RESUMO
BACKGROUND: The immunological and clinical impact of trypanocidal treatment in chronic Chagas' disease (CCD) is unclear. METHODOLOGY AND FINDINGS: Several cytokines were measured in plasma of 66 patients with CCD. Thirty-three patients had been previously treated with benznidazole and 33 had never been treated. The treated group exhibited higher levels of IL-17 (median 142.45×1.22pg/ml, P=0.025), which was the only one significantly associated with Bz treatment, especially after adjusting for time of disease and NYHA class (P=0.024; OR 1.006, 95% CI 1.001-1.010). Compared to untreated patients, the treated group exhibited higher median values of mitral annular E' lateral (13.0×10.0cm/s, P=0.038), S' infero-lateral (8.9×7.6cm/s, P=0.013), S' septal (8.5×7.4cm/s, P=0.034), mean S' (9.0×7.9cm/s, P=0.013) and tricuspid annular S' (13.3×11.1cm/s, P=0.001) and lower values of E/E' septal (7.2×9.5cm/s, P=0.049). After adjustment for time of disease and NYHA class, S' infero-lateral (P=0.031), mean S' (P=0.049) and S' tricuspid (P=0.024) persisted as significantly associated with treatment. CONCLUSION: The present findings suggest that the group of CCD patients treated with Bz displayed increased plasma levels of IL-17 and preserved myocardial function, reinforcing the idea that Bz treatment may be beneficial.