Effect of ozone inhalation on the response to nasal challenge with antigen of allergic subjects

The effect of oxidant inhalation on allergic illness is of interest because allergic patients often report increased respiratory symptoms during episodes of poor air quality, and epidemiologic studies demonstrate an association between increased levels of the air pollutant ozone and exacerbations of asthma. The purpose of this study was to characterize the upper respiratory response to ozone inhalation in asymptomatic, allergic subjects and to determine whether ozone pre-exposure increased the acute response to nasal challenge with antigen in these subjects. A group of 12 asymptomatic subjects with a history of allergic rhinitis were exposed in a randomized, cross-over design, at rest, on each of 2 days, separated by 2 wk, to 4 h of clean air or 0.5 ppm ozone in an environmental chamber. Following the exposure period, subjects underwent nasal challenge with four doses of antigen (1 to 1,000 PNU ragweed or grass). Symptoms were rated and nasal lavage performed after each dose. Measurement of histamine and albumin concentration and TAME-esterase activity and determination of cell counts and differentials were performed. Exposure to ozone caused significant increases in upper and lower respiratory symptoms, a mixed inflammatory cell influx with a sevenfold increase in naval lavage neutrophils, a 20-fold increase in eosinophils, and a tenfold increase in mononuclear cells, as well as an apparent sloughing of epithelial cells. There was a significant increase in nasal lavage albumin concentration on the ozone exposure day and a small increase in nasal lavage histamine concentration on both the ozone and clean air exposure days. TAME-esterase activity showed no significant increase overall, but increased at least twofold in 5 of 12 subjects. (ABSTRACT TRUNCATED AT 250 WORDS)

Release of histamine and tryptase during continuous and interrupted cutaneous challenge with allergen in humans

To help in understanding the patterns of in vivo mediator release in human allergic skin reactions, we have used a skin chamber model to challenge the denuded bases of skin blisters of 11 sensitive subjects with pollen antigens (Ags) and codeine (C), a mast cell degranulator. Challenges were performed either (1) continuously for 6 hours or (2) in an intermittent fashion that is, Ag or C for the first hour, buffer for the next 4 hours, and then Ag or C during the sixth hour. Fluids in the overlying chamber were assayed for levels of the mast cell components, histamine and tryptase. There was peak release of both histamine and tryptase during the first hour of Ag incubation (89 +/- 11 ng/ml and 1428 +/- 260 ng/ml, respectively). At continuous Ag-challenge sites, there was a plateau of histamine levels (8.0 to 9.5 ng/ml) during the next 4 hours, whereas tryptase levels decreased progressively to baseline levels. Challenge of continuous Ag-incubation sites with C, a mast cell activator, led to another peak release of both histamine and tryptase. At interrupted Ag-challenge sites, histamine levels decreased abruptly, and tryptase levels decreased progressively after the first hour. Rechallenge of such sites with Ag during the sixth hour induced a peak release of histamine but no increase in tryptase levels. Continuous challenge with C for up to 5 hours in other sites induced an initial peak histamine release without a subsequent plateau. However, such a plateau of histamine (but not tryptase) release occurred after an initial C challenge if Ag was subsequently incubated in a continuous fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic value of acoustic rhinometry: patients with allergic and vasomotor rhinitis compared with normal controls

By means of the acoustic reflection technique, termed acoustic rhinometry, cross-sectional areas along the whole upper airway can be measured by an acoustic click. This paper describes the normal values obtained from 134 probands. The normal curve shows the minimal cross-sectional area (I-notch) to be located at the isthmus nasi. The second narrowest segment of the nasal cavity is located at the head of the inferior concha (C-notch). In patients with turbinate hypertrophy due to allergic or vasomotor rhinitis the minimal cross-sectional area is sited at the head of the inferior turbinate. Furthermore, acoustic rhinometry allows exact measurements of size and location of the congested mucosa following challenge with allergens in patients affected with allergic rhinitis. After anterior turbinoplasty of patients with turbinate hypertrophy improved nasal breathing was associated with an enlargement of the cross-sectional areas at the head of the anterior inferior turbinate. Acoustic rhinometry not only enables to distinguish the various deviations of the nasal structures from normal (valve stenosis, septal deviation, turbinate hypertrophy, tumour masses) concerning their location and size, but also allows to demonstrate exactly the efficacy of rhinosurgical techniques.

Allergen-induced changes in the nasal mucous membrane in seasonal allergic rhinitis: effect of nedocromil sodium

We have obtained biopsy specimens of the nasal mucous membrane before and during the grass-pollen season in 22 patients with seasonal allergic rhinitis to grass pollen to assess the effects on cellular infiltration of natural exposure to allergen. Biopsy sections were examined by light microscopy, and quantitative assessment was made of numbers of mast cells and eosinophils. The patients were divided into 11 who were treated with placebo and 11 patients who were treated with topical nedocromil sodium. In the group as a whole, there was a significant (p less than 0.001) increase in mast cell density in tissue sections from biopsy specimens obtained during the season compared with out of season (median values, 55.0 and 15.5 cells per square millimeter, respectively). There was also a significant (p less than 0.02) increase in the density of eosinophil infiltration during the season compared with out of season (median values, 6.3 and 0 cells per square millimeter, respectively). Treatment with nedocromil sodium significantly (p less than 0.02) inhibited the accumulation of mast cells but not eosinophils. Compared with the placebo-treated group, the group treated with nedocromil demonstrated a significant (p less than 0.025) reduction in the requirements for treatment with concomitant medication (terfenadine tablets and xylometazoline/antazoline eye drops). These results indicate that natural exposure to allergen in patients with seasonal allergic rhinitis is accompanied by infiltration of mast cells and eosinophils into the nasal mucous membrane. The clinical efficacy of nedocromil sodium in this condition may be related to inhibition of infiltration by mast cells.

[Nasal allergy and leukotriene. 2. Kinetics of peptide leukotrienes and inflammatory cells in nasal lavage fluid after antigen challenge]

The purpose of this study is to clarify the role of peptide leukotrienes (LTs) on the onset of characteristic hyperreactive nasal symptoms of nasal allergy by observing the time course of the correlation among degrees of nasal symptoms, and by observing the amount of chemical mediators and the number of inflammatory cells in the nasal lavage fluid after nasal antigen challenge in subjects with Japanese cedar pollinosis during off season. Sneezing was terminated within 10 minutes and nasal discharge within 2 hours. However, time course change of the percent increase of nasal airway resistance showed dual response consisting of immediate and late phase responses. The peak of the former was seen at 30 minutes and the latter was at 7 hours after provocation. The significant increase of eosinophils in the nasal lavage fluid was observed during both the immediate and the late phase responses, but during the late phase response, the increase was more prominent. Basophilic cells definitely increased during the late phase response. The amount of LTs in the nasal lavage fluid increased significantly during both the immediate and the late phase responses. In contrast, the level of histamine increased significantly only during the immediate phase response. Considering that LTs, especially LTD4, has potent and persistent effect on causing swelling of nasal mucosa, LTs may play important role in causing nasal obstruction during both the immediate and the late phase responses after antigen challenge. On the other hand, the role of histamine may be confined to cause the hyperreactive nasal symptoms during the immediate phase response.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasal mucosal response to repeated challenges with pollen allergen

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)

Nasal eosinophilia in allergic and nonallergic rhinitis: usefulness of the nasal smear in the diagnosis of allergic rhinitis

Diagnostic nasal cytology has been advocated for use in distinguishing allergic from nonallergic rhinitis. We sought to determine prospectively the frequency of nasal eosinophilia (NE) in 100 patients in whom having allergic rhinitis (AR), nonallergic rhinitis, and other atopic conditions not involving the respiratory tract have been diagnosed. A nasal smear was obtained from consenting adults using the Rhino-Probe curette. Patients taking local or systemic corticosteroids, those with chronic rhinitis associated with aspirin sensitivity, and those with sinusitis were excluded. All cytograms were coded and read by a single "blinded" investigator. NE was considered significant if greater than 20% of sampled cells were eosinophils. Twenty-six of 61 (43%) patients with AR had NE. No NE was detected in the control population or in the skin test negative group of patients in whom having nonallergic rhinitis was diagnosed. One of 16 patients with allergic disease not involving the respiratory tract exhibited NE; this patient had atopic dermatitis with peripheral eosinophilia. No cases of eosinophilic nonallergic rhinitis were detected. There was no significant correlation of symptoms or the number of positive skin tests with NE. These data suggest that the nasal smear for eosinophils is an insensitive but specific test for the diagnosis of allergic rhinitis, when patients with nasal polyposis and aspirin sensitivity and/or negative skin tests are excluded.

Fluctuation of the number of CD-1(T6)-positive dendritic cells, presumably Langerhans cells, in the nasal mucosa of patients with an isolated grass-pollen allergy before, during, and after the grass-pollen season

A monoclonal antibody against CD-1(T6) was used for studies in the nasal mucosa of patients with isolated grass-pollen allergy to determine whether the number of CD-1-positive cells, presumably Langerhans cells, depends on the season in which the nasal biopsy is performed. An earlier study had demonstrated that during the grass-pollen season, there are significantly more CD-1-positive cells in nasal mucosa of patients with isolated grass-pollen allergy than in nonallergic control subjects without nasal complaints. During the grass-pollen season, the nasal epithelium of patients with an isolated grass-pollen allergy demonstrated significantly more CD-1-positive cells than before and after the season. Before and after the season, the number of CD-1-positive cells in epithelium of the allergic patients was not significantly greater than the corresponding number in epithelium of nonallergic subjects without nasal complaints.

[Electron microscopic study of intercellular junction in nasal mucosa of nasal allergy by lectin histochemistry]

To explain of the mechanism of the enhanced nasal epithelial permeability to HRP in patients with nasal allergy, the inferior turbinate mucosa was removed from 6 normal adults and 7 adults with nasal allergy. Difference of the fine structure of the intercellular junction was compared between normal mucosa and mucosa of nasal allergy by electron microscope. Staining pattern of four kinds of HRP-conjugated lectin (HRP-WGA, PNA, UEA-I and RCA-I) was also studied by electron microscope. There was no significant difference in the intercellular space of the mucosa between the normal mucosa and mucosa of nasal allergy. In the epithelial cell membrane, pattern of HRP-lectin staining was almost similar in both groups. In normal nasal epithelium, the intercellular junction consisted of junctional complex; adherent junction, desmosome and gap junction. The intercellular space was approximately 150-250 A in width. The tight junction was located beneath the luminal surface of the epithelium, and belt-like continuation connecting the adjacent cells. It was concluded that enhanced permeability to HRP in nasal allergy was not morphologic changes of the intercellular junction and component and distribution of the glycoconjugates in epithelial cellular membrane, but this may be based on functional changes.

[Electron microscopic study of glycoconjugate in nasal mucosa of nasal allergy by lectin histochemistry]

Glycoconjugates in glandular and goblet cells of nasal mucosa were compared between normal and nasal allergy by using various horseradish peroxidase (HRP)-conjugated lectins; WGA, PNA, UEA-I and RCA-I. Specific sugar residues of glycoconjugates could be identified under electron microscope. Golgi's complex of the serous secretory cells in nasal allergic mucosa had positive staining in UEA-I. Goblet cells of nasal allergic mucosa were stained strongly in PNA, compared to normal mucosa, however, they were stained weakly in WGA. In conclusion, glycoconjugates in glandular and goblet cells seem to be changed in nasal allergy.

Natural allergen exposure does not influence the density of goblet cells in the nasal mucosa of patients with seasonal allergic rhinitis

This double-blind, placebo-controlled group-comparative study in patients with seasonal allergic rhinitis was performed to investigate the possible influence of natural allergen exposure on the differentiation of goblet cells in the nasal mucosa. Furthermore, the effect of topical steroid treatment on such a putative influence was evaluated. Twenty adult patients with seasonal allergic rhinitis due to birch pollen were studied. Mucosal samples were obtained by scrapings before and during the pollen season and processed to evaluate the number of goblet cells/mm of intact epithelial lining. No statistically significant differences were found neither when comparing the number of goblet cells before and during the season nor when comparing the 2 treatment groups. In conclusion, the allergic inflammation could not be shown to accelerate the differentiation of goblet cells, and the beneficial effect of topical steroid treatment could not be explained by a prevention of increased goblet cell density.

Ultrastructural changes in human skin mast cells during antigen-induced degranulation in vivo

Human skin mast cells were degranulated in vivo by intradermal injection of antigen. Biopsy specimens of control and stimulated skin were obtained at 5 minutes, again at 10 to 15 minutes, and analyzed by electron microscopy. Degranulation, defined as dissolution of granule contents and swelling in at least 20% of secretory granules of mast cells was observed in one third of mast cells at 5 minutes and in nearly two thirds of mast cells at 10 to 15 minutes, but was absent in biopsy specimens of control subjects. Anaphylactic degranulation was characterized by extensive fusion of granules to form degranulation channels, fusion of channels with the cell membrane to form large pores, and exocytosis of amorphous or fibrillar granule matrix into the connective tissue. Extruded secretory granules of skin mast cells persist for at least 15 minutes in the connective tissues, in apparent contrast to the process of in vivo degranulation in nasal and lung mast cells.

The cellular response of the human allergic mucosa to natural allergen exposure

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)

Methods for obtaining specimens from the nasal mucosa for morphological and biochemical analysis

The nose is the part of the airway system which is most easily accessible for morphological and pathophysiological evaluation of changes occurring as a response to various stimuli. During recent years several new atraumatic techniques for harvesting cells for morphological and biochemical analysis have been introduced, in addition to the more well known surgical biopsy procedures and nasal smears. Such techniques include nasal lavage, scrapings from the nasal mucosa, brush techniques and imprints. Several of these techniques allow repeated samplings, obtaining quantitative as well as qualitative information as to the cells present on the surface of, as well as within, the epithelial lining of the nasal mucosa. Some techniques provide the investigator with a method for obtaining information on the cellular content of certain biochemical markers such as histamine. The present review describes the merits and disadvantages of the old and new methods and provides guidelines as to when each method should be considered.

Seasonal variation of nasal surface basophilic cells and eosinophils in Japanese cedar pollinosis

Nasal pollinosis is caused by pollens of trees and grasses as allergen floating in the air during the seasons of blossom. In Japan, cedar pollinosis is the most prevalent of seasonal allergic rhinitis. We studied the seasonal variation of nasal mucosal basophilic cells (cells with basophilic and metachromatic granules) and eosinophils by nasal scraping of cedar pollinosis patients from June 1986 to May 1987, and found that during the season basophilic cells and eosinophils increased significantly, decreased but still remained for two or three monts after the season, and finally disappeared. The variation of eosinophils was more prominent than basophilic cells. The increase of both cells had close correlation with each other.

Human nasal polyp epithelial basophil/mast cell and eosinophil colony-stimulating activity. The effect is T-cell-dependent

We have previously reported highly potent basophil/mast cell (BMC) and basophil/eosinophil (Eo) colony-stimulating activities (CSA) in conditioned medium derived from cultured human nasal polyp epithelial scrapings (NP-CM). We now have examined the involvement of peripheral blood T-cells in the NP-CM stimulation of colony-forming units (cfu) from the blood of atopic and nonatopic subjects. Because the number of BMC- and Eo-cfu was significantly higher in cultures of peripheral blood from subjects with out-of-season ragweed allergic rhinitis than from control subjects (23.8 +/- 4.1 versus 9.0 +/- 2.4, p less than 0.01), we asked whether the observed colony stimulation could be a T-cell-dependent effect. Indeed, peripheral blood target cells consisting of a reconstituted mixture of T-cells and T-cell-depleted peripheral blood mononuclear cells (non-T-cells) yielded a significantly higher number of colonies in the presence of NP-CM than the non-T-cells alone. NP-CM did not stimulate colony formation by isolated T-cells. These observations point to interactions among nasal epithelial growth and differentiation factors, blood-borne progenitors and T-cells in the local accumulation of basophils, mast cells, and eosinophils in nasal polyps.

A brush method to harvest cells from the nasal mucosa for microscopic and biochemical analysis

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.

The influx of inflammatory cells into nasal washings during the late response to antigen challenge. Effect of systemic steroid pretreatment

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)

Studies on the allergic and nonallergic nasal inflammation

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)

A clinical and pathologic study of chronic sinusitis: the role of the eosinophil

Evidence exists that the eosinophil plays an important role in mediating injury to bronchial epithelium in chronic asthma. Here, the role of the eosinophil in chronic inflammatory disease of the paranasal sinuses was studied with tissue from patients who underwent surgery for chronic sinusitis. Paranasal tissue from patients with chronic asthma and/or allergic rhinitis was extensively infiltrated with eosinophils. Immunofluorescent studies demonstrated a striking association between the presence of extracellular deposition of major basic protein and damage to sinus mucosa. The histopathology of paranasal respiratory epithelium appeared similar to that described in bronchial asthma. These findings suggest that the eosinophil acts as an effector cell in chronic inflammatory disease of paranasal respiratory epithelium. Thus, sinus disease in patients with asthma may be due to the same mechanisms that cause damage to bronchial epithelium.

Secretory activity of nasal mucosal mast cells and histamine release in hay fever

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.

Eosinophils in nasal secretion

In order to understand the migration mechanism and character of eosinophils in the nose, the eosinophils in nasal mucosa and secretion were observed morphologically and physicochemically. In our electron microscopic observation of animal and human nasal mucosa, eosinophils migrated through the intercellular space, projecting pseudopods into the apical region of the space and splitting the junctions between epithelial cells. However, a freeze-fracture study in the experimental animals showed that the morphology of tight junction was not significantly changed except for slight decrease in the number of strands in antigen challenged animals. Eosinophilotactic activity was clearly demonstrated in nasal secretion of patients with allergic rhinitis. The factor in nasal secretion was a molecule smaller than 10,000 and sensitive to heating in higher degree. Additionally, the eosinophils in nasal secretion were hypodense, implying that they may be in activated state.

Localization of IgE synthesis in immediate-type allergy of the upper respiratory tract

The localization of allergen-specific IgE synthesis in allergic diseases of the upper respiratory tract is so far unknown. It has been suggested that the IgE production takes place in the nasal mucosa itself. The present immunohistochemical studies with anti-IgE and monoclonal markers for B lymphocytes, plasma cells, antigens of the major histocompatibility complex, T helper and T suppressor cells indicate that there are no IgE-producing plasma cells in the nasal mucosa of patients with seasonal allergic rhinitis. The IgE-associated cells have been defined as two different types of mast cells. Furthermore we found IgE-associated lymphoid follicles in palatine as well as in nasopharyngeal tonsils and in cervical lymph nodes from allergic patients. IgE-specific activated B lymphocytes and plasma cells were identified in direct contact with migratory mast cells in these lymphoid tissues. We therefore suggest that IgE synthesis takes place in the lymphoid tissues of Waldeyer's ring and in downstream cervical lymph nodes and that migratory mast cells transport specific IgE back to the nasal mucosa to mediate the allergic reaction.

Differences in the kinetics of histamine formation and granulation of human basophilic cells from bone marrow, peripheral blood, and cord blood

Human bone marrow, cord blood, and peripheral blood contain progenitor cells, which during culture mature to histamine-containing basophilic cells. In bone marrow the histamine content per Alcian blue staining basophilic cell was low before culture. Cultivation of BML cells resulted in increased histamine levels in cultures (P less than 0.05), whereas the basophilic cells did not increase significantly. Cell cultures were stimulated with conditioned medium (CM) produced with allergen-stimulated cells from atopics and from the Mo T leukaemic cell line. Cells from cultures stimulated with CM contained less histamine calculated per basophilic cell than did those from unstimulated cultures (P less than 0.05). There was a significant correlation between the numbers of basophilic cells and the histamine content in cells on day 0 prior to cultivation and after 14 days of cultivation (P less than 0.01 and P less than 0.05 respectively). In cord blood there was a correlation between the numbers of basophilic cells and the histamine levels prior to cultivation (P less than 0.05). During cultivation the number of basophilic cells increased five-fold (P less than 0.02), whereas the histamine levels did not increase resulting in a decreased histamine level per basophilic cell (P less than 0.02). In peripheral blood the basophilic cells contained the highest levels of histamine. The numbers of basophilic cells and their content of histamine showed good correlation both before and after unstimulated and stimulated cultivation (P less than 0.01), whereas unstimulated cultures did not show such correlation. The results indicate the presence of different proportions of progenitor cells in bone marrow, cord blood, and peripheral blood, all with different ability to produce histamine and become granulated basophilic cells.