Comparing diagnostic criteria for the salivary component of Sjögren's syndrome

Sjögren's syndrome (SS) is defined by the presence of at least two out of three clinical features: keratoconjunctivitis sicca (KCS), xerostomia and another connective tissue disease (CTD). Various criteria have been used to diagnose the oral component of SS (xerostomia) including the presence of at least two out of the following three: lowered unstimulated whole saliva secretion rate, abnormal salivary scintigraphy and sialadenitis in a labial salivary gland biopsy (LSG) ("Copenhagen criteria"), or the solitary criterion of a focus score (FS) value greater than 1 in a LSG biopsy. We compared the application of these two diagnostic criteria on 52 patients suspected of having SS, and evaluated the interexaminer variation of LSG biopsy FS determination. Compared to the Copenhagen criteria, using FS as the only criterion for the oral component of SS would change the diagnosis in 7 (adding 3 and deleting 4 diagnoses of SS) of 52 patients suspected of having the disease. The FS value may be affected by the size of biopsy and interpretation of pathological changes. The overall interexaminer agreement on FS was 90%.