Arginase activity - a marker of disease status in patients with visceral leishmaniasis in ethiopia.

• Published in: PLoS Neglected Tropical Diseases
• Main Authors: Tamrat Abebe, Yegnasew Takele, Teklu Weldegebreal, Tom Cloke, Ellen Closs, Camille Corset, Asrat Hailu, Workagegnehu Hailu, Yifru Sisay, Karina Corware, Margaux Corset, Manuel Modolell, Markus Munder, Fabienne Tacchini-Cottier, Ingrid Müller, Pascale Kropf
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2013
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doi.org/10.1371/journal.pntd.0002134; https://doaj.org/article/2fe3c333c0614eedb99cb50119d9a622

The underlying mechanisms resulting in the profound immune suppression characteristic of human visceral leishmaniasis (VL) are not fully understood. Here, we tested the hypothesis that arginase, an enzyme associated with immunosuppression, is higher in patients with VL and contributes to impaired T cell responses. We recruited patients with VL before and after treatment and healthy controls and measured the arginase metabolism in the blood of these individuals. Our results show that arginase activity is significantly higher in the blood of patients with active VL as compared to controls. These high levels of arginase decline considerably once the patients are successfully treated. We identified the phenotype of arginase-expressing cells among PBMCs as neutrophils and show that their frequency was increased in PBMCs of patients before treatment; this coincides with reduced levels of L-arginine in the plasma and decreased expression levels of CD3ζ in T cells.