Objective:

Autoantibodies such as rheumatoid factor, anti-nuclear antibody, anti-Ro/SSA, and anti-La/SSB have an important role in the diagnosis of primary Sjogren’s syndrome (PSS), but are not essential in seronegative PSS when there is at least one focus in minor salivary gland biopsy. The aim of this study was to compare the clinical and serological differences between patients with seropositive and seronegative PSS.

Materials and Methods:

The study included 273 patients with PSS who were followed up at Kayseri City Training and Research Hospital, a tertiary hospital, between June 2018 and July 2021. The diagnosis of PSS was based on the 2016 American College of Rheumatology/European League Against Rheumatism PSS classification criteria. Autoantibodies were not detected in 45 (16.5%) patients, and they were evaluated as having seronegative PSS. Clinical and laboratory parameter data of all the patients were collected retrospectively from the hospital database, and compared between the patients with seronegative PSS and patients with seropositive PSS.

Results:

Females constituted 93.9% (n=214) of the seropositive group and 91.1% (n=41) of the seronegative group. The mean age at diagnosis was 47.87±9.07 years in the seropositive group and 44.34±11.48 years in the seronegative group (p=0.026). No statistically significant differences were determined between the groups in terms of sex distribution, clinical features, and the rate of patients with leukopenia, lymphopenia, thrombocytopenia, hypergammaglobulinemia, hypocomplementemia, and increased acute phase reactant. The median C4 value was lower, and the median IgG value was higher in the seropositive PSS group.

Conclusion:

Clinical findings in patients with seronegative PSS overlapped with those of patients with seropositive PSS, but diagnosis was made later in patients with seronegative PSS.

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