Am. J. Respir. Crit. Care Med., Vol 155, No. 2, 02 1997, 426-431.
Bilateral increases in histamine after unilateral nasal allergen challenge
M Wagenmann, FM Baroody, CC Cheng, A Kagey-Sobotka, LM Lichtenstein and RM Naclerio
Department of Medicine (Division of Clinical Immunology), Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Studying the inflammatory response that follows the early response to nasal
challenge with antigen provides a better understanding of allergic rhinitis
than just studying the immediate (early) response. Nine allergic volunteers
were challenged unilaterally with antigen- containing discs, and bilateral
changes in physiologic responses as well as in the concentration of
histamine in nasal secretions were measured for 11 h. We found significant
immediate increases in symptoms, sneezes, ipsilateral nasal airway
resistance, and ipsilateral histamine in the early phase response.
Two-thirds of the allergen- challenged volunteers showed increases in
physiologic parameters or histamine in the hours after allergen challenge.
The pooled data of all subjects exhibited significant increases in
bilateral nasal airway resistance and in ipsilateral and contralateral
histamine, hours after unilateral provocation. These responses differed
significantly from control subjects. In another group of 11 volunteers
challenged ipsilaterally with antigen, the number of basophils increased
both on the side of challenge and on the contralateral side. The magnitude
of the increase on the ipsilateral side correlated with the increase on the
contralateral side (r(s) = 0.72). The basophils are the most likely source
of the contralateral increase in histamine as they are on the ipsilateral
side. Although the mechanisms underlying this contralateral increase in
basophils and histamine are not known, we speculate that delayed,
neurogenic responses play a contributory role.
