Interpretation of Leukocyte Esterase for the Detection of PJI based on Serological Markers

• Published in: The Journal of arthroplasty
• Main Authors: Tarabichi, Majd, MD, Fleischman, Andrew N., MD, Shahi, Alisina, MD, Tian, Shaoqi, MD, Parvizi, Javad, MD, FRCS
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: Orthopedics
• ISSN: 0883-5403
• DOI: 10.1016/j.arth.2017.03.045

Abstract Background Leukocyte esterase (LE) is a rapid, point-of-care test for PJI. The purpose of this study was to provide a tool for interpreting LE based upon an initial serologic screening. Methods We reviewed the records of 319 patients who had ESR and CRP screening prior to hip or knee aspiration; 102 had elevated ESR and CRP, 64 had elevated ESR or CRP, and 153 had normal serology. Likelihood of infection was calculated based on the results of LE testing. Results When LE results were concordant with ESR and CRP, LE served to effectively diagnose or rule out a diagnosis of PJI with more than 95% certainty. When LE was discordant from serology, only the stricter LE thresholds (2+ or negative) were adequately diagnostic to potentially suggest a change in clinical decision-making. Conclusion With discordant results, the lesser thresholds (1+ or trace) should serve to incite further diagnostic inquiry.