Genetic characterization of Trypanosoma cruzi directly from tissues of patients with chronic Chagas disease - Differential distribution of genetic types into diverse organs

We have previously shown that a low-stringency single-specific primer-polym erase chain reaction (LSSP-PCR) is a highly sensitive and reproducible tech nique for the genetic profiling of Trypanosoma cruzi parasites directly in tissues from infected animals and humans. By applying LSSP-PCR to the study of the variable region of kinetoplast minicircle from T. cruzi, the intras pecific polymorphism of the kinetoplast-deoxyribonucleic acid (kDNA) sequen ce can be translated into individual kDNA signatures. In the present articl e, we report on our success using the LSSP-PCR technique in profiling the T . cruzi parasites present in the hearts of 13 patients with chagasic cardio pathy and in the esophagi of four patients (three of them with chagasic meg aesophagus). In two patients, one with the cardiodigestive clinical form of Chagas disease and the other with cardiopathy and an esophageal inflammato ry process, we could study both heart and esophagus and, we detected distin ct kDNA signatures in the two organs. This provides evidence of a different ial tissue distribution of genetically diverse T, cruzi populations in chro nic Chagas disease, suggesting that the genetic variability of the parasite is one of the determining factors of the clinical form of the disease.