Synovasure Osteoarthritis (OA) testing includes tests for cartilage oligomeric matrix protein (COMP) and interleukin-8 (IL-8). The COMP ELISA and IL-8 ELISA are quantitative laboratory-developed tests (LDTs) intended to detect COMP and IL-8, respectively, in the synovial fluid of patients experiencing knee joint pain with suspected arthritis. Results are used in combination to provide clarification in diagnosing osteoarthritis.

• COMP (-) (below 1500 ng/mL) suggests little to no evidence of cartilage damage
• COMP (+) (above 1500 ng/mL) suggests cartilage damage
• COMP/IL-8 ratio (+) (above 4.3 ng/pg) suggests isolated, idiopathic OA
• COMP/IL-8 ratio (-) (below 4.3 ng/pg) suggests cartilage damage and elevated inflammatory status

The values for COMP and IL-8 are assigned using purified recombinant proteins and internal analytical procedures and are not metrologically traceable to an international reference standard.

Synovasure Rheumatoid Arthritis (RA) testing includes tests for anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF). The qualitative Anti-CCP ELISA and quantitative, immunoturbidimetric RF Latex are LDTs intended to detect Anti-CCP and RF, respectively, in the synovial fluid of patients experiencing joint pain or inflammation with suspected arthritis. Results are used in combination to provide further clarification in diagnosing rheumatoid arthritis.

Negative results on the Anti-CCP ELISA and RF Latex should not be used to aid in the exclusion of RA from the differential diagnosis.

Synovasure Crystalline Arthritis testing includes an assessment of synovial fluid using polarized light microscopy is performed for the presence of CPPD (calcium pyrophosphate dihydrate) and/or MSU (monosodium urate) crystals.

Automated high-performance cell count system with differential and RBC count. Elevated white blood cells (>3000 cells/mm3) are confirmed with a manual count.

If the final cell count is >3,000 cells/mm3 and/or PMN% >70%, specimens are reflexed to Synovasure Alpha Defensin for NSA test to determine if elevated levels are due to infection or another cause.

Synovasure Alpha Defensin for NSA ELISA test consists of assays for synovial fluid alpha defensin and lactate. Final result is provided as a qualitative result: Positive, Negative or Indeterminate.

• Alpha Defensin (-) suggests no evidence of NSA, regardless of lactate result
• Alpha Defensin (+), lactate (-) or below 70.0 mg/dL is indeterminate for NSA
• Alpha Defensin (+), lactate (+) suggests NSA

Note: Synovasure Alpha Defensin for NSA has not been validated for the diagnosis of NSA due to lack of industry standard criteria for benchmarking.

Synovasure Alpha Defensin for NSA ELISA test consists of assays for synovial fluid alpha defensin and lactate. Final result is provided as a qualitative result: Positive, Negative or Indeterminate.

• Alpha Defensin (-) suggests no evidence of NSA, regardless of lactate result
• Alpha Defensin (+), lactate (-) or below 70.0 mg/dL is indeterminate for NSA
• Alpha Defensin (+), lactate (+) suggests NSA

Note: Synovasure Alpha Defensin for NSA has not been validated for the diagnosis of NSA due to lack of industry standard criteria for benchmarking.

Anaerobic and aerobic culture bottles incubated for 7 days. Includes organism identification and antibiotic susceptibilities.

The accuracy of diagnostic tests such as synovial fluid white blood cell count, neutrophil percentage, and others, can be significantly impacted by the quality of the specimen that is submitted for evaluation. As part of every analysis, specimen integrity tests are performed. Physicians are notified when a suboptimal specimen has been submitted. Specimen integrity tests assess:

• Absorbance at 280nm (A280) – Specimens that fall outside the normal range for synovial fluid may be caused by dilution via saline lavage or use of contrast agents
• Red Blood Cell Count – Specimens are verified as characteristic of synovial fluid, not blood.