title: Granulomatous reactivation during the course of a leprosy infection: reaction or relapse.
abstract: BACKGROUND
  Leprosy is a chronic granulomatous infectious disease and is still endemic in many parts of the world. It causes disabilities which are the consequence of nerve damage. This damage is in most cases the result of immunological reactions.
  
  
  OBJECTIVE
  To investigate the differences between a type 1 leprosy (reversal) reaction and relapse on using histopathology.
  
  
  METHODS
  The histopathological changes in 167 biopsies from 66 leprosy patients were studied. The patients were selected when their sequential biopsies demonstrated either different patterns or maintained the same pattern of granulomatous reaction over more than two years during or after the treatment of leprosy.
  
  
  RESULTS
  In 57 of the patients studied, a reactivation was seen which coincided with a decrease in the bacteriological index (BI), suggesting that this reactivation (reversal reaction or type 1 leprosy reaction) coincides with an effective capacity for bacteriological clearance. In nine patients, an increase of the bacteriologic index (IB) or persistence of solid bacilli occurred during the reactivation, indicating proliferative activity, suggestive of a relapse. The histopathological aspects of the granulomas were similar in both groups.
  
  
  CONCLUSIONS
  Bacterioscopy provided the only means to differentiate a reversal reaction from a relapse in patients with granulomatous reactivation. The type 1 leprosy reaction may be considered as a part effective immune reconstitution (reversal, upgrading reaction) or as a mere hypersensitivity reaction (downgrading reaction) in a relapse.
authors.affiliation: Health Institute, São Paulo State Health Department, São Paulo, São Paulo, Brazil. angelatrindade@uol.com.br
authors.forename: Maria Angela Bianconcini
authors.initials: MA
authors.lastname: Trindade
authors.forename: Gil
authors.initials: G
authors.lastname: Benard
authors.forename: Somei
authors.initials: S
authors.lastname: Ura
authors.forename: Cássio Cesar
authors.initials: CC
authors.lastname: Ghidella
authors.forename: João Carlos Regazzi
authors.initials: JC
authors.lastname: Avelleira
authors.forename: Francisco Reis
authors.initials: FR
authors.lastname: Vianna
authors.forename: Alfredo Bolchat
authors.initials: AB
authors.lastname: Marques
authors.forename: Ben
authors.initials: B
authors.lastname: Naafs
authors.forename: Raul Negrão
authors.initials: RN
authors.lastname: Fleury
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D006099:Granuloma / Q000276:immunology / Q000382:microbiology* / Q000473:pathology*; D006651:Histocytochemistry; D006801:Humans; D054019:Immune Reconstitution Inflammatory Syndrome / Q000382:microbiology / Q000473:pathology; D007918:Leprosy / Q000276:immunology / Q000382:microbiology* / Q000473:pathology*; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000276:immunology / Q000302:isolation & purification*; D012008:Recurrence