title: Immunohistochemical characterization of infiltrating cells in human chronic chagasic myocarditis: comparison with myocardial rejection process.
abstract: Cellular subpopulations that infiltrate the heart in human chronic chagasic myocarditis were defined immunohistochemically in endomyocardial biopsy (EMB) specimens. T cells formed 96.3% of the inflammatory infiltrate, predominantly CD8+ (cytotoxic/suppressor) T cells. The mean numbers of CD8+ and CD4+ (helper) T cells in the myocarditis were compared to those present in the myocardial rejection process. Mean numbers of CD8+ T cells were similar in both groups of EMB specimens while CD4+ T cell counts, CD4+/CD8+ ratios and CD4+ antigen expression were significantly lower in the chagasic group compared to the myocardial rejection group (P < 0.002). The persistent lower number and diminished expression of CD4+ T cells suggest an immunological imbalance in patients with chronic chagasic myocarditis. A possible participation of Trypanosoma cruzi parasites in the development of such immunological abnormalities is also discussed.
authors.affiliation: Instituto do Coração, Hospital das Clínicas FMUSP, São Paulo, Brasil.
authors.forename: M de L
authors.initials: Mde L
authors.lastname: Higuchi
authors.forename: P S
authors.initials: PS
authors.lastname: Gutierrez
authors.forename: V D
authors.initials: VD
authors.lastname: Aiello
authors.forename: S
authors.initials: S
authors.lastname: Palomino
authors.forename: E
authors.initials: E
authors.lastname: Bocchi
authors.forename: J
authors.initials: J
authors.lastname: Kalil
authors.forename: G
authors.initials: G
authors.lastname: Bellotti
authors.forename: F
authors.initials: F
authors.lastname: Pileggi
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes; D002598:Chagas Cardiomyopathy / Q000276:immunology* / Q000473:pathology*; D002908:Chronic Disease; D006084:Graft Rejection / Q000276:immunology; D016027:Heart Transplantation; D006801:Humans; D007958:Leukocyte Count; D008875:Middle Aged; D009205:Myocarditis / Q000276:immunology* / Q000473:pathology*; D050378:T-Lymphocytes, Regulatory