The University of Georgia College of Veterinary Medicine

Georgia Veterinary Scholars Program

GVSP Summer 2011 Scholars

Georgia Veterinary Scholar	Faculty Mentor

Courtney Sampson UGA College of Veterinary Medicine Class of 2014	Dr. Richard Fayrer-Hosken Department of Large Animal UGA College of Veterinary Medicine

Monitoring changes in equine neutrophil activity using a rapid whole blood assay

Courtney Sampson, Caroline Randinelli, Richard Fayrer-Hosken and Michel Vandenplas

Rapid detection of leukocyte activation in whole blood provides a means of stress detection in animals with disease that have an inflammatory component. We have developed an assay that measures production of reactive oxygen species (ROS) by neutrophils in equine blood samples. As neutrophils are the primary source of ROS in blood, the measured ROS can be normalized against neutrophil number thereby yielding an immune activity index termed leukocyte coping capacity (LCC). LCC changes can evaluate the progress of disease or stress in animals such as horses, and the evaluation is described as positive, negative or unchanged. To demonstrate whether animals are successfully coping with a disease process, our working hypothesis is that systemically ill horses responding poorly to a disease process can be identified using a whole blood luminescent assay to measure induced neutrophil ROS release and consequently LCC. Rapid prospective characterization of LCC depression in animals adversely affected by a disease process, could allow changes to therapy to be implemented. Thus far we have established a normal value range using blood from 20 healthy horses and have shown that disease can induce measurable change in LCC activity. The assay is rapid, inexpensive and can be used stall-side. In addition the assay can also be used as a laboratory tool to monitor the ability of therapeutic agents or immune insults to modulate ROS release in whole blood. Using the LCC assay we have determined the IC50 of N-acetylcysteine, a mucolytic agent also used to treat equine endometritis, and have shown the ability of the assay to rapidly detect neutrophil responses to endotoxin in equine whole blood.