ALPHA-INTERFERON CREAM RESTORES DECREASED LEVELS OF LANGERHANS/INDETERMINATE (CD1A+) CELLS IN AGED AND PUVA-TREATED SKIN

Langerhans/indeterminate (CD1a+) cells are known for their role in stimulating T-lymphocyte-dependent immune reactions. They are normally present in the skin and are modified in a variety of different pathological and physiological events, including aging. Linear decrease of CD1a+ cells with aging (both true aging and photoaging) is considered the most important cause of reduced immunosurveillance in aged old skin of the elderly. Recently it has been suggested that alpha-interferon might have an effect on increasing levels of dendritic cells in aged and photoaged skin. We studied biopsies from the preauricular area in 15 subjects (5 subjects aged 18-21 years, 5 aged 57-75, and 5 aged 30-45 who underwent PUVA therapy, total irradiation 120 J/cm(2)) before and after the application of alpha-interferon cream. Our findings show that dendritic cells are significantly decreased in the 57- to 75-year-old group compared to the 8- to 21-year-old group. After PUVA therapy we also found a decrease in Langerhans cells. Our study shows that the application of alpha-interferon cream induces an increase in cutaneous CD1a+ cells and HLA-DR+ cells in both older subjects and subjects who have undergone PUVA therapy. On the basis of these results, one could hypothesize that alpha-interferon cream may have some beneficial effects on photoaging-reduced immunosurveillance.