Validation Of A Model of Juniperus asheii (Mountain Cedar) Pollen Allergy In The Biogenics Research Chamber

Abstract

RATIONALE: To develop a controlled model of allergy to Juniperus asheii pollen, an antigen not previously utilized in chamber studies. METHODS: Our chambers are constructed with clean room materials and provide single-pass chilled outside air with powered diffusers and exhausts to maintain laminar flow with equalization of pollen delivery. Temperature and humidity are maintained at capacity. The chambers are 10846 and 6655 ft3 and seat 50 and 25 subjects, respectively. Over a 5 hours, thirty-eight Juniperus asheii sensitized subjects and 11 negative controls were exposed to a sham run and increasing concentrations of pollen. Symptoms and pollen counts were recorded at 30 minute intervals. RESULTS: After the sham run, pollen counts ranged from 1300 to11,500 counts/m3. Counts taken at five stations at 30 minute intervals were consistent. No subjects responded during the sham run. Sensitized subjects responded in increasing numbers and with progressive symptoms with increasing pollen levels. Two non-sensitized controls experienced low-level symptoms at high pollen counts. There were no severe adverse effects. CONCLUSIONS: This was the first utilization of Juniperus asheii as an antigen in an environmental chamber. With this pollen, the chamber functioned within anticipated parameters. Subjects did not respond to a sham run. Allergic subjects required higher levels of pollen exposure than average natural exposure. Some non-sensitive subjects experienced minimal symptoms at higher pollen levels.