Alterated integrin expression in lichen planopilaris

BACKGROUND Lichen planopilaris (LPP) is an inflammatory disease characterized by a lymphomononuclear infiltrate surrounding the isthmus and infundibulum of the hair follicle of the scalp, that evolves into atrophic/scarring alopecia. In the active phase of the disease hairs are easily plucked with anagen-like hair-roots. In this study we focused on the expression of integrins and basement membrane components of the hair follicle in active LPP lesions. METHODS Scalp biopsies were taken in 10 patients with LPP and in 5 normal controls. Using monoclonal antibodies against alpha3beta1 and alpha6beta4 integrins we showed the expression of these integrins and of the basement membrane components of the hair follicle in active LPP lesions and in healthy scalp skin. RESULTS In the LPP involved areas, alpha3beta1 was distributed in a pericellular pattern, the alpha6 subunit was present with a basolateral distribution while the beta4 subunit showed discontinuous expression at the basal pole and occasionally, basolateral staining of the hair follicle. CONCLUSION An altered distribution of the integrins in active LPP lesions can explain the phenomenon of easy pulling-out of the hair with a "gelatinous" root-sheath.