New biomarkers are needed to identify asymptomatic Leishmania infection as well as immunity following vaccination or treatment. With the aim of finding a robust biomarker to assess an effective cellular immune response, monocyte chemotactic protein 1 (MCP-1) was examined in plasma from soluble Leishmania antigen (SLA)-stimulated whole blood collected from subjects living in a Leishmania infantum-endemic area. MCP-1, expressed 110 times more strongly than IL-2, identified 87.5% of asymptomatic subjects and verified some asymptomatic subjects close to the cutoff. MCP-1 was also significantly elevated in all patients cured of visceral leishmaniasis (VL), unlike IL-2, indicating the specific memory response generated against Leishmania. These results show MCP-1 to be a robust candidate biomarker of immunity that could be used as a marker of cure and to both select and follow the population in vaccine phase I-III human clinical trials with developed rapid, easy-to-use field tools.
Ibarra-Meneses, A. V., Sanchez, C., Alvar, J., Moreno, J., & Carrillo, E. (2017). Monocyte chemotactic protein 1 in plasma from soluble Leishmania antigen-stimulated whole blood as a potential biomarker of the cellular immune response to Leishmania infantum. Frontiers in Immunology, 8(SEP). https://doi.org/10.3389/fimmu.2017.01208