Expression patterns of galectin-1 and galectin-3 in nasal polyps and middle and inferior turbinates in relation to growth regulation and immunosuppression.

BACKGROUND The term nasal polyposis describes benign growth processes in the nasal and sinus mucosa, which are mainly located in the middle meatus and never in the inferior meatus. As a step to define the biochemical determinants relevant for growth regulation, we focused on endogenous lectins known for anti-apoptotic (galectin-3) and immunomodulatory (galectin-1) activities. DESIGN Using computer-assisted microscopy, we performed an immunohistochemical investigation defining the quantitative parameters of expression of galectin-1 and galectin-3 in 10 nasal polyps, 10 middle turbinates, and 10 inferior turbinates, all of which were obtained from surgical resection. RESULTS Our data show that galectin-3 expression is markedly (P<.001) higher in nasal polyps than in turbinates. No relation to the allergic status was discovered. Galectin-1 expression is higher in nasal polyps than in middle turbinates (P<.001) in nonallergic patients compared with allergic ones (in glandular epithelium, P =.009; in connective tissue, P =.006). The lowest galectin-1 expression was observed in the middle turbinate. CONCLUSIONS These data are in line with a positive influence of galectin-3 on growth and an immunoregulatory role of galectin-1, mimicking an increased expression dependent on glucocorticoid.