Sialic acid residues in the labial salivary glands from Sjögren's syndrome patients.

OBJECTIVE

To investigate the composition and expression of sialic acid in the labial salivary glands (LSG) in Sjögren's syndrome (SS).

METHODS

LSG of 19 patients with primary SS (n = 11) or secondary SS (n = 8) were studied. Specimens from 7 healthy women served as controls. Computer-assisted microscopy was employed to quantitatively determine the percentage of positive structures, the staining intensity and the heterogeneity for the 4 biotinylated plant lectins Tritricum vulgaris L. (WGA), Maackia amurensis (MAA), Sambucus nigra (SNA) and Canavalia ensiformis L. (Con A).

RESULTS

In the acini there was a significant decrease in the staining heterogeneity of WGA in SS compared to controls; the same was observed with respect to MAA staining in the connective tissue and extralobular ducts. In the intralobular ducts, primary SS differed from normal and secondary SS mainly in terms of a decrease in the percentage of positively labeled MAA tissue. In addition, Con A stained acinar cells were significantly more numerous in secondary SS compared with primary SS.

CONCLUSION

Differences in the degree of glycoconjugate sialylation were found in SS labial salivary glands, and may play a role in the disease process.