syndrome and other hyperergic diseases. The central pathogenic event in HS is believed to be the occlusion of the upper part of the hair follicle leading to a perifollicular lympho-histiocytic inflammation. A highly significant association between the prevalence of HS and current smoking (Odds ratio 12.55) and overweight (Odds ratio 1.1 for each body mass index unit) has been documented. The European S1 HS guideline suggests that the disease should be treated based on its individual subjective impact and objective severity. Locally recurring lesions can be treated by classical surgery or LASER techniques, whereas medical treatment either as monotherapy or in combination with radical surgery is more appropriate for widely spread lesions. Medical therapy may include antibiotics (clindamycin plus rifampicine, tetracyclines), acitretin and biologics (adalimumab, infliximab). A Hurley severity grade-relevant treatment of HS is recommended by the expert group following a treatment algorithm. Adjuvant measurements, such as pain management, treatment of superinfections, weight loss and tobacco abstinence have to be considered.

Alteration of the surface glycosylation pattern on malignant cells potentially affects tumor immunity by directly influencing interactions with glycan-binding proteins (lectins) on the surface of immunomodulatory cells. The sialic acid-binding Ig-like lectins Siglec-7 and -9 are MHC class I-independent inhibitory receptors on human NK cells that recognize sialic acid-containing carbohydrates. Here, we found that the presence of Siglec-9 defined a subset of cytotoxic NK cells with a mature phenotype and enhanced chemotactic potential. Interestingly, this Siglec-9 + NK cell population was reduced in the peripheral blood of cancer patients. Broad analysis of primary tumor samples revealed that ligands of Siglec-7 and -9 were expressed on human cancer cells of different histological types. Expression of Siglec-7 and -9 ligands was associated with susceptibility of NK cell-sensitive tumor cells and, unexpectedly, of presumably NK cell-resistant tumor cells to NK cellmediated cytotoxicity. Together, these observations have direct implications for NK cell-based therapies and highlight the requirement to consider both MHC class I haplotype and tumor-specific glycosylation.

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Artículo de publicación IS

Although the precise underlying pathomechanisms of psoriasis have not been fully elucidated, previous reports suggest that T helper 1-type cytokines are critically involved in the pathogenesis of this disease. Interleukin-12 (IL-12), a heterodimeric cytokine, has been suggested to play a major role in the development of T helper 1 cell responses. In this study, the presence of IL-12 mRNA and protein was investigated in normal human skin as well as nonlesional and lesional psoriatic skin. Messenger RNA levels were determined in biopsy specimens by a standard and a nested reverse transcriptase-polymerase chain reaction method. Additionally, IL-12 protein expression was analyzed in situ by immunohistochemistry using an antibody recognizing IL-12 p70. Whereas specific transcripts for IL-12 p35 were reproducibly detected without any significant differences in all samples, enhanced IL-12 p40 mRNA signals were only found in lesional psoriatic skin as compared with normal and nonlesional psoriatic skin. Furthermore, immunoreactivity for IL-12 p70 was markedly increased in the psoriatic skin lesions and was predominantly expressed on mononuclear cells in the dermis. In conclusion, our data suggest a critical role for IL-12 in promoting and maintaining T cell activation and inducing T helper 1-type cytokines such as interferon-gamma in psoriasis. We speculate that IL-12 might be a key cytokine in the pathogenesis of psoriasis.

The role of autophagy in cancer is controversial: Both tumor-suppressing and tumor-promoting functions have been reported. We show that a key regulator of autophagy, autophagy-related protein 5 (ATG5), is often down-regulated in primary melanomas compared to benign nevi, leading to a reduction of basal autophagy as evidenced by a reduced expression of LC3. A follow-up of 158 primary melanoma patients showed that patients with low levels of ATG5 in their tumors had a reduced progression-free survival. In an in vitro model of melanoma tumorigenesis, where the BRAF oncogene was transduced into normal melanocytes, we observed that lowering ATG5 expression promoted proliferation by precluding oncogene-induced senescence. Hence, it appears that down-regulation of ATG5 contributes to tumorigenesis in early-stage cutaneous melanoma, and the expression of ATG5 and LC3 correlates with melanoma diagnosis and prognosis.

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas. Recurrence rates when standard treatment protocols are used are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as lesional and field therapies and has the potential to delay/reduce the development of new lesions. A protocol using daylight to treat actinic keratoses is widely practised, with conventional PDT using a red light after typically a 3‐h period of occlusion employed for other superficial skin cancer indications as well as for actinic keratoses when daylight therapy is not feasible. PDT is a well‐tolerated therapy although discomfort associated with conventional protocol may require pain‐reduction measures. PDT using daylight is associated with no or minimal pain and preferred by patient. There is an emerging literature on enhancing conventional PDT protocols or combined PDT with another treatment to increase response rates. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical PDT in dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

These data indicate that the enhanced expression of TLR2 by infiltrating macrophages and DCs may contribute to the pathogenesis of inflammatory lesions of acne inversa.