title: Association of viable Mycobacterium leprae with Type 1 reaction in leprosy.
abstract: The working hypothesis is that, viable Mycobacterium leprae (M. leprae) play a crucial role in the precipitation of Type 1 reaction (T1R) in leprosy.
  
  
  METHODS
  A total of 165 new multibacillary patients were studied. To demonstrate presence of viable M. leprae in reactional lesion (T1R+), three tests were used concurrently viz. growth in the mouse foot pad (MFP), immunohistochemical detection of M. leprae secretory protein Ag85, and 16s rRNA--using in situ RT-PCR. Mirror biopsies and non reactional lesions served as controls (T1R-).
  
  
  RESULTS
  A significantly higher proportion of lesion biopsy homogenates obtained at onset, from T1R(+) cases have shown unequivocal growth in MFP, proving the presence of viable bacteria, as compared to T1R(-) (P < 0.005). In contrast, few Mirror biopsies were positive in both T1R(+) and T1R(-). With respect to Ag85, while the overall positivity was higher in T1R(+) (74%), however the intensity of staining (Grade 2+) was disproportionately higher in T1R(+) BT-BB lesions 11/20 (55%). In the rebiopsies obtained during a repeat episode of T1R, Ag 85 as well as 16s rRNA, positivity (62% & 100%) was higher in T1R(+). It is inferred therefore 'viable' bacteria are an essential component in T1R and difference in the quality of bacilli, not the quantity or the ratio of dead to viable play a role in the precipitation of T1R. In conclusion, the findings show that 'metabolically active' M. leprae is a component/prerequisite and the secretory protein Ag 85, might be the trigger for precipitation of T1R.
authors.forename: Mrudula Prakash
authors.initials: MP
authors.lastname: Save
authors.forename: Anju Rajaram
authors.initials: AR
authors.lastname: Dighe
authors.forename: Mohan
authors.initials: M
authors.lastname: Natrajan
authors.forename: Vanaja Prabhakaran
authors.initials: VP
authors.lastname: Shetty
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000942:Antigens, Bacterial / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000302:isolation & purification; D001681:Biological Assay; D005260:Female; D006801:Humans; D056006:Leprosy, Multibacillary / Q000150:complications* / Q000382:microbiology* / Q000473:pathology; D008297:Male; D051379:Mice; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000502:physiology*; D012329:RNA, Bacterial / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000302:isolation & purification; D012867:Skin / Q000382:microbiology / Q000473:pathology; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S