Table 1.

Overview of anti-dsDNA tests used in the participating laboratories for analysis of serum aliquots from all patients

Name	Methodology	Antigen	Reference interval	Manufacturer	Centre
CLIFT 1	IIF	Crithidia luciliae kinetoplast	<titre 10	ImmunoConcept	CPH
CLIFT 2	IIF	Crithidia luciliae kinetoplast	<titre 10	ImmunoConcept	Tromsø
CLIFT 3	IIF	Crithidia luciliae kinetoplast	<titre 10	Euroimmune	Lund
EliA	Solid phase ELISA	Recombinant plasmid dsDNA	<10 IU/mL	Phadia	Tromsø
SPADE	Solution phase ELISA	Biotinylated plasmid dsDNA and biotinylated, S1 nucleased human dsDNA	<1 AU/mL	Inhouse	Tromsø
Varelisa 1	Solid phase ELISA	Recombinant plasmid dsDNA	<55 IU/mL	Phadia	Tromsø
Varelisa 2	Solid phase ELISA	Recombinant plasmid dsDNA	<35 IU/mL	Phadia	CPH

AU, arbitrary units; CLIFT, Crithidia Lucillia Immunofluorescence Test; CPH, Copenhagen; IIF: indirect immunofluorescence technique; IU, international units; SPADE, solution phase anti-dsDNA ELISA.