Edgar Dippel

Alternative versus Classical Activation of Macrophages

In parallel to the Th1/Th2 paradigm, antigen-presenting cells (APC) are divided into classically activated APC (dendritic cells/effector macrophages) and alternatively activated APC (IL-4-induced, alternatively activated macrophages/IL-10-induced, immature dendritic cells). Alternatively activated APC share a special molecular repertoire including receptors of innate immunity with broad specificity for foreign antigen and anti-inflammatory cytokines such as IL-1Ra and alternative macrophage activation-associated CC-chemokine-1. Alternatively activated APC mediated tolerance and downregulated inflammation. Abuse of alternatively activated APC in support of infectious susceptibility or tumor immune escape is counteracted by the classical pathway. Thus, classically and alternatively activated APC secure the balance between proinflammatory and anti-inflammatory immune reactions.

Malignant Melanoma S3-Guideline "Diagnosis, Therapy and Follow-up of Melanoma"

This first German evidence-based guideline for cutaneous melanoma was developed under the auspices of the German Dermatological Society (DDG) and the Dermatologic Cooperative Oncology Group (DeCOG) and funded by the German Guideline Program in Oncology. The recommendations are based on a systematic literature search, and on the consensus of 32 medical societies, working groups and patient representatives. This guideline contains recommendations concerning diagnosis, therapy and follow-up of melanoma. The diagnosis of primary melanoma based on clinical features and dermoscopic criteria. It is confirmed by histopathologic examination after complete excision with a small margin. For the staging of melanoma, the AJCC classification of 2009 is used. The definitive excision margins are 0.5 cm for in situ melanomas, 1 cm for melanomas with up to 2 mm tumor thickness and 2 cm for thicker melanomas, they are reached in a secondary excision. From 1 mm tumor thickness, sentinel lymph node biopsy is recommended. For stages II and III, adjuvant therapy with interferon-alpha should be considered after careful analysis of the benefits and possible risks. In the stage of locoregional metastasis surgical treatment with complete lymphadenectomy is the treatment of choice. In the presence of distant metastasis mutational screening should be performed for BRAF mutation, and eventually for CKIT and NRAS mutations. In the presence of mutations in case of inoperable metastases targeted therapies should be applied. Furthermore, in addition to standard chemotherapies, new immunotherapies such as the CTLA-4 antibody ipilimumab are available. Regular follow-up examinations are recommended for a period of 10 years, with an intensified schedule for the first three years.

Stem cell factor, a novel cutaneous growth factor for mast cells and melanocytes.

Mechanisms affecting mast cell and melanocyte growth and function are still poorly understood. This report summarizes the current state of knowledge on a recently described growth factor for both these cell types and for primitive haematopoietic stem cells. Stem cell factor (SCF), also named mast cell growth factor or kit-ligand, has only recently been cloned and has been shown to be encoded on human chromosome 12. It may be of specific importance in cutaneous physiology and pathology since it is produced by several cell types in the skin (e.g. fibroblasts, keratinocytes, endothelial cells) and since it affects melanocyte and mast cell growth, survival, secretion and adhesion as well as migration into tissues. Defects in the genes encoding for the SCF receptor (c-kit-protein) have been shown to be responsible for human piebaldism. A pathogenetic role in mastocytosis has recently been proposed, but remains to be proven. SCF receptor expression is decreased on cells of some malignant cell lines compared to their physiological counterparts, making it unlikely that SCF is a key factor in malignant transformation and cellular hyperproliferation. In haematopoiesis, SCF acts primarily in concert with other growth factors, and we show here that alone in serum-free culture it has no effect on mast cell growth. Furthermore, there is evidence that besides SCF, additional mast cell growth factors are secreted by fibroblasts and keratinocytes, suggesting a complex orchestration of several growth factors in the regulation of cutaneous growth and differentiation in which SCF plays only one part.

Clonal T-cell receptor γ-chain gene rearrangement by PCR-based GeneScan analysis in advanced cutaneous T-cell lymphoma: a critical evaluation

Detection of clonal T‐cell receptor γ (TCRγ)‐chain gene rearrangement is a promising approach to distinguish between cutaneous T‐cell lymphomas (CTCLs) and reactive T‐cell infiltrates. Despite the improved sensitivity by using the polymerase chain reaction (PCR) rather than Southern blot analysis, monoclonality could be demonstrated in only 53–90 per cent of CTCL biopsies in recent studies. In the present study, formalin‐fixed, paraffin‐embedded specimens of 21 selected patients with clear‐cut advanced‐stage CTCL were analysed using a semi‐nested TCRγ PCR with newly developed consensus primer pairs. Detection of PCR products was done by GeneScan analysis (GSA); this technique is advantageous due to its sensitivity and accuracy in the detection and size determination of PCR products and it is easier to interpret than direct read‐outs from TGGE or DGGE gels. In serial dilution experiments, TCRγ‐PCR‐GSA allowed the detection of clonal, rearranged T‐cells with a high in vitro sensitivity against a polyclonal background (1–6 per cent). Despite the selection of clear‐cut, advanced‐stage CTCL cases, however, dominant clonal TCRγ‐chain gene rearrangement was found in only 16 of the 21 patients analysed, indicating an overall clinical sensitivity of 76 per cent. Specificity was evaluated using biopsy specimens from 21 control patients suffering from long‐standing psoriasis (n = 13) and eczema (n = 8). Surprisingly, GeneScan profiles showing apparently single dominant peaks were detected in 14 per cent of these skin lesions, but these profiles turned out to be pseudo‐monoclonal by repeated determinations. In conclusion, TCRγ‐PCR‐GSA does not suffice reliably to exclude malignancy, due to its limited clinical sensitivity, but with precautions taken to detect pseudo‐monoclonality and to secure specificity, TCRγ‐PCR‐GSA is a valuable instrument in the diagnosis of CTCL. Copyright

Differential expression of a gene signature for scavenger/lectin receptors by endothelial cells and macrophages in human lymph node sinuses, the primary sites of regional metastasis

Sentinel lymph node biopsy for several cancers has shown that metastatic tumour cells are preferentially arrested in the lymph node sinuses. To study the molecular components of this sinusoidal trap, gene profiling of lymph node (sinuses) versus tonsil (no sinuses) was performed. Among other groups of molecules, an intriguing gene signature of scavenger and lectin‐like receptors was identified. Nine of the 13 genes were preferentially expressed in sinusoidal cells by immunohistochemistry. Using stabilin‐2 and monoclonal antibody 3A5 as exclusive endothelial cell (EC) and macrophage (Mφ) markers, respectively, lymph node sinusoidal ECs (stabilin‐2+, LYVE‐1+, DC‐SIGNR+, MARCO+, stabilin‐1+, MMR+) and sinusoidal Mφ (MMR+, DC‐SIGN+, sialoadhesin+, CD163+, stabilin‐1+ ) showed distinct, but overlapping expression patterns of the signature molecules by double labelling immunofluorescence. The number of stabilin‐1+ sinusoidal Mφ, however, varied considerably between samples, indicating turnover/differentiation dynamics in this sinusoidal cell population. In the hepatic sinuses, LYVE‐1 and CD36 were strongly up‐regulated on both sinusoidal ECs and Mφ, while DC‐SIGNR and DC‐SIGN were strongly down‐regulated; in contrast to lymph node sinusoidal ECs, MARCO was confined to Mφ (Kupffer cells) in the liver sinuses. As Mφ are not present in the wall and lumen of splenic sinuses, splenic sinuses expressed a considerably reduced repertoire of scavenger/lectin receptors lacking sialoadhesin, CD36, CD163, and MARCO; in addition, DC‐SIGNR was absent from splenic sinusoidal ECs, while DC‐SIGN and thrombomodulin were strongly expressed. Interestingly, most of the signature molecules are known to mediate tumour cell adhesion in addition to their functions as scavenger or pattern recognition receptors. This study establishes a gene and tissue database platform to test the hypothesis that additive expression of the lymph node sinus signature genes in sinusoidal ECs and Mφ may contribute to selective tumour cell metastasis in lymph nodes and liver including organ‐specific mechanisms, such as intraluminal retention or transmigration, while sparing the spleen. Copyright

Clonal T cell receptor γ-chain gene rearrangement by PCR-based GeneScan analysis in the skin and blood of patients with parapsoriasis and early-stage mycosis fungoides

Cutaneous T cell lymphoma (CTCL) and reactive T cell skin diseases represent opposite ends of a spectrum of diseases ranging from overtly malignant to persistently benign. Within this spectrum, the parapsoriasis group is not clearly defined regarding malignant potential. In contrast to consistent findings in advanced‐stage CTCL, clonality analysis of parapsoriasis has produced conflicting results in previous studies. As T cell receptor γ‐chain polymerase chain reaction GeneScan analysis (TCR‐γ‐PCR‐GSA) stands out by its sensitivity, its accuracy in size determination of PCR products, its capacity to identify false positives by repeated analysis and its easy applicability, this approach was used to analyse the clonality status of 41 patients with borderline T cell lymphoproliferative skin diseases, including parapsoriasis (n=27) and early‐stage mycosis fungoides (MF) (n=14). A monoclonal T cell infiltrate was demonstrated by repeated TCR‐γ‐PCR‐GSA in lesional skin specimens in 19.2% of parapsoriasis patients and in 66.6% of early‐stage MF cases (p=0.013). In peripheral blood, a monoclonal T cell population was found in a similar percentage of parapsoriasis and of early‐stage MF patients (26.7% versus 12.5%; p=0.611). A detailed analysis of parapsoriasis subentities, namely small and large plaque parapsoriasis, and parapsoriasis lichenoides, revealed monoclonality in 2(6)/2(5), 3(14)/2(8) and 0(6)/0/(3) of the skin and peripheral blood specimens, respectively. The high detection rate of false positive cases by repeated analysis (20–37.5%) provides a corrected perspective for the high rates of dominant T cell clones found by others in the peripheral blood of such patients. From the results obtained, three major conclusions can be drawn: firstly, CTCL is clearly associated with detection of monoclonality, even in its early stages; secondly, monoclonality is not a prerequisite for potential CTCL precursor entities; and thirdly, recirculating malignant T cells identical to the skin clone are not readily detected in parapsoriasis or early‐stage MF, but may rather indicate disease progression. Copyright

Cutaneous lymphomas in Germany: an analysis of the Central Cutaneous Lymphoma Registry of the German Society of Dermatology (DDG).

Background: Primary cutaneous lymphomas form a heterogenous group of lymphatic neoplasias.They manifest themselves on the skin and are the second most frequent group of non‐Hodgkin lymphoma (NHL) following gastrointestinal lymphomas.The number of epidemiologic studies is small due to limited availability and limited comparability on population‐based data.

Management of Severe Scleroderma with Long-Term Extracorporeal Photopheresis

Background: The management of systemic sclerosis remains unsatisfactory. Thus far, the action of extracorporeal photopheresis (ECP) in severe systemic scleroderma has been evaluated in short-term studies, and only limited experience has been obtained with long-term application. Objective: The aim of the present study was to evaluate prospectively the long-term effect of ECP in a group of 16 patients suffering from severe scleroderma, showing visceral involvement and progressive clinical course. Methods: Fourteen patients with systemic scleroderma involving several organs, 1 with CREST syndrome and another with scleroderma-myositis overlap syndrome were treated with ECP over a period of 6–45 months. In 3 cases, γ-IFN was additionally administered. Skin and visceral involvement were assessed by evaluating a series of clinical criteria and results from laboratory, imaging and functional tests. Results: Overall, clear improvement was encountered in 6 patients, mixed response in 2, stable disease in 3 and continuing progressive course in 5 patients. Four out of 6 patients with improvement were treated with ECP early after onset of scleroderma (≤2 years), whereas all patients with a progressive course under ECP had had scleroderma for longer than 2 years. Immunosuppressive drugs previously administered could be reduced or fully withdrawn under ECP treatment in 5 patients, but additional oral medication was introduced in 4 patients due to disease progression. Addition of γ-IFN to ECP did not reveal further benefit. No side-effects were recorded under ECP treatment. Conclusions: Based on this observation, we believe that long-term ECP represents an effective treatment modality in severe scleroderma particularly when started early, with stabilization of the disease course and partial remission of the cutaneous findings, whereas visceral involvement, if present, may rarely improve.

Expression of the c-kit receptor in hypomelanosis: a comparative study between piebaldism, naevus depigmentosus and vitiligo

In order to investigate possible alterations in c‐kit protein expression on epidermal melanocytes in different hypopigmentary disorders, we have examined skin specimens from one patient with piebaldism, one patient with naevus depigmentosus, and five patients with vitiligo. Cryosections were examined by immunohistochemistry using monoclonal antibodies against the c‐kit protein (YB5.B8) and melanosomes (TA99).

Unilateral angiolymphoid hyperplasia with eosinophilia involving the left arm and hand

A case report of recurrent angiolymphoid hyperplasia with eosinophilia (ALHE) in an otherwise healthy 20‐year‐old female with manifestation of the disease limited to the left arm and hand is presented together with brief evaluation of the literature as well as the features distinguishing ALHE and Kimuras disease. Immunohistochemical investigations support the hypothesis that ALHE represents a reactive inflammatory lesion rather than a benign vascular neoplasm. A viral cause of ALHE (e.g., HHV8 or Epstein‐Barr virus (EBV); could not be demonstrated. The recurrent nature of the disease is shown by this cases which also demonstrates the need for frequent medical and surgical management.