Focus score in the diagnosis of Sjögren's syndrome.

According to current agreements, the verification of SS should consider all three components of diagnostic relevance: focal sialadenitis, keratoconjunctivitis sicca and an associated disease. Focus score (the number of mononuclear cell infiltrates containing at least 50 inflammatory cells in a 4 mm2 glandular section) of greater than 1 is probably the single most important test result in the diagnosis of the oral component in SS. Without such quantitation mild, nonspecific inflammation is often falsely classified as focal sialadenitis suggesting an underlying SS. This was confirmed by a retrospective study of a slide library, which showed that most cases descriptively diagnosed as focal sialadenitis actually had focus scores of less than 1. Furthermore, conditions other than SS can result in focus scores of greater than 1. Firstly, in 8/17 patients, sialolithiasis of the submandibular glands was associated with focus scores of greater than 1, usually with little or no histological signs of obstruction and/or infection. Secondly, focus score values of greater than 1 were found in the labial salivary glands in 6/40 coroner's autopsies although the subjects had no clinical history or findings suggesting SS; simultaneous specific involvement of both salivary and lacrimal glands was, however, observed in 0/40 of the subjects. Based on our observations we suggest that a postmortem diagnosis of SS should be made on the demonstration of focus score of greater than 1 in both the labial salivary glands and the lacrimal glands.