PROLIFERATING ACTIVITY OF DERMAL FIBROBLASTS IN KELOIDS AND HYPERTROPHIC SCARS

Monoclonal antibodies were used to demonstrate proliferating cell nucl ear antigen (PCNA) and Ki-67 antigen of dermal fibroblasts in formalin -fixed, paraffin-embedded tissue sections of keloids, hypertrophic sca rs and normal skin, PCNA-stained fibroblasts were more pronounced than Ki-67, which showed only scanty Ki-67-positive fibroblasts. The mean density of dermal fibroblasts was significantly higher in keloids and hypertrophic scars than in normal skin (p<0.01). The proliferating act ivity of fibroblasts detected by PCNA was significantly higher in kelo ids than in hypertrophic scars or normal skin (p<0.01), The mean densi ties and the proliferating activities were apparently not correlated w ith the age of the patient. This indicates that keloids, with higher d ensity and proliferating activity of dermal fibroblasts, continue to i ncrease their volume and invade the surrounding tissue, while hypertro phic scars, with higher density and lower proliferating activity, show a tendency towards spontaneous regression.