Cytokines and chemokines measured in dried SLA-stimulated whole blood spots for asymptomatic Leishmania infantum and Leishmania donovani infection

A V Ibarra-Meneses,E Carrillo,J Moreno,D Mondal,J Alvar

doi:10.1038/s41598-017-17315-z

Abstract

Whole blood stimulation with soluble Leishmania antigen (SLA), followed by plasma cytokine and chemokine determination, provides means of detecting subjects with asymptomatic Leishmania infection. This work examines the potential of Protein Saver 903 cards for the storage and transport of SLA-stimulated dried plasma spot samples. Blood was collected from asymptomatic and negative control subjects living in a Leishmania infantum- (Spain) and Leishmania donovani-endemic area (Bangladesh). After SLA-stimulation, three types of sample were prepared: frozen liquid plasma (−20 °C), and plasma dropped onto Protein Saver cards kept at −20 °C (DPS-FZ), and at ambient temperature (DPS-AT). The concentrations of IFN-γ, IL-2, CXCL10, CXCL9, CCL2 and CXCL8 in the thawed liquid plasma (TLP), DPS-FZ and DPS-AT samples were then determined. Strong correlations were seen between the TLP and DPS-FZ/AT samples for all the studied cytokines/chemokines in both the L. infantum and L. donovani areas. Protein Saver 903 cards would therefore appear to allow for the transport of SLA-stimulated plasma samples by courier at ambient temperature. The CXCL10 and CXCL9 detectable in these plasma spots provided robust markers for identifying asymptomatic subjects from both endemic areas. This easy procedure opens up new possibilities for field studies in resource-limited settings, which could help in Leishmania control.

Highlights

IntroductionStimulation for diagnosing bovine brucellosis and human tuberculosis[10,15,17,18,19]
Leishmaniasis is a chronic infectious disease caused by a group of protozoan parasites of the genus Leishmania
The aim of the present work was to determine whether plasma from soluble Leishmania antigen (SLA)-stimulated blood transported on Protein Saver 903 cards at ambient temperature (DPS-AT) for 10 days can be used instead of liquid plasma samples for the later detection of cytokines/chemokines - interferon gamma (IFN-γ), interleukin-2 (IL-2), IFN-γ-induced protein 10 (IP-10 or CXCL10), the monokine induced by IFN-γ (MIG or CXCL9), monocyte chemoattractant protein-1 (MCP-1 or CCL2) and interleukin-8 (IL-8 or CXCL8) and the identification of subjects with asymptomatic Leishmania infection

Summary

Introduction

Stimulation for diagnosing bovine brucellosis and human tuberculosis[10,15,17,18,19] Such systems have not been tested with regard to the detection of cytokines and chemokines for the identification of Leishmania infection even though they potentially offer a safer and more logistically-friendly alternative to the transport of frozen SLA-stimulated plasma samples. They could, be of great use in Leishmania control programmes, validation studies, and clinical trials

Objectives

Results

Conclusion