The Adenosine Deaminase (ADA) test in synovial fluid is used to evaluate the presence of tuberculosis (TB) in joints, a condition known as tuberculous arthritis. ADA is an enzyme involved in the breakdown of purines and plays an essential role in immune system function. Elevated ADA levels in synovial fluid may suggest TB as the underlying cause of joint swelling, helping differentiate it from other causes such as septic arthritis or autoimmune disease
Indications
This test is recommended for you in the following cases:
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Joint effusion (fluid buildup in joints) of unknown cause
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Chronic joint pain, stiffness, or swelling with no obvious diagnosis
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Suspected tuberculous arthritis, especially in high-risk individuals
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Negative results from routine bacterial cultures but continued joint symptoms
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Need for differentiation between TB arthritis and other inflammatory or septic arthritis
Patient Preparation
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No fasting or special preparation is required.
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The patient should be briefed on the arthrocentesis (joint aspiration) procedure and post-procedure care.
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The procedure is typically performed at the bedside under aseptic conditions.
Sample Collection
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Sample Type: Synovial fluid
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Collection Method: Arthrocentesis using a sterile syringe and needle
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Volume Required: Minimum 1 mL
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Transport: The sample must be kept sterile and transported at room temperature to the laboratory without delay.
Reference Values & Interpretation
| ADA Level (U/L) | Interpretation |
|---|---|
| <30 U/L | TB arthritis unlikely |
| 30–76 U/L | Borderline; consider other clinical findings |
| >76 U/L | Strongly suggestive of TB arthritis, especially if culture-negative |
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Sensitivity: 83–100%
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Specificity: 67–100%
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An elevated ADA level in the absence of bacterial growth strengthens suspicion for TB arthritis, warranting mycobacterial culture, GeneXpert testing, or empirical anti-TB treatment.
Turnaround Time
Results for the ADA test in synovial fluid are generally available within 4 hours to a few days, depending on the laboratory’s processing capabilities.
How To Order Adenosine Deaminase (ADA) Test
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You are welcome to visit our laboratory in Kilimani, Nairobi. This will initiate the process for obtaining your test