Dados do Trabalho

Título

Assessment of antibody decay through serum dilution of patients with Chagas disease using commercial ELISA kits as a potential predictor of cure after treatment with Benznidazole

Introdução

Chagas disease (CD) remains a significant public health problem due to its neglected status, with only one available treatment in Brazil, the Benznidazole (BZN). Diagnosis of CD is done through serology, but seroconversion to negative after treatment can take many years, and other methods such as PCR have been used as a criterion for cure. However, it has low sensitivity that is a challenge for monitoring the disease cure.

Objetivo (s)

To evaluate if serum diluted of Chagas patients treated with BZN can shorten the time of seroconversion, using commercial ELISA kits.

Material e Métodos

Methodology: Serum from a cohort of 87 patients treated with BZN, collected at 0 days (before treatment), 6, 12 and 36 months after treatment initiation. These samples were diluted from 1/10 to 1/8100 and evaluated using 5 commercial ELISA kits (Architect - Abbott, Wiener, Euroimmun, Biolisa, and DiaPro) to determine the optimal dilution. The results were compared with serum samples of 50 untreated CD patients from another cohort (SaMi-Trop), followed up at 3 visits with intervals of 2-3 years between each visit.

Resultados e Conclusão

Dilutions of 1/10 were chosen for Euroimmun and Biolisa kits, and of 1/40 for Abbott, Wiener, and DiaPro kits. Percentage reduction in antibody levels compared to pre-treatment and visit 1 was used to compare reduction in treated and untreated cohorts, respectively. The coefficient of variation (CV) of samples/positive controls as reported by each kit was used to assess if the percentage variation was inherent to the kit (CV Abbott = 3.6%; Wiener = 7.89%; Euroimmun = 4.5%; Biolisa = 7.7%; DiaPro = 2.3%). We observed a reduction in antibody levels in samples diluted from the 36-month, but a significant reduction (16% to 38%) was already observed from the 6-month, except for the DiaPro kit, which 5% of reduction. By the 12-month, higher reduction (21% to 45%) was observed. In contrast, samples diluted from untreated patients showed a reduction of only 4% to 7% at visits 2 and 3, i.e., 4 to 6 years after initial sampling. Conclusions: Our initial findings indicate that reduction in antibody levels is associated with treatment. Further analyses are needed to determine if this reduction in antibody levels can be a reliable indicator of therapeutic cure of CD within a short period after treatment. If validated, this approach may have important implications for monitoring treatment response and evaluating the effectiveness of Chagas disease treatment programs.

Palavras-chave

Chagas Disease Seroconversion treatment

Agradecimentos

NIH