Expressions of nerve growth factor and its high-affinity receptor, tyrosine kinase A, as well as low-affinity common receptor, p75 neurotrophin receptor, in the lesions of lichen planus and their clinical significance

Abstract

Objective To detect the expressions of nerve growth factor (NGF) and its receptors tyrosine kinase A (TrkA) as well as p75 neurotrophin receptor (p75NTR) in the lesions of lichen planus.Methods Biopsy specimens were collected from the lesions of 32 patients with lichen planus and normal skin of 12 healthy human controls and subjected to paraffin embedding.Immunohistochemical avidin-biotin complex (ABC) method was used to detect the expressions of NGF,TrkA and p75NTR.Results NGF and TrkA,which were located in the cytoplasm of keratinocytes,were strongly or moderately expressed in the lesional skin specimens,but absent or weakly expressed in the normal skin specimens (both P ＜ 0.01).No significant differences were observed in the expression of p75NTR between the lesional and normal skin specimens,or in the expressions of NGF,TrkA or p75NTR among specimens from patients in different age groups,patients of different gender or lesions at different sites (all P ＞ 0.05).There was a positive correlation between the expression of NGF and TrkA in the lesions of lichen planus (R2 =0.535,P ＜ 0.01).Conclusion NGF may play a certain role in the development of lichen planus via its highaffinity receptor TrkA. Key words: Lichen planus; Nerve growth factor, Protein-tyrosine kinases; p75NTR