title: Chronic telogen effluvium and female pattern hair loss are separate and distinct forms of alopecia: a histomorphometric and immunohistochemical analysis.
abstract: BACKGROUND
  Chronic telogen effluvium (CTE), a poorly understood condition, can be confused with or may be a prodrome to female pattern hair loss (FPHL). The pathogenesis of both is related to follicle cycle shortening and possibly to blood supply changes.
  
  
  OBJECTIVE
  To analyze a number of histomorphometric and immunohistochemical findings through vascular endothelial growth factor (VEGF), Ki-67, and CD31 immunostaining in scalp biopsies of 20 patients with CTE, 17 patients with mild FPHL and 9 controls.
  
  
  METHODS
  Ki-67 index and VEGF optical density were analyzed at the follicular outer sheath using ImageJ software. CD31 microvessel density was assessed by a Chalkley grid.
  
  
  RESULTS
  Significant follicle miniaturization and higher density of nonanagen follicles were found in FPHL, compared with patients with CTE and controls. Ki-67+ index correlated positively with FPHL histological features. The FPHL group showed the highest VEGF optical density, followed by the CTE and control groups. No differences were found in CD31 microvessel density between the three groups.
  
  
  CONCLUSIONS
  Histomorphometric results establish CTE as a distinct disorder, separate from FPHL from its outset. Its pathogenic mechanisms are also distinct. These findings support the proposed mechanism of 'immediate telogen release' for CTE, leading to cycle synchronization. For FPHL, accelerated anagen follicular mitotic rates and, thus, higher Ki-67 and VEGF values, would leave less time for differentiation, resulting in hair miniaturization.
authors.affiliation: Department of Pathology, Unicamp, Campinas, São Paulo, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Bittencourt
authors.forename: D A
authors.initials: DA
authors.lastname: Ferraro
authors.forename: T C B
authors.initials: TC
authors.lastname: Soares
authors.forename: A M
authors.initials: AM
authors.lastname: Moraes
authors.forename: M L
authors.initials: ML
authors.lastname: Cintra
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000505:Alopecia / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D018859:Hair Follicle / Q000098:blood supply / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008875:Middle Aged; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D011446:Prospective Studies; D012535:Scalp / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A