Nasal histamine and heparin in chronic rhinitis

Histamine and heparin, both free and cellular, were assayed in the nasal mucosa of 11 atopic and 15 nonatopic patients undergoing turbinectomy for chronic rhinitis. There was no significant difference between the free and cellular histamine levels of the atopic and nonatopic patients. There was also no significant difference between the free heparin levels of atopic and nonatopic patients. Mean cellular heparin was, however, significantly greater in the nonatopic group. This finding, together with the results of mast cell counting, suggests either that in atopic patients heparin stores are already depleted prior to turbinectomy, or that in nonatopic individuals nasal mast cells contain an excess of heparin in nonreleasable stores.

Allergen-induced leukotriene production by nasal mucosa and peripheral blood leukocytes

The relationship between release of leukotriene C4 (LTC4) from nasal mucosa in vivo and from peripheral blood leukocytes (PBLs) in vitro was examined in 18 patients with untreated rhinitis allergic to the house dust mite, Dermatophagoides pteronyssinus, and in 20 nonallergic control subjects following challenge with the specific allergen. Allergic patients were subjected to intranasal and PBL challenge with D pteronyssinus and a nonrelevant allergen, Artemisia vulgaris. In all allergic patients, intranasal challenge by D pteronyssinus, but not by A vulgaris, resulted in a release of substances from the nasal mucosa that reacted in a radioimmunoassay with antiserum to LTC4. Dermatophagoides pteronyssinus challenge in vitro of PBLs from the same patients, but not A vulgaris challenge, induced release of the same immunoreactive material into the supernatant. By comparison, the nonallergic subjects challenged with D pteronyssinus showed significantly lower LTC4 levels in their nasal secretions and PBL supernatants. The results show that, following specific allergen challenge, the release of LTC4 by the allergic nasal mucosa is similar in extent and nature to that of PBLs, indicating that these procedures can be used as tools to measure the efficacy of topically and systemically administered antiallergic drugs.

Asthma and rhinitis related to laboratory rats: use of a purified rat urinary allergen to study exposure in laboratories and the human immune response

Using the major rat allergen as a model has made it possible to study both natural exposure and the human immune response to an important laboratory animal. The close correlation between positive skin tests to whole rat urine and IgE antibody to the major urinary allergen in this and previous studies supports the use of this protein as a model rat allergen. Measurements of airborne rat allergen confirm that the maximum levels are higher than those reported with pollen or mite allergens. However, it is possible that exposure to rat allergens is comparable to levels of exposure to cat salivary allergens in houses with cats. The clear implication is that the high levels of exposure are responsible for the fact that a large proportion of exposed individuals develop IgG antibodies. Our results suggest that the prevalence of IgG antibodies (not individual levels) in a group of workers would be a good guide to exposure. This leaves unresolved why some of the individuals who develop IgG ab also develop IgE ab and become at risk for developing asthmatic responses. Only part of this risk is related to atopy. A striking feature of all the studies on animal allergy is the close association between IgE ab and asthma. It appears clear that it is those immune responses that include IgE ab that are a risk factor for asthma. It is not sensible for anyone to remain consistently sick with asthma and continue working with laboratory animals because there are well documented examples of occupational asthma that has not resolved after ceasing exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Decrease of beta-receptors in asthmatic and rhinitic patients

The number of beta-receptors was determined in 60 atopic patients: 30 asthmatics with sensitization to domestic inhalant allergens and 30 rhinitic patients with sensitization to pollen and/or Dermatophagoides antigens. A L-iodocyanopindolol radio-active marker was used. Our control population (20 healthy individuals) showed 908 +/- 396 receptors/cell. The rhinitic individuals showed a 24% decrease in receptors in relation to the control population. On the other hand, within the asthmatic patients there existed 2 differentiated groups: inactive asthmatics whose receptors were found to be within the normal limits and active asthmatics with a 36% decrease in receptors in relation to the healthy individuals (673 receptors/cell) establishing a significant statistical difference (p less than 0.005). As a consequence these data seem to support Szentivanyi's B-adrenoreceptor theory.

Histamine H1 receptors and affinity analyses in human nasal mucosa in cases of nasal allergy

An increased number (density) or sensitivity (affinity) of histamine H1 receptors could cause an increase of allergic symptoms. Using the specific H1 receptor blocker 3H-mepyramine, we have demonstrated for the first time an H1 receptor number (Bmax) and a binding affinity (Kd) in guinea pig and human nasal mucosa. H1 antihistamines inhibited that 3H-mepyramine binding sites represent H1 receptors in nasal mucosa. Bmax and Kd values were not significantly different among the nonallergic sinusitis, vasomotor rhinitis, or the nasal allergy group, suggesting that H1 receptors do not change quantitatively and qualitatively in allergic nasal mucosa. There was no significant correlation between H1 receptor number and clinical data (IgE, peripheral eosinophils, RAST). These data suggest that H1 receptor number and affinity are not main etiological and pathophysiological factors in nasal allergy.

Decreased haptoglobin levels in respiratory allergy

As unusually high frequency of decreased haptoglobin levels in patients with asthma and/or rhinitis is described. The condition is significantly associated with haptoglobin 2-2 phenotype. Decreased haptoglobin levels are more frequently associated with young age, atopic antecedents, positive skin tests for pollens, higher IgE and higher RAST activity for pollens and housedust mite. Whether the association of decreased haptoglobin levels and IgE-mediated respiratory disease has a physiopathological significance or is solely the expression of a common genetic determinate remains to be investigated.

Adrenergic and cholinergic receptors in human nasal mucosa in cases of nasal allergy

We have demonstrated for the first time alpha-1 adrenergic, beta-adrenergic, and muscarinic cholinergic receptors in human nasal mucosa obtained from patients with nasal allergy or sinusitis. Using the radioligand 3H-prazosin, 3H-dihydroalprenolol (3H-DHA) and 3H-quinaclidinyl benzilate (3H-QNB), we determined the receptor densities (Bmax) and affinities (KD) of alpha-1, beta, and muscarinic receptors. There was an increased number of muscarinic receptors and a decreased number of alpha-1, beta receptors in patients with nasal allergy but not in those with sinusitis. Binding affinities (KD) of alpha-1, beta, and muscarinic receptors were unchanged in all patients with nasal allergy and sinusitis. Disorders of the autonomic nerve receptors appear to play a definite role in pathology of nasal allergy.

Indomethacin modification of immediate-type immunologic airway responses in allergic asthmatic and non-asthmatic subjects: evidence for altered arachidonic acid metabolism in asthma

To examine the role of arachidonic acid metabolism in the modulation of immediate-type immunologic airway responses, we compared the effects of indomethacin (50 mg every 6 h for 96 h) and placebo on responses to antigen inhalation challenge in allergic asthmatic subjects and a group of nonasthmatic subjects with allergic rhinitis. Sensitivity to antigen was determined for changes in one-second forced expiratory volume, specific airway conductance, and expiratory flow at 25% of the forced vital capacity measured from partial flow-volume curves. The groups differed in terms of prechallenge pulmonary function and non-immunologic airway reactivity as determined by methacholine challenge, but were comparable with respect to intradermal sensitivity to ragweed antigen. After placebo, asthmatic subjects demonstrated approximately 3.5-fold greater sensitivity to antigen than that of nonasthmatic subjects. Indomethacin had no effect on prechallenge pulmonary function in either group. However, after indomethacin, non-asthmatic subjects had a significant increase in antigen sensitivity. Indomethacin had no effect on antigen sensitivity in asthmatic subjects as measured by one-second forced expiratory volume or expiratory flow at 25% of the forced vital capacity, and produced a slight but significant decrease as measured by specific airway conductance. Indomethacin failed to alter methacholine sensitivity in atopic, non-asthmatic subjects. These findings indicate that products of arachidonic acid metabolism participate in vivo in the modulation of airway responses to immediate-type immunologic stimuli, and that this participation differs in asthmatic and non-asthmatic subjects.

Cyclic nucleotide levels of nasal secretions in allergic patients and control subjects

Cyclic nucleotides (CND) levels of nasal secretions were studied in allergic rhinitis patients and control subjects. In methacholine-induced nasal secretion, allergic rhinitis patients had lower cAMP levels, higher cGMP levels and a lower cAMP/cGMP ratio than the control subjects. A close relationship was found between CND levels and the severity of daily symptoms in both methacholine-induced and antigen-induced nasal secretions.