Test Code dsDNA Double-Stranded (ds-DNA) Antibody
Performing Laboratory
Memorial Hospital Laboratory- Virology Laboratory | 304-388-9618 |
Specimen Requirements
Serum-Plain Red Top Tube
Draw 4 ml (minimum 2 mL) blood
Allow sample to clot naturally before centrifugation
Centrifuge and remove serum within 8 hours of collection
Specimen Rejection
- Improperly labeled, collected, stored, and transported
- Quantity not sufficient
Storage and Stability
Room Temperature | Up to 8 hours |
Refrigerate | > 8 hours prior to testing |
Frozen | > 5 days before testing |
Reference Values
<10 is Negative
Titers are provided on all positive samples > 10
Interpretation
Positive antibody to ds-DNA is associated with systemic lupus erythematosus.
Antibody response to any antigen will be affected by the immune competence of the patient. Immune response to a specific antigen will vary with the individual.
Methodology
Indirect Immunofluorescence Assay
Days Test Set Up and Turnaround
Monday thorugh Friday, 8:00 AM Start Time
Results available same day as testing performed
May be collected any time-no patient preparation requried
CPT Coding
86256
Additional Information
DsDNA is an important auto antigen in SLE with a specificity of 95% when this method is used. It has a sensitivity of over 70% in patients with active SLE and levels fluctuate with disease activity.
The antibody target epitopes on dsDNA largely comprise base-paired DNA nucleotides that are present only in the native molecule. Antibodies to ssDNA react with epitopes on the purine and pyrimidine bases that are hidden in dsDNA. Hep 2 cells can be used to screen for dsDNA antibodies but patterns are rarely specific because of the frequent occurrence of antibodies against ssDNA and many other antigens. Crithidia luciliae, a monoflagellate protozoa, contains a giant mitochondrion, the kinetoplast, that contains dsDNA and no ssDNA, histones or other common auto antigens. Immunofluorescence shows a characteristic double spot pattern in the presence of anti=dsDNA whilst only the nucleus is fluorescent with non-dsDNA nuclear autoantibodies. Enzyme immunoassay and similar quantitative techniques are useful for monitoring patients, but may contain dsDNA that has degraded to ssDNA that is not SLE specific. Although less sensitive than enzyme immunoassay and only semi-quantitative, the Crithidia luciliae test retains and important role because of its high specificity for dsDNA.