Tissue factor and thrombomodulin expression on keratinocytes as coagulation/anti-coagulation cofactor and differentiation marker.

Immunohistochemistry was used to investigate the expression of tissue factor (TF) as a coagulation factor and thrombomodulin (TM) as an anticoagulation cofactor in the epidermis. TM was expressed on Malpighian layer keratinocytes while TF was located on the supra-Malpighian layer. Epidermal shave extracts were biologically active for both factors. Keratinocytes cultured in high calcium, but not low calcium media, expressed both TF and TM. In pemphigus vulgaris pemphigus foliaceus and bullous pemphigoid, TF expression was increased on keratinocytes shielding the blister compared to the down-regulated TM expression by keratinocytes around the blister.