Immunological profile of acute Chagas disease patients infected via oral transmission and treated with Benznidazole: a two-year follow-up of immune responses

The state of Pernambuco, Brazil, reported its biggest outbreak of Acute Chagas disease (ACD) caused by oral transmission, in 2019. During the acute phase, timely access to treatment must be quick and performed in all cases, regardless of the transmission route, as approximately 70-80% of cases are cured. Monitoring the immunological profile after Benznidazole (BZ) treatment in ACD patients may help identify tools to support disease progression assessment. This study aimed to evaluate the immune response, especially cytokines and antibodies levels, in patients with ACD and treated with BZ. A total of 28 laboratory-confirmed patients from the outbreak were included. Th1 and Th2 cytokines were quantified in serum samples using flow cytometry, and antibody levels were assessed by indirect immunofluorescence. Our findings indicate that BZ reduced the inflammatory response, as evidenced by decreased levels of Th1-type cytokines (IFN-γ, TNF, IL-2 and IL-6). Anti-inflammatory cytokines (IL-4 and IL-10) also showed a decline following treatment. Only IgM antibody titers were reduced, with no consistent pattern observed for IgG. These results support the use of BZ in acute phase and suggest the potential use of cytokines as auxiliary biomarkers for therapeutic monitoring.