In its rare occurrence, Langerhans cell histiocytosis (LCH) is a dangerous but intriguing deviation of mononuclear phagocytes, especially dendritic cells (DCs). Clinically, the disease ranges from self-resolving or well manageable to severe and even fatal. LCH lesions in skin, bone, and other sites contain high numbers of cells with phenotypic features resembling LCs admixed with macrophages, T cells, eosinophils, and multinucleated giant cells. Here we review current progress in the LCH field based on two central questions: (i) are LCH cells intrinsically aberrant, and (ii) how does the lesion drive pathogenesis? We argue that LCH cells may originate from different sources, including epidermal LCs, tissue Langerin+ DCs, or mononuclear phagocyte precursors. Current and prospective in vitro and in vivo models are discussed. Finally, we discuss recent insights into plasticity of T-helper cell subsets in light of the lesion microenvironment. LCH continues to provide urgent clinical questions thereby inspiring innovative DC lineage research.

, , , , , , , , , , , , , , , , , , , , , , , , , , ,
doi.org/10.1111/j.0105-2896.2009.00883.x, hdl.handle.net/1765/19873
Immunological Reviews
Erasmus MC: University Medical Center Rotterdam

Egeler, R.M, van Halteren, A.G.S, Hoogendoorn, P.C.W, Laman, J.D, & Leenen, P.J.M. (2010). Langerhans cell histiocytosis: Fascinating dynamics of the dendritic cell-macrophage lineage. Immunological Reviews (Vol. 234, pp. 213–232). doi:10.1111/j.0105-2896.2009.00883.x