Figure 1.

The classification of periductal inflammatory infiltrates with different levels of organization. (a) Immunohistochemical stainings of FFPE sections from representative examples of LSG sections. For rating the periductal lymphocytic infiltrates, paraffin specimens were stained for CD4, CD20, and in some cases CD21. We distinguished four different grades. Grade 1 displayed scattered T and B cells around the ducts. Grades 2 and 3 showed mild and more organized lymphocytic aggregates. Grade 4 indicated a highly organized structure with extensive FDC network in the center. The magnification of digitalized slides is 10x. Scale bar 200 μm. (b) Distribution of different organizational levels in patients with pSS. n: number of biopsy specimens contained at the stage of organization.