Sensitivity of the HEp-2000 substrate for the detection of anti-SSA/Ro60 antibodies.
Anti-SSA/Ro antibodies are the most prevalent type of antinuclear antibody (ANA). Anti-SSA/ Ro-positive sera may recognise two proteins: a 52 kDa (Ro52) and a 60 kDa (Ro60) subunit. We studied the sensitivity for Ro60 detection using the HEp-2000 substrate, which consists of HEp-2 cells transfected with Ro60 cDNA in an anti-SSA/Ro-positive population consecutively identified by double immunodiffusion (DID) with thymus/spleen nuclear extract and line immunoassay (LIA) with recombinant Ro52 and Ro60. One hundred and twenty-seven consecutive anti-SSA/Ro-positive sera defined by DID with thymus/spleen nuclear extract and LIA using recombinant Ro52 and Ro60 were analysed on HEp-2000 and DID with natural Ro60. Of these, 91 were anti-Ro60 positive on LIA and/ or DID with natural Ro60. The HEp-2000 substrate detected 70/91 (sensitivity 77%) and correlated strongest with DID. Most of the missed anti-Ro60-positive sera had high ANA intensity. The substrate did not detect monospecific anti-Ro52 antibodies (sensitivity 9.7%; 3/31). HEp-2000 substrate can therefore be considered a reliable, simple and alternative method for DID in the detection of anti-Ro60 reactivity. Special follow-up should be given to sera with strong ANA patterns in which the SSA/Ro60 staining pattern may be hidden.
Peene
I
I
Department of Rheumatology, University Hospital, Gent, Belgium. isabelle.peene@rug.ac.be
Van Ael
W
W
Vandenbossche
M
M
Vervaet
T
T
Veys
E
E
De Keyser
F
F
D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D034961:Antigens, Nuclear; D001324:Autoantigens / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000276:immunology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007118:Immunoassay; D005779:Immunodiffusion; D007231:Infant, Newborn; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D009687:Nuclear Proteins / Q000276:immunology*; D012261:Ribonucleoproteins / Q000276:immunology*; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D014162:Transfection; D014407:Tumor Cells, Cultured
D000974:Antibodies, Antinuclear; D034961:Antigens, Nuclear; D001324:Autoantigens; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012261:Ribonucleoproteins