CD27 and infection: To dissect the relationship between altered CD27+ B cell frequencies and disease progression, immunologic data was further analyzed according to the clinical classification of Kuschnir [25], namely individuals with long-term non-progressive infection (G0), individuals with electrocardiographic abnormalities associated to chronic Chagas heart disease (G1) and patients with non-dilated chagasic cardiomyopathy (G2).