Immunohistochemical study of vestibular gingival blood vessel density and internal circumference in smokers and non-smokers

Background: This study was undertaken to determine: 1) if sections stained with monoclonal antibody to CD34 can be used for measurement of gingival blood vessel density and circumference and 2) if long-term smoking affects either of these 2 parameters. Methods: Vestibular gingival biopsy samples were obtained from 17 adults (5 smokers and 12 non-smokers) who were undergoing routine periodontal surgery independently of this study. Hematoxylin and eosin staining was used for histological assessment of inflammation, while immunohistochemical staining with CD34 mouse monoclonal antibody was used to mark the endothelial cells of the blood vessels within each sample. Stringent selection criteria were applied to the 17 biopsy samples, and 7 (from 3 smokers and 4 non-smokers) were chosen to have their vascular density (number of vessels/unit area) and internal vessel circumference (IC) measured under a blinded protocol. Results: Repeated measurements of vascular density and internal circumference showed small standard deviations, indicating the high reproducibility of the measurement technique. The smoker group showed a higher proportion of small (IC < 50 mum) and a lower proportion of large blood vessels (IC > 100 mum), which was statistically significant (P = 0.0403 and P <0.001, respectively). The difference between the vascular density of smokers and non-smokers was not significant (P = 0.092). Conclusions: The present study indicates that the CD34 immunohistochemical staining technique is a simple and reproducible method for the measurement of density and internal circumference of gingival blood vessels. Based on this technique, cigarette smokers show a higher percentage of smaller blood vessels and a lower percentage of larger vessels, but similar vascular density, to non-smokers.