Plasminogen activation in lesional skin of Pemphigus vulgaris type Neumann.

Zymographic and immunological studies revealed that primarily tissue-type plasminogen activator and to a lesser extent urokinase-type plasminogen activator were present in fluids of pemphigus vulgaris (type Neumann) skin blisters. Furthermore, plasmin activity was detected in pemphigus blister fluids using chromogenic peptide substrate assays. In pemphigus, but not in control, suction blister fluids plasmin/alpha 2-antiplasmin and plasmin/alpha 2-macroglobulin complexes were found by immunoprecipitation or by testing in immunoassays after fractionation by molecular-sieve chromatography. Plasmin activity, detected by a low molecular weight chromogenic peptide assay, was ascribed to plasmin/alpha 2-macroglobulin complexes. Since formation of plasmin/inhibitor complexes requires active plasmin, the finding indicates previous activation of plasminogen in pemphigus lesions.