Effect of ageing on mast cell density in human skin: a comparative analysis of photoexposed and photoprotected regions.

Abstract

Background: Mast cells are mononuclear cells originating from bone marrow. They produce various biologically active substances which allow them to actively participate in immune and inflammatory processes associated with intrinsic and extrinsic skin ageing. This study was focused on the distribution and density of mast cells in healthy skin in different stages of skin ageing.

Materials and methods: This project included samples of photoexposed and photoprotected skin obtained from 90 cadavers aged 0-82 years. The samples were classified into five age groups: newborns, young age, middle age, senior age and oldest age. In order to visualise the mast cells, the authors employed several histochemical staining protocols.

Results: The number of mast cells in the photoexposed skin significantly correlated with the individual's age. The number of mast cells in the photoprotected skin was in general statistically significantly lower in younger than in older groups; however, the correlation of mast cell density in photoprotected skin and age did not reach statistical significance. In the middle, senior and oldest age groups, a significantly higher number of mast cells were recorded in the skin of the photoexposed compared to the photoprotected regions.

Conclusions: An increase in mast cell density correlates with age only in photoexposed skin. Age-related higher accumulation of dermal mast cells in photoexposed skin can be an important factor in the photoageing process, as well as a contributory factor in the occurrence of skin cancer.