Beta 2 microglobulin in tear fluid from patients with primary Sjögren's syndrome.

beta 2 Microglobulin concentration in tear fluid was measured in 35 patients with primary Sjögren's syndrome (SS), in 28 normal control subjects matched for age and sex, and in 18 patients with arthralgias or myalgias and sicca complaints, in whom the diagnosis primary SS had been excluded. Increased beta 2 microglobulin concentrations were found in the patients with SS, but no correlation was found with the duration of the disease, age, or tear fluid production. Tear fluid beta 2 microglobulin determinations may be useful as an adjunctive diagnostic test for primary SS.