Ab0834 Anticentromere Antibodies in the Setting of Sjögren Syndrome: Analysis of a Multicentric Cohort

Background: In addition to anti-SSA and anti-SSB antibodies, considered hallmarks of Sjogren Syndrome, recent studies described several other autoantibodies in the disease, but the clinical associations are not yet well known. Particularly, anti-centromere antibodies (ACA) have been increasingly studied in the context of primary Sjögren Syndrome (pSS). Approximately 3-5% of pSS patients show positivity for ACA. Different studies from national registries or data collections examined the clinical phenotype of ACA-positive SS patients with contrasting results, then definitive characterizations of this subgroup remain to be established Objectives: To describe the clinical characteristics of an Italian multicenter cohort of ACA positive (ACA+) pSS patients and compare them to a matched ACA-negative (ACA-) pSS cohort and an ACA+ Systemic Sclerosis (SSc) cohort. Methods: A retrospective analysis was conducted on patients meeting the ACR/EULAR SS classification criteria showing ACA positivity, referring to participating centers. Organ involvement and related clinical, instrumental and laboratory characteristics were evaluated. Results: The cohort comprised 55 ACA+ patients diagnosed with pSS, including 36 females, with a mean age of 69.15 years. Predominant clinical manifestations were Raynaud's phenomenon (n=45), arthralgias (n=37), xerostomia (n=48), and xerophthalmia (n=39). Comparison to an ACA- pSS cohort revealed no significant demographic variance. However, the ACA+ cohort exhibited significantly higher incidence of Raynaud's phenomenon, puffy fingers, scleroderma, telangiectasia, and gastrointestinal involvement (pConclusion: Our study shows that in a large cohort of Italian pSS patients, ACA positivity significantly influences disease clinical expression, with a more pronounced pSS-related extraglandular phenotype compared to ACA- pSS patients. However, when compared to SSc patients, ACA+ pSS patients display a less severe vascular profile, resulting in an intermediate clinical phenotype between limited cutaneous scleroderma and pSS. ACA presence in pSS patients may play a pivotal role in clinical features across disease settings. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.