Impact of aetiological treatment on conventional and multiplex serology in chronic Chagas disease

The main criterion for treatment effectiveness in Chagas Disease has been the seronegative conversion of previously reactive serology, generally achieved many years post-treatment. The lack of reliable tests to ensure parasite clearance and to examine the effect of treatment is the main difficulty in evaluating treatment for chronic Chagas disease. Decreases of conventional and non-conventional serological titers can be useful tools to monitor the early impact of treatment. We serially measured changes in antibody levels, including seronegative conversion as well as declines in titers in 53 benznidazole-treated and 89 untreated chronically T. cruzi-infected subjects. Seronegative conversion as well as decreases of titers was significantly higher in treated compared with untreated patients. A strong concordance was found between decreases of titers of conventional and non-conventional serologic tests post-treatment, reaffirming the findings. When seronegative conversion plus decreases of titers were considered altogether, the impact of treatment was higher, in a shorter follow-up period than previously considered. New tools for monitoring the effectiveness of treatment of chronic Chagas disease are necessary, and the results showed in this study is a contribution to researchers and physicians who assist patients suffering from this disease

Trypanosoma cruzi modulates the profile of memory CD8+ T cells in chronic Chagas’ disease patients. Int. Immunol

We present a cross-sectional analysis of the maturation and migratory properties of the memory CD8 1 T cell compartment, in relation to the severity of heart disease in individuals with chronic Trypanosoma cruzi infection removed from endemic areas for longer than 20 years. Subjects with none or mild heart involvement were more likely to mount T. cruzi-specific memory IFN-c responses than subjects with more advanced cardiac disease, and the T. cruzi-specific CD8 1 T cell population was enriched in early-differentiated (CD27 1 CD28 1) cells in responding individuals. In contrast, the frequency of CD27 1 CD28 1 CD8 1 T cells in the total memory CD8 1 T cell population decreases, as disease becomes more severe, while the proportion of fully differentiated memory (CD27 ÿ CD28 ÿ) CD8 1 T cells increases. The analysis of CCR7 expression revealed a significant increase in total effector/memory CD8 1 T cells (CD45RA ÿ CCR7 ÿ) in subjects with mild heart disease as compared with uninfected controls. Altogether, these results are consistent with the hypothesis of a gradual clonal exhaustion in the CD8 1 T cell population, perhaps as a result of continuous antigenic stimulation by persistent parasites