Browsing by Author "Beckmann, I."

Dermatomyositis/ polymyositis (DM/PM) and Lambert- Eaton myasthenic syndrome (LEMS) are two autoimmune disorders that have very rarely been reported to occur together in the same patient. We report on two patients with DM who were later diagnosed with concomitant LEMS, and point out diagnostic challenges in identifying LEMS in patients with DM/PM. As specific treatment for LEMS is available, it is important to identify those DM/PM patients who suffer from concomitant LEMS.

Psoriasis is a chronic inflammatory skin disorder characterized by accumulation of Th1-type T cells and neutrophils, regenerative keratinocyte proliferation and differentiation, and enhanced epidermal production of antimicrobial peptides. The underlying cause is unknown, but there are some similarities with the immunologic defense program against bacteria. Development of psoriasiform skin lesions has been reported after administration of granulocyte colony-stimulating factor (G-CSF), a cytokine induced in monocytes by bacterial antigens. To further investigate the relation between this type of cytokine-induced dermatitis and psoriasis, we analyzed the cutaneous cytokine profile [tumor necrosis factor-alpha (TNF-alpha), interferon-gamma, transforming growth factor-beta1 (TGF-beta1), interleukin-10 (IL-10), IL-12p35 and p40, and IL-8] and expression of markers of epidermal activation [Ki-67, cytokeratin-16, major histocompatibility complex (MHC) class II, intercellular adhesion molecule-1 (ICAM-1)] in a patient who developed G-CSF-induced psoriasiform dermatitis by using quantitative real-time reverse transcriptase-polymerase chain reaction and immunohistology. The histologic picture resembled psoriasis with regard to epidermal hyperparakeratosis and the accumulation of lymphocytes in the upper corium. CD8(+) T cells were found to infiltrate the epidermis which was associated with an aberrant expression of Ki-67, cytokeratin-16, MHC class II, and ICAM-1 on adjacent keratinocytes. As compared to normal skin (n = 7), there was an increased expression of TNF-alpha, IL-12p40, and IL-8, a decreased expression of TGF-beta1, and a lack of IL-10, similar to the findings in active psoriasis (n = 8). Therefore, G-CSF may cause a lymphocytic dermatitis that, similar to psoriasis, is characterized by a pro-inflammatory Th1-type cytokine milieu and an epidermal phenotype indicative of aberrant maturation and acquisition of non-professional immune functions.

With regard to malignant melanoma, the impact of lymph node surgery on the development of loco-regional cutaneous metastases (LCM) has not yet been adequately addressed. However, this aspect is of interest, since sentinel lymphonodectomy (SLNE) has been suspected of causing LCM by inducing entrapment of melanoma cells. We analysed 244 patients with SLNE and compared the data with 199 patients treated with delayed lymph node dissection (DLND) for clinically palpable metastases. Analysis of both groups commenced at the time of excision of the primary tumour, using the Kaplan-Meier method. LCM that appeared as a first recurrence, as well as the overall probability of developing LCM, were recorded. For sentinel-negative patients with a primary melanoma > 1 mm thick, the 5-year probability of developing LCM as a first recurrence was 6.9 +/- 0.02% (standard error of the mean (SEM)). The probability was 17.6 +/- 0.03% in the DLND group. Comparing the two node-positive subgroups, the probability of developing LCM as a first recurrence was significantly higher in patients with positive SLNE (27.3 +/- 0.05%, P = 0.03). However, the 5-year overall probability of developing LCM did not differ significantly in the node-positive groups (33.3% in the DLND group vs. 33.7% in patients with positive sentinel lymph nodes (SLNs)). Since early excision of lymphatic metastases by SLNE avoids nodal recurrences, thereby prolonging the recurrence-free interval, the chance of LCM to manifest as a first recurrence should inevitably increase. However, the overall in-transit probability is not increased after SLNE. (c) 2004 Elsevier Ltd. All rights reserved.

P>Background Infantile haemangioma (IH) is a tumour of the microvasculature composed predominantly of proliferating endothelial cells. It expresses markers associated with endothelial, haematopoietic and mesenchymal lineages. We have previously shown that the cells forming the capillary endothelium of proliferating IH express cell surface markers and transcriptions factors consistent with it being a haemogenic endothelium. Objectives We wished to determine whether the expression of transcription factors associated with the erythroid lineage was of physiological relevance and sufficient for IH tissue cultured in vitro to undergo erythropoiesis. Methods Immunohistochemical staining of paraffin-embedded sections of proliferating IHs was undertaken and expression of the embryonically associated haemoglobin zeta (HBZ) chain and the erythropoietin receptor (EPO-R) was determined. Relative expression of mRNA encoding these proteins was determined by quantitative reverse transcription-polymerase chain reaction using snap-frozen biopsy samples. Differentiation towards erythrocytes was investigated using freshly resected tissue cultured as explants in Matrigel. Results The endothelium of the microvessels, but not the pericyte layer, was strongly immunoreactive for the EPO-R and the embryonically associated HBZ chain. Abundant expression of transcripts encoding these proteins was also detected, corroborating the immunohistochemical staining. When tissue was grown in culture the cells emanating from IH explants were able to generate enucleated erythrocytes in vitro. The erythrocytes were immunoreactive for the erythrocyte-specific marker glycophorin A. Conclusions The microvessels in IH are a functional haemogenic endothelium that expresses the embryonically associated HBZ chain and is able to form erythrocytes in vitro. IH thus represents a possible extramedullary site for tumour-associated primitive erythropoiesis.