title: Differential distribution of Trypanosoma cruzi clones in human chronic chagasic cardiopathic and non-cardiopathic individuals.
abstract: PCR and Southern blot hybridization were used to determine the distribution of Trypanosoma cruzi clones in 37 chronic chagasic cardiopathic and non-cardiopathic patients. Parasite DNA amplified from peripheral blood or dejections of Triatoma infestans fed on patient blood was hybridized with probes containing hypervariable minicircle nucleotide sequences capable of detecting three sublineages of T. cruzi. Probes Z-I and Z-IIb detect unique sequences in lineages TcI and TcIIb, respectively. Probe Z-hybrid detects sequences of lineages TcIId and TcIIe. T. cruzi clones of the Z-I sublineage were detected in 62.2% of T. infestans dejections and 5.4% of peripheral blood samples. Clones of Z-IIb and Z-hybrid sublineages had similar distribution in blood and dejection samples. Interestingly, clones of the Z-IIb sublineage were significantly lower in cardiopathic than in non-cardiopathic patients (23.5% versus 75%; P=0.0006). Clones of the Z-hybrid sublineage were found in 29.4% of cardiopathic and 75% of non-cardiopathic patients, respectively (P=0.0051). By contrast, clones of sublineage Z-I were similarly distributed in both groups of patients. The low frequency of Z-IIb and Z-hybrid sublineage clones detected in cardiopathic patients suggests that the immunological mechanisms involved in controlling and eliminating these T. cruzi parasites may be detrimental to the host, leading to the development of chagasic cardiomyopathy.
authors.affiliation: Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago, Chile. jvenega@med.uchile.cl
authors.forename: Juan
authors.initials: J
authors.lastname: Venegas
authors.forename: William
authors.initials: W
authors.lastname: Coñoepan
authors.forename: Sergio
authors.initials: S
authors.lastname: Pichuantes
authors.forename: Sandra
authors.initials: S
authors.lastname: Miranda
authors.forename: Werner
authors.initials: W
authors.lastname: Apt
authors.forename: Arturo
authors.initials: A
authors.lastname: Arribada
authors.forename: Inés
authors.initials: I
authors.lastname: Zulantay
authors.forename: Ximena
authors.initials: X
authors.lastname: Coronado
authors.forename: Jorge
authors.initials: J
authors.lastname: Rodriguez
authors.forename: Eduardo
authors.initials: E
authors.lastname: Reyes
authors.forename: Aldo
authors.initials: A
authors.lastname: Solari
authors.forename: Gittith
authors.initials: G
authors.lastname: Sanchez
mesh_terms: D000328:Adult; D000818:Animals; D001483:Base Sequence; D001769:Blood / Q000469:parasitology; D015139:Blotting, Southern; D002598:Chagas Cardiomyopathy / Q000469:parasitology*; D014355:Chagas Disease / Q000150:complications* / Q000469:parasitology*; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D014224:Triatoma / Q000469:parasitology; D014349:Trypanosoma cruzi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D016054:DNA, Protozoan