Lysozyme in abnormal dermal elastic fibers of cutaneous aging, solar elastosis and pseudoxanthoma elasticum

Staining of elastic fibres with antilysozyme antibodies has been noted previously. In this study, we examined the staining pattern of dermal elastic fibres in aging, solar elastosis, and lesional skin of pseudoxanthoma elasticum (PXE) using an antibody to lysozyme and the indirect-peroxidase technique. To assess the effects of aging, sun-protected skin (buttock) from a younger and an older group of patients was used. Sun damage was studied in skin specimens from varying sun-exposed body regions (trunk; head and neck). No staining was seen in sun-protected skin from younger individuals, whereas sun-protected skin from older persons had scattered positive fibres. Solar elastotic material was intensely positive and the number of positive fibres appeared to correlate with the amount of sun damage. Abnormal elastic fibres in PXE also stained positively, but less intensely, than fibres in solar elastosis. This study shows that changes in the elastic fibres due to degenerative processes or genetic factors results in altered antigenic expression of the fibres. This may be an epiphenomenon secondary to changes in proteoglycans, which are known to occur with solar elastosis and PXE, or may represent an adaptive phenomenon to maintain the elastic properties of the altered fibres or to decrease their antigenicity.