Evolution of anti-Trypanosoma cruzi antibody production in patients with chronic Chagas disease: Correlation between antibody titers and development of cardiac disease severity

Fig 1. Study flowchart. Strategy used to define groups and sub-groups in the study.

Fig 2. Kinetics of anti-T. cruzi IgG1 during the course of infection in Chagas disease patients. (A) and (B) represent the kinetics of anti-T. cruzi IgG1 titers during the follow-up ordered from first to sixth serum collection for each patient in IND and CCC(S) groups, respectively. Blood samples were obtained sequentially with a minimum of one-year interval between each other. Dashed lines delimitate the range of the antibody titer, represented in the vertical axis. (C) and (D) represent the kinetics of anti-T. cruzi IgG1 titers during the follow-up from 48 months before to 48 months after disease progression for each patient in CCC(P-WD/MD) and CCC(P-MOD/SD) sub-groups, respectively. The time 0 corresponds to the titer measured at the time of disease progression. Open and filled circles represent CCC(P-WD/MD) patients without and with mild LVEF dysfunction, respectively, while open and filled squares represent CCC(P-MOD/SD) patients with moderate and severe LVEF dysfunction, respectively.

Fig 3. Reactivity of IgG1 for anti-T. cruzi antigen and correlation with ventricular ejection fraction in patients with Chagas disease. (A) Inverse of the anti-T. cruzi IgG1 titers in sera of patients with chronic form of Chagas Disease in the indeterminate form of disease (IND), stable cardiomyopathy (CCC(S)), progressive cardiomyopathy (CCC(P)) before disease progression (BP) and progressive cardiomyopathy after disease progression (AP), respectively. The statistical analysis was calculated using ANOVA-one way plus Kruskal-Wallis post-test for multiple comparisons. (B) Inverse of anti-T. cruzi IgG1 titers in sera of patients with progressive cardiac form of Chagas disease (CCC(P) group) before and after disease progression sub-grouped according to the severity of cardiac commitment. Patients with progressive cardiac disease without (circles) or mild (squares) (CCC(P-WD/MD)) and moderate (triangles) or severe (inverted triangles) (CCC(P-MOD/SD)) cardiac dysfunction before (open symbols) and after (filled symbols) disease progression were represented. The statistical analysis was calculated using ANOVA-two way of repeated measures with Sidak’s multiple comparisons test. The data of A…

Fig 4. Reactivity of IgG2 for anti-T. cruzi antigen and correlation with ventricular ejection fraction in patients with Chagas disease. (A) Inverse of the anti-T. cruzi IgG2 titers in sera of patients with chronic form of Chagas Disease in the indeterminate form of disease (IND), stable cardiomyopathy (CCC(S)), progressive cardiomyopathy (CCC(P)) before disease progression (BP) and progressive cardiomyopathy after disease progression (AP), respectively. The statistical analysis was calculated using ANOVA-one way plus Kruskal-Wallis post-test for multiple comparisons. (B) Inverse of anti-T. cruzi IgG2 titers in sera of patients with progressive cardiac form of Chagas disease (CCC(P) group) before and after disease progression sub-grouped according to the severity of cardiac commitment. Patients with progressive cardiac disease without (circles) or mild (squares) (CCC(P-WD/MD)) and moderate (triangles) or severe (inverted triangles) (CCC(P-MOD/SD)) cardiac dysfunction before (open symbols) and after (filled symbols) disease progression were represented. The statistical analysis was calculated using ANOVA-two way of repeated measures with Sidak’s multiple comparisons test. The data of A…

Fig 5. Reactivity of IgG3 for anti-T. cruzi antigen and correlation with ventricular ejection fraction in patients with Chagas disease. (A) Inverse of the anti-T. cruzi IgG3 titers in sera of patients with chronic form of Chagas Disease in the indeterminate form of disease (IND), stable cardiomyopathy (CCC(S)), progressive cardiomyopathy (CCC(P)) before disease progression (BP) and progressive cardiomyopathy after disease progression (AP), respectively. The statistical analysis was calculated using ANOVA-one way plus Kruskal-Wallis post-test for multiple comparisons. (B) Inverse of anti-T. cruzi IgG3 titers in sera of patients with progressive cardiac form of Chagas disease (CCC(P) group) before and after disease progression sub-grouped according to the severity of cardiac commitment. Patients with progressive cardiac disease without (circles) or mild (squares) (CCC(P-WD/MD)) and moderate (triangles) or severe (inverted triangles) (CCC(P-MOD/SD)) cardiac dysfunction before (open symbols) and after (filled symbols) disease progression were represented. The statistical analysis was calculated using ANOVA-two way of repeated measures with Sidak’s multiple comparisons test. The data of A…

Fig 6. Reactivity of IgG4 for anti-T. cruzi antigen in patients with Chagas disease. (A) Inverse of the anti-T. cruzi IgG4 titers in sera of patients with chronic form of Chagas Disease in the indeterminate form of disease (IND), stable cardiomyopathy (CCC(S)), progressive cardiomyopathy (CCC(P)) before disease progression (BP) and progressive cardiomyopathy after disease progression (AP), respectively. The statistical analysis was calculated using ANOVA-one way plus Kruskal-Wallis post-test for multiple comparisons. (B) Inverse of anti-T. cruzi IgG4 titers in sera of patients with progressive cardiac form of Chagas disease (CCC(P) group) before and after disease progression sub-grouped according to the severity of cardiac commitment. Patients with progressive cardiac disease without (circles) or mild (squares) (CCC(P-WD/MD)) and moderate (triangles) or severe (inverted triangles) (CCC(P-MOD/SD)) cardiac dysfunction before (open symbols) and after (filled symbols) disease progression were represented. The statistical analysis was calculated using ANOVA-two way of repeated measures with Sidak’s multiple comparisons test. The data of A and B were plotted as the mean ± standard deviation…

Fig 7. Disease classification in CCC(P) patients before and after disease progression. Disease classification from entry into the study (BP) to after disease progression (AP) in CCC(P) sub-groups are represented (horizontal axis). The vertical axis represents the levels of disease severity according to LVEF values as described in Methods. Connecting lines link the patients’ disease classification BP and AP disease progression. Open squares represent CCC(P-WD/MD) patients, while filled triangles represent CCC(P-MOD/SD) patients. *Statistical difference between CCC(P-WD/MD) and CCC(MOD/SD) sub-groups BP calculated by chi-square test, p = 0.033). **** Statistical difference between CCC(P-WD/MD) and CCC(MOD/SD) sub-groups calculated by paired ANOVA-two way with Sidak’s multiple comparisons test, p<0.0001. To perform this calculation the vertical axes were transformed in arbitrary units where: CCC(P-WD) = 4; CCC(P-MD) = 3; CCC(P-MOD) = 2; and CCC(P-SD) = 1.