SOLUBLE PITYROSPORUM-DERIVED CHEMOATTRACTANT FOR POLYMORPHONUCLEAR LEUKOCYTES OF PSORIATIC PATIENTS

The chemoattraction of polymorphonuclear leukocytes (PMNs) from psoria tic patients, atopic patients and healthy control persons by Pityrospo rum orbiculare/ovale was investigated using the Boyden chamber method. The chemotactical attraction of PMNs from psoriatic patients by Pityr osporum (stimulation index SI = 58+/-50) was significantly increased ( p<0.05) compared to PMNs from atopic patients (SI=20+/-17) and control persons (SI=26+/-24). This effect seems to be specific for Pityrospor um, since the chemotactical response to Staphylococcus epidermidis was not increased in psoriasis. The chemotactical factor produced by Pity rosporum is hydrophilic and is destroyed by acid hydrolysis, indicatin g its protein nature, The yeast Pityrosporum may thus play a role in t he koebnerization of psoriasis.