Anti-gangliosides antibodies in Chagas' cardioneuropathy

Abstract

Chagas' disease is one of the most common causes of congestive heart failure and sudden death in the world. It is manifested by cardiovascular, digestive, and autonomic nervous system disorders with lesion of the conduction system. We have studied the presence of IgG and IgM anti-gangliosides antibodies by enzyme-linked immunosorbent assay (ELISA) and dot blot immune stain in 34 patients with positive serology for Chagas' disease, divided into three groups (G); GI: no cardiac symptoms, normal ECG, and chest X-ray; GII: arrhythmias, left anterior hemiblock (LAHB), complete right bundle branch block (CRBBB), ventricular premature beats (VPB), without signs or symptoms of congestive heart failure; GIII: arrhythmias, LAHB, CRBBB, VPB, congestive heart failure, and cardiomegaly. The percentages of IgG reactive sera against gangliosides (GM1, GD1a, GD1b, GT1b) by ELISA were as follows:

Group	GMI	GD1a	GD1b	GT1b
I	11%	0%	11%	0%
II	38%	31%	38%	46%
III	42%	50%	33%	67%

IgM anti-gangliosides was present only against GT1b in one patient of GI and in one of GII. It is interesting to point out that in Groups II and III patients with signs or symptoms of heart disease, the percentages of positive sera as well as the titers of antibodies against gangliosides were significantly higher than in Group I. The greater cardiac and autonomic damage was associated with the greater reactivity against gangliosides. After the absorption of patient's serum with GM1 ganglioside or with T. cruzi epimastigotes, the percentage of reactivity against GM1 was diminished on a similar proportion suggesting a cross-reactivity between GM1 and T. cruzi antigens.