Effect of chronic sun exposure on human Langerhans cell densities.

This study evaluated the Langerhans cell density in chronically sun-exposed skin (hand) and non-exposed skin (buttock) in subjects that were divided into 4 age groups (20-40; 41-60; 61-80; greater than 81 years). Two markers (OKT-6 and anti-HLA-DR) were used to identify the Langerhans cells (LC), and their count was performed either on epidermal sheets (52 individuals) or skin sections (43 individuals). Three major findings result from this study: 1) there are more LC in the non-exposed skin than in the chronically sun-exposed area; 2) there were no age-related changes in LC counts, and 3) LC co-express the T6 and HLA-DR antigens.