title: Comparative immunohistological analysis of the Montenegro skin test reaction in asymptomatic infection and in acute and chronic cutaneous leishmaniasis.
abstract: BACKGROUND
  The Montenegro skin test reaction and leishmaniasis lesions share fundamental characteristics of a delayed type hypersensitivity reaction.
  
  
  OBJECTIVE
  To determine whether the Montenegro skin test reaction (response to leishmanin) might approximate and thereby provide insight into the early inflammatory and immune response to Leishmania infection.
  
  
  METHODS
  We compared the inflammatory response in biopsies of acute (evolution time < or = one month), and chronic lesions (evolution time > or = 6 months) with the Montenegro skin test reaction in the corresponding patients, and with the Montenegro skin test of asymptomatically infected volunteers.
  
  
  RESULTS
  The proportion of CD4+ and CD8+ T lymphocytes, mononuclear phagocytes and granulocytes were similar in acute lesions and in their corresponding Montenegro skin test reactions. In contrast, CD4+ lymphocytes (32.6%) represented a significantly lower, and B cells (20%) and macrophages (27%) a significantly higher proportion of the cellular infiltrate in chronic lesions as compared to reactions in the corresponding skin test site (CD4+: 43.7%, B cells: 0.9%; macrophages: 17.5%). CD8+ T lymphocytes and macrophages were positively associated (P = 0.038) in the Montenegro skin test of asymptomatically infected individuals whereas CD8+ and CD4+ T cells were positively associated in the Montenegro skin test of chronic patients (P = 0.002). Notably, B cells were markedly more frequent in chronic lesions (20%) than in acute lesions (5.3%) (P = 0.002).
  
  
  CONCLUSIONS
  The Montenegro skin test distinguished the cellular immune response to Leishmania in asymptomatic infection and chronic disease and may provide a surrogate of the early response to infection.
authors.affiliation: Centro Internacional de Entrenamiento e Investigaciones Medicas, Cali, Colombia.
authors.forename: Nora
authors.initials: N
authors.lastname: Guarín
authors.forename: Gloria I
authors.initials: GI
authors.lastname: Palma
authors.forename: Claude
authors.initials: C
authors.lastname: Pirmez
authors.forename: Liliana
authors.initials: L
authors.lastname: Valderrama
authors.forename: Rafael
authors.initials: R
authors.lastname: Tovar
authors.forename: Nancy Gore
authors.initials: NG
authors.lastname: Saravia
mesh_terms: D000208:Acute Disease; D000328:Adult; D002908:Chronic Disease; D005260:Female; D006801:Humans; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000473:pathology*; D008297:Male; D012882:Skin Tests / Q000379:methods