Background/Purpose: Sjögren’s Syndrome (SS) diagnosis depends on clinic examinations that involve measurements of serum levels of anti-Ro\SSA, anti-La\SSB, and rheumatoid factor antibodies; the first is part of EULAR/ACR research classification criteria. Salivary glands in SS are sites where antibody secreting cells (ASC) accumulate and produce autoantibodies, which may be present in the saliva. Previously we found ASC producing anti-Ro/La in the salivary glands of SS and non-SS sicca (NSS) subjects without these antibodies in their serum. Patients that present to the clinic with Sjögren’s-like symptoms but do not meet the classification criteria are characterized NSS sicca, such patients are commonly understudied and excluded from clinical trials. We hypothesize that there is significant presence of autoantibodies in saliva of SS and NSS sicca subjects, and that there is a correlation between IgG/IgA levels and clinical characteristics.

Methods: We screened frozen whole unstimulated saliva samples from SS (n=200), NSS (n=200), and healthy controls (HCs; n=46) to detect salivary autoantibodies using ELISA. All subjects in this study have been evaluated and classified for SS. We validated our ELISA results using a capillary western blot method, and correlated disease manifestations among those with, and without, salivary antibodies.

Results: Our analysis showed that salivary anti-Ro antibodies were significantly more prevalent among pSS (80; 40%) compared to NSS sicca subjects (15; 7.5%) and HC (2; 4.35%). Similarly, salivary anti-La antibodies were significantly more common in pSS patients (80; 40%) compared to NSS sicca subjects (30; 7.5%), which in turn had higher anti-La antibody levels compared to HCs (1; 2.17%). A similar pattern holds for RF which were more common in saliva of pSS (55; 27%) and NSS sicca subjects (23; 11.5%) compared to HCs (2; 4.35%). NSS subjects with salivary anti-Ro/La were not statistically distinct in terms of disease manifestations compared to pSS subjects. In this cohort, 24 SS and 29 NSS sicca subjects were seronegative, but saliva positive, for anti-Ro antibodies. Lastly, NSS sicca subjects with salivary autoantibodies had more severe ocular (39%) and oral (65%) dryness compared to NSS without salivary autoantibodies and similar to that of SS subjects. Extraglandular manifestations were similar between SS and NSS with antibodies.

Conclusion: Our results indicate a subset of NSS sicca subjects who have salivary autoantibodies. These NSS subjects with salivary autoantibodies have clinical manifestations that are similar to SS; thus, is a new phenotype of disease, which may be early disease onset that will eventually seroconvert or remain seronegative as a distinct phenotype of the disease.

« Back to ACR Convergence 2022

ACR Meeting Abstracts - https://acrabstracts.org/abstract/salivary-autoantibodies-in-sicca-patients-are-associated-with-dry-symptoms/