A new and highly sensitive immunohistologic diagnostic criterion for Sjögren's syndrome.

Immunohistologic investigation of the sublabial salivary glands of 65 surgical patients who were free of systemic disease (control) and 19 patients with Sjögren's syndrome resulted in a new diagnostic criterion for SS that was more disease-specific than the widely used lymphocytic focus score criterion. Our bivariate classification criterion, which is based on the percentages of IgA- and IgG-containing plasma cells, has a specificity of 95.4% and a sensitivity of 100%, while its overall percentage of misclassification is 3.6%. This immunohistologic diagnostic criterion results in a reduction of the percentage of false-positive diagnoses from 9% to 4.6%.