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Test ID: VDRL Screen CSF
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VDRL Antigen
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Useful For
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Qulitative and semi quantitative non-treponemal flocculation test for the detection of reagin antibodies in human CSF.
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Method name and description
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Aliases
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Neurosyphilis, Congenital syphilis
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Specimen type / Specimen volume / Specimen container
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Specimen type: CSF
Specimen volume: 1-2 mL
Specimen container: Sterile container
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Collection instructions / Special Precautions / Timing of collection
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C Collection by lumbar puncture as per organization guidelines
No special precautions / No timing of collection
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Storage and transport instructions
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Maintain specimen at 2-8°C
The specimens should be transported to Virology Section in cold box immediately
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Specimen Rejection Criteria
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Quantity of sample not sufficient
Mixed with blood
Wrong container
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Biological reference intervals and clinical decision values
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Non-Reactive: Indicates that the sample tested does not contain reagin antibodies.
Reactive: Indicates that the sample tested contains reagin antibodies
Reactive with titer (e.g. 1:2; 1:4; 1:8; 1:16; 1:32), indicates the highest dilution that showed a reactive result.
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Factors affecting test performance and result interpretation
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- Biological false-positive VDRL results may occur, particularly in individuals with drug abuse or conditions such as systemic lupus erythematosus (SLE), malaria, vaccinia, infectious mononucleosis, leprosy, viral pneumonia, and after smallpox vaccination.
- Samples should be free from bacterial contamination, gross hemolysis or lipemia.
- Only CSF and serum is suitable for use in this test. Plasma is not acceptable.
- Samples should be stored in the original tube at 2–8°C for up to 4 hours. For longer storage, the serum should be separated and stored at 2–8°C for up to 5 days or at –20°C for long-term storage.
- Repeated freezing and thawing of specimens should be avoided.
- A prozone effect may occur in samples with high antibody concentrations, causing weak or false-negative VDRL results; therefore, weakly reactive or nonreactive samples should be tested quantitatively to determine the true endpoint.
- Pinta, yaws, bejel and other treponemal diseases produce positive reactions in this test.
- The results of the VDRL Test must be confirmed by a treponemal test for reactive serum samples.
- A final diagnosis should not be made on the result of a single test but should be based on a correlation of test results with other clinical findings.
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Turnaround time / Days and times test performed / Specimen retention time
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Turnaround time: within 48 hours
Days and times test performed: The sample is tested on the day of receipt or on the following day
Specimen retention time: 2 weeks.
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