TOPOGRAPHIC RELATION BETWEEN SKIN-DERIVED ANTILEUKOPROTEINASE (SKALP)AND LEUKOCYTE ELASTASE IN A CASE OF ANNULAR PUSTULAR PSORIASIS

We have assessed the distribution pattern of a new epidermal elastase inhibitor, skin-derived antileukoproteinase (SKALP) and polymorphonucl ear leukocytes (PMN) in a patient with annular pustular psoriasis, usi ng immunohistochemical methods. In clinically uninvolved skin SKALP wa s not expressed and only occasionally a few PMN could be identified, I n the erythematous distal margin of the lesion, expression of SKALP wa s shown in suprabasal keratinocytes. Although PMN were present in the dermis, no transepidermal PMN migration had occurred, at this stage, I n the pustular region a dense SKALP-positive zone was demonstrated in the suprabasal compartment. In the centrally healed area neither SKALP expression nor PMN accumulation was shown. The present case report su ggests that the induction of SKALP expression does not result from the passage of PMN through the epidermis, The offswitch of SKALP expressi on coincides with the disappearance of the PMN infiltration and not wi th the resolution of the mononuclear infiltrate.