title: T regulatory cells (TREG)(TCD4+CD25+FOXP3+) distribution in the different clinical forms of leprosy and reactional states.
abstract: BACKGROUND
  Leprosy is characterized histologically by a spectrum of different granulomatous skin lesions, reflecting patients' immune responses to Mycobacterium leprae. Although CD4+CD25+ FoxP3+ T regulatory cells are pivotal in the immuneregulation, presence, frequency, and distribution of Tregs in leprosy, its reactional states have been investigated in few studies.
  
  
  OBJECTIVE
  This study aimed to verify the frequency and distribution of regulatory T cells in different clinical forms and reactional states of leprosy.
  
  
  METHODS
  We performed an immunohistochemical study on 96 leprosy cases [Indeterminate (I): 9 patients; tuberculoid tuberculoid: 13 patients; borderline tuberculoid: 26 patients; borderline borderline: 3 patients; borderline lepromatous: 8 patients; lepromatous lepromatous: 27 patients; reversal reaction: 8 patients; and erythema nodosum leprosum: 2 patients].
  
  
  RESULTS
  FoxP3-positive cells were present in 100% of the cases with an average density of 2.82% of the infiltrate. Their distribution was not related to granulomatous structures or special locations. There was a statistically significant increment of FoxP3 expression in patients with leprosy reversal reactions when compared with patients presenting with type I leprosy (P= 0.0228); borderline tuberculoid leprosy (P = 0.0351) and lepromatous leprosy (P = 0.0344).
  
  
  CONCLUSIONS
  These findings suggest that Tregs play a relevant role in the etiopathogenesis of leprosy, mainly in type I leprosy reaction.
authors: Centro Universitário Christus, Fortaleza, CE, Brazil.
authors: José Napoleão Tavares
authors: JN
authors: Parente
authors: Universidade Estadual do Amazonas, Manaus, AM, Brazil.
authors: Carolina
authors: C
authors: Talhari
authors: Fundação Alfredo da Matta, Manaus, AM, Brazil.
authors: Antônio Pedro Mendes
authors: AP
authors: Schettini
authors: Universidade de Graz, Graz, Austria.
authors: Cesare
authors: C
authors: Massone
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000032:analysis; D005260:Female; D051858:Forkhead Transcription Factors / Q000032:analysis; D006099:Granuloma / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D007918:Leprosy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000473:pathology*; D055815:Young Adult
chemical_list: D016207:Cytokines; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C508017:IL2RA protein, human; D053645:Interleukin-2 Receptor alpha Subunit