Diagnostic associations in a large and consecutively identified population positive for anti-SSA and/or anti-SSB: the range of associated diseases differs according to the detailed serotype.
OBJECTIVE
To determine the diagnostic distribution in a consecutive anti-SSA and/or anti-SSB positive population.


METHODS
A total of 15 937 serum samples from 10 550 consecutive patients were analysed for antinuclear antibodies (ANAs) on HEp-2 cells. Serum samples positive for ANAs were analysed by immunodiffusion and line immunoassay with recombinant SSA-Ro52, natural SSA-Ro60, and recombinant SSB.


RESULTS
Among ANA positive patients in whom clinical information was available, 181 consecutive patients with anti-SSA and/or anti-SSB antibodies were identified, Disease associations were systemic lupus erythematosus (SLE) (45.3%), primary Sjögren's syndrome (pSS) (14.4%), scleroderma (8.8%), RA (7.7%), cutaneous lupus (7.7%), and dermatomyositis (2.2%). The ratio of diagnoses differed according to the anti-SSA/anti-SSB serotype. Scleroderma and dermatomyositis were enriched among mono-Ro52 reactive serum samples (34.2% and 10.5% respectively). Single reactivity towards Ro60 or anti-Ro60 with anti-Ro52 predisposed for SLE (80.0% and 52.2% respectively). Triple reactivity towards Ro52, Ro60, and SSB was primarily linked with SLE (55.8%) followed by pSS (20.9%). Anti-SSA on immunodiffusion increased the chance for SLE (62.8%), whereas isolated anti-SSB reactivity on immunodiffusion was less indicative for SLE (14.3%) and predisposed more for cutaneous lupus (23.8%) and pSS (33.3%).


CONCLUSIONS
The diagnostic range associated with anti-SSA or anti-SSB reactivity differs significantly according to the detailed serotype defined by line immunoassay and immunodiffusion.
Peene
I
I
Department of Rheumatology, Ghent University Hospital, Ghent, Belgium. filip.dekeyser@rug.ac.be
Meheus
L
L
Veys
E M
EM
De Keyser
F
F
D000974:Antibodies, Antinuclear / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002460:Cell Line; D003882:Dermatomyositis / Q000097:blood; D005455:Fluorescent Antibody Technique; D006801:Humans; D007118:Immunoassay / Q000379:methods; D005779:Immunodiffusion; D008178:Lupus Erythematosus, Cutaneous / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000097:blood*; D008177:Lupus Vulgaris / Q000097:blood*; D011994:Recombinant Proteins; D012595:Scleroderma, Systemic / Q000097:blood*; D012703:Serotyping / Q000379:methods
D000974:Antibodies, Antinuclear; D015415:Biomarkers; D011994:Recombinant Proteins; C035356:SS-A antibodies; C035357:SS-B antibodies