Dermatofluoroscopy diagnostics in different pigmented skin lesions: Strengths and weaknesses.

BACKGROUND: The melanin fluorescence of skin lesions is measurable with two-photon excitation, a process termed dermatofluoroscopy, which has shown a shift from the green spectra in benign melanocytic lesions to the red spectra in melanoma. This study addressed the question as to which kind of pigmented lesions can be correctly diagnosed as melanin-bearing malignant tumors. METHODS: 476 pigmented lesions including 101 cutaneous melanomas were analyzed with dermatofluoroscopy, measuring the melanin fluorescence in a grid-like fashion with a separation of measurement points of 0.2 mm. The results of the dermatofluoroscopy are presented as a diagnostic score with a cut-off score of ≥ 28 for the diagnosis of melanin-bearing malignant tumors, and were compared to the gold standard of histopathology. RESULTS: A highly significant difference (p < 0.0001) between the diagnostic scores of different skin tumors was found. Dermatofluoroscopy scores showed the highest sensitivity for melanomas (92.1 %). Interestingly, most pigmented basal cell carcinomas (BCCs, 88.9 %) were diagnosed as melanin-bearing malignant tumors. A higher sensitivity for the correct diagnosis was observed in older patients (≥ 53 years, p = 0.003), in patients with skin tanning (p = 0.025), and in patients with freckles during childhood (p = 0.046). CONCLUSIONS: Two-photon fluorescence is an innovative technique for the diagnosis of pigmented skin lesions, and shows a high sensitivity for detection of melanomas and pigmented BCCs.

Effect of IL-15 on IgG versus IgE antibody-secreting cells in vitro.

Immunoglobulin E (IgE) antibodies are major contributors to the pathology of atopic and allergic diseases as well as to immune response to helminth infections. Development of an adequate immunoglobulin G (IgG) immune response against infectious agents and vaccine antigens is considered in most cases as crucial for protection from disease. In vivo and in vitro production of IgE and IgG depends on cytokines and other soluble factors. Recently it has been shown that IgG antibody secreting cells (ASCs) can be generated by in vitro maturation of blood cells with Interleukin- (IL-)15 and CpG DNA or other stimulation cocktails, while IgE-ASCs develop upon cultivation with anti-CD40 and IL-4. In the present study we employed an enzyme linked immunospot assay (ELISPOT) to assess the capacity of individuals to develop into either IgE-ASCs or IgG-ASCs upon stimulation with different combinations of stimulation cocktails in order to investigate the influence of cytokines that are dysregulated in IgE-mediated immune reactions on ASC generation. Furthermore, we modified the method to assess IgG- and IgE-ASCs specific for two model antigens causing allergic rhinitis in humans. We demonstrate that IL-15, which is important for development of IgG-ASCs, decreases the number of IgE-ASCs when added to media commonly used for in vitro development of IgE-ASCs. We show that our method is suitable for the detection of specific and non-specific IgE-ASCs and IgG-ASCs and allows the investigation of the interplay between IgG-ASCs and IgE-ASCs in different populations.