Figure 7

Double staining of IL-6 and CD138 in salivary glands of pSS patients and non-SS controls. A) IL-6 expression (brown) and CD138+ plasma cells (red) detected in a pSS patient with FS = 1, a pSS patient with FS = 4, in a subject with chronic inflammation and a subject with normal gland histology. IL-6 was expressed on the interstitial cells in all groups studied and the majority of salivary gland epithelial cells were negative for IL-6. In the focal infiltrates IL-6 expressing cells were mostly detected in pSS patients with FS ≥2. Interaction between CD138+ plasma cells and IL-6 expressing cells were detected in the pSS glands with both FS = 1 and FS ≥2 and not in chronically inflamed or normal glands. Interactions between IL-6 and CD138 plasma cells are indicated by arrows. B) Amount of CD138+ interstitial cells in contact with IL-6+ cells and C) amount of CD138+ plasma cells in contact with IL-6+ cells in the focal infiltrates presented as number of cells per mm². Grey bars represent FS = 1 (n = 9), black bars represent FS ≥2 (n = 8), striped bars represent chronic inflammation (n = 5) and white bars represent normal gland histology (n = 5). Results presented as mean ± SEM. Statistical analyses determined by Kolmogorov-Smirnov and Student t-test (*P < 0.05, **P < 0.005 and ***P < 0.001).