The Evaluation of ANA and dsDNA results

Abstract

Detection of auto-antibody by Enzyme Linked Immunosorbent Assay (ELISA) technique is used method for diagnosis of autoimmune disease.  This study was aimed to compare the measurement of antinuclear antibodies (ANA) and double-stranded DNA (ds DNA) by ELISA in serum samples.

Serum samples were obtained from 2 sources of: sent to the laboratory for ANA testing and sent to the laboratory for dsDNA. Each of these sera was tested for the presence of ANA and dsDNA by ELISA kits. This tests were performed by commercial ‘‘Aeskulisa dsDNA check” (AESKU DIAGNOSTICS, GERMANY) according to the manufacturer's instructions. ANA and ds DNA results were classified as positive or negative for each patient. Borderline results were arbitrarily classified as positive.

In patients, 2,96% (58/1975) were ANA positive and 4,52% (29/642) were ds DNA positive by ELISA. There is no significant correlation between ANA and ds DNA positivity. Only two patient both ANA and ds DNA positivity were found by ELISA kits. Agreement between assays is generally marginal.

There are a number of factors which may contribute to the variability between these assays. The ELISA ANA assay in our laboratory uses a commercial kit utilize an IgG-specifik second antibody. Finally, each of the assays provides different criteria for clinicians and ANA screen test should be followed up with a fluorescent tests to provide information on ANA pattern.

Keywords

• Autoimmunity, ANA, anti-dsDNA

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