Labial salivary gland biopsy in Sjögren's syndrome. Assessment as a diagnostic criterion in 362 suspected cases.

Xerostomia is an unsatisfactory diagnostic criterion for the salivary component of Sjögren's syndrome (SS). To determine the diagnostic usefulness of the presence of focal sialadenitis in labial salivary gland (LSG) biopsy specimens, 362 patients suspected of having SS prospectively underwent a unique LSG biopsy procedure. The pattern and severity of LSG inflammation were compared with measurements of parotid flow rate, and the presence or absence of symptomatic xerostomia, major salivary gland enlargement, keratoconjunctivitis sicca (KCS), and other connective tissue diseases (CTD). LSG biopsy focus scores of greater than 1 correlated more closely with the diagnoses of KCS alone and with KCS plus a CTD than did either reduced parotid flow rate or symptoms of xerostomia (P less than 0.0005 and P less than 0.05, respectively). Focal sialadenitis in an adequate LSG specimen is an objective criterion and a more disease-specific feature of SS than xerostomia or any other feature of salivary disease. The salivary component of SS should be redefined as the presence of LSG focal sialadenitis.