title: Trypanosoma cruzi persistence in the native heart is associated with high-grade myocarditis, but not with Chagas' disease reactivation after heart transplantation.
abstract: BACKGROUND
  Chagas' disease reactivation (CDR) after heart transplantation (HTx) is characterized by relapse of the infectious disease, with direct detection of Trypanosoma cruzi parasites in blood, cerebrospinal fluid, or tissues. We investigated whether a detailed pathologic examination of the explanted heart at HTx with evaluation of myocarditis and parasitic persistence or load in the myocardium could be useful to identify patients at high risk of CDR.
  
  
  METHODS
  The native hearts of 18 chagasic patients who presented CDR after HTx (CDR+ group) were compared with the native hearts of 16 chagasic patients who never presented CDR in a follow-up of at least 18 months after HTx (CDR- group). The intensity of myocarditis was evaluated semiquantitatively. Parasite persistence/load in the myocardium was investigated through immunohistochemistry for T cruzi antigens and by qualitative and quantitative real-time PCR for T cruzi DNA.
  
  
  RESULTS
  The rate of high-grade myocarditis, parasite persistence, and the median of parasitic load and parasitic load/10(6) cells in the CDR+ group were 83.3%, 77.8%, 8.43 × 10(-3), and 9.890, respectively, whereas in the CDR- group the values were 87.5%, 50%, 7.49×10(-3), and 17.800. There was no statistical difference between the groups. High-grade myocarditis was present in all 22 samples (100%) with parasite persistence and in 7 of 12 samples (58.3%) with no parasite persistence (p = 0.003).
  
  
  CONCLUSIONS
  Although associated with high-grade myocarditis, T cruzi parasite persistence in the myocardium of the native heart is not associated with the occurrence of CDR after HTx.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. Electronic address: anpluiz@incor.usp.br.
authors.forename: Luiz A
authors.initials: LA
authors.lastname: Benvenuti
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Roggério
authors.affiliation: Fundação Pró-Sangue/Hemocentro of São Paulo, Molecular Biology Department, São Paulo, Brazil; Infectious Disease Division (DIPA), Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Nishiya
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Silvia V
authors.initials: SV
authors.lastname: Campos
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Alfredo I
authors.initials: AI
authors.lastname: Fiorelli
authors.affiliation: Fundação Pró-Sangue/Hemocentro of São Paulo, Molecular Biology Department, São Paulo, Brazil.
authors.forename: José E
authors.initials: JE
authors.lastname: Levi
mesh_terms: D000328:Adult; D000953:Antigens, Protozoan / Q000097:blood; D002598:Chagas Cardiomyopathy / Q000469:parasitology* / Q000601:surgery*; D014355:Chagas Disease / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000469:parasitology; D016027:Heart Transplantation; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D059208:Parasite Load; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D014349:Trypanosoma cruzi / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000953:Antigens, Protozoan
keywords: Chagas’ disease; Trypanosoma cruzi; heart transplantation; myocarditis; polymerase chain reaction