RESUMEN
Background & objectives: The gingiva is a tissue with a high turnover rate of both epithelial and connective tissue cells. In an attempt to identify the possible source of cells which maintain the tissue turnover, we used CD 34, a well established marker of peripheral blood stem cell in healthy human gingiva to determine the origin of progenitor cells in healthy gingiva. Methods: Healthy human gingival samples (n=15) were collected from patients undergoing orthodontic extraction. Immunohistochemistry was done on 5 micron paraffi n fi xed section using the primary antibody CD34 and a universal secondary immunoperoxidase kit. The sections were examined for a golden brown stain indicative of a positive staining. Results: Of the 15 samples 12 demonstrated a positive staining for the endothelial cells. Of these 12 samples, 11 demonstrated positive staining for stromal and paravascular cells and 10 a positive staining for the basal epithelium layers. Interpretation & conclusions: The presence of CD 34 positive cells in gingiva in stromal, paravascular location, and basal layer of the gingival epithelium was demonstrated. We speculate that these could be fi broblastic progenitors originating from the peripheral blood stem cells and the positivity stained epithelial cells could be gingival epithelial stem cells.