THE STUDY OF ACTINIC KERATOSIS CELL PROLIFERATION AND DERMAL ELASTOSIS PREVALENCE CORRELATION
Actinic keratosis (AK) is a premalignant lesion caused by ultraviolet (UV) radiation and characterized by epithelial and connective tissue alterations. Objective and Methods: To examine the potential relationship between connective tissue degeneration and cell proliferation in epithelial cells. 35 cases were immunohistochemically analyzed for the expression of Ki-67 and elastin. Dermal elastosis was divided into three areas (zones) according to its prevalence: narrow area - elastosis located in papillary dermis and upper layers of reticular dermis; wide area - up to the deep layers of the reticular dermis; and total area - equal to dermis width. Results: The increase in the solar elastosis grade was associated with an increase in positive cell numbers for Ki-67. A low proliferative activity of epidermal cells was observed in lesions with the narrow area of elastosis, whereas the moderate activity was found in actinic keratoses with the wide and the total areas of elastosis. Basal and suprabasal expression predominated in the lesions with narrow area of connective tissue degeneration; expression in spinosum layer and full-thickness of epidermis was prevalent in the lesions with wide and total areas of degeneration. These results demonstrate that the epithelial expression of cell proliferation is augmented with the increase of the solar elastosis grade. Thus, the grade of solar elastosis could be a helpful morphologic marker in the assessment of neoplastic changes in sun-damaged skin.