Glycohistochemical characteristics of nasal polyps from patients with and without cystic fibrosis

Objective: To investigate whether cystic fibrosis (CF)-related nasal polyps exhibit significantly distinct glycohistochemical characteristics when com pared with single vs massive nasal polyps obtained from patients without CF . Design: Glycohistochemical characteristics were identified by means of 8 hi stochemical probes, including 5 plant lectins (peanut, gorse seed, wheat ge rm, Maackia amurensis, and Sambucus nigra agglutinins), 2 animal lectins (1 4- and 16-kd galectins), and 1 neoglycoprotein (exposing the Thomsen-Friede nreich antigen). The binding of the 8 glycohistochemical markers was determ ined by means of computer-assisted microscopy. For each probe, 3 quantitati ve parameters were computed: the labeling index, which describes the percen tage of tissue area specifically stained by a given marker; the mean optica l density, which reflects the staining intensity and the concentrational he terogeneity, which characterizes the level of heterogeneity of the staining intensity. Subjects: A series of 61 nasal mucosa specimens was analyzed, including 6 n ormal cases, 23 single and 18 massive polyposis cases without CF, and 14 na sal polyps associated with CF. Results: Normal and polyposal nasal mucosa differed in terms of the amounts and linkage types of sialic acids (revealed by the wheat germ, M amurensis , and S nigra agglutinins) rather than the characteristics of galactoside e xpression (monitored with the peanut agglutinin and 2 animal galectins). In contrast, nasal pol>rps markedly differed between patients with and withou t CF with respect to galactoside expression (revealed by the peanut aggluti nin and the 14-kd galectin) and the display of binding site(s) for the neog lycoprotein. Conclusion: Normal and polyposal nasal mucosa differ essentially in sialic acid presentation, while nasal polyps from patients with CF have a higher l evel of various lectin-reactive galactoside residues than nasal polyps from those without CF.