Native Septic Arthritis testing includes White Blood Cell (WBC) count with differential, which is an automated, high-performance cell count that provides overall number of white blood cells, as well as the percentage breakdown of white blood cell type in synovial fluid.
- All counts >3,000 confirmed with a manual count
- If the final reported WBC count is >3,000 cells/μL or neutrophils percent is >70%, specimens are reflexed to the Synovasure Alpha Defensin for Native Septic Arthritis (NSA) test
The Synovasure Alpha Defensin for NSA test examines the levels of the alpha defensin biomarker and lactate in synovial fluid.
The alpha defensin biomarker has shown to be highly accurate in diagnosing the presence of periprosthetic joint infection1 and is unaffected by:
- Prior Antibiotic Administration2,3
- History of Inflammatory Conditions2,4
- Type/Virulence of Organism2,5
Note: Validation and performance of alpha defensin is based on cases of PJI and has not been defined for NSA due to no comparative “Gold Standard” criterion.