Adenosine Deaminase in Peritoneal Fluid
Use
Adenosine Deaminase (ADA) testing in peritoneal fluid is used to diagnose or evaluate possible tuberculous peritonitis, which can occur due to Mycobacterium tuberculosis infection. Elevated levels of ADA in peritoneal fluid can indicate the presence of tuberculosis in the abdominal cavity. This test is particularly useful in differentiating tuberculous peritonitis from other causes of ascites, as tuberculosis is a treatable condition with specific therapies that need to be initiated in a timely manner. Clinicians often use ADA levels along with other clinical findings to guide diagnosis and treatment plans.
Special Instructions
This test requires specific handling and processing steps, including centrifugation and freezing of the specimen to preserve the activity of adenosine deaminase. The specimen must remain frozen until received by the performing laboratory to ensure accurate test results. Clinicians should indicate the source of the peritoneal fluid on the requisition form to aid in proper interpretation of results.
Limitations
While ADA testing can provide valuable diagnostic information, its levels can be elevated in conditions other than tuberculosis, such as malignancies and non-tuberculous mycobacterial infections. It should not be solely relied upon to confirm a diagnosis of tuberculous peritonitis, but rather used alongside clinical findings and other diagnostic tests, such as cultures and imaging, to achieve a comprehensive assessment. Turbid specimens and those submitted in glass tubes, or obtained from rejected sources like bronchoalveolar lavage or whole blood, should be avoided to ensure test accuracy.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 49759-4
- 49759-4
Result Turnaround Time
1-8 days
Related Documents
For more information, please review the documents below
Specimen
Body Fluid
Volume
0.5 mL
Minimum Volume
0.2 mL
Container
Plastic vial
Collection Instructions
Centrifuge specimen at ambient temperature. Transfer 0.5 mL into a plastic vial and freeze. Send frozen. Specimen must remain frozen until received at the performing lab. Indicate source on requisition.
Causes for Rejection
Bronchoalveolar lavage (BAL), Glass tubes, Turbid specimens, Whole blood
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 30 days |