INVESTIGADORES
VIGLIANO Carlos
congresos y reuniones científicas
Título:
MOLECULAR IDENTIFICATION OF T. CRUZI LINEAGES AND POPULATIONS IN END-STAGE CHAGAS HEART DISEASE PATIENTS UNDERGOING HEART TRANSPLANTATION: PREDOMINANCE OF LINEAGE I
Autor/es:
BURGOS JM; DIEZ M; VIGLIANO C; BISIO M; DUFFY T; FAVALORO LE; FAVALORO RR; LEVIN MJ; SCHIJMAN A
Lugar:
Buenos Aires
Reunión:
Congreso; The 2008 World Congress of Cardiology; 2008
Institución organizadora:
World Heart Federation
Resumen:
The aim of this study was to identify T. cruzi lineages directly from target tissues and
bloodstream of end-stage Chagas heart disease (ESChHD) patients who underwent heart
trasplantation (HT) and developed Chagas reactivation (RA). Patients´ groups ESChHD:
seven argentinean patients submitted to HT due to end-stage chronlc Chagas heart
disease. non-ChHD: three patients seropositive for T. cruzi, who underwent heart
transplantation because of concomitant dlsorders (fibrosis, myocardlal infarct and valvular
heart diseases). Indeterminate Chagas disease patients (IChD): forty six T. cruzi seropositive individuals without signs and symptoms of cardiac manifestations. Molecular
identificaron of parasite lineages (Lg) Attempts to identify the parasite lineages were
carried out directly in peripheral blood and tissue biopsy samples. Lg-PCR-based Iineage
identification was assessed by: i) Amplification of the intergenic spacer of the splicedleader
genes ii) Hot-start heminested amplification of the dimorphic D7 domain of the
24S-ribosomal RNA genes, and iii) Real Time Hemi-nested PCR targeted to the A10 ONA
fragment. Analysis of minicircle signatures The 330-bp minicircle variable region of the
kinetoplastid genome was amplified by PCR and the products were digested (RFLP-PCR)
with Mspl + Rsal restriction enzymes. Results ESChHD: Between 1 and 6 weeks after
transplantation, Tc I DNA was detected in peripheral blood samples from 5/7 ESChHD
patients. Tc lId DNA in one case and Tc IIe in the remaining one. Lg-PCR positivity occurred
earlier in Tc II reactivated patients than in those infected wlth Tc I, suggesting that Tc II
displayed higher parasitemia levels. Consecutive post-transplant blood samples, characterized
by Lg-PCR and RFLP-PCR, revealed that the same bloodstream populations
persisted during RA, which was also observed in a patient who suffered two RA episodes.
Among 5 ESChHD-RA patients, 4 presented lesions (epidermic chagomas and/or endomyocardial
biopsy samples) with the same parasite lineages that were detected in bloodstream. In each patient, the minicircle signatures from blood and tissue samples were nearly identical, indicating that the parasites causing the lesions were those found in blood. The fifth patient
had skin chagomas and endomyocardial biopsy samples positive for Tc Ild/e DNA despite
only lineage I was detected in blood. Minicircle signatures of the paraslte populations
characterized from blood, skin and EMB were all different. Interestingly, T. cruzi II was
linked to all our 3 ESChD patients with myocarditis reactivation whereas Tc I was only
detected in skin chagomas. Non-ChHD group: Between 4 and 6 weeks after transplantation,
T. cruzi lId populations were identified in 2 patients. The other one was PCR negative.
IChD group: Out of the 19 characterized patients, 17 were infected by Tc Ild parasites and
2 by Tc I. The 27 remaining patients were PCR negative. Finally, our study showed a
differential distribution of bloodstream lineages I and II between ESChHD patients and the
other patients´ groups (Fisher exact test, p= 0.005), in contrast of the original assumption
of innocuity of T. cruzi I in southern endemic regions of America.