Trypanosoma cruzi discrete typing units in Chagas disease patients from endemic and non-endemic regions of Argentina.

Genetic diversity of Trypanosoma cruzi may play a role in pathogenesis of Chagas disease forms. Natural populations are classified into 6 Discrete Typing Units (DTUs) Tc I-VI with taxonomical status. This study aimed to identify T. cruzi DTUs in bloodstream and tissue samples of Argentinean patients with Chagas disease. PCR-based strategies allowed DTU identification in 256 clinical samples from 239 Argentinean patients. Tc V prevailed in blood from both asymptomatic and symptomatic cases and Tc I was more frequent in bloodstream, cardiac tissues and chagoma samples from immunosuppressed patients. Tc II and VI were identified in a minority of cases, while Tc III and Tc IV were not detected in the studied population. Interestingly, Tc I and Tc II/VI sequences were amplified from the same skin biopsy slice from a kidney transplant patient suffering Chagas disease reactivation. Further data also revealed the occurrence of mixed DTU populations in the human chronic infection. In conclusion, our findings provide evidence of the complexity of the dynamics of T. cruzi diversity in the natural history of human Chagas disease and allege the pathogenic role of DTUs I, II, V and VI in the studied population.

Results of heart transplantation: 16 years' experience in a center in Argentina.

UNLABELLED: Heart transplantation (HTx) is the treatment of choice for advanced heart failure refractory to other treatments. OBJECTIVE: To report the outcomes of patients undergoing orthotopic HTx in a center with 16 years' experience. METHODS: We retrospectively examined the outcomes from three hundred nine HTx recipients between February 1993 and March 2009. The mean recipient age was 46 +/- 16 years, and 80% were male. Ischemic cardiomyopathy was present in 37%; 43% (n = 133) were elective procedures and 57% (n = 176) were urgent/emergency procedures. The mean donor age was 26 years; their main cause of death was head/brain trauma. Survival was studied using Kaplan-Meier curves. RESULTS: The global survival rates at 1, 5, 10, and 15 years were 80%, 74%, 71%, and 65%, respectively. Excluding losses during the first year after transplantation (conditional survival), the survival rate at 5 and 10 years reached 92% and 88.5%, respectively. The median follow-up was 7.7 years. The etiology and the urgent/emergency nature of the procedures did not show significant differences regarding the mortality rate (P = .8). The main causes of death were sepsis (28%) and primary nonfunction (18%). In-hospital mortality reached 16%. No significant differences were observed between the urgent/emergency versus the elective transplant procedures (P = .06). During the follow-up, the incidence of severe acute cellular rejection episodes was <3% after 5 years. The global incidence of antibody-mediated rejection reached 4.5%. Eleven subjects (3.5%) were diagnosed with post-transplantation lymphoproliferative disorder. During long-term follow-up, the incidences of kidney failure, diabetes mellitus, hypertension, and dyslipemia were 21%, 24%, 69%, and 70%, respectively. One percent required chronic dialysis. CONCLUSION: In our center, post-HTx survival rates at 1, 5, 10, and 15 years were 80%, 74%, 71%, and 65%, respectively, which were similar to those reported by the International Society of Heart and Lung Transplantation (ISHLT).

Usefulness of PCR strategies for early diagnosis of Chagas' disease reactivation and treatment follow-up in heart transplantation.

Heart transplantation (HTx) is a useful therapy for end-stage Chagas cardiomyopathy; however, Chagas reactivation remains a mayor complication. Parasitological methods offer poor diagnostic sensitivity, and use of more sensitive tools such as the Polymerase chain reaction (PCR) is usually necessary. In the present study, reactivation incidence and PCR usefulness for early reactivation diagnosis, as well as for treatment response evaluation during follow-up, were analyzed using Strout parasite detection test, in 10 of 222 consecutive HTx patients suffering Chagas cardiomyopathy. PCR strategies targeted to minicircle sequences (kDNA, detection limit 1 parasite/ 10 mL blood) and miniexon genes (SL-DNA, 200 parasite/10 mL) were performed to compare parasite burdens between samples. No patients received prophylactic antiprotozoal therapy (benznidazole). Five patients (50%) exhibited clinical reactivation within a mean period of 71.6 days; positive Strout results were observed in most cases presenting clinical manifestations. kDNA-PCR was positive 38-85 days before reactivation, whereas SLDNA-PCR became positive only 7-21 days later, revealing post-HTx parasitic load enhancement present prior to clinical reactivation development. Reactivations were successfully treated with benznidazole and generated negative PCR results. Results observed in this study indicate the value of PCR testing for an early diagnosis of Chagas reactivation as well as for monitoring treatment efficacy.

Orthotopic heart transplantation in elderly patients: a 10-year experience at a single center.

INTRODUCTION: A consensus has not yet been reached regarding the indications for orthotopic heart transplantation (OHT) in elderly patients or the age limit contraindicating the procedure. The objective of this study was to assess OHT outcomes to determine whether elderly patients benefit from the procedure. METHODS: From February 1993 to February 2003, 178 OHTs were performed on recipients of mean age 47.4 +/- 15 years (range, 4 to 74) including 80.3% men. The population was divided into two groups: group A included patients >/= 60 years, and group B those younger than that age. Survival was analyzed for the overall population and for both age groups during a 10-year follow-up period. RESULTS: Group A included 36 patients (20.8%) and group B 142 patients (79.2%). Mean age was 63.7 +/- 2.9 years (60 to 74) in A, and 43 +/- 13.9 years (4 to 59) in B. In-hospital mortality was significantly higher among group A (n = 11, 31.4%) compared to B (n = 17, 12.1%, P =.008). Survival at 1, 5, and 10 years was 61.5% +/- 8%, 58.1% +/- 8.3%, and 49.8% +/- 10.5% group A; and 84.2% +/- 3%, 73.7% +/- 4.1%, and 69.9% +/- 4.7 for group B. Elderly patients showed a lower survival rate (49.8%) compared with the younger group (69.9%) at 10-year follow-up (P =.007). Conditional survival at 9 years failed to show significant differences (A 72.2% vs B 79.6%, P =.4). CONCLUSION: In our population, elderly recipients showed a higher in-hospital mortality. However, when the first post-OHT year was excluded, we found similar survival rates for both age groups.

Study of the left ventricular function in pregnancy-induced hypertension.

Left ventricular (LV) morphological and functional characteristics in 9 women suffering from pregnancy-induced hypertension (PIH) were studied by means of echocardiograms. In order to distinguish which changes depended on the pressure values and which were the result of pregnancy, 10 nonpregnant control women with no heart disease and 10 normal pregnant women (NP) were studied and the results of each of the groups compared. To evaluate the structure, left ventricular systodiastolic diameters and wall thickness were measured. The only statistically significant difference was in the diastolic diameters between the PIH (4.7 +/- 0.3 cm) and the control group (4.4 +/- 0.2 cm) p less than 0.01. Left ventricular mass was significantly increased (p less than 0.01) in the PIH patients (185 +/- 53.1 g) compared to the NP patients (161 +/- 29.6 g) and the control group (125 +/- 17.4 g). No statistically significant differences were found in the radius thickness ratio in the three groups. The systolic function assessed by the shortening percentage was significantly lower (p less than 0.05) in the control group (32.8 +/- 4.4%) and in the NP patients (37.8 +/- 5.2%) than in the PIH group (39 +/- 6.5%). Afterload assessed by isovolumic period stress was significantly greater (p less than 0.01) in the PIH patients (157 +/- 10.6 dyne/cm2) compared with the NP group (118.9 +/- 7.01 dyne/cm2). There were no significant differences between the first group and the control group (134.09 +/- 8.7 dyne/cm2). As evidence of the diastolic function, analysis was made, on the one hand, of diastolic isovolumic period length (DIP).(ABSTRACT TRUNCATED AT 250 WORDS)