Seronegative conversion after incomplete benznidazole treatment in chronic Chagas disease.

In 12-18% of adult patients, treatment with benznidazole for chronic Chagas disease has to be discontinued because of side-effects. We identified and analysed a cohort of 81 adult patients with three positive tests for Trypanosoma cruzi infection and serological monitoring following incomplete treatment with benznidazole for a median of 10 days. Twenty percent of these patients (16/81) met the criteria of cure, showing that the optimal schedule of benznidazole administration remains to be determined.

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.

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.

Lung transplant at the Favaloro Foundation: a 13-year experience.

BACKGROUND: The outcomes of lung transplantation (LT) are well known in developed countries, but not in Latin America. Our objective was to report the LT experience at a single center in Argentina. METHODS: From June 1994 to February 2003, the 54 LT that were performed included 36 single-lung transplants SLT (45.5%) and 18 double-lung transplants (DSLT) (22.7%). Indications for SLT (n = 36) were emphysema (n = 23) and pulmonary fibrosis (n = 13); for DSLT (n = 18), bronchiectasis (n = 8), cystic fibrosis (n = 8), pulmonary emphysema (n = 1), and bronchiolitis obliterans syndrome caused by graft-versus-host disease after bone-marrow transplantation (n = 1). A univariate analysis, chi-square test with Yates' correction was used for qualitative variables; Wilcoxon-Mann-Whitney test, for quantitative and ordinal variables. Survivals were estimated by the Kaplan-Meier method. RESULTS: In-hospital mortality (HM) was 21.1%. Among SLT, early death was due to sepsis in six patients and by ischemia-reperfusion injury (IRI) and acute rejection in other two. In DSLT, two patients died due to IRI and one, sepsis. The overall estimated survival rates at 1, 2, and 4 years were 70.1% +/- 6.5%, 54.3% +/- 7.2%, and 44.3% +/- 7.9%, respectively. The median overall survival was 26.5 (10 to 34) months. When HM was excluded, survival at 4 years was 51.3% +/- 8.7%. The estimated survival at 3 years was 43.3% +/- 9.3% for SLT and 58.7% +/- 13% for DSLT (P = 6). Survival differences according to the baseline diagnosis were not significant (P =.6). Median follow-up time (percentiles 25 to 75) was 16 (2 to 27) months. CONCLUSIONS: Our LT program shows similar results to those reported by the International Society for Heart and Lung Transplantation for developed countries.

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.

Value of echocardiography for diagnosis and prognosis of chronic Chagas disease cardiomyopathy without heart failure.

OBJECTIVES: To establish the usefulness of echocardiography for the clinical classification of patients with Chagas disease and to determine the predictors of mortality and clinical events. METHODS: 849 patients with chronic Chagas disease with a mean follow up of 9.9 years were studied. On admission, ECG, chest radiograph, and two dimensional echocardiogram were obtained from all patients. Clinical events were defined as new ECG abnormalities, change in clinical status resulting in transfer to another group, and death. Morphologically characterised segmental lesions were also seen in 12 patients on a second harmonic echocardiogram with intravenous contrast agent. Univariate and multivariate analysis for clinical events and mortality were performed. SETTING: Community of San Martín, Buenos Aires, Argentina. RESULTS: Change in clinical group (68 of 833 survivors v 15 of 16 who died, p < 0.001), left ventricular systolic dimension (mean (SD) 3.06 (0.72) cm v 4.71 (0.90) cm, p < 0.0001), and ejection fraction (mean (SD) 0.67 (0.11)% v 0.42 (0.17)%, p < 0.0001) were found to be the only predictors of mortality. ECG abnormalities related to the disease (in 220 of 699 patients with no clinical event v 98 of 150 patients with a clinical event, p < 0.0001), left ventricular diastolic dimension (mean (SD) 4.88 (0.54) cm v 5.44 (0.83) cm, p < 0.0001), left ventricular systolic dimension (mean (SD) 2.98 (0.62) cm v 3.64 (1.03) cm, p < 0.0001), and ejection fraction (mean (SD) 0.68 (0.10)% v 0.60 (0.16)%, p < 0.0001) were predictors of clinical events. Segmental lesions were observed in 211 of 849 patients (25%). Segmental lesions were seen in 66 (13%) and systolic dysfunction was seen in four of 505 (0.8%) patients with normal ECG. Significant differences were found between the groups of patients (group 0: reactive serology and normal ECG and chest radiography without cardiac enlargement and no signs of heart failure; group 1: reactive serology and abnormal ECG and chest radiography without cardiac enlargement; group 2: reactive serology and abnormal ECG and chest radiography with cardiac enlargement and no signs of heart failure). CONCLUSION: Echocardiography was useful both to characterise and to determine the prognosis of patients with chronic Chagas disease without heart failure.

Cardiac myocyte nuclear size and ploidy status decrease after mechanical support.

Two patients with end-stage dilated cardiomyopathy of ischemic and idiopathic origin were treated with a left ventricular assist device (LVAD) as a bridge for heart transplantation. Myocardial tissue was collected during LVAD insertion and from the left ventricular apex of the explanted hearts. The myocyte diameter, nuclear area and DNA content of myocyte nuclei were measured by static cytomorphometry in tissue sections and in isolated myocytes with a digital analysis system. The presence of apoptotic nuclei was investigated by the TdT mediated X-dUTP nick end labeling technique (TUNEL). The prolonged use of a LVAD was associated with a reduction in myocyte diameter, indicating that the LVAD may induce a reversion of myocyte hypertrophy, a process described as "reverse remodeling." In addition, unloading of the heart induced a reduction in the size and DNA content of myocyte nuclei. These results suggest that the cardiomyocyte nuclei are in a dynamic state and, as it occurs with cell hypertrophy, nuclear hypertrophy and polyploidization may be a reversible phenomenon.

Anti-human skeletal muscle glycolipid antibodies in unstable angina.

BACKGROUND: We studied whether the level of anti-skeletal muscle glycolipid antibodies (AGA), a marker of acute rejection in heart transplantation, may be associated with an adverse prognosis in unstable angina. METHODS AND RESULTS: The in-hospital evolution of 50 patients with unstable angina (Braunwald class III B) was assessed. We determined the incidence of death, myocardial infarction, and refractory angina. Blood was collected at admission and 24 hours later for determination of AGA levels by enzyme-linked immunosorbent assay. Twenty-three patients showed a decrease in the AGA level at 24 hours after admission. Ten in-hospital cardiac events occurred in these patients (43.4%) as compared with 4 (14.8%) in the 27 patients who did not show a decrease (P =.025). In patients with previous myocardial infarction (n = 26), the AGA assay was a powerful predictor of outcome. In this subgroup, 66.6% of patients who had decreased AGA levels (8 of 12) had cardiac events as compared with 14.2% (2 of 14) of those who did not have that decrease (P =.001). CONCLUSIONS: We conclude that a decrease of AGA levels 24 hours after admission is associated with a complicated in-hospital course. This finding may provide new insights in the phenomenon of plaque instability involved in the development of acute coronary syndromes.

Early diagnosis of recurrence of Trypanosoma cruzi infection by polymerase chain reaction after heart transplantation of a chronic Chagas' heart disease patient.

Heart transplantation is contraindicated as an effective treatment for end-stage Chagas' heart disease because of post-operative recurrence of Trypanosoma cruzi infection and reactivation of disease after immunosupression. In a follow-up study of a heart transplanted patient with Chagas' disease, we prospectively evaluated the usefulness of the polymerase chain reaction (PCR) for early diagnosis of reactivation. We monitored post-operative recurrence of Trypanosoma cruzi infection with microscopic observation of the parasite in peripheral blood (Strout's method), endomyocardial biopsies (EMBs), skin lesions, and 2 PCR assays, based on the amplification of specific T cruzi kinetoplastid and nuclear DNA sequences. During follow-up, parasite DNA was amplified in blood samples and EMB sections 41 days before we observed patent parasitemia and cutaneous manifestations of reactivation, proving that PCR is much more sensitive than direct microscopic observation for early diagnosis of disease reactivation in heart-transplanted Chagas' disease patients.

Primary pulmonary artery sarcoma resembling chronic thromboembolic pulmonary disease.

Two cases of primary pulmonary artery sarcoma resembling chronic thromboembolic disease features are presented. Tumour identification was achieved after pulmonarv thromboendarterectomy, which was indicated by documentation of a prothrombotic state in both patients. A doubtful history of pulmonary emboli or deep venous thrombosis should alert medical personnel to the possible presence of a primary pulmonary artery sarcoma. Advanced imaging methods such as gadolinium-enhanced magnetic resonance imaging could be useful in considering pulmonary thromboendarterectomy. If a tumour is detected, its surgical resection should be considered with caution, taking into account the poor survival results. Invasion of the adventitia or the right ventricle, as documented in the present cases, is unusual. As far as the present authors know, this is the first report of this kind of tumour and its coexistence with an activated protein C resistance state and type II heparin-induced thrombocytopenia.

[Pathogenesis of human chronic chagasic myocarditis]. / Patogenia de la miocarditis chagásica crónica humana.

Studies carried out during the last decades provided evidence in support of an autoimmune pathogenesis for chronic chagasic myocarditis. This opinion was based on 1) the demonstration of molecular mimicry between parasite and host antigens, 2) the appearance of autoantibodies recognizing heart epitopes during the chronic phase of infection, 3) the induction of myocarditis and electrocardiographic alterations in animals immunized with whole parasites, parasite fragments or with biochemically-defined antigens, 4) the isolation from the heart of inflammatory infiltrates of B cells elaborating antibodies against myocardial antigens and 5) or of T cell clones reacting with heart epitopes and 6) induction of heart and nervous tissue alterations by transfer of lymphocytes from infected animals into naive syngeneic hosts. However, the characteristics of the inflammatory infiltrate in human myocarditis, displaying a wide variety of cells, many of them not involved in autoreactivity, such as the presence of giant cell granulomas and abundant eosinophils, as well as its focality and asynchrony, and the frequent association with pericarditis, casts doubts about the possibility of autoimmunity being responsible for the perpetuation of the myocarditis. This is supported by the recent observation that treatment of asymptomatic patients with trypanocidal drugs prevents the development of cardiopathy and that parasite components, either antigens or genomic fragments, are present at the site of the inflammatory lesions. On the basis of this new evidence, other alternative pathogenetic mechanisms should be sought to explain the appearance of a polymorphic long-lasting myocarditis that needs the presence of tiny fragments of parasites to develop. In addition to the well known immunological pathogenesis, the link between such a small amount of parasite components, below the level of microscopic detection, and the induction of such an extensive inflammatory infiltrate, represents interesting avenues for research in the near future.

Anti-skeletal muscle glycolipid antibodies in human heart transplantation as predictors of acute rejection: comparison with other risk factors.

In forty-five patients who underwent orthotopic heart transplantation, the titer of anti-human skeletal muscle glycolipid antibodies (AGA) present in the sera at the moment of transplantation was correlated with the number of histologically diagnosed cellular grade 3A and humoral acute rejection episodes during the first 120 days after transplantation. Determination of a cutoff value of 0.800 for the AGA level was determined by a receiver operating characteristic curve. Thirteen of 19 patients (68.4%) with an AGA titer above 0.800 developed 24 severe rejection episodes, and of the 26 patients with an AGA titer below 0.800, only 4 (15.3%) presented 6 severe rejection episodes during that time. This was especially evident for the humoral rejection episodes, which were diagnosed in only 1 of the 26 patients with AGA below 0.800 and in 7 of the 19 with AGA above 0.800. Comparison by univariate analysis of other well-known risk factors for a greater number of rejection episodes during the early posttransplant period with the AGA level at the moment of transplantation revealed that the latter distinguished a greater number of patients at risk than the other factors, such as a female donor, the lymphocyte direct cross-match, or the status of the patients at transplantation; the odds ratios were 6.33 for the AGA level, 3.17 for the direct cross-match, and 2.76 for the status at transplantation. By multiple logistic regression analysis, the only relevant risk factors in our group of patients were the AGA level (P=0.0009) and the status at transplantation (P=0.0285). These results indicate that determination of the AGA level at the moment of transplantation could represent a useful method for distinguishing which patients are at risk for a greater number of rejection episodes during the early posttransplant period, with a greater sensitivity than other risk factors.

Anti-skeletal muscle glycolipid antibodies in human heart transplantation as markers of acute rejection. Correlation with endomyocardial biopsy.

In seventeen patients the result of the histological study of 153 endomyocardial biopsies (EMB) was compared with the ELISA titer of anti-human skeletal muscle glycolipid antibodies (AGA) present in serum samples collected simultaneously with the EMB procedure during the first four months following cardiac transplantation. The glycolipids were extracted from the quadriceps femoralis of blood group O patients. In the serum samples corresponding to the histological rejection grades with myocyte necrosis (greater than or equal to 2, International Society for Heart and Lung Transplantation grading) the AGA titer was significantly higher (P<0.005) than in the less severe rejection grades. The follow-up in each patient showed that the AGA titer raised in the serum samples collected immediately after, before, or coincidentally with a histological diagnosis of rejection grade 2 or 3A. In only one rejection grade 3A case was a false-negative result observed. Determination of the cut-off of the AGA level versus rejection grades 2 and 3A was determined by a relative-operating characteristic curve. An optical density (OD) of 0.040 showed maximum efficiency with sensitivity 53% and specificity 79%. Four patients who had AGA with an OD above 0.040 at the time of transplant had a significantly higher number of rejection grade 2 and 3A episodes than eleven patients with low pre-transplant AGA titers (P<0.05). These results indicate that search of anti-skeletal muscle glycolipid antibodies may represent a useful noninvasive method for monitoring heart rejection, and suggest that its investigation prior transplant may be a predictor of the number of grades 2 and 3A rejection episodes.

Treatment of chronic Chagas' disease with benznidazole: clinical and serologic evolution of patients with long-term follow-up.

Prescribing etiologic treatment for chronic Chagas' disease is highly controversial because of the difficulties involved in assessing its therapeutic efficacy--the low degree of parasitemia, the persistence of positive immunologic reactions, the lack of clinical findings to support each type of treatment, and the necessarily prolonged follow-up of the patient. An 8-year average follow-up was performed on 131 patients treated with benznidazole (5 mg/kg/day for 30 days) (TP) and 70 untreated patients (UTP) by serial electrocardiograms and analysis of the cardiomyopathic progress of the clinical groups, and by immunologic tests at both the beginning and end of the study. TPs presented less electrocardiographic changes during the follow-up period (4.2% vs 30%) and a lower frequency of deterioration in their clinical condition (2.1% vs 17%). The percentage of TPs who were serologically negative was 19.1% whereas 6% of the UTPs became serologically negative, a result that correlated with a lack of progress in the cardiomyopathy. Benznidazole treatment significantly decreased serologic titers, signifying parasitologic cure in two patients.