Studies on the function of mast cells infiltrating in nasal polyps

Abstract

The function of nasal polyp mast cells has not been elucidated despite the large number of these cells observed in tissues. We examined these mast cells histochemically, immunohistologically and functionally. Ninety-three percent of collagenase dispersed cells in a nasal polyp were formalin-sensitive. These dispersed cells released histamine in reaction to calcium ionophore A23187 in a dose dependent manner, but not in response to C5a, Compound 48/80 or Substance P. From these results, dispersed mast cells from nasal polyps were considered to be analogous to dispersed mast cells from the human lung and nasal mucosa but not those from human skin. On the other hand, in the reaction with anti-human IgE, dispersed mast cells from a non allergic nasal polyp could not be seen to release histamine. In only 2 of 7 patients, could histamine release in response to Japanese red cedar antigen, from mast cells sensitized passively with the serum of Japanese red cedar pollinosis, seen. Using small tissue samples from polyps, histamine was released by anti-human IgE in allergic patients but not in non allergic patients. Immunohistologically in allergic nasal polyps, some IgE positive mast cells could be seen, whereas in non allergic polyps these cells were absent. These observations suggest that mast cells which had accumulated in nasal polyps both with and without allergy were capable of functional histamine release, whereas in the nasal polyps of allergy patients but not in non-allergic patients these cells are involved in IgE mediated reactions.