The role of atopy in grain dust-induced airway disease.
Blaski-CA; Clapp-WD; Thorne-PS; Quinn-TJ; Watt-JL; Frees-KL; Yagla-SJ; Schwartz-DA
Am J Respir Crit Care Med 1996 Aug; 154(2):334-340
A study of a possible role for atopy in grain dust induced airways disease was conducted. Twenty nonsmoking volunteers, 17 males, with similar baseline pulmonary function participated. Ten subjects were atopic, as indicated by their producing two or more positive responses to skin prick testing with a panel of common environmental aeroallergens. Ten tested nonatopic with the test allergens. The subjects underwent two inhalation challenges consisting of a nebulized corn dust extract (CDE) containing 0.4 microgram per kilogram endotoxin or nebulized Hank's balanced salt solution (HBSS) (control exposure) in random order. Pulmonary function testing was performed periodically from 10 minutes to 24 hours (hr) after each challenge. Bronchoalveolar lavage (BAL) was performed 4hr after inhalation challenge. Changes in BAL fluid cellularity and histamine, tumor-necrosis-factor-alpha (TNFa), interleukin-1beta (IL1b), interleukin-6 (IL6), and interleukin-8 (IL8) concentrations were determined. Both the atopic and nonatopic subjects demonstrated significant decreases in one second forced expiratory volume (FEV1), forced vital capacity (FVC), and the FEV1/FVC ratio that persisted for 24hr following CDE exposure compared to changes induced by HBSS challenge. BAL total cell, neutrophil, and macrophage counts and TNFa, IL1b, IL6, and IL8 concentrations were significantly increased by CDE challenge in both groups. CDE challenge produced no changes in eosinophil counts or histamine concentration, expected responses if an allergic or hypersensitivity reaction was involved in grain induced airways disease. The magnitude of the pulmonary function and BAL fluid cellular and cytokine changes did not differ between the atopics and nonatopics. The authors conclude that atopy does not appear to play a major role in the development of grain dust induced airway disease. The mechanism underlying the airway response to inhaled grain dust remains to be elucidated.
NIOSH-Publication; NIOSH-Cooperative-Agreement; Pulmonary-system-disorders; Humans; Laboratory-testing; Grain-dusts; Pulmonary-function-tests; Dust-exposure; Inhalation-studies; Allergic-reactions; Respiratory-system-disorders
David A. Schwartz, M.D., M.P.H., Division of Pulmonary, Critical Care, and Occupational Medicine, Department of Internal Medicine, The University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242
American Journal of Respiratory and Critical Care Medicine
University of Iowa, Iowa City, Iowa