title: Clinical and immunological evaluation after BCG-id vaccine in leprosy patients in a 5-year follow-up study.
abstract: BACKGROUND
  The use of bacillus Calmette-Guérin (BCG) has long been considered a stimulus for immune reactivity in leprosy household contacts. Probably, the combination of multidrug therapy with BCG could facilitate the clearance of leprosy bacilli in the host, reduce relapse rates, and shorten the duration of skin-smear positivity.
  
  
  METHODS
  To investigate the mechanism of action of BCG, a study involving 19 leprosy patients, eleven multibacillary (MB) and eight paucibacillary, was performed to assess the in vitro production of interleukin (IL)-10, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-6, and IL-17 in the supernatant of peripheral blood mononuclear cells, before and 30 days after inoculation with BCG intradermally (BCG-id). Peripheral blood mononuclear cells isolated by Ficoll-Hypaque gradient were cultivated with Concanavalin-A (Con-A), lipopolysccharides (LPS), or BCG. The supernatant was collected for ELISA quantification of cytokines. The immunohistochemistry of IFN-γ, IL-1, IL-10, IL-12, transforming growth factor (TGF)-β, and TNF-α was carried out in biopsies of skin lesions of leprosy patients before and 30 days after inoculation of BCG-id. These patients were followed up for 5 years to assess the therapeutic response to multidrug therapy, the occurrence of leprosy reactions, and the results of bacterial index and anti-PGL-1 serology after the end of treatment.
  
  
  RESULTS
  The results showed increased production of cytokines after BCG-id administration in MB and paucibacillary leprosy patients. There was statistically higher levels of TNF-α (P = 0.017) in MB patients and of IL-17 (P = 0.008) and IFN-γ (P = 0.037) in paucibacillary patients. Immunohistochemical staining, especially for TNF-α, was more intense in biopsies of MB leprosy patients taken after BCG-id administration, probably for induction of innate human immunity. The clinical evaluation suggests that BCG-id is able to induce a more effective therapeutic response, with reduction of the number and the intensity of leprosy reactions.
  
  
  CONCLUSIONS
  These results suggest that BCG-id induces activation of the initial phase of immunocellular activity: innate human immunity (increase in TNF-α, IL-12 and macrophage activation). Therefore, we conclude that the use of BCG-id could be indicated as an adjuvant to multidrug therapy in treatment of leprosy patients.
authors.affiliation: Division of Dermatology, Ribeirão Preto Medical School, São Paulo University, São Paulo, Brazil.
authors.forename: Erika Muller Ramalho
authors.initials: EM
authors.lastname: Zenha
authors.forename: Carlos Gustavo
authors.initials: CG
authors.lastname: Wambier
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Novelino
authors.forename: Thiago Antônio Moretti
authors.initials: TA
authors.lastname: de Andrade
authors.forename: Maria Aparecida Nunes
authors.initials: MA
authors.lastname: Ferreira
authors.forename: Marco Andrey Cipriani
authors.initials: MA
authors.lastname: Frade
authors.forename: Norma Tiraboschi
authors.initials: NT
authors.lastname: Foss
keywords: BCG; immunology; leprosy