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An allergen challenge was performed in 10 asymptomatic patients with strictly seasonal allergic rhinitis. For comparison; seven nonallergic subjects were challenged with allergen, and seven allergic patients were challenged with diluent. Cell samples, obtained with use of a brush technique to recover cells from within the epithelium and nasal lavage to collect cells from the epithelial surface, and symptom scores were taken before challenge and at 2-hour intervals during 12 hours. The cell suspensions were cytocentrifuged onto object slides for light microscopy. Histamine was determined in the cell pellets. In brush samples from the allergic patients challenged with allergen, eosinophils, expressed as a percentage of the total granulocytes, increased from 4.3% +/- 2.7% (mean +/- SEM) to 10.3% +/- 3.8% (p < 0.05) 4 hours after challenge. This level was maintained for up to 12 hours. A similar increase was noted in the lavage specimens 2, 6, and 8 hours after the challenge. In the brush samples the proportion of eosinophils containing two or more cytoplasmic vacuoles, taken as a sign of activation, increased from 20% to 72% (p < 0.05) 8 hours after provocation. In brush samples from the allergic patients challenged with allergen, the numbers of metachromatic cells increased to a maximum of eightfold at 10 hours. In the lavage specimens, no metachromatic cells were observed before provocation, but they progressively increased in number 2 to 12 hours after provocation. Cell pellet histamine content decreased temporarily 2 to 4 hours after challenge (p < 0.05) in brush samples from allergen-challenged allergic patients. The local metachromatic cell density before challenge, as reflected in the brush specimens, correlated with nasal congestion, sneezing, and the degree of eosinophilia.

This study set out to examine the effects of histamine on airway absorption of macromolecules. By employment of a novel "nasal pool" technique instillates containing 125I-albumin, with or without histamine, were kept for 15 min on human nasal mucosa. Unaffected by the presence of histamine, the instillations produced significant levels of plasma radioactivity, increasing for 60 min. However, gel-filtration data showed that only 30% of the plasma radioactivity was still bound to albumin. Incubation experiments indicated that radioiodine did not dissociate from albumin in nasal liquids nor in the blood. Further experiments involved oral ingestion of the entire nasal instillate. Prompt gastrointestinal absorption of radioactivity occurred, giving rise to plasma levels about two orders of magnitude higher than those recorded after the nasal applications. Moreover, only 25% of the plasma radioactivity was now bound to albumin. It must be considered unavoidable that a small portion (less than 1%) of the nasal instillate is swallowed. Hence, the plasma radioactivity detected in this study may largely reflect gastrointestinal break-down of 125I-albumin and subsequent absorption of radioiodine. We conclude that 125I-albumin may not be employed in studies addressing macromolecular absorption across the human nasal mucosa and that previous work and conclusions based on nasal absorption of 125I-albumin are invalid.

Macrophages are the most common cell type residing in the lumen of the lower airways. However, very little is known about the presence and putative pathogenic implications of macrophages in the upper airways. Using specific immunohistochemical techniques, the presence of and changes in macrophage density were studied before and after allergen exposure in the laboratory and during natural allergen exposure of subjects with seasonal allergic rhinitis. The monoclonal antibody EBM 11 combined with the alkaline phosphatase-anti-alkaline phosphatase-technique was applied on cytospin-prepared slides. In the challenge experiment, 0.5 +/- 0.2% (mean +/- SEM; n = 10) of the total cell number were positive for the EBM 11 marker before challenge, thereby not differing from the controls (0.2 +/- 0.2%; mean +/- SEM; n = 3). Local allergen challenge induced an increase of these cells to a peak of 1.3 +/- 0.4% after 4 h (p less than 0.05). During seasonal exposure there was also a similar increase, from 0.7 +/- 0.2 to 1.3 +/- 0.3% (p less than 0.05; n = 11) in placebo-treated patients and from 0.7 +/- 0.2 to 1.6 +/- 0.4% (p less than 0.05; n = 11) in patients treated with topical glucocorticoids. There was, however, no direct relationship between nasal symptoms and number of macrophages present on the mucosal surface. The study indicates that macrophages are involved in the inflammatory processes of allergic rhinitis.

The determination of histamine in nasal secretions and nasal lavage fluid may be of importance to monitor activation of histamine containing cells in the nasal cavity. However, such studies have been besieged by controversy, specifically to findings of changes in histamine levels in relation to allergenic stimulation. This controversy may be due to the specificity and accuracy of the various methods used to determine histamine in the nasal fluid. We have therefore applied and compared three new methods to determine histamine in nasal lavage fluids obtained before and after allergen challenge in normal subjects and patients with allergic rhinitis. We used a fluorometric glass fiber-based histamine method (FHR) and two RIAs, I and II. The FHR (detection limit, 7.0 nmol) and the RIA II (detection limit, 0.2 nmol) are specific for histamine itself, whereas the RIA I (detection limit, 18.0 nmol) measures mainly methylhistamine and cross-reacts to some extent with histamine. The histamine levels in the nasal lavage fluids from the nasal challenges demonstrated histamine values between 100 and 2000 nmol/L of histamine with significantly higher levels in the postallergen challenges for the allergic subjects as compared to the normal control subjects. The FHR correlated well with the RIA I and RIA II methods with correlation coefficients of 0.77 to 0.88 ( p

Several new techniques for atraumatic harvesting of cells from the nasal mucosa in vivo in humans have been utilized in allergen challenge experiments and during natural allergen exposure. Using biochemical techniques to monitor the release of substances or mediators, suggestive evidence has been provided for the participation of specific cells in these conditions. After a local challenge with allergen, a release of histamine indicates the activation of mast cells in the initiating part of the allergic response. This initial response to allergen is followed by a late inflammatory phase characterized by late occurring symptoms, a local influx of granulocytes, and a change in mucosal responsiveness to specific as well as unspecific stimuli. The interrelationship between these different manifestations of the postallergen inflammatory response remains to be sorted out. The most prominent finding is the increase in the number of eosinophilic granulocytes. Biochemical evidence has also been provided that these cells together with basophilic granulocytes also appearing during the late phase are activated. Similar evidence for the participation of mast cells in hay fever during natural allergen exposure has been provided through the demonstration of changes in the distribution of these cells, a change in intracellular histamine content and ultrastructural findings of cell activation. In addition, seasonal allergen exposure was accompanied by a prominent increase in eosinophils on the surface of the nasal epithelium, an increase that correlated strongly to the degree of pollen exposure and symptoms experienced by the patients. Thus, human in vivo data point to, at least to some extent, similar cellular changes in the laboratory following a local challenge and the clinical disease of hay fever.

This study examined plasma- and eosinophil-derived products in nasal lavage fluids obtained from patients with hay fever during natural allergen exposure. Nine patients with strictly seasonal allergic rhinitis and five normal, nonallergic subjects (control group) were studied. Nasal lavages were performed twice weekly, starting 1 week before the expected birch-pollen season and continuing for 6 weeks, thereby covering the entire birch-pollen season. Nasal symptoms and pollen counts were recorded daily. The lavage fluid was analyzed for it content of albumin, bradykinins, and eosinophil cationic protein (ECP). During the pollen season, each of these solutes was significantly increased in the nasal lavage fluid from the allergic patients (p less than 0.05) but not from the control subjects. Albumin, bradykinins, and ECP generally correlated better between themselves than with symptoms and pollen counts. We conclude that natural exposure to allergens induces plasma exudation and increased levels of ECP on the human nasal mucosa.

Topical steroids are known to be effective in allergic inflammatory airway diseases. However, progress in the treatment of these diseases has also called for the use of unadulterated drugs, without lubricants and preservatives. Rhinocort Turbuhaler, a multi-dose inhaler containing budesonide as a pure powder, is a newly developed device without any carrier gas, preservatives or lubricants. The efficacy and tolerance of this product were evaluated in 60 patients with birch pollen rhinitis. After a run-in period of 1 week the patients received once daily for 4 weeks either budesonide pure powder (400 micrograms) or placebo in a double-blind randomized fashion. Assessment of efficacy was made by comparing scores for different nasal and eye symptoms. The additional use of antihistamine tablets was assessed. In 22 of the patients nasal peak inspiratory flow rate was measured before and after 1 week of treatment. Budesonide was significantly more effective than placebo in controlling the nasal symptoms (P-values ranging from 0.011-0.045). The use of antihistamine tablets was significantly lower in the budesonide group (P = 0.012). The nasal inspiratory flow rate was increased after 1 week of treatment in the budesonide treated group of patients as compared with placebo (P = 0.007). No differences were observed between the groups with regard to eye symptoms or adverse effects. The results show that budesonide delivered from a dry powder inhaler is an effective and well tolerated treatment of seasonal allergic rhinitis.

Antihistaminic compounds have been suggested to possess other properties besides H1-receptor antagonism. To evaluate whether two different antihistamines could inhibit local eosinophil infiltration and allergen-induced nonspecific nasal hyperreactivity, 15 subjects with seasonal allergic rhinitis participated in a double-blind, randomized, placebo-controlled study outside the pollen season. At steady-state levels of either 60 mg of terfenadine, twice daily, cetirizine, 10 mg once daily, or placebo, a nasal methacholine challenge was performed before and 24 hours after a nasal allergen challenge. The volume of the methacholine-induced nasal secretions was measured. The response to allergen was determined with a scoring technique. Cells from the nasal mucosal surface were harvested with the aid of a rhinobrush. Both antihistamines induced a similar (p less than 0.01) reduction in nasal symptoms after the allergen challenge compared with placebo. Both antihistamines inhibited the increased nonspecific nasal reactivity induced by methacholine 24 hours later (p less than 0.05). The allergen challenge induced an increase in surface eosinophils, which, however, appeared unaffected by any of the active treatments. Since histamine per se does not induce changes in nonspecific reactivity, we suggest that the antihistamines possess other properties besides being H1-receptor antagonists.

Skin prick tests with allergen and histamine were performed on the volar aspect of the forearms in a double-blind, cross-over study with 40 mg of prednisolone and placebo in 16 pollen-allergic subjects. Skin biopsies were taken before any treatment and 15 min (group 1; n = 8) and 6 h (group 2; n =8) after local challenge with allergen, corresponding to the timing of an early- and late-phase reaction. The specimens were used for the histological evaluation of mast cell and eosinophil density as well as for the determination of the histamine and protein content. The size of the induced weal and flare area as well as of any late-phase reaction was determined using digitized planimetry. The single dose of prednisolone, given 2 h prior to challenge, did not affect the size of the weal and flare response. Only 4 of the individuals developed a visible late-phase response. Eosinophils were virtually absent before allergen exposure, but were already present 15 min after allergen challenge, largely associated with the blood vessels, and were numerous at 6 h. There was, however, no relationship between eosinophil density and the presence or extent of any visual late phase. The mast cells/basophils showed a tendency to increase at the 6-hour determination. The infiltration of eosinophils was blocked by the glucocorticoid. This treatment also induced a difference in the mast cell density at the 6-hour determinations, associated with a similar difference in the histamine content of the biopsy specimens. From the present study, we can conclude that the eosinophil infiltration is an early event and can be blocked by a single dose of prednisolone only 2 h after the administration of the glucocorticoid.

The "vasoconstrictor" effect of dermally applicated steroids is a widely used parameter when determining the potency of glucocorticoids. A similar effect on the nasal mucosa has been suggested as providing an explanation for the clinical effect of topically administered glucocorticoids in the treatment of nasal disorders such as allergic and vasomotor rhinitis. The recently described 133Xe wash-out method was used for the purpose of blood flow determination in 11 healthy subjects. In a randomized double-blind cross-over study, the effect of topically administered budesonide, a non-halogenated glucocorticoid, for 1 week was compared with that of placebo. No difference was found to occur in the mucosal blood flow after the administration of budesonide, as compared with placebo. It seems likely that a more complex activity than vasoconstriction is responsible for the clinical effect in the treatment of nasal disorders, and further research is required in order to clarify this issue.

Nasal lavage after antigenic and nonantigenic nasal stimulation has become an important tool for the study of inflammatory phenomena in the upper airway. Biochemical and cytologic information is relatively easily obtainable, and pharmacologic manipulations can be readily monitored. This article is of several studies aiming toward a more profound understanding of the mechanisms of allergic and nonallergic rhinitis by the use of laboratory-challenge procedures and nasal-lavage techniques. An early and a late reaction are detected clinically in the nose after antigen challenge of allergic individuals. In addition, the sensitivity to antigen significantly increases after the initial challenge, and this phenomenon is not obligatorily linked to the presence of a late-phase reaction (LPR). Inflammatory mediators, mostly mast cell- and/or basophil-derived, are detected in the nasal washes and correlate with the symptomatology in both the early and the late reactions. The allergen-induced LPR is marked by an early influx of eosinophils and, later, basophils and neutrophils. Elevation of major basic protein and histamine, but not prostaglandin D2, is detected during the LPR, giving evidence of active eosinophil and basophil participation. Systemic steroids can effectively suppress the clinical, biochemic, and cellular manifestations of antigen-induced LPR. Topical steroids have a similar effect but are also capable of suppressing the early reaction to antigen. A nonallergic form of rhinitis can be induced in the laboratory by nasal inhalation of dry air at freezing temperatures in individuals who report sensitivity to cold and windy environments.(ABSTRACT TRUNCATED AT 250 WORDS)

In a nasal allergen challenge test, the effect of the glucocorticosteroid, Budesonide, on the pollen allergic type I reaction has been investigated. Placebo and two different dosages of budesonide were administered intranasally for 1 week before the challenge was performed. The study was designed as a double-blind cross-over trial. One week of treatment with the active steroid significantly reduced the nasal secretion compared to placebo as measured with the aid of a symptom score, and significantly reduced the induced nasal blockage measured objectively by means of rhinomanometry. No difference was found between the two dosages of budesonide, 400 micrograms and 100 micrograms daily, used in the study.

The technique of nasal provocation followed by lavage was used to study the pharmacology and pathophysiology of upper airway allergic reactions. The levels of histamine, TAME-esterase activity, kinins, and arachidonic acid metabolites were measured in the recovered nasal lavage fluid obtained during the early and, in certain cases, the late phase and rechallenge reactions to antigen. Leukocytes contained in the lavage were counted and differentiated. Topical application of azatadine and systemic administration of theophylline reduced both mediators and symptoms during the early reaction, probably by inhibiting antigen-induced mast cell activation. Pretreatment with aspirin decreased the concentration of cyclooxygenase products during the early reaction without ameliorating symptoms. Administration of systemic steroids ablated the increase of mediators and symptoms and the mucosal accumulation of eosinophils and mononuclear cells, but not of neutrophils during the late phase reaction, without affecting the mediators or symptoms of the early reaction, with the exception of kinins. Topical steroids reduced both the amount of mediators and the severity of symptoms during the early, late, and rechallenge reactions. The accumulation of eosinophils, basophils, neutrophils, and mononuclear cells during the late phase reaction was also significantly reduced. Thus, this nasal challenge model has helped us to gain insights into the pathophysiology of allergic reactions and the pharmacology of their treatment and can be used to examine the efficacy of pharmacologic agents designed for the treatment of such reactions.

Symptomatic seasonal allergic rhinitis has previously been found to be associated with a redistribution of mast cells from the subepithelial stroma to the epithelial lining and the surface of the nasal mucosa. The present study was designed in order to elucidate the interaction between topical glucocorticosteroids, effective in the treatment of allergic rhinitis, and the migration of mast cells described earlier. Six patients treated prophylactically in the nose with budesonide were studied. Imprints and biopsies from the nasal mucosa were taken 2–3 weeks before and 2–3 weeks into the birch pollen season. The biopsies were used for light microscopy and tissue histamine determination. The morphologic studies showed, also in the actively treated patients, an increased number of metachromatically stained cells on the nasal mucosal surface of the same order of magnitude as previously reported for untreated patients. We did, however, find a decrease in the histamine content of the nasal mucosa, which was not associated with a decrease in the number of mast cells. Together with similar previous findings in the unstimulated allergic nasal mucosa these results suggest that glucocorticosteroids induce a decrease in the mast cell histamine pool, possibly due to an inhibition of the intracellular synthesis of histamine. This effect might contribute to the clinically beneficial effect of topical glucocorticosteroids in the treatment of hay fever.

In order to determine the effect of PAF-acether on the vascular bed in the human nose, 11 healthy volunteers were studied. Rhinomanometry was performed to determine the effect on the capacitance vessels, and the 133Xe wash-out method enabled determination of the mucosal blood flow, regulated mainly by the resistance vessels. These measurements were made before and after topical administration of PAF-acether in three different doses; 0.26 micrograms, 2.6 micrograms and 26 micrograms per nostril. The results indicate that PAF-acether induces a dose-dependent vasoconstriction of the capacitance vessels and a reduction in mucosal blood flow. That PAF-acether should be a principal mediator in the allergic reaction in the human nose is not supported by these findings.

Both the pattern of mediator release during the late-phase response (LPR) and the reduction of the LPR with corticosteroid pretreatment have suggested that basophils, not mast cells, represent the main source of histamine in the late response to nasal antigen challenge. We tested this hypothesis by examining alcian blue-stained cytospin slides of nasal washings obtained before and for 11 hours after nasal antigen challenge in 11 asymptomatic subjects with seasonal allergic rhinitis. In a double-blind manner, subjects received placebo or topical flunisolide (50 micrograms, each nostril, twice daily) for 1 week before antigen challenge. One month later, the challenge was repeated with the alternate pretreatment. On placebo-treatment days, a twelve-fold increase occurred in the number and a threefold increase in the percentage of alcian blue-stained positive cells in nasal washings in the LPR compared to baseline. At least 68% of these alcian blue-stained positive cells were basophils, as determined by light microscopic criteria. Alcian blue-stained cell influx correlated with increases in histamine levels in nasal washes (p less than 0.001). Topical steroid pretreatment blocked the influx of alcian blue-stained positive cells, as well as other inflammatory cells, including eosinophils, neutrophils, and mononuclear cells. Symptoms and mediator release were also blocked. These data demonstrate an influx of basophils and suggest that these cells are responsible for the histamine release observed in the LPR. Our findings indicate that pharmacologic control of basophil histamine release may represent a strategy for the treatment of a variety of chronic allergic diseases that are believed to resemble the LPR.

Insight into the pathogenesis of human allergic and inflammatory disorders has been obtained through a combination of in vitro and in vivo studies. These investigations have demonstrated that human basophils and mast cells release mediators after nonimmunologic as well as immunologic activation in vitro and in vivo: nonimmunologic triggers include changes in osmolarity. Although these cells share many properties, including the presence of high-affinity receptors for IgE on their cell surface, the presence of histamine in granules, the ability to generate and release large quantities of leukotriene C4 (LTC4) after activation, and the ability of several pharmacologic agents including phospholipase inhibitors, acetylene analogues of arachidonic acid (ETYA, ETI), methylxanthines, prostaglandin E2 (PGE2) beta-agonists, and cyclic AMP to inhibit mediator release, they also display notable differences. Human lung mast cells generate and release large quantities of prostaglandin D2 (PGD2) after activation; basophils generate no known cyclooxygenase product. Indomethacin, arachidonic acid, and 5-hydroperoxyeicosatetraenoic acid (5-HPETE) all enhance histamine and LTC4 release from human basophils; no effect is seen with human lung mast cells. Overnight incubation of basophils with glucocorticoids produces a marked inhibition of mediator release; this treatment does not affect the release of mast cell mediators. These in vitro observations are consistent with our in vivo observations and our hypotheses concerning the importance of these cells in allergic disease.(ABSTRACT TRUNCATED AT 250 WORDS)

The possible mode of action of the lately demonstrated steroid effect on the immediate type allergic reaction was investigated. The influence of a topical steroid, budesonide, on the effects that released mediators have on the nasal mucosa was also studied. A nasal histamine challenge study was performed in a double-blind, cross-over fashion, a 1-week pretreatment with budesonide or placebo preceding the challenge. Symptoms were recorded by means of symptom score as well as objectively via rhinomanometry. In contrast to a previous allergen challenge study, the steroid was found to have minimal effect on the histamine-induced nasal symptoms. It is therefore concluded that other modes of steroid action must also be involved in the steroid effect on the immediate type allergic reaction.

Mast cells were studied by light microscopy in mucosal imprints and in biopsies of nasal mucosa of 12 birch pollen allergic individuals before and during the pollen season, using techniques optimized for the demonstration of mucosal mast cells. We also measured the histamine content of nasal mucosa, whole blood and plasma, and counted the numbers of circulating blood basophils. Before the pollen season the nasal mucosa was found to contain many mast cells located in the mucosal connective tissue stroma, and very few cells with basophilic and metachromatic granules were found in mucosal imprints. During the pollen season there was a redistribution of mast cells into the epithelium, many such cells now being recovered in mucosal imprints. The total number of mucosal mast cells counted in tissue sections did not change significantly with the onset of the pollen season, suggesting a redistribution of mucosal mast cells by migration. Judged by morphologic appearance and naphthol-AS-D chloroacetate esterase activity, the intraepithelial mast cells found in tissue sections had rather the properties of tissue mast cells than of blod basophils, and only a few of the basophilic cells of the imprints had a morphology compatible with blood basophils. The histamine content of the mucosa, as well as histamine levels of whole blood and plasma, and circulating blood basophil numbers did not change significantly in relation to the pollen season. These findings suggest that an intraepithelial migration of mucosal mast cells is part of the allergic mucosal response. This reaction resembles the nematode response of certain rodents and may explain how contact is established between mucosal allergens and effector cells when the allergic reaction is initiated.

The correlation between allergen-induced specific and non-specific (histamine) nasal reactions was studied, especially as regards topical glucocorticosteroid effects on the non-specific reactions. Thirteen patients with strictly seasonal allergic rhinitis participated. A nasal challenge with histamine and three increasing doses of allergen was performed on the first day. The patients were rechallenged 24 h later with the same histamine dose and the lowest allergen dose from the previous day. The same 2-day challenge was also performed after pretreatment for one week with budesonide in 8 of these patients. Symptom scores were recorded. The N-alpha-tosyl-L-arginine-methyl-esterase (TAME esterase) activity in nasal lavages was determined. The nasal symptoms and the TAME-esterase activity increased at rechallenge for both histamine and allergen, compared with the initial challenge. The mean ( +/- SE) composite nasal symptom score after histamine increased from 3.5 +/- 0.49 to 4.9 +/- 0.35 (p less than 0.01) and after allergen from 1.62 +/- 0.3 to 3.2 +/- 0.5 (p less than 0.01) at rechallenge. Similar increases were recorded for the TAME-esterase activity. A close correlation between the allergen-induced increase in specific (allergen) and non-specific (histamine) reactivity was found (r = 0.7, p less than 0.01, composite nasal symptom score). Treatment with topical glucocorticosteroids abolished the allergen-induced increase in both specific (p less than 0.001) and non-specific (histamine) (p less than 0.01) nasal reactivity.

Previous studies have demonstrated symptoms and mediator release occurring as long as 11 h after nasal challenge with antigen in selected allergic subjects. Pretreatment with systemic steroids reduced symptoms and mediators including histamine, TAME-esterase activity, and kinins. The aims of the present study were to characterize the cell influx during the late-phase response to antigen challenge and to determine the effect of pretreatment with systemic steroids on this response. We examined cytospin slides of nasal washings obtained before and hourly for 11 h after nasal antigen challenge in 10 asymptomatic allergic subjects with a history of seasonal rhinitis and 5 normal, nonallergic subjects. Allergic subjects received oral prednisone (20 mg 3 times a day) or placebo in a random, double-blind crossover manner for 2 days before each of 2 challenges 1 month apart. On placebo days, a mixed cell influx occurred in allergic subjects during the late response that was 50-fold greater than the cell influx in the nonallergic control subjects (p less than 0.005). During the first 3 h after antigen challenge, eosinophils (p less than 0.005), but not neutrophils or mononuclear cells, were observed. During the late phase (4 to 11 h), neutrophils, eosinophils, and mononuclear cells were all increased. Oral steroid pretreatment blocked the influx of eosinophils (p less than 0.005), but not that of other cells. These data demonstrate an inflammatory cell influx associated with the nasal late-phase response and suggest an important pathogenetic role for the eosinophil.(ABSTRACT TRUNCATED AT 250 WORDS)

The possible mode of action of the recently demonstrated steroid effect on the immediate type allergic reaction has been studied. The influence of a topical steroid, budesonide, on the nasal mucosal histamine content and anti-IgE induced histamine release was studied in an open study. A 1-week treatment with budesonide, used locally in the nose, was administered to 22 hay fever patients who were studied out of the pollen season. There was a decrease of histamine content after steroid treatment and also a blockade of the anti-IgE mediated histamine release, as shown in an in vitro release procedure. This steroid effect may partly explain the effect of steroids on the immediate reaction, as it has been demonstrated in allergen challenge studies.

It has been previously demonstrated in nasal challenge studies that there is an increased sensitivity to allergen following an initial allergen challenge. A similar feature has been demonstrated following natural allergen exposure in patients with seasonal allergic rhinitis. To further explore the characteristics of this “priming” phenomenon and its relationship to other expressions of their allergic airway disease, 28 hay fever patients with strictly seasonal disease were studied. Skin tests with the relevant pollen allergen and histamine were performed and the size of the immediate and late phase allergic reaction was determined. An initial nasal allergen challenge was followed by a rechallenge of the nose with allergen 24 h later using a lavage technique. Determinations of TAME-esterase activity, as a biochemical marker of the allergic reaction, were made in the returned lavage fluid. The number of sneezes was counted and nasal symptoms were also assessed using a scoring technique. 19 of 28 patients (67%), displayed an increased responsiveness at rechallenge with similar findings in terms of symptom scores and TAME-esterase measurements. The increase was statistically significant for the symptoms of nasal blockage, which increased from 0.7 ± 0.1 (mean ± SEM) to 1.1 ±0.2 (P ± 0.05), and nasal secretion which rose from 1.1 ± 0.2 to 1.7 ± 0.2 (P < 0.01). A composite nasal symptom score which also took account of the number of sneezes, increased from 2.9 ± 0.4 to 4.0 ± 0.3 (P < 0.01). The TAME-esterase activity in the recovered lavage fluid following challenge with the same allergen dose increased from 11.7 ± 2.4 to 18.7 ± 2.8 CPM/103 (P < 0.01). No correlation was found between the increased responsiveness and the size of initial immediate reaction either in the nose or in the skin, or the presence or size of any late phase dermal reaction. There was, however, a correlation between the size of initial allergen response in the nose and skin (r = 0.43). As an increased responsiveness to allergen appears to be of clinical significance at natural allergen exposure, further studies of the pathophysiology of this phenomenon are called for.

We studied the effect of alpha-fluoromethyl histidine, an irreversible histamine synthesis inhibitor, on the immediate nasal reaction to antigen challenge in a double-blind, placebo controlled, randomized, parallel study using 13 subjects. The patients received either active drug 100 mg twice daily or placebo, for 3 weeks. A nasal allergen challenge was performed before and after at weekly intervals. Symptoms at challenge were assessed and the levels of histamine, TAME-esterase activity and kinins were measured in nasal lavages before and after antigen challenge. Skin tests were also performed at weekly intervals. In addition, the urinary excretion of the main histamine metabolite, telemethylimidazole acetic acid, was measured before and after 3 weeks of treatment. The active treatment induced 60% reduction in histamine levels in the lavage fluids before and after antigen challenge, as well as a reduction in the histamine levels in the lavage fluids before and after antigen challenge, as well as a reduction in the main urinary histamine metabolite. However, no reduction was found in nasal symptoms obtained after antigen challenge. The levels of kinins and TAME-esterase activity were not significantly reduced.

By means of rhinomanometry the effects of two oral decongestants, d-pseudoephedrine and phenylpropanolamine were compared in acute infectious rhinitis. In a single-blind study involving 20 patients no difference was found between 120 mg d-pseudoephedrine and 100 mg phenylpropanolamine in relieving nasal congestion.In an open study, the effect of 100 mg phenylpropanolamine as related to body position was measured in 14 patients. No difference was found between taking medicine and remaining recumbent as compared with assuming an upright position only.

A method is presented for the objective monitoring of the inflammatory response of the nasal mucosa to natural allergen exposure through measurements of biochemical markers such as TAME-esterase activity in a daily nasal lavage. Nine patients with strictly seasonal allergic rhinitis caused by birch pollen and five healthy nonatopic control subjects participated in the present study, which started 1 wk before the birch pollen season and continued throughout the entire pollen season. A diary card was used to assess daily nasal symptoms, and a daily nasal lavage was performed once every afternoon. The degree of pollen exposure was assessed by daily pollen counts. The TAME-esterase activity in the lavage fluid from the allergic patients, but not in that from the nonallergic control subjects, increased significantly during pollen exposure despite low pollen counts and was found to correlate with daily nasal symptoms (r = 0.36; p less than 0.05) and the degree of pollen exposure (r = 0.45; p less than 0.01). The area under the curve for the daily TAME-esterase measurements thus differed significantly (p less than 0.02) between allergic patients (158 +/- 28) and control subjects (74 +/- 9). This approach for the monitoring of patients with hay fever during natural allergen exposure will make further objective studies on the pathophysiology and pharmacology of hay fever possible. We also provide support for the validity of previous findings obtained in allergen challenge situations utilizing the lavage approach.

Dermally applied topical glucocorticoids induce a pallor of the skin. 'vasoconstriction', which has been used to grade the anti-inflammatory potency of such preparations. This study was performed in order to explore the possibility of a similar 'vasoconstrictor' phenomenon existing in the upper airway mucosa, which might thus offer one explanation for the clinically beneficial effect of topical glucocorticosteroid preparations in the treatment of allergic and non-allergic rhinitis. The possibility of a changed sensitivity to alpha and/or beta-adrenergic stimulation was also evaluated. Ten normal subjects participated in the present double-blind, randomized, crossover, placebo-controlled study. After establishing a baseline in nasal peak flow and nasal mucociliary clearance, the patients were treated for 8 days with either budesonide 100 micrograms/nasal cavity morning and evening, or a matching placebo. After a wash-out period of 2 weeks the treatment was repeated using the other treatment alternative. Nasal peak flow measurements were taken immediately before and 1 h after each application of treatment. After 1 week of treatment the nasal mucociliary transport was determined and the subjects were subjected to an intranasal challenge with 0.05 mg of oxymetazoline and 5.2 mg terbutaline on 2 different days in order to test for alpha and beta-adrenoceptor sensitivity. The response to these challenges was monitored by symptom scores and nasal peak flow measurements. Neither active treatment with budesonide aqueous suspension nor the placebo treatment induced any change in the mucociliary transport time nor in nasal airway as measured with the peak flow meters.(ABSTRACT TRUNCATED AT 250 WORDS)

Although theoretical considerations and experimental evidence implicate the mast cells in the pathophysiology of the immediate type hypersensitivity reaction, the evidence of their active participation in human allergic disease is still fragmentary. We have therefore sought evidence of mast cell activation in allergic mucosal disease using strictly seasonal allergic rhinitis as a model. Twelve patients with birch pollen-induced hay fever were examined before and well into the birch pollen season. Allergen exposure was monitored by pollen counts and the degree of symptoms registered daily. Small surgical biopsies and mucosal imprints were obtained from each patient before and during the season. Mast cells were analysed by light and electron microscopy and mucosal histamine was measured using a sensitive HPLC assay. We found a reduction in the number of mast cells in the nasal mucosa during pollen exposure (p less than 0.05) but no significant reduction of the histamine content. There was a correlation between the nasal mucosal mast cell density and histamine content before the pollen season (r = 0.76; p less than 0.01), but no such correlation was found during the period of pollen exposure (r = 0.19; n.s.). This finding points to secretory activity by the mast cells during the pollen season and to the appearance of a non-mast cell pool of tissue histamine. Evidence for a secretory activity of the mast cells during the pollen season was also confirmed by electron microscopy. In addition, we found a strong correlation (r = 0.77; p less than 0.01) between the histamine content of the nasal mucosa during the pollen season and the degree of nasal symptoms. The number of epithelium-associated mast cells found on mucosal imprints prior to the pollen season showed a strong correlation with the symptoms experienced later during the period of pollen exposure (r = 0.83; p less than 0.01). Taken together these observations indicate that the mast cell has a pathogenetic role in continuous allergic airway disease and re-emphasizes the role of histamine in the induction of the symptoms of allergic rhinitis.

The nasal mucosal blood flow in patients with allergic rhinitis was determined at nasal allergen challenges with the 133Xenon washout method. Determinations were made in 12 subjects before and 15 minutes after challenge with diluent and increasing doses of allergen. The time course was followed in eight subjects by means of repeated measurements during 1 hour after a single allergen dose. Finally, the blood flow was measured after unilateral allergen challenge in the contralateral nasal cavity. A dose-dependent decrease in blood flow was found after nasal challenge with increasing doses of allergens, whereas challenge with diluent alone did not induce any changes. The highest allergen dose, which also induced pronounced nasal symptoms, resulted in a decrease in blood flow of 25% (p less than 0.001). The time-course study demonstrated a maximum decrease in blood flow 10 to 20 minutes after challenge and then a gradual return to baseline. Unilateral allergen challenge resulted in a decrease in blood flow in the contralateral, unchallenged nasal cavity, suggesting that part of the allergen-induced changes in blood flow were reflex mediated.

Evidence has been presented suggesting that a migration of nasal mast cells from the mucosal connective tissue stroma into the epithelium is part of the mucosal response in birch pollen allergy. In a previous study, the identification of these intraepithelial cells as tissue mast cells rather than blood basophils was based on light microscopical morphology and histochemistry. We have now studied the ultrastructure of these cells in mucosal biopsies taken before and during the birch pollen season. Intraepithelial cells with basophil or metachromatic granules were only observed in biopsies taken during the season. Some of these cells had the ultrastructural appearance of tissue mast cells, including cytoplasmic lipid droplets and a granular substructure composed of multilamellar arrays and scrolls, serving to distinguish human mast cells from blood basophils. The ultrastructural traits of the remaining cells were heterogeneous, some reminiscent of human blood basophils, others of globule leucocytes of other species, but entirely typical blood basophils could not be identified. The results thus support our previous suggestion that a migration of mucosal mast cells from the connective tissue stroma into the epithelium is part of the human allergic mucosal response. It cannot be determined whether the ultrastructural heterogeneity of these cells is the result of an adaptation to the intraepithelial environment of one single mast cell type or to the existence of an ultrastructurally distinct mucosal mast cell.

Important immunological reactions take place on the surface of mucosal membranes. Improved methods for the sampling and quantitative study of the cells taking part in these reactions are therefore desirable. We here describe a new technique for the preparation of imprints from the nasal mucosa. The method utilizes a plastic film coated with a thin layer of an albumin-glycerol mixture to improve cell adherence to the surface. The membrane is gently pressed onto a defined portion of the mucous membrane. Fixation and staining procedures are performed on the plastic film, which is then mounted on a slide and covered by a coverslip. The preparations have excellent optical properties and specific cell types can be easily studied, quantified and related to the specific area of the mucosa from which the imprint was taken.

A method is described for the sampling of epithelial cells and other effector cells from the human airway mucosa for structural and biochemical analysis. The cell samples are obtained from the nasal mucosa using a small nylon brush which is rotated over the epithelium and soaked and shaken in a small volume of a balanced salt solution. Morphological evaluation using light microscopy and transmission electron microscopy revealed excellently preserved cytological detail. In asymptomatic individuals the cells harvested were as follows: 45 +/- 5.9% (mean +/- SEM) epithelial cells, 38 +/- 7.1% granulocytes, 16 +/- 2.3% large mononuclear cells (monocytes), and 1.3 +/- 2.3% eosinophils. Repeated measurements in the same individual revealed a coefficient of variation of the order of 40% for the proportions of cells harvested. In comparison with nasal airway lavage, a higher proportion of epithelial cells and monocytes were obtained with the brush method. The cells harvested could also be used for biochemical analysis. The histamine content of the cell pellets was found to be strongly correlated with the mast cell count (r = 0.93) and was estimated to about 10 pg/cell, which is higher than previously reported for mast cells obtained from human lung tissue dispersed by an enzymatic method. The present method appears to be appropriate for the study of cellular events in the nasal mucosal epithelium.

(1987). Observations on Nasal Late Phase Reactions. Immunological Investigations: Vol. 16, No. 8, pp. 649-685.

In order to explore the dynamics of the cellular response of the airway mucosa to allergen exposure, controlled daily allergen challenges were performed for 7 days during the pollen-free winter months in nine patients with strictly seasonal allergic rhinitis caused by birch pollen allergen. Symptoms obtained after the challenge were related to morphologic changes within and on the surface of the nasal mucosa. Cell samples were obtained daily prior to challenge from the nasal mucosa using mucosal imprints on plastic strips, brush samplings from the nasal mucosa, and nasal lavage. For light microscopy, the cellular material obtained by brushing and nasal lavage were cytocentrifuged onto object slides. Histamine was measured in the cell pellets that were obtained using the lavage and brush procedures as well as in the lavage supernatant fluid. Four symptoms (sneezes, itching, secretion, and blockage) were recorded and expressed individually as well as in the form of a composite symptom score. Nasal blockage was measured using a nasal peak flow meter. The patients displayed an increase in nasal symptoms after the allergen challenge, which was further increased between Days 2 to 7 (p less than 0.05). The light microscopic evaluation of the lavage revealed an immediate increase in eosinophils from 2.3 to 13.1% and was maintained on the same level throughout the period of challenges. A similar increase was noted in the brush specimens, and a strong correlation was obtained between these two methods of sampling.(ABSTRACT TRUNCATED AT 250 WORDS)

Compared to the lower airways the human nose offers an extremely accessible part of the human airways. In recent years, several methods have been devised allowing us to study different components in reactions that occur in the upper airways. By choosing the right methods for the right questions, we will be able to obtain valuable information on the pathophysiology and pharmacology of nasal disorders. This information might not only be relevant to the upper airway; it may well be applicable to other parts of the airways as well.

Glococorticoids were previously considered not to affect the immediate allergic reaction. However, in a nasal allergen challenge, an inhibitory effect on the nasal symptoms induced at the challenge has been shown to occur in patients treated with a recently developed Glucocorticoid, budesonide, for 1 week prior to the challenge. This treatment was also found to reduce tissue histamine levels in the nasal mucosa. Mast cells in the mucosa were therefore studied with a view to finding out whether this reduction could be due to a reduction of mast cells. A double-blind study was performed in 14 asymptomatic patients. Nasal biopsies were made before and after I week's treatment with either budesonide or placebo. The number of mast cells was counted in two Epon sections after the specimens has undergone specific staining with toluidine blue. No quantitative or qualitative morphological changes in the mast cells were found as a result of treatment.

Dermal blood flow was evaluated after skin prick test with histamine and allergen in six patients with seasonal allergic rhinitis. Blood flow was registered continuously for 60 minutes after the test procedure with laser doppler flowmetry, which allows noninvasive measurements. Blood flow was measured close to the skin test in the wheal obtained, and at a greater distance from the prick in the flare reaction. Tests were performed with preloaded skin test needles with histamine and the appropriate allergen freeze-dried on the point of the lancet, as well as with the appropriate negative control. The prick test procedure, by itself, induced a transient increase in blood flow that was normalized again after 9 minutes for the closest measurement. Histamine induced a rapid increase in blood flow in both the flare and wheal reaction that was normalized after about 45 minutes. The increase was significantly higher in the flare compared to the wheal for the time points from 6 1/2 to 13 minutes. Allergen induced a similar increase in blood flow. However, the increase was not noticeable until 2 1/2 minutes after the allergen application and was not completely abolished within 60 minutes. Furthermore, the difference between the flare and wheal reaction, with the higher values for the flare reaction, was present for a longer period of time than for the equivalent histamine measurements. In conclusion, laser doppler flowmetry appears useful for continuous evaluation of vascular changes induced at skin prick tests.(ABSTRACT TRUNCATED AT 250 WORDS)

A redistribution of mast cells into the epithelium and towards the mucosal surface was previously observed during the allergy season in individuals allergic to birch pollen. We have therefore attempted to investigate in greater detail the role of mast cells in mucosal allergy by the study of the morphological and biochemical changes that occur in the nasal mucosa of allergic individuals during natural allergen exposure. An activation of the intraepithelial mast cells was indicated by the observation of ultrastructural signs of a secretory activity. We also found that the normal strong correlation between mast cell numbers and histamine content in the nasal mucosa was absent in specimens taken during allergen exposure, which was interpreted as a result of a release of histamine from the mast cells with the appearance of a transient, non-mast cell pool of tissue histamine. Furthermore, the histamine content of the nasal mucosa during the pollen season was strongly correlated to the severity of symptoms experienced by the patients. These observations provide additional evidence that mucosal mast cells have a pathogenetic role in continuous allergic airway disease.

It has been suggested that the IgE-dependent late-phase reaction to allergen exposure, with the features of an inflammatory cellular infiltration and airway hyperreactivity, is a link between anaphylaxis and continuous allergic airway disease. Our main knowledge of the cellular response to allergen in sensitized individuals has been derived from allergen-challenge models. To explore the dynamics of the cellular response during the actual disease, patients with a strictly seasonal allergic rhinitis were studied during natural allergen exposure. Ten patients suffering from an isolated birch-pollen allergy were followed from a symptom-free state before, during, and to the height of the birch-pollen season. Repeated parallel cell samplings from the nasal mucosa were performed with cytologic imprints on plastic strips, nasal lavages with the recovery of the cells in the lavage fluid with cytocentrifugation on object slides for cytologic study, and scrapings from the nasal surface with a curette for histologic and ultrastructural evaluation. The histamine content was determined in lavage fluid and cell pellets. The tosyl-alpha-tosyl-L-arginine methyl esterase activity of the nasal lavage fluid was also determined as a biochemical marker of the allergic inflammatory reaction. The birch-pollen season was moderate in terms of pollen counts, and this resulted in mild to moderate nasal symptoms that ran parallel to the birch-pollen counts. The total number of cells recovered in the lavage fluid was 1.2 +/- 0.4 (SEM) x 10(6) before and 3.2 +/- 2.0 per 10(6) cells (not significant) during pollen exposure. Most cells were neutrophils and mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)