Background

In humans, Trypanosoma cruzi infection is controlled by a complex immune response. Immunoglobulin G (IgG) is important for opsonizing blood trypomastigotes, activating the classic complement pathway, and reducing parasitemia. The trypanocidal activity of benznidazole is recognized, but its effects on the prevention and progression of Chagas disease is not well understood

Objective

We aimed to evaluate the levels of total IgG and cross-specific IgG subclasses in patients with chronic Chagas disease of different clinical forms before and after 4 years of benznidazole treatment.

Methods

Eight individuals with the indeterminate form and nine with the cardiac form who completed the treatment protocol were evaluated. The levels of total IgG and IgG1, IgG2, IgG3, and IgG4 isotypes were quantified in the serum of each individual using the fluorescent immunosorbent assay. The results are expressed as relative fluorescence unit.

Results

Patients with chronic Chagas disease presented decreased levels of total IgG at 48 months after benznidazole treatment. Increased IgG1 and decreased IgG3 levels were observed in patients with the cardiac form and those with exacerbated clinical forms. In addition, a decrease in the IgG3/IgG1 ratio was observed in individuals with the cardiac form of Chagas disease.

Conclusions

Benznidazole administration in the chronic phase differentially changes IgG subclasses in patients with cardiac and indeterminate forms, and monitoring the IgG3 level may indicate the possible prognosis to the cardiac form or worsening of the already established clinical form.

中文翻译：

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苯并硝唑治疗 4 年后南美锥虫病患者的 IgG 亚类分析

背景

在人类中，克氏锥虫感染是由复杂的免疫反应控制的。免疫球蛋白 G (IgG) 对调理血液色鞭毛体、激活经典补体途径和减少寄生虫血症很重要。苯并硝唑的杀锥虫活性已得到认可，但其对南美锥虫病预防和进展的影响尚不清楚

客观的

我们旨在评估不同临床形式的慢性恰加斯病患者在苯并硝唑治疗 4 年之前和之后的总 IgG 和交叉特异性 IgG 亚类水平。

方法

对完成治疗方案的 8 名未定型个体和 9 名心脏型个体进行了评估。使用荧光免疫吸附测定法对每个个体的血清中总 IgG 和 IgG1、IgG2、IgG3 和 IgG4 同种型的水平进行量化。结果以相对荧光单位表示。

结果

慢性恰加斯病患者在苯并硝唑治疗后 48 个月时总 IgG 水平下降。在心脏型和临床型加重的患者中观察到 IgG1 水平升高和 IgG3 水平降低。此外，在患有心脏形式的恰加斯病的个体中观察到 IgG3/IgG1 比率降低。

结论

慢性期苯并咪唑给药可不同地改变心脏型和不确定型患者的 IgG 亚类，监测 IgG3 水平可能表明心脏型的可能预后或已建立的临床型的恶化。