Abnormal expression of the co‐stimulatory molecule B7‐H3 in lichen simplex chronicus is associated with expansion of Langerhans cells

Summary Background The co‐stimulatory molecule B7‐H3, a cell surface transmembrane glycoprotein, was assessed for its functional and prognostic role in lichen simplex chronicus (LSC). Aim To investigate if abnormal expression of the co‐stimulatory molecule B7‐H3 in LSC is associated with Langerhans cell (LC) expansion. Methods We used immunohistochemistry to stain LSC skin tissue, and evaluated if the immunostaining of B7‐H3 and interleukin (IL)‐6 was significantly different. Results Our results indicated that B7‐H3 is abnormally expressed in LSC skin tissue and positively regulates LC expansion. We also found that IL‐6 might modulate B7‐H3 expression. Moreover, LC expansion in LSC leads to the proliferation of T cells. Conclusions Our study indicates the potential value of immunotherapy as a treatment for LSC.