A prostaglandin d-synthase-positive mast cell gradient characterizes scalp patterning
Pattern (androgenetic) alopecia is commonly encountered in scalp biopsies obtained for non-scarring hair loss. Prostaglandin d-synthase is known to be elevated in bald vs. non-alopetic scalp of patients with androgenetic alopecia. We hypothesized that this difference in pattern of prostaglandin d-synthase expression may constitute a developmental pattern inherent to normal as well as alopecic scalp skin, thus defining a ‘field’ vulnerable to acquired hair loss.
We immunohistochemically mapped prostaglandin d-synthase expression from supra-auricular to vertex scalp skin of 11 cadavers.
We found significantly more dermal mast cells immunoreactive for prostaglandin d-synthase in the vertex compared to the lateral aspects of the scalp, with a decrement that spatially approximated the pattern of androgenetic alopecia. This difference was present in both balding and non-balding scalps and was independent of gender. Dual labeling established dermal cells expressing prostaglandin d-synthase as mast cells.
These data indicate that scalp is spatially programmed via mast cell prostaglandin d-synthase distribution in a manner reminiscent of the pattern seen in androgenetic alopecia.