By comparing the results with the Malbrán Institute, a national reference laboratory, the UNNE Institute for Regional Medicine has validated the sensitivity of the methods it uses to detect NEA’s “comparison sickness.” The research emphasized the “high sensitivity and specificity” of UNNE’s techniques.
Human toxocariasis is a zoonotic disease, not often recognized as a related public health problem.
It is caused by the nematode Toxocara canis, whose definitive host is the dog and which reaches humans through ingestion of chewed eggs, generally from a contaminated environment, causing various clinical syndromes.
This disease is diagnosed by detection of specific antibodies, by serological methods.
The enzyme-linked immunosorbent assay (ELISA) is currently the main tool used to diagnose human sarcoid, while the Western Blot technique is used as a confirmation method, for cases where the ELISA test is negative or positive with a low titer. In the presence of signs and/or symptoms of infection.
Both methods were developed and refined by a group of researchers from the UNNE Institute of Regional Medicine and are currently used by the institute, which also produces local antigens from Chaco and Corrientes.
But in order to demonstrate the sensitivity of the techniques used, IMR-UNNE researchers carried out a project to validate the methods used by comparison with the Malbrán Institute (ANLIS), the national reference laboratory.
For the study, 61 serum samples were selected from patients from Chaco, with clinical suspicion of toxococcus disease. The sera for the study were sent to the Parasitological Laboratory of the Malbrán Institute and processed in parallel at the Regional Institute of Medicine.
IMR-UNNE used an IgG ELISA method of antigen-secreting/secreting of autologous strains of T. canis obtained by culturing larvae in vitro. Positive results were confirmed by Western Blot.
Meanwhile, the reference laboratory used the ELISA IgG method with an OD cut-off value ≥0.260, and confirmation with WB.
The authors of the study emphasized that “the global concordance between both centers was 95%, which allows validation of this working methodology for the diagnosis of human comparatoria in the Near East and North Africa region.”
The team responsible for the study consists of researchers from UNNE’s Regional Institute of Medicine, Mgter. Maria de los angeles lopez, dra. Maria Viviana Boyanic, extrovert. Laura Formicelli, Buick. Guillermo Armando Acevedo is tempted. Marcelo Gabriel Medina, and physicians Graciela Santillan and Sonia Sosa from the ANLIS Institute – Malbran.
Samples details
Regarding the technical details of the study, in the Regional Medicine Institute of 16 ELISA-positive serum, 10 were confirmed by WB. While in Malbrán, of the 29 sera that gave positive ELISA, 7 were confirmed by the WB.
Combining ELISA and WB, in 58 samples (95.0%) results were consistent for both laboratories (7 positive and 51 negative).
There were 3 sera that were positive in IMR and negative in Malbrán.
According to the UNNE researchers, the IMR ELISA method uses a higher cut-off value (lower sensitivity) than that used in the reference laboratory. However, there were no false negatives in this study.
There were 3 conflicting results, positive for IMR and negative for Malbrán, which may be due to the use of native antigens that were better recognized by sera from the same region.
“The research confirms that the techniques we apply at the Regional Institute of Medicine have high sensitivity and specificity,” said Dr. Bojanic regarding the results.
He noted that the importance of the work done by IMR-UNNE in the approach to comparatoria in the Near East and North Africa region was underlined.
