Autoantibodies against double-stranded DNA (dsDNA)

Crithidia luciliae (anti-dsDNA)

Crithidia luciliae: antibodies against dsDNA
  • Detection of antibodies against dsDNA.
  • Indication: systemic lupus erythematosus
  • Initial dilution: 1:10, conjugate class anti-human IgG, FITC-labelled.
  • Animal-pathogenic haemoflagellates of Crithidia luciliae are used for the detection of autoantibodies against double-stranded, native DNA (dsDNA, nDNA) with indirect immunofluorescence. These protozoa possess a giant mitochondrion containing dsDNA (kinetoplast) that, in general, does not show any of the other antigens present in the cell nuclei. Antibodies reacting with the kinetoplast are therefore only directed against dsDNA.
  • Alongside the conventional CLIFT, which shows a particularly high disease specificity, EUROIMMUN has developed an Crithidia luciliae sensitive IFT (order no. FA 1572-1), which is comparable in sensitivity to the Anti-dsDNA-NcX ELISA and the Farr assay. However, despite comparable sensitivities, the assays identify different patients. To increase the serological hit rate different test systems are often combined.

ProductOrder number
Crithidia luciliae (anti-dsDNA) IIFTFA 1572
Crithidia luciliae sensitive (anti-dsDNA) IIFTFA 1572-1

Anti-dsDNA-NcX

Incubated Anti-dsDNA-NcX ELISA
  • Monospecific detection of antibodies against dsDNA.
  • Indication: systemic lupus erythematosus.
  • Serum dilution 1: 201, conjugate class anti-human IgG, POD-labelled.
  • Antibodies against dsDNA can be determined quantitatively in IU/ml.
  • 3-point calibration, quantitative.
  • Antigen: double-stranded DNA, complexed with nucleosomes (NcX).
  • Due to good sensitivity and specificity, the Anti-dsDNA-NcX ELISA stands out by high diagnostic efficiency. High concentrations of autoantibodies against dsDNA in the ELISA are considered to be a reliable marker for the diagnosis or prognosis of SLE. Individual changes in the dsDNA antibody concentration correlate with the activity of the disease and can be used for monitoring the development of the disease in SLE patients. Under immunosuppressive therapy or in clinical remission dsDNA antibodies often cannot be detected with ELISA anymore.
ProductOrder number
Anti-dsDNA-NcX ELISA (IgG)EA 1572 G

Anti-dsDNA RIA by Farr

Anti-dsDNA RIA
  • Monospecific detection of antibodies against dsDNA.
  • Indication: systemic lupus erythematosus.
  • Use of undiluted samples.
  • Antigen: 125I-labelled dsDNA from plasmid DNA.
  • The Farr radioimmunoassay has always been of great importance. On the whole, it has the same specificity as the immunofluorescence test and the same sensitivity as the ELISA. Its well-known high diagnostic efficiency is apparently based on the fact that only the fraction of the anti-dsDNA antibodies that is able to form bigger precipitating immune complexes with circulating DNA in liquid phase contributes to the measuring signal. The principle of the Farr test reflects, as it were, the significant step in the pathomechanism of SLE: the formation of corresponding immune complexes, deposits of which build up in the joints, kidneys, liver and other organs.

ProductOrder number
Anti-dsDNA RIARA 1571