NASAL POLYPS - EFFECTS OF SEASONAL ALLERGEN EXPOSURE

Nasal polyps are characterized by chronic eosinophilic inflammation and often coexist with rhinitis and asthma. Many patients with polyps have no detectable allergy, and it is considered that allergy, at least in many cases, is not relevant to polyp pathogenesis. To explore the association of nasal polyps with allergy, 16 patients with polyps and ragweed allergy (PRW+) and 16 patients with polyps who were not allergic to ragweed (PRW-) were compared with patients without polyps, 16 who were allergic to ragweed (NPRW+) and 16 who were not allergic to ragweed (NPRW-), before and during the ragweed season. The level of ragweed allergy was comparable in the PRW+ and NPRW+ populations as determined by ragweed skin test wheal diameter, ragweed IgE RAST percent binding, and total serum IgE. Symptom scores before the ragweed season recorded on visual analog scales for the symptoms of blockage, sneezing, decreased smell, itch, postnasal drip, and runny nose were high in patients in the PRW+ and PRW- groups and did not change during ragweed season. Mean symptom scores were low in the NPRW+ group before ragweed season and increased during the season to levels similar to those of patients in the PRW+ and PRW- groups. Preseason nasal lavage albumin concentration was higher in subjects with polyps than those without polyps (58.5, 98) versus (13.6, 15 mug/ml) (p = 0.02) and did not change significantly in any group with seasonal exposure. Data are presented as mean, 1 SD; comparisons are made with unpaired t tests. The preseason percent eosinophils in the nasal irrigation fluid was higher in the subjects with polyps than in subjects without polyps (18, 25) versus (0.9, 2%), (p = 0.0002) and changed little for patients in the PRW+ group during ragweed season. In the NPRW+ group the percent eosinophils increased greatly from low preseason counts, (comparison made with paired t test) (2.2%) to 28, 33% (p = 0.02), the latter comparable to those of subjects with polyps. The nasal lavage eosinophil cationic protein concentration out of season was higher in subjects with polyps than in those without polyps (9.7, 10) versus (1.4, 1.0) (p = 0. 0001) and did not change in subjects with polyps during seasonal exposure. Nasal resistance was measured by head-out body plethysmography. It was slightly higher in subjects with polyps than in those without polyps out of season. In conclusion, highly ragweed-allergic patients with polyps had symptoms and elevated markers of nasal mucosal inflammation (percent eosinophils and eosinophil cationic protein and albumin concentrations) out of season, and these did not increase in relation to natural seasonal allergen exposure. Ragweed allergic subjects with no polyps had large seasonal increases in symptoms and nasal irrigation fluid percent eosinophils. We conclude that ongoing conditions, perhaps nasal airway mucosal inflammation, in nasal polyposis may lead to a loss of susceptibility to potential additional effects of inhaled allergen.