CGRP-immunoreactive nerves in prurigo nodularis - an exploration of neurogenic inflammation

• Published in: Journal of cutaneous pathology Vol. 27; no. 7; pp. 359 - 366
• Main Authors: Liang, Yong, Jacobi, Henrik H., Reimert, Claus M., Haak-Frendscho, Mary, Marcusson, Jan A., Johansson, Olle
• Format: Journal Article
• Language: English
• Published: Copenhagen Munksgaard International Publishers 01.08.2000; Blackwell
• Subjects: Aged; Aged, 80 and over; Antibodies; Axons - chemistry; Axons - pathology; Axons - ultrastructure; Biological and medical sciences; Biopsy; Blood Proteins - analysis; Calcitonin Gene-Related Peptide - analysis; Calcitonin Gene-Related Peptide - immunology; Chymases; Dermatology; Eosinophil Granule Proteins; Eosinophils - chemistry; Eosinophils - immunology; Female; Fluorescent Antibody Technique; Humans; Male; Mast Cells - enzymology; Mast Cells - immunology; Medical sciences; Medicin och hälsovetenskap; Microscopy, Immunoelectron; Middle Aged; Neuritis - immunology; Neuritis - pathology; Peripheral Nerves - chemistry; Peripheral Nerves - pathology; Prurigo - pathology; Ribonucleases; Serine Endopeptidases - analysis; Skin involvement in other diseases. Miscellaneous. General aspects; Tryptases; Human; Immunohistochemistry; Skin disease; Immunogold labelling; Pathogenesis; Peptide hormone; Nodular prurigo; Calcitonine gene related peptide; Neuropeptide; Pathology; Cutaneous nerve; Neurotransmitter; Immunoelectron microscopy; Neurogenic inflammation
• ISSN: 0303-6987; 1600-0560
• DOI: 10.1034/j.1600-0560.2000.027007359.x

Background: The present study has explored the localization and distribution of calcitonin gene‐related peptide (CGRP)‐immunoreactive (IR) nerve fibers in prurigo nodularis, especially emphasizing its relationships to mast cells and eosinophils, which all are important contributors to inflammation. Methods: The exact localization of CGRP in the nerve fibers of prurigo nodularis lesional skin has been clarified by an ultrastructural immunogold labelling technique; and the relationships of CGRP‐IR nerve fibers to tryptase‐IR mast cells or eosinophil cationic protein (ECP)‐IR eosinophils were also investigated by immunofluorescence double‐labelling. Results: This ultrastructural study has demonstrated that CGRP immunoreactivity is increased in the dense‐core vesicles in the axons of the prurigo nodularis lesional skin; the axons which contain CGRP are, in addition, enlarged and have more dense‐core vesicles than the axons which do not contain CGRP. The immunofluorescence investigation demonstrated that tryptase‐containing mast cells and ECP‐containing eosinophils also are significantly increased in the lesional skin. Conclusions: The results indicate that certain neurons increasingly express CGRP, which may dynamically result in a neurogenic inflammation in the lesional skin, through vasodilatation, and recruitment and regulation of inflammatory cells, e.g. eosinophils and mast cells.