Analysis for opisthorchiasis: antibodies to the causative agent of opisthorchiasis in the blood

Antibodies to the causative agent of opisthorchiasis in serum are normal.

The causative agent of opisthorchiasis is the trematode Opisthorchis felineus. Trematodoz of the liver proceeds at an early stage in the form of an acute allergosis with high eosinophilia of the blood, at a late stage - with a predominant lesion of the hepatobiliary system, with a moderately elevated or normal eosinophil content. Serological diagnosis (using ELISA and RPHA) of opisthorchiasis at an early stage of the disease, before the beginning of egg isolation by the parasite, is the only method of laboratory diagnosis, with chronic opisthorchiasis an auxiliary method.

The sensitivity of the ELISA method for the diagnosis of opisthorchiasis in the acute phase is close to 100%, in the chronic phase of the disease - to 70%, depends on the intensity of the invasion. IgM antibodies appear in the blood 1 week after infection, reach the maximum values after 1.5-2 weeks, and after 6-8 weeks their titer begins to decrease rapidly. Antibodies of class IgG begin to be synthesized for 2-3 weeks later antibodies IgM. Their concentration becomes maximum by the 2nd-3rd month after infection and can be kept at this level for up to 1 year or more. However, for long periods of the disease, patients often notice a decrease in the titer of specific antibodies below the sensitivity threshold of diagnostic methods due to binding of antibodies to the helminth antigen and formation of the CEC.

False positive results of the analysis are possible in the study of healthy serum in 1% of cases, patients with non-parasitic diseases (allergies, gastrointestinal diseases, hepatobiliary system, systemic diseases) - 1.5%, toxoplasmosis - 5.6%, toxocarose - 7, 3%, echinococcosis - 15.4%, trichinosis - 20.0%, fascioliasis - in 29.4% of cases.

In the outbreaks of opisthorchiasis, indigenous people record low rates of serological reactions due to congenital tolerance. In an alien population (for example, shift workers, migrants, etc.) , as a rule, high serological responses are noted due to the lack of congenital immunity to Opisthorchis felineus infection .

With serological diagnosis, it is possible to obtain false-negative results against the background of immunodeficient conditions due to concomitant chronic diseases or medication (antibiotics, glucocorticosteroids, chemotherapy drugs).

Indications for the appointment of analysis for opisthorchiasis:

• high eosinophilia of the blood or leukemoid reaction according to the eosinophilic type in persons eating river fish;
• a survey of persons who worked or lived in areas endemic for the opisthorchiasis, and at the time of examination of the bile ducts suffering from diseases.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11]