title: Morphological and immunohistochemical clues for the diagnosis of cutaneous leishmaniasis and the interpretation of CD1a status.
abstract: BACKGROUND
  CD1a immunoexpression by amastigotes of Leishmania major and L tropica has been demonstrated.
  
  
  OBJECTIVE
  We studied the CD1a and the langerin status of amastigotes in cases of L infantum.
  
  
  METHODS
  We investigated 19 cases of cutaneous leishmaniasis. All cases were immunostained with CD1a, langerin, and CD68. We also studied 4 cases of visceral leishmaniasis.
  
  
  RESULTS
  We found expression of CD1a by amastigotes in all of these 19 cases. CD1a(-) amastigotes are found in reticular areas of the dermis. The pattern of CD1a immunostaining of amastigotes is characteristic, with peripheral positivity, a negative nucleus in the center, and reinforcement of the kinetoplast in 1 pole. Leishmania amastigotes were langerin-negative. Visceral Leishmania amastigotes also express CD1a.
  
  
  CONCLUSIONS
  Our study was limited because it only included cases of infection by L infantum.
  
  
  CONCLUSIONS
  (1) L infantum is CD1a(+), (2) the pattern of CD1a immunostaining of amastigotes is peculiar, (3) CD1a(-) amastigotes are found in reticular areas of the dermis, and (4) visceral Leishmania amastigotes also express CD1a.
authors.affiliation: Department of Cellular Pathology, Hospital El Bierzo, Ponferrada, Spain. Electronic address: dermatopathonline@gmail.com.
authors.forename: Angel
authors.initials: A
authors.lastname: Fernandez-Flores
authors.affiliation: Department of Pathology, Hospital Universitario 12 de Octubre, Universidad Complutense, I+12, Madrid, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rodriguez-Peralto
mesh_terms: D018949:Antigens, CD1 / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018314:Leishmania infantum / Q000737:chemistry* / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000175:diagnosis* / Q000469:parasitology; D008297:Male
chemical_list: D018949:Antigens, CD1; C419393:CD1a antigen
keywords: CD1a; Langerhans cell; Leishmania; Leishmania infantum; Leishmania major; Leishmania tropica; MTB1; amastigotes; antigen transfer; granuloma; granulomatous inflammation; langerin; leishmaniasis; transepidermal elimination