ABNORMAL IMMUNO-MORPHOLOGICAL FEATURES OF HAIR-FOLLICLES IN ALOPECIA-AREATA - A QUANTITATIVE INVESTIGATION

The pathogenetic stages of alopecia areata (AA) involve various cellul ar mediators, such as lymphocytes (Ly), Langerhans cells (LC's) and ke ratinocytes (Kc), having abnormal immunomorphological features. In our immunohistochemical study, we assessed the distribution, quantity and some phenotypic expressions (HLA-DR, ICAM-1, LFA-1) of the LC's (LC-C D1a), keratinocytes and T lymphocytes (CD3). Our investigation has sho wn an abnormal presence and expression in the alopecic areas of HLA-DR +, ICAM-1+ and LFA-1+ LC's, indicating a condition of high activation for such immunomediators in the course of AA. The accumulation of T-he lper (CD4+) lymphocytes, macrophages (Ber-mar 3+) and activated kerati nocytes (HLA-DR+ and ICAM-1+) in the alopecic areas further highlights the hyper-responsiveness of these cutaneous zones to stimuli, as yet poorly understood, though probably sustained by predisposing genetic f actors.