Background Primary Sjögren’s syndrome (pSS) is a chronic autoimmune disease often diagnosed years after appearance of the first symptoms. Therefore, little is known about initial development of the disease. Anti-Ro antibodies can be found years before the first symptoms appear.

Objectives To identify individuals at risk for pSS and follow up over 10 years to examine symptoms and immunopathology before and during the development of pSS.

Methods This ongoing longitudinal study enrolled individuals at risk for developing pSS but have not met the ACR-EULAR classification criteria. We recruited three groups: A.) Anti-Ro positive individuals without any symptoms for an underlying systemic autoimmune disease; B.) First degree relatives of patients with a diagnosis of pSS AND an abnormal immunologic laboratory value (ANA ≥ 1:160 and/or anti-Ro⁺ and/or rheumatoid factor⁺) C.) Individuals with at least one feature of the ACR-EULAR classification criteria for pSS, but not fulfilling the criteria.

At screening and at annual follow-up visits, demographic data, blood, urine and saliva samples were obtained. Salivary flow, Schirmer’s test, and salivary gland ultrasonography (SGUS) using Hocevar-Score were performed. A lip salivary gland biopsy (LSB) was obtained at the screening visit and repeated once when typical symptoms appeared within the follow-up visits. The primary endpoint was the development of definite pSS according to the ACR-EULAR classification criteria or a diagnosis of another systemic autoimmune disease.

Results After two years, 53 subjects were recruited from all three groups, of whom 31 were enrolled in the study (Anti-SSA⁺ n=25, relatives n=4, incomplete n=2). Most of the 22 screening failures were relatives who did not have an abnormal immunologic laboratory value.

28 individuals were female, they had a mean age of 49.6 ± 12.7 years (SD; standard deviation) and a mean body weight of 71.4 ± 15 kg. 11 individuals reported having a relative with an underlying autoimmune disease. The median ESSDAI was 0 (0-5; min-max). individuals had a pathological stimulated whole saliva flow (mean 3.7 ± 1.4 g) and eight had pathological Schirmer’s test (left eye: mean 13.6 ± 13.1 mm; right eye: 13.2 ±12.2 mm). Three of 14 individuals had a pathological SGUS score. All three individuals were recruited in the Anti-Ro⁺ group. At screening visit, 11 LSB were performed (mean focus score of 0.53 ± 1.2) and one individual reached a focus score ≥ 1.

So far, 18 individuals have completed the two-year visit. Two of them had pathological stimulated whole saliva flow (mean 3.85 ± 1.4 g) and five of them a pathological Schirmer’s test (left eye: mean 15.4 ± 13 mm; right eye: 14.5 ± 13). The median ESSDAI was 0 [0-4]. Eight SGUS were performed with a mean Hocevar-Score of 5.6 ± 8.

Within two years, four patients (13%) were diagnosed with pSS, one (3%) with systemic lupus erythematosus and one (3%) with rheumatoid arthritis.

Conclusion This longitudinal study for the first time provides us with data on the evolution of pSS. Future recruitment at multiple centers and longer follow-ups will shed light on the earliest phase of pSS.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests None Declared.