Taking, Processing, Analyzing, Learning: Skin Punch Biopsies – More Than Just Fiber Count

Guidelines on the use of skin biopsy in clinical practice have never described in detail how immunohistological staining process and microscopy analysis of skin samples should be performed. Although a consensus on these technical issues has been reached among highly referenced skin biopsy laboratories, a wide inter-laboratory variability in procedures still exists, conditioning skin biopsy diagnostic accuracy in a clinical setting and results heterogeneity in research. In order to highlight in a simple way the most widely accepted procedures, Eleonora will step-by-step describe the staining process through bright field immunohistochemistry and indirect immunofluorescence with PGP 9.5 via pre-recorded video and short presentation. Through a light microscope with attached camera (or alternatively histological images video-library) she will give a practical demonstration of intraepidermal nerve fibers counting, providing useful tips to carry out a correct intraepidermal nerve fibre density calculation. She will then show how to approach a semiquantitative assessment of autonomic innervation of piloerector muscle and sweat gland stained by PGP 9.5. Slides marked with alternative sensory biomarkers such as Growth associated protein 43 and TRPV1, nowadays principally used in a research setting, will also be shown and discussed.