Immunolocalization of CD 34 positive progenitor cells in healthy human gingiva - a pilot study.

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.

Immunohistochemical Study on Expression of CD34 in Basal Cell Carcinomas and Trichoepitheliomas / 대한피부과학회지

BACKGROUND: The differentiation between basal cell carcinoma(BCC) and trichoepithelioma(TE) is sometimes difficult clinically and histologically, and their differentiation is important since their treatment and prognosis are sometimes different. OBJECTIVE: Our purpose was to investigate whether there was a difference in CD34 staining patterns in the stromas (immediate and distant stromas from the tumor lobules) of BCC and TE, since the histopathologic characteristics of the stromas are one of the most important features to differentiate the two tumor. METHOD: We perfomed immunoperoxidase staining(modified ABC technique) by using a monoclonal anti CD34 antibody(QBEND10, IgG1) on the formalin-fixed, paraffin-embedded biopsy specimens of 11 BCC as and 10 TEs. RESULTS: 1. In the immediate strcimas, spindle-shaped cells were stained in 4 out of ll cases of BCC and in 9 out of 10 cases of TE. However, the staining patterns observed in the 4 cases of BCC were all loosely scattered, week staining, while those of the 9 cases of TE were all densely compact, strong staining. CD34 was not expressed in one case of TE. 2. In the distant stromas, all cases of BCC and TE showed staining of loosely scattered spindle-shaped cells, and there was no difference in staining patterns of the two tumors. 3. Papillary mesenchymed bodies were observed in 8 cases of TE and in none of BCC, and they expressed CD34 focally. CONCLUSION: CD34 sta ining patterns of the immediate peritumoral stromas of BCCs and TEs were different and could differentiate the two tumors.