Immunohistochemical pattern of tumor necrosis factor alpha (TNF-α)‎ in lichen planus skin lesion

Abstract EN

Background : Lichen planus (LP) is a chronic inflammatory mucocutaneous disorder with characteristic violaceous polygonal, flat-topped papules and plaques.

TNF-α, a 17 kDa protein, is a cytokine produced by a wide variety of cell types.

TNF-α is a cytokine that plays an important role in host defense, including immunoregulatory responses implicated in the pathogenesis of many inflammatory and autoimmune diseases.

Aim : detection of tissue expression pattern of TNF-α in lichen planus skin lesion.

Patients and Methods : This work involved lesional and normal control skin specimens divided into two groups ; group (I) included 29 specimens from patients suffering from cutaneous lichen planus, and group (II) included 29 normal individuals.

An immunohistochemical (IHC) technique was applied using a mouse monoclonal IgG1 100 μg / ml raised against purified full length native TNF-α, of human origin in order to study the expression pattern of TNF-α in lichen planus skin lesions and the normal skin.

Results : The majority (72.4 %) of the specimens in lichen planus group had moderate to strong TNF-α expression, while, (62.1 %) specimens of the normal control skin had negative TNF-α expression and (37.9 %) specimens had mild TNF-α expression in less than 5 % of the resident cells (p < 0.0001) which is highly significant and revealed that the expression of TNF-α in the lesional skin of patients with lichen planus is higher than the expression in the skin of the control group and this could be explained that TNF-α has an important role in the pathogenesis of lichen planus.

Conclusion : Immunohistochemical detection of TNF-α in lichen planus skin lesion is indicative of its involvement in LP immuopathogenesis.

This allows better understanding of LP pathogenic mechanism and suggests new modalities for its treatment.