Barbara Maria Ianni

Ten-Year Incidence of Chagas Cardiomyopathy Among Asymptomatic Trypanosoma cruzi–Seropositive Former Blood Donors

Background— Very few studies have measured disease penetrance and prognostic factors of Chagas cardiomyopathy among asymptomatic Trypanosoma cruzi–infected persons. Methods and Results— We performed a retrospective cohort study among initially healthy blood donors with an index T cruzi–seropositive donation and age-, sex-, and period-matched seronegatives in 1996 to 2002 in the Brazilian cities of São Paulo and Montes Claros. In 2008 to 2010, all subjects underwent medical history, physical examination, ECGs, and echocardiograms. ECG and echocardiogram results were classified by blinded core laboratories, and records with abnormal results were reviewed by a blinded panel of 3 cardiologists who adjudicated the outcome of Chagas cardiomyopathy. Associations with Chagas cardiomyopathy were tested with multivariate logistic regression. Mean follow-up time between index donation and outcome assessment was 10.5 years for the seropositives and 11.1 years for the seronegatives. Among 499 T cruzi seropositives, 120 (24%) had definite Chagas cardiomyopathy, and among 488 T cruzi seronegatives, 24 (5%) had cardiomyopathy, for an incidence difference of 1.85 per 100 person-years attributable to T cruzi infection. Of the 120 seropositives classified as having Chagas cardiomyopathy, only 31 (26%) presented with ejection fraction <50%, and only 11 (9%) were classified as New York Heart Association class II or higher. Chagas cardiomyopathy was associated (P<0.01) with male sex, a history of abnormal ECG, and the presence of an S3 heart sound. Conclusions— There is a substantial annual incidence of Chagas cardiomyopathy among initially asymptomatic T cruzi–seropositive blood donors, although disease was mild at diagnosis.

Heterozygosity for the S180L Variant of MAL/TIRAP, a Gene Expressing an Adaptor Protein in the Toll‐Like Receptor Pathway, Is Associated with Lower Risk of Developing Chronic Chagas Cardiomyopathy

BACKGROUND Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. Among T. cruzi-infected individuals, only a subgroup develops severe chronic Chagas cardiomyopathy (CCC); the majority remain asymptomatic. T. cruzi displays numerous ligands for the Toll-like receptors (TLRs), which are an important component of innate immunity that lead to the transcription of proinflammatory cytokines by nuclear factor-kappaB. Because proinflammatory cytokines play an important role in CCC, we hypothesized that single-nucleotide polymorphisms (SNPs) in the genes that encode proteins in the TLR pathway could explain differential susceptibility to CCC among T. cruzi-infected individuals. METHODS For 169 patients with CCC and 76 T. cruzi-infected, asymptomatic individuals, we analyzed SNPs by use of polymerase chain reaction-restriction fragment length polymorphism analysis for the genes TLR1, TLR2, TLR4, TLR5, TLR9, and MAL/TIRAP, which encodes an adaptor protein. RESULTS Heterozygous carriers of the MAL/TIRAP variant S180L were more prevalent in the asymptomatic group (24 [32%] of 76 subjects) than in the CCC group (21 [12%] of 169) (chi2=12.6; P=.0004 [adjusted P (Pc)=.0084]; odds ratio [OR], 0.31 [95% confidence interval {CI}, 0.16-0.60]). Subgroup analysis showed a stronger association when asymptomatic patients were compared with patients who had severe CCC (i.e., patients with left-ventricular ejection fraction<or=40%) (chi2=11.3; P=.0008 [Pc=.017]; OR, 0.22 [95% CI, 0.09-0.56]) than when asymptomatic patients were compared with patients who had mild CCC (i.e., patients with left-ventricular ejection fraction>40%) (chi2=7.7; P=.005 [Pc=.11]; OR, 0.33 [95% CI, 0.15-0.73]). CONCLUSION T. cruzi-infected individuals who are heterozygous for the MAL/TIRAP S180L variant that leads to a decrease in signal transduction upon ligation of TLR2 or TLR4 to their respective ligand may have a lower risk of developing CCC.

Myocardial Chemokine Expression and Intensity of Myocarditis in Chagas Cardiomyopathy Are Controlled by Polymorphisms in CXCL9 and CXCL10

Background Chronic Chagas cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy, affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi. Even though the Th1 T cell-rich myocarditis plays a pivotal role in CCC pathogenesis, little is known about the factors controlling inflammatory cell migration to CCC myocardium. Methods and Results Using confocal immunofluorescence and quantitative PCR, we studied cell surface staining and gene expression of the CXCR3, CCR4, CCR5, CCR7, CCR8 receptors and their chemokine ligands in myocardial samples from end-stage CCC patients. CCR5+, CXCR3+, CCR4+, CCL5+ and CXCL9+ mononuclear cells were observed in CCC myocardium. mRNA expression of the chemokines CCL5, CXCL9, CXCL10, CCL17, CCL19 and their receptors was upregulated in CCC myocardium. CXCL9 mRNA expression directly correlated with the intensity of myocarditis, as well as with mRNA expression of CXCR3, CCR4, CCR5, CCR7, CCR8 and their ligands. We also analyzed single-nucleotide polymorphisms for genes encoding the most highly expressed chemokines and receptors in a cohort of Chagas disease patients. CCC patients with ventricular dysfunction displayed reduced genotypic frequencies of CXCL9 rs10336 CC, CXCL10 rs3921 GG, and increased CCR5 rs1799988CC as compared to those without dysfunction. Significantly, myocardial samples from CCC patients carrying the CXCL9/CXCL10 genotypes associated to a lower risk displayed a 2–6 fold reduction in mRNA expression of CXCL9, CXCL10, and other chemokines and receptors, along with reduced intensity of myocarditis, as compared to those with other CXCL9/CXCL10 genotypes. Conclusions Results may indicate that genotypes associated to reduced risk in closely linked CXCL9 and CXCL10 genes may modulate local expression of the chemokines themselves, and simultaneously affect myocardial expression of other key chemokines as well as intensity of myocarditis. Taken together our results may suggest that CXCL9 and CXCL10 are master regulators of myocardial inflammatory cell migration, perhaps affecting clinical progression to the life-threatening form of CCC.

The Monocyte Chemoattractant Protein–1 Gene Polymorphism Is Associated with Cardiomyopathy in Human Chagas Disease

BACKGROUND Only a subset of individuals infected with Trypanosoma cruzi develop chronic Chagas cardiomyopathy (CCC). Familial aggregation of CCC in areas of endemicity indicates that susceptibility may be genetic, which may be a plausible explanation for why only one-third of T. cruzi-infected individuals develop CCC. The monocyte chemoattractant protein-1 (CCL2/MCP-1) has been shown to enhance the uptake of T. cruzi in murine macrophages and to up-regulate the inducible nitric oxide synthase/nitric oxide system, with a consequent increased production of nitric oxide that controls the replication of the parasite. METHODS We assessed CCL2 variants at position -2518A/G, which are known to influence transcriptional activity, by polymerase chain reaction and restriction fragment-length polymorphism in 245 individuals, all of whom were infected with T. cruzi. One hundred sixty-nine patients had CCC, and 76 were asymptomatic. RESULTS Genotype distributions differed between the CCC and asymptomatic groups (chi2 = 9.4; P = .009), with an excess of genotypes with the A allele (AA + AG) in the CCC group. Among patients with CCC, 5% were homozygous for the G allele, compared with 16% of the asymptomatic subjects (odds ratio [OR], 4.1; 95% confidence interval [CI], 1.7-11; P = .001). A similar trend was observed when individuals heterozygous for the G allele were compared with individuals homozygous for the G allele between the CCC and asymptomatic groups (OR, 2.7; 95% CI, 0.97-7.2; P = .026). The A allele seems to confer susceptibility to CCC (OR, 1.9; 95% CI, 1.3-2.9; P = .001). CONCLUSIONS The CCL2 variant correlated with a low transcriptional level behaves as a genetic modifier of clinical outcome for T. cruzi infection, and subjects with the CCL2 -2518AA genotype have a 4-fold greater risk of developing CCC than do those without this genotype.

BAT1, a Putative Anti-Inflammatory Gene, Is Associated with Chronic Chagas Cardiomyopathy

BACKGROUND It is not understood why only a subset of individuals infected with Trypanosoma cruzi develop chronic Chagas cardiomyopathy (CCC). Patients with CCC display high levels of circulating proinflammatory cytokines. Heart-infiltrating lymphocytes from patients with CCC also express proinflammatory cytokines (tumor necrosis factor- alpha and interferon- gamma ) that are detectable in biopsy samples and surgical heart-tissue samples. BAT1, a putative anti-inflammatory gene, presents functional polymorphisms in its promoter region that influence its transcriptional level. METHODS We assessed, by polymerase chain reaction restriction fragment-length polymorphism analysis, BAT1 variants in the promoter region at positions -22C/G and -348C/T in 154 patients with CCC and in 76 T. cruzi-infected but asymptomatic (ASY) patients. RESULTS Of the patients with CCC, 16% were homozygous for the -22C allele, compared with 4% of the ASY patients (P=.004; odds ratio [OR], 4.7 [95% confidence interval {CI}, 1.4-16]). A similar trend was observed for the -348C homozygotes (P=.01; OR, 1.9 [95% CI, 1.0-3.5]). Susceptibility to CCC was conferred by the C variants at nt -22 (P=.003; OR, 1.8 [95% CI, 1.2-2.8]) and at nt -348 (P=.02; OR, 1.7 [95% CI, 1.0-2.8]). CONCLUSIONS BAT1 variants previously associated with reduced expression of HLA-B-associated transcript 1 are predictive of the development of CCC. These variants may be less efficient in down-regulating inflammatory responses and may contribute to the elevated production of proinflammatory cytokines in patients with CCC.

Primary Neoplasms of the Heart. Clinical and Histological Presentation of 50 Cases

OBJECTIVE To analyze clinical and histologic findings of 50 patients with primary neoplasms of the heart in a tertiary referral center. METHODS From 1980 to 1998, we retrospectively analyzed 50 patients, 32 of whom were females, whose ages ranged from 9 to 73 years (mean age = 44.16+/-18 years). RESULTS Most tumors were located in the left side of the heart (72%), myxoma being the most common (84%) histologic type. The other histologic types found were as follows: fibroma (4%), lipoma (2%), rhabdomyosarcoma (2%), hemangioma (2%), sarcoma (2%), angiosarcoma (2%), and lymphoma (2%). Diagnosis was established by echocardiography in 94% of the cases. Clinical findings were as follows: dyspnea (36%), weight loss (20%), palpitations (18%), chest pain (16%), fever (8%), and arthralgia (6%). All patients with thromboembolic phenomena (10%) had left atrial myxoma. Approximately 20% of the patients were asymptomatic at the initial clinical assessment. CONCLUSION Primary cardiac tumors are a rare entity with diverse clinical and histologic findings, requiring, therefore, a high level of clinical suspicion.

Electrocardiographic Abnormalities in Trypanosoma cruzi Seropositive and Seronegative Former Blood Donors

Background Blood donor screening leads to large numbers of new diagnoses of Trypanosoma cruzi infection, with most donors in the asymptomatic chronic indeterminate form. Information on electrocardiogram (ECG) findings in infected blood donors is lacking and may help in counseling and recognizing those with more severe disease. Objectives To assess the frequency of ECG abnormalities in T.cruzi seropositive relative to seronegative blood donors, and to recognize ECG abnormalities associated with left ventricular dysfunction. Methods The study retrospectively enrolled 499 seropositive blood donors in São Paulo and Montes Claros, Brazil, and 483 seronegative control donors matched by site, gender, age, and year of blood donation. All subjects underwent a health clinical evaluation, ECG, and echocardiogram (Echo). ECG and Echo were reviewed blindly by centralized reading centers. Left ventricular (LV) dysfunction was defined as LV ejection fraction (EF)<0.50%. Results Right bundle branch block and left anterior fascicular block, isolated or in association, were more frequently found in seropositive cases (p<0.0001). Both QRS and QTc duration were associated with LVEF values (correlation coefficients −0.159,p<0.0003, and −0.142,p = 0.002) and showed a moderate accuracy in the detection of reduced LVEF (area under the ROC curve: 0.778 and 0.790, both p<0.0001). Several ECG abnormalities were more commonly found in seropositive donors with depressed LVEF, including rhythm disorders (frequent supraventricular ectopic beats, atrial fibrillation or flutter and pacemaker), intraventricular blocks (right bundle branch block and left anterior fascicular block) and ischemic abnormalities (possible old myocardial infarction and major and minor ST abnormalities). ECG was sensitive (92%) for recognition of seropositive donors with depressed LVEF and had a high negative predictive value (99%) for ruling out LV dysfunction. Conclusions ECG abnormalities are more frequent in seropositive than in seronegative blood donors. Several ECG abnormalities may help the recognition of seropositive cases with reduced LVEF who warrant careful follow-up and treatment.

Polymorphisms in the Gene for Lymphotoxin-αPredispose to Chronic Chagas Cardiomyopathy

BACKGROUND Chagas disease, caused by Trypanosoma cruzi infection, displays clinical heterogeneity and may be attributable to differential genetic susceptibility. Chronic Chagas cardiomyopathy (CCC) develops only in a subset of T. cruzi-infected individuals and may lead to heart failure that has a worse clinical course and that leads to reduced life expectancy, compared with heart failure of other etiologies. Proinflammatory cytokines play a key role in the development of CCC. Clinical, genetic, and epidemiological studies have linked lymphotoxin-alpha (LTA), a proinflammatory cytokine, to coronary artery disease and myocardial infarction. METHODS We used polymerase chain reaction to genotype the LTA +80A-->C and LTA +252A-->G variants in 169 patients with CCC and in 76 T. cruzi-infected asymptomatic (ASY) patients. RESULTS Homozygosity with respect to the LTA +80C and LTA +252G alleles was significantly more frequent in the patients with CCC than in the ASY patients (homozygosity for LTA +80C, 47% vs. 33%; homozygosity for LTA +252G, 16% vs. 8%). Haplotype LTA +80A-252A was associated with protection against CCC, whereas haplotype LTA +80C-252G was associated with susceptibility to CCC. Furthermore, homozygosity for the LTA +80A allele correlated with the lowest levels of plasmatic tumor-necrosis factor-alpha. CONCLUSIONS Our results suggest that the study of genetic variations in patients with Chagas disease may help in the identification of individuals at increased risk of progressing to CCC and, by providing early treatment, reduce the morbidity and mortality associated with this disease.

Genetic susceptibility to Chagas disease cardiomyopathy: involvement of several genes of the innate immunity and chemokine-dependent migration pathways

BackgroundChagas disease, caused by the protozoan Trypanosoma cruzi is endemic in Latin America. Thirty percent of infected individuals develop chronic Chagas cardiomyopathy (CCC), an inflammatory dilated cardiomyopathy that is, by far, the most important clinical consequence of T. cruzi infection. The others remain asymptomatic (ASY). A possible genetic component to disease progression was suggested by familial aggregation of cases and the association of markers of innate and adaptive immunity genes with CCC development. Migration of Th1-type T cells play a major role in myocardial damage.MethodsOur genetic analysis focused on CCR5, CCL2 and MAL/TIRAP genes. We used the Tag SNPs based approach, defined to catch all the genetic information from each gene. The study was conducted on a large Brazilian population including 315 CCC cases and 118 ASY subjects.ResultsThe CCL2rs2530797A/A and TIRAPrs8177376A/A were associated to an increase susceptibility whereas the CCR5rs3176763C/C genotype is associated to protection to CCC. These associations were confirmed when we restricted the analysis to severe CCC, characterized by a left ventricular ejection fraction under 40%.ConclusionsOur data show that polymorphisms affecting key molecules involved in several immune parameters (innate immunity signal transduction and T cell/monocyte migration) play a role in genetic susceptibility to CCC development. This also points out to the multigenic character of CCC, each polymorphism imparting a small contribution. The identification of genetic markers for CCC will provide information for pathogenesis as well as therapeutic targets.

Atrial fibrillation in endomyocardial fibrosis is a marker of worse prognosis

We studied the incidence of AF in patients with endomyocardial fibrosis (EMF) and its influence on prognosis and associated clinical events. One hundred and sixty consecutive patients with EMF were followed for a mean period of 4 years. Their mean age was 39.7 years. There were 114 women. During follow-up there were 56 deaths. Eighty-eight patients (55%) were submitted to surgical intervention. AF was observed in 58 cases (36.2%). The presence of AF was associated with a greater prevalence of dyspnea, peripheral edema, hepatomegaly, lower left ventricular ejection fraction, lower right ventricular systolic pressure (37.8 vs 45.6 mmHg, P=0.0392), and greater incidence of tricuspid regurgitation (86.0 vs 63.2%, P=0.004). AF was more frequent among patients in whom the disease involved the right ventricle, particularly those with intense fibrosis. Overall, patients with AF had a higher mortality rate than those who did not have AF (43.1 vs 30.3%, P=0.0195), but among those submitted to surgery, AF did not have an impact on survival. In conclusion, AF is frequent among patients with EMF. It is more prevalent among patients with right ventricular involvement and its presence is associated with a greater incidence of heart failure. AF is associated with worse prognosis, but surgery potentially reverses this bad evolution.