Serum antibody responses in opisthorchiasis

Area of Science:

• Immunology
• Parasitology
• Medical Diagnostics

Background:

• Opisthorchis viverrini is a liver fluke causing opisthorchiasis, a significant public health concern in Southeast Asia.
• Accurate immunodiagnostic tools are crucial for managing O. viverrini infections.
• Current diagnostic methods may face challenges in specificity and differentiating active from past infections.

Purpose of the Study:

• To evaluate the utility of an enzyme-linked immunosorbent assay (ELISA) using crude parasite homogenates for diagnosing Opisthorchis viverrini infection in humans.
• To assess serum antibody responses to O. viverrini adult worm homogenate (AWH) and metacercaria homogenate (MH).

Main Methods:

• An ELISA was developed using crude O. viverrini adult worm homogenate (AWH) and metacercaria homogenate (MH).
• Serum samples were collected from 83 individuals with confirmed O. viverrini infection in an endemic area of Thailand.
• Antibody levels were measured and analyzed for persistence post-treatment and cross-reactivity with other parasitic infections.

Main Results:

• Elevated serum antibody levels against O. viverrini antigens persisted for over one year after curative treatment with praziquantel.
• Cross-reactivity was observed with sera from individuals infected with other parasitic diseases, indicating a lack of specificity.
• The use of crude AWH and MH in ELISA showed significant limitations for reliable immunodiagnosis.

Conclusions:

• Crude O. viverrini adult worm and metacercaria homogenates are unsuitable antigens for developing specific immunodiagnostic tests.
• The observed antibody persistence and cross-reactivity limit the ability of this ELISA to differentiate between current and past infections.
• Further research is needed to identify more specific antigens for accurate O. viverrini diagnosis.