Tear fluid analysis in primary Sjögren's syndrome.

Tear fluid analysis was performed in 44 patients with primary SS, 21 patients suspected of having primary SS in whom the syndrome had been excluded, and 24 control subjects. In the primary SS patients the tear fluid levels of lactoferrin and a1-antitrypsin were increased and the tear fluid levels peroxidase, lysozyme and amylase were decreased. However, a considerable overlap in the concentrations of all of the tested substances in the different groups was found and the measurement of these substances cannot be advocated for diagnostic use.