Association of caspase-1 polymorphisms with Chagas cardiomyopathy among individuals in Santa Cruz, Bolivia

Abstract INTRODUCTION: Trypanosoma cruzi (Tc) infection is usually acquired in childhood in endemic areas, leading to Chagas disease, which progresses to Chagas cardiomyopathy in 20-30% of infected individuals over decades. The pathogenesis of Chagas cardiomyopathy involves the host inflammatory response to T. cruzi, in which upstream caspase-1 activation prompts the cascade of inflammatory chemokines/cytokines, cardiac remodeling, and myocardial dysfunction. The aim of the present study was to examine the association of two caspase-1 single nucleotide polymorphisms (SNPs) with cardiomyopathy. METHODS: We recruited infected (Tc+, n = 149) and uninfected (Tc−, n = 87) participants in a hospital in Santa Cruz, Bolivia. Cardiac status was classified (I, II, III, IV) based on Chagas cardiomyopathy-associated electrocardiogram findings and ejection fractions on echocardiogram. Genotypes were determined using Taqman probes via reverse transcription-polymerase chain reaction of peripheral blood DNA. Genotype frequencies were analyzed according to three inheritance patterns (dominant, recessive, additive) using logistic regression adjusted for age and sex. RESULTS: The AA allele for the caspase-1 SNP rs501192 was more frequent in Tc+ cardiomyopathy (classes II, III, IV) patients compared to those with a normal cardiac status (class I) [odds ratio (OR) = −2.18, p = 0.117]. This trend approached statistical significant considering only Tc+ patients in class I and II (OR = −2.64, p = 0.064). CONCLUSIONS: Caspase-1 polymorphisms may play a role in Chagas cardiomyopathy development and could serve as markers to identify individuals at higher risk for priority treatment.

Papel do óxido nítrico no desenvolvimento de lesões cardíacas na fase aguda da infecção experimental pelo Trypanosoma cruzi / Role of nitric oxide in the development of cardiac lesions during the acute phase of experimental infection by Trypanosoma cruzi

A doença de Chagas é causada pelo Trypanosoma cruzi e o coração é o órgão mais acometido. O óxido nítrico apresenta importante ação anti-Trypanosoma, porém, com pouca evidência de seu papel no mecanismo de lesão tecidual. O objetivo deste estudo foi analisar a contribuição do óxido nítrico no desenvolvimento da inflamação e da fibrose cardíaca na fase aguda da infecção experimental por cepas Y e Colombiana do Trypanosoma cruzi. A inflamação foi significativamente maior nos animais infectados pela cepa Colombiana, comparada com os infectados com a cepa Y, tanto nos animais C57BL/6 (3,98x1,87 por cento; p=0,004) quanto nos animais C57BL/6 deficientes na sintase do óxido nítrico induzível (3,99x2,4 por cento; p=0,013). O parasitismo cardíaco dos animais C57BL/6 deficientes na sintase do óxido nítrico induzível infectados pela cepa Colombiana foi significativamente maior que o destes mesmos animais infectados com a cepa Y (2,78x0,17 ninhos/mm²; p=0,004) assim como, os animais C57BL/6 infectados com a cepa Colombiana (2,78x1,33 ninhos/mm²; p=0,006) ou cepa Y (2,78x0,53 ninhos/mm²; p=0,005). Os dados reforçam o papel do óxido nítrico no controle do parasitismo e sugerem seu papel na proteção tecidual, controlando a inflamação e potencialmente diminuindo lesões cardíacas durante a fase aguda na doença de Chagas experimental.

Chagas disease is caused by Trypanosoma cruzi and the heart is the organ most affected. Nitric oxide has notable anti-Trypanosoma action, but with little evidence regarding its role in the mechanism for tissue injury. The objective of this study was to analyze the contribution of nitric oxide towards the development of inflammation and cardiac fibrosis during the acute phase of experimental infection by Y and Colombian strains of Trypanosoma cruzi. The inflammation was significantly more intense in animals infected with the Colombian strain, compared with those infected with the Y strain, both in C57BL/6 animals (3.98 vs 1.87 percent; p = 0.004) and in C57BL/6 animals deficient in inducible nitric oxide synthase (3.99 vs 2.4 percent; p = 0.013). The cardiac parasite load in inducible nitric oxide synthase-deficient C57BL/6 animals infected with the Colombian strain was significantly greater than in those infected with the Y strain (2.78 vs. 0.17 nests/mm²; p = 0.004), and also significantly greater than in the C57BL/6 infected with both the Colombian strain (2.78 vs 1.33 nests/mm²; p = 0.006) and Y strains (2.78 vs 0.53 nests/mm²; p = 0.005). The data confirm that nitric oxide has a role in parasite load control and suggest that it has a role in tissue protection, through controlling inflammation and potentially reducing cardiac lesions during the acute phase of Chagas disease.

Atividade colinesterásica no plasma e em eritrócitos de pacientes com as formas cardíaca e indeterminada da doença de Chagas / Cholinesterase activity in plasma and in erythrocytes of patients with cardiac and indeterminate form of Chagas' disease

A atividade colinesterásica foi determinada no plasma e em eritrócitos de 10 indivíduos normais e em 26 pacientes chagásicos crônicos, sendo 6 com insuficiência cardíaca congestiva compensada, 10 com cardiopatia sem insuficiência cardíaca congestiva e 10 com a forma indeterminada. Os valores enzimáticos encontrados foram (média + ou - sd): 2196 + ou - 442 UI/L no plasma e 19,4 + ou - 3,3 UI/g Hb em eritrócitos do grupo controle; 2291 + ou - 317 UI/L no plasma e 19,2 + ou - 3,7 UI/g Hb em eritrócitos dos chagásicos com insuficiência cardíaca congestiva compensada; 2445 + ou - 357 UI/L no plasma e 18,3 + ou - 3,0 UI/g Hb em eritrócitos dos cardiopatas chagásicos sem insuficiência cardíaca congestiva; 2006 + ou - 327 UI/L no plasma e 17,8 + ou - 3,1 UI/g Hb em eritrócitos de chagásicos com a forma indeterminada. Nossos dados mostram que o comprometimento neuronal que ocorre nos cardiopatas chagásicos crônicos näo é suficiente para levar a alteraçöes significativvas (p>0,05) das atividades colinesterásicas no plasma e em eritrócitos