The most important diagnostic criterion in Sjögren's syndrome (SS) is considered to be the histologic focus score of the labial salivary glands. The focus score is defined as the number of lymphocytic foci per 4 mm2 of the salivary gland according to the criterion of Chisholm & Mason. On the other hand, in the criteria of the Sjögren's Disease Research Committee of the Ministry of Health and Welfare in Japan it is defined as the number of lymphocytic foci per a lobule of the salivary gland. By setting the limited criteria for SS on the basis of objective signs of both dry eyes and dry mouth, we compared the usefulness of these two diagnostic criteria for the diagnosis of SS in terms of the sensitivity, the specificity and laboratory data.
The biopsy of labial salivary glands was performed in 245 patients (230 females and 15 males, with a mean age of 54.9 years) who were suspected of SS in our hospital during the time between 1975 and 1996. Labial salivary glands were histologically assessed and the focus score was calculated according to the criterion of Chisholm & Mason and to that of the Sjögren's Disease Research Committee, respectively.
The average area per a lobule of the salivary gland was 0.70 mm2. According to the limited criteria for SS, the Japanese histologic diagnostic criteria showed a higher specificity (93.3%) and a lower sensitivity (23.5%). The sensitivity of the criterion of Chisholm & Mason was 72.1%, and the specificity was 80.0%. The margin of the lobule was sometimes difficult to be identified because of the fatty change and fibrosis in some salivary glands.
By comparing the two different histologic criteria using our limited criteria, it was better to use the histologic criterion of Chisholm & Mason as a criterion for the diagnosis of SS than that of the Sjogren's Disease Research Committee of the Ministry of Health and Welfare in Japan in terms of the sensitivity, the specificity and laboratory data.