Screening for autoantibodies to SS-A/RO by indirect immunofluorescence using HEp-2000 cells.
We evaluated indirect immunofluorescence (IF) using HEp-2000 slides, which are transfected with SS-A cDNA, for screening for anti-SS-A antibodies, by comparing it with counterimmunoelectrophoresis (CIE). A total of 2427 specimens were screened for IF reactivity and for SS-A precipitins, of which 1033 (43%) were negative on both IF and CIE. There were 1271 SS-A precipitin-negative specimens (52%) which were IF-positive but lacked the distinctive SS-A staining pattern. One precipitin-negative serum was IF-positive with the distinctive SS-A pattern in the HEp-2000 system. One hundred and twenty-two specimens (5%) were positive for anti-SS-A precipitins on CIE, 107 showed the distinctive SS-A fluorescence staining pattern, whereas 15 of these precipitin-positive samples (12%) were IF-positive but did not display the distinctive SS-A pattern on the transfected cells. Fourteen of the 15 samples in which the distinctive SS-A pattern was not observed displayed other significant antinuclear antibody (titre equal or >1:320) patterns. In conclusion, the presence of the typical 'distinctive' SS-A pattern on IF using the HEp-2000 slides is highly specific for the presence of autoantibodies to SS-A and has a sensitivity of 88% for detecting these antibodies.
Bossuyt
X
X
Laboratory of Medicine, University Hospital Leuven, The Netherlands. xavier.bossuyt@uz.kuleuven.ac.be
Meurs
L
L
Mewis
A
A
Mariën
G
G
Blanckaert
N
N
D000974:Antibodies, Antinuclear / Q000097:blood*; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000235:genetics / Q000276:immunology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007122:Immunoelectrophoresis; D020733:RNA, Small Cytoplasmic; D012216:Rheumatic Diseases / Q000097:blood / Q000276:immunology; D012261:Ribonucleoproteins / Q000235:genetics / Q000276:immunology; D014162:Transfection; D014407:Tumor Cells, Cultured; D000099207:SS-A Antigen
D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D001324:Autoantigens; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C116006:RO60 protein, human; C035356:SS-A antibodies