title: D2-40 expression in primary scarring and nonscarring alopecia.
abstract: The pathogenesis of scarring alopecia is believed to be related to damage to stem cells within, and outside the confines of, the follicular bulge region. Scattered reports indicate that D2-40, a monoclonal antibody that specifically detects a fixation-resistant epitope on podoplanin, highlights the basal cell layer of the outer root sheath. Given this, we sought to ascertain involvement of the same in a total of 52 cases of alopecia (33 scarring and 19 nonscarring). D2-40 expression, noted in the peripheral layer of the outer root sheath (above and below attachment of the pilar muscle), was similar in 24/33 (73%) and increased in 9/33 (27%) in the infundibular region of cases of scarring alopecia in comparison to its expression in 17/19 (90%; no expression noted in the other 2) of cases of nonscarring alopecia. The absence of a unifying diagnosis in entities demonstrating an increase precludes any correlation from being made regarding D2-40 expression and histologic diagnosis. However, more recently, podoplanin has been shown to be a novel Fos target gene in some skin cancers. Thus, from a scientific perspective, involvement of Fos-dependent transcription mechanisms in the etiopathogenesis of select scarring alopecias does not seem entirely unreasonable although studies defining the role of the Fos-podoplanin axis in development of the normal hair follicle are required before a definitive conclusion can be drawn.
authors.affiliation: Dermatopathology Section, Department of Dermatology, Boston University School of Medicine, 609 Albany Street, Boston, MA 02118, USA. mmahalin@bu.edu
authors.forename: Meera
authors.initials: M
authors.lastname: Mahalingam
authors.forename: Mai P
authors.initials: MP
authors.lastname: Hoang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000505:Alopecia / Q000378:metabolism / Q000473:pathology*; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D001706:Biopsy; D002921:Cicatrix / Q000378:metabolism / Q000473:pathology*; D000939:Epitopes / Q000276:immunology; D018859:Hair Follicle / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000276:immunology* / Q000378:metabolism*; D008875:Middle Aged; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology; D055815:Young Adult; D000098853:Podoplanin
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000939:Epitopes; D008562:Membrane Glycoproteins; C117468:PDPN protein, human; D000098853:Podoplanin; C500987:monoclonal antibody D2-40