Chagas Disease and Heart Failure Section, Cardiology Department, Hospital Eva Perón, San Martín, Buenos Aires, Argentina.
PLoS Negl Trop Dis. 2011 Sep;5(9):e1314. doi: 10.1371/journal.pntd.0001314. Epub 2011 Sep 6.
The main criterion for treatment effectiveness in Chagas Disease has been the seronegative conversion, achieved many years post-treatment. One of the main limitations in evaluating treatment for chronic Chagas disease is the lack of reliable tests to ensure parasite clearance and to examine the effects of treatment. However, declines in conventional serological titers and a new multiplex assay can be useful tools to monitor early the treatment impact.
METHODOLOGY/PRINCIPAL FINDINGS: Changes in antibody levels, including seronegative conversion as well as declines in titers, were serially measured in 53 benznidazole-treated and 89 untreated chronic patients in Buenos Aires, Argentina with a median follow-up of 36 months. Decrease of titers (34/53 [64%] treated vs. 19/89 [21%] untreated, p<0.001) and seronegative conversion (21/53, [40%] treated vs. 6/89, [7%] untreated, p<0.001) in at least one conventional serological test were significantly higher in the benznidazole-treated group compare with the untreated group. When not only complete seronegative conversion but also seronegative conversion on 2 tests and the decreases of titers on 2 or 3 tests were considered, the impact of treatment on conventional serology increased from 21% (11/53 subjects) to 45% (24/53 subjects). A strong concordance was found between the combination of conventional serologic tests and multiplex assay (kappa index 0.60) to detect a decrease in antibody levels pos-treatment.
CONCLUSIONS/SIGNIFICANCE: Treatment with benznidazole in subjects with chronic Chagas disease has a major impact on the serology specific for T. cruzi infection in a shorter follow-up period than previously considered, reflected either by a complete or partial seronegative conversion or by a significant decrease in the levels of T. cruzi antibodies, consistent with a possible elimination or reduction of parasite load.
在恰加斯病的治疗效果中，主要的标准是治疗后多年的血清学阴性转换。在评估慢性恰加斯病的治疗方法时，主要的限制之一是缺乏可靠的测试来确保寄生虫清除，并检查治疗效果。然而，传统血清学滴度的下降和新的多重分析可以是有用的工具，以监测早期治疗的影响。
方法/主要发现：在阿根廷布宜诺斯艾利斯，对 53 名贝那唑嗪治疗的慢性患者和 89 名未治疗的慢性患者进行了连续测量，中位随访时间为 36 个月，包括血清阴性转换和滴度下降在内的抗体水平变化。与未治疗组相比，贝那唑嗪治疗组的滴度下降（34/53 [64%] 治疗组与 19/89 [21%] 未治疗组，p<0.001）和血清学阴性转换（21/53 [40%] 治疗组与 6/89 [7%] 未治疗组，p<0.001）更高。当不仅考虑完全血清学阴性转换，而且还考虑到两种检测方法的血清学阴性转换，以及两种或三种检测方法的滴度下降时，治疗对常规血清学的影响从 21%（53 名受试者中的 11 名）增加到 45%（53 名受试者中的 24 名）。传统血清学检测和多重分析相结合发现，在治疗后抗体水平下降的检测中，两者具有很强的一致性（kappa 指数 0.60）。
结论/意义：在慢性恰加斯病患者中，用贝那唑嗪治疗在比以前认为的更短的随访时间内对 T. cruzi 感染的血清学有重大影响，这反映在完全或部分血清学阴性转换，或 T. cruzi 抗体水平的显著下降，这与寄生虫负荷的可能消除或减少一致。
