To compare the clinical and laboratory characteristics of patients with primary Sjögren's syndrome (SS) with an elderly onset to those with a younger onset.
The study group comprised 85 consecutive patients (79 women and 6 men) attending the Sjögren's clinic. Primary SS was diagnosed according to the San Diego criteria. Elderly onset disease (EOD) was determined as the appearance of symptoms suggestive of SS after age 65. Clinical and laboratory variables for EOD were compared to those of a younger onset disease (YOD). Salivary and serum samples of all patients were examined for concentrations of interleukin 6 (IL-6) and hyaluronic acid (HA).
Seventeen patients with SS (20%) matched the definition of EOD and their median disease onset was 71 years (range 65-80). No significant differences were noted in the clinical disease manifestations between the 2 groups of patients. Rheumatoid factor and anti-Ro(SSA) antibodies were more common in the YOD group (p = 0.012 and p = 0.023, respectively). Significant elevations of salivary IL-6 and HA levels were detected in the YOD group compared to the EOD group with SS (17.3 +/- 3.6 vs 8.8 +/- 2.1 pg/ml and 230.2 +/- 41.1 vs 128.8 +/- 33.3 ng/ml, respectively) (p < 0.0001).
EOD SS has somewhat milder clinical symptoms with fewer immunological manifestations than YOD. The elevations of salivary IL-6 and HA in the younger group of SS patients support in part the differences in the inflammatory process between the 2 groups.