Abstract: Objective To investigate the relationship between keratinocyte growth factor (KGF), nerve growth factor(NGF)and psoriasis;and to study the interaction between keratinocytes and interstitial cells in psoriasis. Methods The expression of KGF, KGF receptor (KGFR), NGF, NGF receptor (NGFR), epidermal growth factor receptor (EGFR) and proliferating cell neuclear antigen (PCNA) was studied with immunohistochemical technique (SP) in lesional skin, non-lesional skin and normal controls. Results Significant overexpression of KGF and KGFR was present in psoriatic basal cell layers and suprabasal cell layers compared to that in non-lesional and normal controls (P<0.05), but was not significant between the non-lesional skin and the controls (P >0.05). Expression of KGF and KGFR was absent in dermis. Expression of NGF and NGFR was observed mainly in granular cell layers and upper spinous layers, and was significantly different between normal controls and non-lesional, between non-lesional and lesional skin (P<0.05). Conclusions KGF and NGF may mediate hyperplasia and incomplete differentiation of keratinocytes in psoriasis. The disorder of interaction between keratinocytes and interstitial cells may exist in psoriasis.

Key words: Psoriasis, Epidermal growth factor urogastrone, Nerve growth factors, Keratinocyte growth factor