Serum cytokine levels are altered in subjects chronically infected with <i>T</i>. <i>cruzi</i>.

IL-21, IL-27 and sCD127 serum levels were measured using ELISA, and IL-6 and IL-8 levels were measured using CBA. Each point represents the serum levels of IL-21 (A), IL-27 (B), IL-6 (C), and IL-8 (D). Values under the limit of detection are graphed as zero. Horizontal lines indicate median values. Black symbols indicate subjects treated with benznidazole. Based on the ELISPOT assay, responses of T. cruzi-infected subjects were used to determine IFN-γ producers (P) and IFN-γ nonproducers (NP), as described in Materials and Methods. Comparisons between P and NP for each clinical group and uninfected subjects were performed using ANOVA followed by Dunn’s multiple comparisons test. * p ≤ 0.05. (A) ### p ≤ 0.001 compared with P G0, NP G0 and P G1; (B) ## p ≤ 0.01 compared with P G0; (C) ## p ≤ 0.01 compared with P G2-G3 and NP G2-G3; (D) # p ≤ 0.05 compared with NP G0, ## p ≤ 0.01 compared with P G0. Correlation analysis between IL-6 levels and the frequency of CD127+CD132+ memory CD4+ and CD8+ T cells (E). IL-8 levels and the frequency of CD127—CD132+ memory CD4+ T cells (F). IL-8 levels and sCD127 (G) were assessed using Spearman correlation analysis.