Fine specificity of anti-Ro(SSA) autoantibodies and clinical manifestations in patients with systemic lupus erythematosus.
OBJECTIVE
To determine the fine specificity of the anti-Ro(SSA) autoimmune response in patients with systemic lupus erythematosus (SLE), and to correlate it with clinical and serological manifestations.


METHODS
The frequency of anti-Ro and anti-La autoantibodies was determined by double immunodiffusion (DID), ELISA, and immunoblotting (IB) in 69 patients with SLE and 39 controls. Protein and RNA immunoprecipitation were used to further characterize anti-Ro positive sera.


RESULTS
Anti-Ro antibodies were detected in 37 (54%) patients: 33 (48%) were positive by DID, 35 (51%) by ELISA, and 25 (35%) by IB; 32 sera were reactive in at least 2 of these 3 assay systems. By IB, 12 patients had antibodies to both the 60 kDa Ro (Ro60) and the 52 kDa Ro (Ro52), 11 patients were anti-Ro60 positive, 2 patients were anti-Ro52 positive, and 12 patients were not reactive with blotted Ro antigens. However, in immunoprecipitation assays all but one anti-Ro positive sera precipitated both Ro proteins. Anti-La reactivities were found in 15 anti-Ro positive patients: 13 sera were positive by IB, 11 by ELISA, and 9 by DID. Significant associations of anti-Ro antibodies with clinical symptoms were found for sicca syndrome, which was increased in anti-Ro positive patients (p < 0.05 vs anti-Ro negative patients), and for nephritis, for which an inverse correlation was found, since it was less frequently diagnosed in anti-Ro positive patients (p < 0.01). However, this association was seen only for those anti-Ro positive patients who were not reactive with Ro52 by IB. No difference was observed between anti-Ro/La and anti-Ro positive patients.


CONCLUSIONS
DID and ELISA were of comparable sensitivity for detection of anti-Ro, IB was the most sensitive method for detection of anti-La. Moreover, our data indicate that IB may help to characterize clinically distinct subgroups of anti-Ro positive patients with SLE. Thus, determination of anti-Ro by IB may increase the prognostic value of this autoantibody.
Zimmermann
C
C
Second Department of Medicine, Lainz Hospital, Vienna, Austria.
Smolen
J S
JS
Graninger
W
W
Petera
P
P
Fabini
G
G
Hassfeld
W
W
Höfler
E
E
Steiner
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001324:Autoantigens / Q000276:immunology*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000209:etiology; D015415:Biomarkers / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015151:Immunoblotting; D005779:Immunodiffusion; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000276:immunology*; D008875:Middle Aged; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins / Q000276:immunology*; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D014157:Transcription Factors / Q000276:immunology*; D000097585:SS-B Antigen; D000099207:SS-A Antigen
D001324:Autoantigens; D015415:Biomarkers; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D014157:Transcription Factors; D000097585:SS-B Antigen; D000099207:SS-A Antigen; C116006:RO60 protein, human