Antikeratin 14 monoclonal antibody staining in psoriasis and seborrhoeic keratosis: immunofluorescence and two colour FACS studies.

A monoclonal antibody (ES3A) was raised against a mouse graft-versus-host reaction (GVHR) model. This antibody was against basal cell cytoplasm and reacted with an acidic (pI 6.2) 50 kDa keratin of human epidermis. However, ES3A reacted with several lower layers of epidermal cells in psoriasis and seborrhoeic keratosis. Acanthotic seborrhoeic keratosis showed varying patterns even in a single lesion. If combined with FACS analysis, ES3A-positive cells could be quantified. Normal skin showed 28%, while psoriasis and seborrhoeic keratosis showed 44% and 51%, respectively. ES3A-positive compartments of the acanthotic type of seborrhoeic keratosis were larger than those of the hyperkeratotic type. ES3A may be suitable for quantification of germinative or proliferative cells.