Mucoglycoprotein hypersecretion in allergic rhinitis and cystic fibrosis.

There is little information about specific changes in submucosal gland exocytosis in diseases such as allergic rhinitis (AR), nonallergic rhinitis (NAR), and cystic fibrosis (CF). Nasal lavage fluids were collected from normal, AR, NAR, and CF subjects. Concentrations of lysozyme, Alcian blue-staining mucoglycoconjugate material (AB+m), and human high-molecular-weight mucoglycoconjugates recognized by the 7F10 murine monoclonal antibody [7F10-immunoreactive mucoglycoconjugates (7F10-irm)] were measured. AB+m and 7F10-irm were characterized by Sepharose-2B column chromatography and glycosidase digestion. 7F10-irm was increased in CF (2.4-fold; P = 0.001) and AR (12.7-fold; P = 0.00007) subjects. AB+m was increased in CF (1.8-fold; P = 0.049) and AR (1.2-fold; P = 0.07) subjects. There were no changes in NAR subjects. On Sepharose-2B columns, AB+m peaks were at 1.3-3.0 × 106 and 0.36-0.65 × 106 Da. 7F10-irm showed four distinct peaks at 1.5, 1.2, 0.85, and 0.53 × 106 Da that were nearly identical in both normal and CF samples. Sialic acid was present in both 7F10-irm and AB+m. 7F10-irm and AB+m are mutually exclusive sialylated mucoglycoproteins that are significantly induced in AR and CF but not in NAR.