The immune response is crucial for protection against disease; however,
immunological imbalances can lead to heart and digestive tract lesions
in chagasic patients. Several studies have evaluated the cellular and
humoral immune responses in chagasic patients in an attempt to
correlate immunological findings with clinical forms of Chagas disease.
Moreover, immunoglobulins and cytokines are important for parasitic
control and are involved in lesion genesis. Here, cytokine and IgG
isotype production were studied, using total epimastigote antigen on
sera of chagasic patients with indeterminate (IND, n = 27) and cardiac
(CARD, n = 16) forms of the disease. Samples from normal, uninfected
individuals (NI, n = 30) were use as controls. The results showed that
sera from both IND and CARD patients contained higher levels of
Trypanosoma cruzi-specific IgG1 (IgG1) antibodies than sera from NI. No
difference in IgG2 production levels was observed between NI, IND and
CARD patients, nor was a difference in IL-10 and IFN-γ production
detected in the sera of IND, CARD and NI patients. However, IND
patients displayed a positive correlation between IL-10 and IFN-γ
levels in serum, while CARD patients showed no such correlation,
indicating an uncontrolled inflammatory response in CARD patients.
These findings support the hypothesis that a lack of efficient
regulation between IFN-γ and IL-10 productions in CARD patients
may lead to cardiac immunopathology