CELL INFILTRATE IN PROGRESSIVE PIGMENTED PURPURA (SCHAMBERGS-DISEASE)- IMMUNOPHENOTYPE, ADHESION RECEPTORS, AND INTERCELLULAR RELATIONSHIPS

Background. Progressive pigmented purpura (Schamberg's disease), a for m of purpura pigmentosa chronica, is a lymphocytic capillaritis of unk nown etiology and obscure pathogenesis. Our purpose was to assess the expression of cell membrane antigens (CD3, CD4, CD1a, CD36), of adhesi on receptors (leukocyte function adhesion 1, LFA-1, endothelial leukoc yte adhesion molecule 1, ELAM-1) intercellular adhesion molecule 1, IC AM-1), and the intercellular relationships in the early phase of the d isease. Methods. Quantitative immunohistochemistry and electron-micros copy were performed on specimens of five subjects, aged 45 to 63 years . These studies were repealed in two patients after treatment with top ical corticosteroid (betamethasone valerate cream 0.1%) and psoralen-u ltraviolet A (PUVA). Results. The infiltrate consisted mainly of CD4lymphocytes and CD1a+ dendritic cells. Electron-microscopic investigat ion showed typical lymphocytes and two distinct types of dendritic cel ls. In the very early phase of the disease the adhesion receptors LFA- 1 and ICAM-1 were expressed in tensely by all infiltrating cells; the adhesion receptors ICAM-1 and ELAM-1 were expressed by endothelial cel ls. Close contact occured between lymphocytes and dendritic cells. Aft er puva (120 J per cm(2)) and topical steroid therapy the infiltrate d isappeared completely. Conclusions. These data suggest that a cell-med iated immune mechanism may be important in progressive pigmented purpu ra and that the early endothelial expression adhesion receptors may de termine the pattern of organization of the pericapillary infiltrate.