To determine whether prognostic immunological profiles predict the severity of keratoconjunctivitis sicca (KCS) in patients with Sjögren's syndrome (SS).
121 patients diagnosed with SS and followed for at least 1 year were enrolled in this study. Patients were allocated to either a mild KCS group (Mi-KCS; n=65) or to a moderate to severe KCS group (MS-KCS; n=56) based on the Oxford scheme and response to treatment. These groups were each sub-divided into two groups based on the clinical severity of KCS and the presence of associated rheumatic disease (primary SS vs secondary SS). Anti-Ro/anti-La antibody, rheumatoid factor and tear interleukin (IL)-17 levels and Schirmer test results were compared between each group.
Anti-Ro/SSA antibody and anti-La/SSB antibody concentrations were significantly higher in the MS-KCS group than in the Mi-KCS group for total and primary SS. The presence of anti-La/SSB antibody was significantly higher in the MS-KCS than the Mi-KCS group for total and primary SS. The mean tear IL-17 concentration in the MS-KCS group was significantly higher than in the Mi-KCS group for both total SS and primary SS patients.
Serum anti-La/SSB antibody, serum anti-Ro/SSA antibody and tear IL-17 are likely to be strongly involved in the clinical severity of KCS in patients with primary SS.