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 α(3)β(1 )and α(6)β(4 )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, α(3)β(1 )was distributed in a pericellular pattern, the α(6 )subunit was present with a basolateral distribution while the β(4 )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.