Luis E. Echeverría

SNP/haplotype associations of CCR2 and CCR5 genes with severity of chagasic cardiomyopathy.

BACKGROUND Chronic inflammation plays a major role in the tissue injury seen in the chronic chagasic cardiomyopathy. The CCR2 and CCR5 chemokine receptors are involved with the type of cellular infiltrate present in cardiac tissue and CCR5-gene variants were previously associated with this pathology. METHODS AND RESULTS This is a replication study in an independent cohort with larger sample size. Nine SNPs of CCR5 and CCR2 were typified to confirm the association previously found with Chagas disease. Evidence of association with severity was found for the A allele of rs1799864 of CCR2 (pad=0.02; OR=1.91, 95% CI=1.10-3.30), the T allele of the rs1800024 of CCR5 (pad=0.01; OR=1.95, 95% CI=1.13-3.38), and the HHF(∗)2 haplotype (p=0.03, OR=1.65, 95% CI=1.03-2.65). These results were replicated in the study combined with previous data. In this analysis it was replicated the allele T of rs2734648 (pad=0.009, OR=0.52, 95% CI=0.32-0.85) with protection. In addition, the allele G of rs1800023 (pad=0.043, OR=0.61, 95% CI=0.38-0.98), and the HHC haplotype (p=0.004, OR=0.62, 95% CI=0.44-0.86) were also associated with protection. In contrast, the allele A of rs1799864 of CCR2 (pad=0.009; OR=1.90, 95% CI=1.17-3.08); and the allele T of rs1800024 of CCR5 (pad=0.005, OR=1.98, 95% CI=1.22-3.23) were associated with greater severity. No evidence of association between symptomatic and asymptomatic patients was observed. CONCLUSIONS These results confirm that variants of CCR5 and CCR2 genes and their haplotypes are associated with the severity but not with susceptibility to develop chagasic cardiomyopathy.

Investigation of the role of IL17A gene variants in Chagas disease.

Human host genetic factors have been suggested to be determinants of the prevalence and clinical forms of Chagas disease. In this regard, IL-17A is believed to control parasitemia and protect against heart disease. In this work, we assessed whether IL17A gene polymorphisms are related to infection and/or development of the cardiac form of Chagas disease by genotyping for five IL17A SNPs (rs4711998, rs8193036, rs3819024, rs2275913 and rs7747909) in 1171 individuals from a Colombian region endemic for Chagas disease, classified as seronegative (n=595), seropositive asymptomatic (n=175) and chronic Chagas cardiomyopathy (n=401). Our results showed that SNP rs8193036, which is located upstream of the coding region of the gene, was slightly associated with protection against T. cruzi infection (P=0.0170, PFDR=0.0851, odds ratio (OR)=0.80, confidence interval (CI)=0.66–0.96) and associated with protection against the development of cardiomyopathy (P=0.0065, PFDR=0.0324, OR=0.75, CI=0.60–0.92). This finding suggests that this IL17A polymorphism could be associated with Trypanosoma cruzi infection and the development of chronic cardiomyopathy due to differential expression of cytokine IL-17A.

IL18 Gene Variants Influence the Susceptibility to Chagas Disease

Chagas disease is a parasitic disorder caused by the infection with the flagellated protozoan Trypanosoma cruzi. According to the World Health Organization, more than six million people are currently infected in endemic regions. Genetic factors have been proposed to influence predisposition to infection and development of severe clinical phenotypes like chronic Chagas cardiomyopathy (CCC). Interleukin 18 (IL18) encodes a proinflammatory cytokine that has been proposed to be involved in controlling T. cruzi infection. In this study, we analyzed the possible role of six IL18 gene variants (rs5744258, rs360722, rs2043055, rs187238, rs1946518 and rs360719), which cover most of the variation within the locus, in the susceptibility to infection by T. cruzi and/or CCC. In total, 1,171 individuals from a Colombian region endemic for Chagas disease, classified as seronegative (n = 595), seropositive asymptomatic (n = 175) and CCC (n = 401), were genotyped using TaqMan probes. Significant associations with T. cruzi infection were observed when comparing seronegative and seropositive individuals for rs187238 (P = 2.18E-03, OR = 0.77), rs360719 (P = 1.49E-03, OR = 0.76), rs2043055 (P = 2.52E-03, OR = 1.29), and rs1946518 (P = 0.0162, OR = 1.22). However, dependence analyses suggested that the association was mainly driven by the polymorphism rs360719. This variant is located within the promoter region of the IL18 gene, and it has been described that it creates a binding site for the transcription factor OCT-1 affecting IL-18 expression levels. In addition, no evidence of association was observed between any of the analyzed IL18 gene polymorphisms and the development of CCC. In summary, our data suggest that genetic variation within the promoter region of IL18 is directly involved in the susceptibility to infection by T. cruzi, which provides novel insight into disease pathophysiology and adds new perspectives to achieve a more effective disease control.

Profiles of cardiovascular biomarkers according to severity stages of Chagas cardiomyopathy

BACKGROUND/OBJECTIVES Up 30 to 40% of Chagas patients exhibit cardiomyopathy with different degrees of cardiac involvement. Biomarkers may help in differentiation of the severity of Chagas cardiomyopathy (CCM). This study sought to examine the diagnostic value of a panel of biomarkers to distinguish the severity of (CCM). METHODS 100 patients with CCM were included in this cross-sectional study. Based on electrocardiogram and echocardiogram, CCM patients were classified in three stages according to diseases severity. Levels of high-sensitivity cardiac troponin T (Hs-cTnT), N-terminal pro B-type natriuretic peptide (NT-proBNP), galectin-3 (Gal-3), neutrophil gelatinase-associated lipocalin (NGAL), soluble ST2 (sST2) and cystatin-c (Cys-c) were measured. Logistic regression models were used to assess the association between levels of natural log-transformed values of biomarkers and stages C/D versus B. We also calculated the area under curve (AUC) for each of the models. RESULTS In models adjusted for age, sex, body mass index, kidney function and medication use, increased levels of NT-proBNP (per 1 unit natural log-transformed values, odds ratio (OR)=5.55; 95CI%:1.65-18.72) and Hs-cTnT (per 1 unit natural log-transformed values, OR=7.11; 95CI%:1.41-35.90) showed significant association with the severity of CCM per 1 unit increase of biomarkers. The accuracy of NT-proBNP and Hs-cTnT for diagnosis of the severity of CCM was high: AUC of 0.968 and 0.956 respectively. No significant difference was found in the AUC between NT-proBNP and Hs-cTnT. No association was found between Gal-3, NGAL, sST2 and Cys-C and severity of CCM. CONCLUSIONS NT-proBNP and Hs-cTnT have both same diagnostic value in distinguishing severity of CCM.

Comprehensive analysis of three TYK2 gene variants in the susceptibility to Chagas disease infection and cardiomyopathy

Tyrosine kinase 2 (TYK2) is a member of the Janus kinases family implicated in the signal transduction of type I interferons and several interleukins. It has been described that genetic mutations within TYK2 lead to multiple deleterious effects in the immune response. In this work, we have analyzed three functional independent variants from the frequency spectrum on the TYK2 gene (common and low-frequency variants) suggested to reduce the function of the gene in mediating cytokine signaling and the susceptibility to infections by Trypanosoma cruzi and/or the development of Chagas cardiomyopathy in the Colombian population. A total of 1,323 individuals from a Colombian endemic region for Chagas disease were enrolled in the study. They were classified as seronegative (n = 445), seropositive asymptomatic (n = 336), and chronic Chagas Cardiomyopathy subjects (n = 542). DNA samples were genotyped using TaqMan probes. Our results showed no statistically significant differences between the allelic frequencies of the three analyzed variants when seropositive and seronegative individuals were compared, therefore these variants were not associated with susceptibility to Chagas disease. Moreover, when Chagas cardiomyopathy patients were compared to asymptomatic patients, no significant associations were found. Previous reports highlighted the association of this gene in immune-related disorders under an autoimmunity context, but not predisposing patients to infectious diseases, which is consistent with our findings. Therefore, according to our results, TYK2 gene variants do not seem to play an important role in Chagas disease susceptibility and/or chronic Chagas cardiomyopathy.

Electrocardiographic abnormalities in Chagas disease in the general population: A systematic review and meta-analysis

Background Chagas disease (CD) is a major public health concern in Latin America and a potentially serious emerging threat in non-endemic countries. Although the association between CD and cardiac abnormalities is widely reported, study design diversity, sample size and quality challenge the information, calling for its update and synthesis, which would be very useful and relevant for physicians in non-endemic countries where health care implications of CD are real and neglected. We performed to systematically review and meta-analyze population-based studies that compared prevalence of overall and specific ECG abnormalities between CD and non-CD participants in the general population. Methods Six databases (EMBASE, Ovid Medline, Web of Science, Cochrane Central, Google Scholar and Lilacs) were searched systematically. Observational studies were included. Odds ratios (OR) were computed using random-effects model. Results Forty-nine studies were selected, including 34,023(12,276 CD and 21,747 non-CD). Prevalence of overall ECG abnormalities was higher in participants with CD (40.1%; 95%CIs=39.2-41.0) compared to non-CD (24.1%; 95%CIs=23.5-24.7) (OR=2.78; 95%CIs=2.37-3.26). Among specific ECG abnormalities, prevalence of complete right bundle branch block (RBBB) (OR=4.60; 95%CIs=2.97-7.11), left anterior fascicular block (LAFB) (OR=1.60; 95%CIs=1.21-2.13), combination of complete RBBB/LAFB (OR=3.34; 95%CIs=1.76-6.35), first-degree atrioventricular block (A-V B) (OR=1.71; 95%CIs=1.25-2.33), atrial fibrillation (AF) or flutter (OR=2.11; 95%CIs=1.40-3.19) and ventricular extrasystoles (VE) (OR=1.62; 95%CIs=1.14-2.30) was higher in CD compared to non-CD participants. Conclusions This systematic review and meta-analysis provides an update and synthesis in this field. This research of observational studies indicates a significant excess in prevalence of ECG abnormalities (40.1%) related to T. cruzi infection in the general population from Chagas endemic regions, being the most common ventricular (RBBB and LAFB), and A-V B (first-degree) node conduction abnormalities as well as arrhythmias (AF or flutter and VE). Also, prevalence of ECG alterations in children was similar to that in adults and suggests earlier onset of cardiac disease.

Extracorporeal Membrane Oxygenation in Dengue, Malaria, and Acute Chagas Disease

Extracorporeal membrane oxygenation (ECMO) is widely used in acute respiratory distress syndrome (ARDS) and myocarditis. Severe vector-mediated diseases may be complicated by ARDS or myocarditis, which are both associated with a high mortality rate. We present six cases of severe dengue, malaria, and acute Chagas disease that were treated with ECMO from September 2007 to September 2015. Patients included two pediatric and four adults (aged 12–48). Survival to decannulation was 83% and to discharge was 66%. Overall, the mean duration on ECMO was 25.4 days. We conclude that ECMO treatment can be beneficial in patients with severe dengue, malaria, and acute Chagas disease, if complicated by pulmonary or cardiac complications.