1.5 Diagnostic mimotopes for antibody detection in visceral leishmaniasis

Coris BioConcept (CORIS), Gembloux, Belgium - Institute of Tropical Medicine (ITM), Antwerp, Belgium   - University of Gondar (GONDAR), Gondar, Ethiopia

Area of research: Diagnostic/Treatment
Research programme: Translational Science

Objective:

To develop a rapid diagnostic test (RDT) for VL serodiagnosis with high diagnostic accuracy in East-Africa 

Expected results:

(1) Synthetic peptides that can replace the DAT native antigens.

(2) An accurate rapid diagnostic test for VL serodiagnosis in East Africa. 

Summary:

Background: The currently available rk39 dipstick test for antibody detection in visceral leishmaniasis (VL) patients has high diagnostic accuracy in the Indian subcontinent but not in East Africa. Therefore in East Africa, the direct agglutination test (DAT) is still the method of choice for serodiagnosis of VL. However, the DAT is a laboratory test that cannot be applied in field conditions and needs several hours of incubation before the results are available. These two limitations of the DAT hinder accurate diagnosis and control of VL in East Africa. 

Methodology: Using random peptide phage display we will identify synthetic peptide sequences that mimic the immunodominant DAT antigens. The selected peptides will be characterised and optimised, and their diagnostic potential will be measured by ELISA in a phase I evaluation study with sera available at the Institute of Tropical Medicine (ITM) biobank. Peptides showing the highest diagnostic potential will be used to build a rapid diagnostic test based on lateral flow. The sensitivity and specificity of the dipstick test will be evaluated in a phase II study in Ethiopia on 100 VL cases and 100 endemic controls. 

The project will be developed by student based at the Institute of Tropical Medicine, Antwerp, in collaboration with Coris BioConcept, Gembous. The latter Belgian SME has collaborated with ITM on the development of other Rapid Diagnostic Tests for human African trypanosomosis and for surra (Trypanosoma evansi infection in domestic animals. Field evaluation of the newly developed Rapid Diagnostic Test for VL will be conducted in collaboration with another established partner of ITM, the University of Gondar in Ethiopia.