The SSB-positive/SSA-negative antibody profile is not associated with key phenotypic features of Sjögren's syndrome.
OBJECTIVE
To determine whether the Sjögren's syndrome B (SSB)-positive/Sjögren's syndrome A (SSA)-negative antibody profile is associated with key phenotypic features of SS.


METHODS
Among registrants in the Sjögren's International Collaborative Clinical Alliance (SICCA) with possible or established SS, we compared anti-SSA/anti-SSB reactivity profiles against concurrent phenotypic features. We fitted logistic regression models to explore the association between anti-SSA/anti-SSB reactivity profile and each key SS phenotypic feature, controlling for potential confounders.


RESULTS
Among 3297 participants, 2061 (63%) had negative anti-SSA/anti-SSB, 1162 (35%) had anti-SSA with or without anti-SSB, and 74 (2%) anti-SSB alone. Key SS phenotypic features were more prevalent and had measures indicative of greater disease activity in those participants with anti-SSA, either alone or with anti-SSB, than in those with anti-SSB alone or negative SSA/SSB serology. These between-group differences were highly significant and not explained by confounding by age, race/ethnicity or gender. Participants with anti-SSB alone were comparable to those with negative SSA/SSB serology in their association with these key phenotypic features. Among SICCA participants classified with SS on the basis of the American-European Consensus Group or American College of Rheumatology criteria, only 2% required the anti-SSB-alone test result to meet these criteria.


CONCLUSIONS
The presence of anti-SSB, without anti-SSA antibodies, had no significant association with SS phenotypic features, relative to seronegative participants. The solitary presence of anti-SSB antibodies does not provide any more support than negative serology for the diagnosis of SS. This serological profile should thus be interpreted cautiously in clinical practice and potentially eliminated from future classification criteria.
Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Alan N
AN
Baer
Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Mara
M
McAdams DeMarco
University of California, San Francisco, California, USA.
Stephen C
SC
Shiboski
University of California, San Francisco, California, USA.
Mi Y
MY
Lam
King's College, London, UK.
Stephen
S
Challacombe
University of California, San Francisco, California, USA.
Troy E
TE
Daniels
Peking Union Medical College, Beijing, China.
Yi
Y
Dong
University of California, San Francisco, California, USA.
John S
JS
Greenspan
King's College, London, UK.
Bruce W
BW
Kirkham
University of Buenos Aires and German Hospital, Buenos Aires, Argentina.
Hector E
HE
Lanfranchi
Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
Morten
M
Schiødt
Aravind Eye Care System, Madurai, India.
Muthiah
M
Srinivasan
Kanazawa Medical University, Ishikawa, Japan.
Hisanori
H
Umehara
Penn Presbyterian Medical Center and University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Frederick B
FB
Vivino
University of Buenos Aires and German Hospital, Buenos Aires, Argentina.
Cristina F
CF
Vollenweider
Peking Union Medical College, Beijing, China.
Yan
Y
Zhao
University of California, San Francisco, California, USA.
Lindsey A
LA
Criswell
University of California, San Francisco, California, USA.
Caroline H
CH
Shiboski
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000378:metabolism*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012698:Serologic Tests; D012859:Sjogren's Syndrome / Q000235:genetics / Q000276:immunology*; D055815:Young Adult
D000974:Antibodies, Antinuclear; C035356:SS-A antibodies; C035357:SS-B antibodies
Autoantibodies; Sjögren's Syndrome; Systemic Lupus Erythematosus