Vascular adhesion molecules and initial development of inflammation in clinically healthy human keratinized mucosa...

Expression of vascular cell adhesion molecules (HEV-CAMs) by capillary loops represents an early step necessary for leukocyte extravasation and subsequent migration to sites of inflammation. The purpose of this investigation was to compare, the presence and distribution of ICAM-1, ELAM-1, VCAM-1 and PECAM-1 expression in the microvasculature of healthy gingiva and peri-implant keratinized mucosa. The selected HEV-CAMs were detected by a three stage immunoperoxidase technique in serial sections from clinically characterized sites. Biopsies were qualitatively and quantitatively analyzed. All biopsies displayed a small inflammatory infiltrate subjacent to the most coronal extension of the junctional epithelium. HEV-CAMs were expressed both in the sulcular and oral aspects of biopsies. Intensity of ICAM-1, ELAM-1 and VCAM-1 staining, however, was consistently higher in the region of the infiltrated connective tissue subjacent to the most coronal extension of the junctional epithelium. Only a fraction of microvascular loops were positive for ICAM-1, ELAM-1 or VCAM-1 when compared to the constitutively expressed PECAM-1. No significant differences were observed between gingiva and keratinized peri-implant mucosa. It was concluded that in healthy gingiva or peri-implant mucosa 1. HEV-CAM expressing capillary loops were in close topographic association with the inflammatory infiltrate; 2. only a fraction of capillary loops are activated to express ICAM-1, ELAM-1 and VCAM-1 at any given time; and 3. HEV-CAM expression in the periodontium may be influenced by local factors.