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S R Durham

Publications and source records attributed to S R Durham.

At least 127 records · Page 7Linked to original sources

Allergic inflammation.

A greater understanding of the basic mechanisms of allergic inflammation is pertinent to the development of new treatments. Previous studies have focused on the role of mediators of hypersensitivity and effector cells, including mast cells and eosinophils. Recent evidence suggests that IgE-dependent activation and tissue eosinophilia are under the local regulation of distinct cytokines. Originally described as products from T lymphocytes, these peptide messengers are produced by alternative cells, including mast cells, eosinophils and the respiratory epithelium. In vitro studies in murine models and using cloned human T lymphocytes indicate the preferential production of "Th2-type" cytokines, including interleukin-4 (IL-4) and IL-5. This review considers the evidence from in vivo studies in humans that "Th2-type" cytokines have a primary role in orchestrating both IgE-dependent events and local tissue eosinophilia. Novel therapeutic approaches might include a broad strategy directed against T lymphocytes, including the use of immunosuppressive agents or anti CD4 antibodies or more precise targeting of IL-4 and/or IL-5.

Animals↗

Activated memory T helper cells in bronchoalveolar lavage fluid from patients with atopic asthma: relation to asthma symptoms, lung function, and bronchial responsiveness.

BACKGROUND: Bronchial mucosal inflammation and epithelial damage are characteristic features of asthma. Activation of T helper lymphocytes may contribute to this process by mechanisms including the release of cytokines promoting eosinophil infiltration and activation. METHODS: Bronchial washings and bronchoalveolar lavage fluid were obtained from 29 atopic asthmatic patients (19 with current symptoms and 10 symptom free) and 13 normal volunteers. Flow cytometry was used to assess T cell phenotype and activation status in bronchoalveolar lavage fluid and peripheral blood, and differential cell counts were made on bronchial washings and bronchoalveolar lavage fluid. Findings were related to severity of disease as reflected by symptom scores, baseline lung function, and airway responsiveness. RESULTS: CD4 T lymphocytes in bronchoalveolar lavage fluid and blood from asthmatic patients were activated by comparison with controls (CD4 CD25, median 16.8% v 8.7% for bronchoalveolar lavage fluid, and 15.3% v 8.7% in blood). Bronchoalveolar lavage fluid CD4 T cells from both asthmatic patients and controls were of memory phenotype (95.8% and 96.8% CD45RO and 1.7% and 0.4% CD45RA respectively), whereas both CD45RO and CD45RA T cells were present in blood. Patients with asthma and current symptoms showed increased bronchoalveolar T cell activation compared with patients without symptoms (CD4 CD25 18.7% v 12.3%). Within the asthmatic group there was a significant association between CD4 CD25 lymphocytes and asthma symptom scores (rs = 0.75), airway methacholine responsiveness (log PC20, rs = -0.43) and baseline FEV1 (rs = -0.39). A correlation was also found between CD4 CD25 lymphocytes and eosinophils in bronchoalveolar lavage fluid (rs = 0.48). Eosinophils in bronchoalveolar lavage fluid were increased in asthmatic patients compared with controls and the percentage of eosinophils in bronchoalveolar lavage fluid correlated with asthma symptom score. A relation was found between percentage of epithelial cells in bronchoalveolar lavage fluid and FEV1 and methacholine PC20. CONCLUSION: These results support the hypothesis that selective activation of memory CD4 T cells contributes to eosinophil accumulation, bronchial hyperresponsiveness, and symptoms in asthma.

Adult↗

Identification of neutral endopeptidase mRNA in human nasal mucosa.

Neutral endopeptidase (NEP) may regulate peptide-induced inflammation in the upper respiratory tract. NEP mRNA was detected by Northern blotting in poly(A)+ mRNA prepared from human turbinates. NEP mRNA bands were detected at 3.9 and 1.8 kb. In situ hybridization identified NEP mRNA in epithelial cells, serous cells of submucosal glands, and vessel walls. The vacuoles of goblet and mucous cells were not stained, but it is likely that the cytoplasm of these cells contained some NEP mRNA. Radioactive in situ hybridization with 35S-UTP appeared to be more sensitive than nonradioactive in situ hybridization with biotin-UTP and immunogold detection. The NEP mRNA-containing cells identified by in situ hybridization were the same as those identified by immunohistochemistry to contain immunoreactive NEP. These NEP-containing cells have been previously shown to possess peptide receptors. This is consistent with the hypothesis that NEP on cells bearing peptide receptors may regulate neuropeptide-induced inflammation in human nasal mucosa.

Biotin↗

CD4 T-lymphocyte activation in asthma is accompanied by increased serum concentrations of interleukin-5. Effect of glucocorticoid therapy.

Peripheral blood mononuclear cells (PBMC) and serum were obtained, on two occasions, from 15 asthmatic patients who required oral glucocorticoid therapy for moderate to severe disease exacerbations. Samples were obtained immediately before commencement of oral glucocorticoids (Day 1) and again after 7 days of treatment (Day 7), when lung function had significantly improved. Samples were also isolated on two occasions 7 days apart from a group of seven untreated volunteers. Expression of CD25, human lymphocyte antigen (HLA-)DR, CD45RA, and CD45RO on CD4 and CD8 T lymphocytes was measured by flow cytometry, and serum concentrations of interleukin-5 (IL-5) were measured using an enzyme-linked immunosorbent assay technique. On Day 1 the asthmatic patients showed significantly higher percentages, as compared with the control subjects of CD4 T lymphocytes expressing the markers CD25, HLA-DR, and CD45RO and significantly lower percentages of CD4 T cells expressing CD45RA. After glucocorticoid therapy, the percentages of CD4 T cells expressing CD25, HLA-DR, and CD45RO were significantly reduced in the asthmatic patients, and the percentages of those expressing CD45RA significantly increased so that by Day 7 expression of all four markers was no longer significantly different from that of the control subjects. By contrast, the percentages of CD8 T cells expressing HLA-DR, CD45RA, and CD45RO in the PBMC of the asthmatic patients on Day 1 were not significantly different from those in control subjects, whereas the percentages of CD25 expressing CD8 T cells were only marginally elevated. Glucocorticoid therapy resulted in no significant change in the expression of all four markers on CD T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Increases in activated T lymphocytes, eosinophils, and cytokine mRNA expression for interleukin-5 and granulocyte/macrophage colony-stimulating factor in bronchial biopsies after allergen inhalation challenge in atopic asthmatics.

Immunohistology and in situ hybridization were used to evaluate the presence, activation status, and cytokine mRNA profile of cells in the bronchial mucosa during human allergen-induced asthma. Fifteen atopic asthmatic subjects underwent inhalation challenge with allergen and with allergen diluent, performed in random order separated by an interval of at least 3 wk. Bronchial biopsies were obtained 24 h after challenge. Immunostaining revealed increases in the numbers of secreting eosinophils (EG2+; P < 0.05) and in interleukin-2 receptor (IL-2R)-positive cells (CD25+; P < 0.01) after allergen compared with diluent challenge. No differences were observed in the numbers of total leukocytes (CD45+), T lymphocytes (CD3+, CD4+, and CD8+), elastase-positive neutrophils, macrophages (CD68+), or mast cell subtypes (MCT+ or MCTC+). In situ hybridization revealed significant increases in the numbers of cells expressing mRNA for IL-5 (P < 0.02) and granulocyte/macrophage colony-stimulating factor (P < 0.01) after allergen compared with diluent challenge. A significant inverse relationship was observed between the number of cells expressing mRNA for IL-4 and for interferon-gamma (r = -0.75, P < 0.02). The results support the view that cytokines possibly from activated T lymphocytes may contribute to local eosinophil accumulation during allergen-induced asthma.

Adult↗

T cells are the principal source of interleukin-5 mRNA in allergen-induced rhinitis.

We have investigated the phenotype of interleukin-5 (IL-5) mRNA+ cells in the nasal mucosa of subjects with allergic rhinitis. Serial cryostat sections were cut from paraformaldehyde-fixed snap-frozen nasal biopsies from six patients, before and 24 h after local allergen provocation with grass pollen. Immunocytochemistry (APAAP) was followed by in situ hybridization on the same sections. For immunocytochemistry, antibodies against CD3, tryptase, and major basic protein (MBP) were used to identify T cells, mast cells, and eosinophils, respectively. Hybridization studies were performed using a Digoxigenin-labeled IL-5 riboprobe. Nitroblue tetrazolium (NBT) and X-phosphate-5-bromo-4-chloro-3- indoly phosphate (BCIP) served as chromogens to detect hybridized IL-5 mRNA signals. The majority of IL-5 mRNA+ cells were CD3+ (83.2%), whereas the remainder were either tryptase+ (11.3%) or MBP+ (5.4%). In contrast, only a few IL-5 mRNA+ cells were observed in nasal biopsies before challenge, all of which were co-localized to CD3+ cells. These results indicate that CD3+ cells are the principal cellular source of IL-5 transcripts in the nasal mucosa 24 h after allergen-induced late-phase nasal responses.

Adult↗

Influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses.

We have studied the influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. In a double-blind, placebo-controlled trial of immunotherapy in 40 adult hay fever sufferers, clinical improvement was accompanied by a decrease in the size of the late-phase skin response. When the immunotherapy-treated group was compared with the placebo group, analysis of skin biopsies obtained 24 h after intradermal allergen revealed a significant reduction in the number of infiltrating CD3+ (P = 0.04) and CD4+ (P = 0.009) cells and a trend for a decrease in EG2+ eosinophils (P = 0.08). Treatment did not influence allergen-induced recruitment of CD8+ cells, neutrophils, or macrophages. Unexpected increases in expression of CD25 (P = 0.006) and HLA-DR (P = 0.007) were observed in the actively treated group. In situ hybridization using a panel of riboprobes demonstrated "TH2-type" (IL-4, IL-5) cytokine mRNA responses in both groups of patients. In contrast, significant hybridization for IL-2 (8/16 patients, P = 0.02) and for interferon-gamma (6/16 patients, P = 0.04) was observed only in the actively treated group. These findings indicate that immunotherapy is associated with suppression of allergen-induced CD4+ T lymphocyte infiltration, but among the cells that are recruited, there is upregulation of CD25 and HLA-DR. At least in this model, immunotherapy does not appear to affect expression of TH2-pattern cytokines in response to allergen exposure, but expression of mRNA for Th1-type cytokines was enhanced in half of the patients. The results support the view that immunotherapy may possibly be working through induction of T cell tolerance.

Adult↗

Increased stroke risk predicted by compromised cerebral blood flow reactivity.

The authors sought to determine risk for stroke in individuals with symptomatic carotid stenosis or occlusion based upon an assessment of cerebral blood flow (CBF) reserves. Vascular reserve was assessed by two consecutive xenon/computerized tomography (Xe/CT) CBF studies with intravenous acetazolamide introduced 20 minutes prior to the second study. Patients were assigned to one of two vasoreactivity groups. Group 2 included individuals who experienced a CBF reduction of more than 5% in at least one vascular territory and had a baseline flow of 45 cc/100 gm/min or less. Group 1 included all other individuals. Any territory with volume loss on CT of more than 50% was eliminated from analysis. Sixty-eight individuals were followed at 6-month intervals for a mean of 24 months. In Group 1 two strokes were observed contralateral to the side with lowest reserve, for a stroke incidence of 4.4%; in Group 2 eight strokes were observed ipsilateral to the side with lowest reserve, for a stroke incidence of 36%. The latter group had a 12.6 times greater chance of stroke (p = 0.0007). History of stroke, history of transient ischemic attacks, baseline CBF, and degree of stenosis were not associated with an increased stroke rate. In this study, significantly compromised vascular reserves accompanied by relatively low initial flow identified individuals who subsequently demonstrated a significantly increased rate of ipsilateral stroke.

Acetazolamide↗

Cytokine messenger RNA expression for IL-3, IL-4, IL-5, and granulocyte/macrophage-colony-stimulating factor in the nasal mucosa after local allergen provocation: relationship to tissue eosinophilia.

Tissue eosinophilia is characteristic of human atopic allergic inflammation, although the mechanism is largely unknown. In this study we test the hypothesis that eosinophil infiltration during allergen-provoked rhinitis in hayfever sufferers may occur as a consequence of activation of a population of cells having a characteristic cytokine profile equivalent to the murine Th lymphocyte Th2 subset. Biopsies of the nasal inferior turbinate were obtained from 10 grass pollen-sensitive patients 24 h after local nasal provocation with allergen and after a control challenge with the allergen diluent. Biopsies were divided into two and subsequently processed for in situ hybridization using 35S-labeled RNA probes for selected cytokines and for immunohistology using an eosinophil granule mAb (EG2) which recognizes secreting eosinophils. At allergen-challenged sites compared with control sites there were significant increases in mRNA+ cells for IL-3 (p less than 0.04), IL-4 (p = 0.01), IL-5 (p = 0.02) and granulocyte/macrophage-CSF (p = 0.03). In contrast, only occasional hybridization signals were observed for IL-2 and IFN-gamma at both allergen and control sites. After allergen there was an increase (p = 0.01) in EG2+ eosinophils and significant correlations were observed between EG2+ cells and mRNA expression for "Th2-type" cytokines, particularly IL-5 (r = 0.90, p less than 0.0001). These results demonstrate that recruitment of eosinophils during human allergen-induced rhinitis is associated with cells expressing mRNA for IL-3, IL-4, IL-5, and granulocyte/macrophage-CSF.

Adult↗

Preferential messenger RNA expression of Th1-type cells (IFN-gamma+, IL-2+) in classical delayed-type (tuberculin) hypersensitivity reactions in human skin.

We recently established that the allergen-induced late-phase cutaneous reaction in atopic subjects was associated with high mRNA expression for the cytokine gene cluster IL-3, IL-4, IL-5, and granulocyte/macrophage-CSF (GM-CSF), compared with IFN-gamma and IL-2, suggesting that allergic skin reactions contained the equivalent of murine Th2 cells. We now show that, in humans, classical delayed-type hypersensitivity is associated with cells preferentially expressing a Th1-type cytokine profile. Cryostat sections from skin biopsies from 24-h tuberculin reactions in 10 nonatopic subjects were hybridized with 35S-labeled RNA probes and processed by using in situ hybridization. On the whole, tuberculin biopsies showed preferential expression of mRNA encoding IFN-gamma and IL-2, although in some cases mRNA expression for IL-3, IL-4, IL-5, and GM-CSF was also observed. Biopsies from diluent control sites gave only occasional signals. The difference in the number of cells expressing mRNA in the diluent compared with tuberculin sites was statistically significant for IL-2 and IFN-gamma (p less than 0.01) but not for IL-3, IL-4, IL-5, and GM-CSF. These results suggest that cells infiltrating the site of the 24-h tuberculin reaction preferentially transcribe mRNA encoding IFN-gamma and IL-2, supporting the hypothesis that delayed-type hypersensitivity is associated with preferential activation of cells having a cytokine profile similar to the murine Th1 subset.

Adult↗

Predominant TH2-like bronchoalveolar T-lymphocyte population in atopic asthma.

BACKGROUND: In atopic asthma, activated T helper lymphocytes are present in bronchial-biopsy specimens and bronchoalveolar-lavage (BAL) fluid, and their production of cytokines may be important in the pathogenesis of this disorder. Different patterns of cytokine release are characteristic of certain subgroups of T helper cells, termed TH1 and TH2, the former mediating delayed-type hypersensitivity and the latter mediating IgE synthesis and eosinophilia. The pattern of cytokine production in atopic asthma is unknown. METHODS: We assessed cells obtained by BAL in subjects with mild atopic asthma and in normal control subjects for the expression of messenger RNA (mRNA) for interleukin-2, 3, 4, and 5, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interferon gamma by in situ hybridization with 32P-labeled complementary RNA. Localization of mRNA to BAL T cells was assessed by simultaneous in situ hybridization and immunofluorescence and by in situ hybridization after immunomagnetic enrichment or depletion of T cells. RESULTS: As compared with the control subjects, the subjects with asthma had more BAL cells per 1000 cell that were positive for mRNA for interleukin-2 (P less than 0.05), 3 (P less than 0.01), 4 (P less than 0.001), and 5 (P less than 0.001) and GM-CSF (P less than 0.001). There was no significant difference between the two groups in the number of cells expressing mRNA for interferon gamma. In the subjects with asthma, mRNA for interleukin-4 and 5 was expressed predominantly by T lymphocytes. CONCLUSIONS: Atopic asthma is associated with activation in the bronchi of the interleukin-3, 4, and 5 and GM-CSF gene cluster, a pattern compatible with predominant activation of the TH2-like T-cell population.

Adult↗

Activated T-lymphocytes and eosinophils in the bronchial mucosa in isocyanate-induced asthma.

We have studied the phenotype and activation status of leukocytes in the bronchial mucosa in patients with isocyanate-induced asthma. Fiberoptic bronchial biopsy specimens were obtained from nine subjects with occupational (five toluene- and four methylene diisocyanate-sensitive) asthma, 10 subjects with extrinsic asthma, and 12 nonatopic healthy control subjects. Bronchial biopsy specimens were examined by immunohistology with a panel of monoclonal antibodies and the alkaline phosphatase-antialkaline phosphatase method. There was a significant increase in the number of CD25+ cells (interleukin-2 receptor-bearing cells, presumed "activated" T-lymphocytes; p less than 0.01) in isocyanate-induced asthma compared with that of control subjects. There were also significant increases in major basic protein (BMK-13)-positive (p less than 0.02) and EG2-positive (p less than 0.01) cells that represent total and "activated" eosinophil cationic protein-secreting eosinophils, respectively. In agreement with our previous findings, CD25+ (p less than 0.01), BMK-13 (p less than 0.03), and EG2+ (p less than 0.01) cells were also elevated in extrinsic asthma. No significant differences were observed in the numbers of T-lymphocyte phenotypic markers (CD3, CD4, and CD8) between subjects with asthma (isocyanate-induced and extrinsic) and control subjects. Similarly, no significant differences in immunostaining for neutrophil elastase (neutrophils) or CD68 (macrophages) were observed. The results suggest that isocyanate-induced occupational asthma and atopic (extrinsic) asthma have a similar pattern of inflammatory cell infiltrate. The results support the view that T-lymphocyte activation and eosinophil recruitment may be important in asthma of diverse etiology.

Adult↗

Immunohistology of the nasal mucosa in seasonal allergic rhinitis: increases in activated eosinophils and epithelial mast cells.

The immunohistology of the nasal mucosa was examined in 13 grass pollen-sensitive patients and in seven normal nonatopic control subjects before and during the pollen season. Cryostat sections (6 microns) of biopsy specimens from the inferior turbinate were immunostained with the alkaline-phosphatase antialkaline-phosphatase method and a panel of monoclonal antibodies. Mast cell subtypes were measured with a double sequential immunostaining method. Within the submucosa, seasonal increases in total (MBP+, p less than 0.01) and "activated" (EG2+, p less than 0.01) eosinophils were observed for the patients, which were significant when these counts were compared with counts for those of control subjects (MBP+ p less than 0.01; EG2+ p less than 0.001). Within the nasal epithelium, seasonal increases in total (p less than 0.05) and "activated" (p less than 0.02) eosinophils were also observed. Mast cell counts revealed seasonal increases in tryptase-only positive mast cell (MCT) (p less than 0.02) but not chymase plus tryptase-positive mast cells (MCTC) within the epithelium that were significant when counts were compared with those of control subjects (p less than 0.03). No significant changes were observed within the submucosa or epithelium for total leukocytes (CD45+ cells) or T-lymphocytes (CD3+, CD4+, CD8+, and CD 25+ cells) for either group. Similarly, no significant changes were observed for neutrophils (antielastase), macrophages (CD68+), nor HLA-DR+ cells. In the subjects with rhinitis, seasonal submucosal CD3+ counts correlated with MBP+ eosinophils (r = 0.56; p less than 0.05) and MCTS (r = 0.65; p less than 0.02). Similarly, seasonal epithelial EG2+ eosinophil counts correlated with MCTs (r = 0.56; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Asthma as an inflammatory disease: clinical perspectives.

Asthma is characterised by a persistent, ongoing airway submucosal inflammatory process which may underlie bronchial hyperresponsiveness and airways obstruction. Indirect assessment of airway inflammation includes examination of sputum or serum for eosinophils or eosinophil-derived products, but examination of bronchial mucosal biopsies or bronchoalveolar lavage fluid or cells remains the gold standard. Lymphocyte and eosinophil activation, with the release of certain cytokines such as interleukin-5, lipid mediators such as leukotrienes and eosinophil products such as major basic protein, may be important mechanisms of inflammation in asthma. Less invasive indirect measures of submucosal inflammation are needed to assess the impact of asthma treatment in the clinic. Antiinflammatory treatment in asthma should be introduced as early as possible. A greater understanding of the inflammatory mechanism or of the actions of corticosteroids may lead to the development of more effective and safer drugs for asthma.

Allergens↗

Application of monoclonal antibodies against major basic protein (BMK-13) and eosinophil cationic protein (EG1 and EG2) for quantifying eosinophils in bronchial biopsies from atopic asthma.

A monoclonal antibody prepared against the eosinophil major basis protein (MBP) was compared with the anti-eosinophil cationic protein (ECP) antibodies (EG1 and EG2) in immunostaining of bronchial biopsies from atopic asthma and controls. Anti-MBP (designated BMK-13) did not cross-react with other eosinophil basic proteins (i.e. ECP, eosinophil peroxidase [EPO] or eosinophil-derived neurotoxin [EDN]) and stained more than 98% of peripheral blood eosinophils irrespective of their degree of activation. EG2 stained 15% of resting and 75% of activated eosinophils; EG1 recognized 74% and 78% of resting and activated cells, respectively. The numbers of BMK-13, EG1 or EG2-positive staining cells in bronchial biopsies from asthma were significantly greater than atopic non-asthmatics (P less than 0.02, P less than 0.01 and P less than 0.05, respectively) and normal non-atopic controls (P less than 0.001). For each of the various groups studied, the rank order for the number of eosinophils stained was BMK-13 greater than EG1 greater than EG2. BMK-13 stained significantly more cells from bronchial biopsies of atopic asthma and atopic non asthma when compared to EG2 (P less than 0.001 and P less than 0.05, respectively). Since only a proportion of BMK-13+ cells were EG2+, these results suggest that not all tissue eosinophils are actively secreting. Thus, BMK-13 can serve as a useful pan-eosinophil marker in tissue sections since it appears to stain most eosinophils.

Antibodies, Monoclonal↗

Immunohistology of the nasal mucosa following allergen-induced rhinitis. Identification of activated T lymphocytes, eosinophils, and neutrophils.

We have studied the immunohistology of the nasal mucosa in allergen-induced rhinitis. Sixteen grass pollen-sensitive patients were challenged twice by randomly allocated allergen or control solutions applied on filter paper disks to the inferior turbinate. All had immediate nasal responses, but late-phase responses were equivocal and only evident as nostril blockage. When cell counts in the nasal submucosa were compared with control values 24 h after allergen, there were no changes in CD45+ (total leukocytes), CD3+, or CD8+ cells. Significant increases were found in the numbers of CD4+ T-helper cells (p less than 0.05) and CD25+ [interleukin-2 receptor (IL-2R+)] cells (p less than 0.02). Increases in eosinophils (anti-major basic protein, p less than 0.01) and neutrophils (antineutrophil elastase, p less than 0.01) were also observed. There were increases in tissue macrophages and HLA-DR-positive immunostaining and a reduction in mast cells (tryptase positive), but none of these changes was statistically significant. No significant changes in epithelial thickness, cross-sectional area, or integrity were observed. There was a significant correlation between CD4+ and CD25+ cells (r = 0.61, p less than 0.01) but not between macrophages and CD25+ cells (r = 0.18). The changes in the nasal submucosa were not merely a reflection of alterations in circulating cell populations since it was shown that a significant increase in the lymphocyte CD4/CD8 ratio (p less than 0.05) was observed in nasal biopsies but not in peripheral blood after allergen challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Identification of T lymphocytes, macrophages, and activated eosinophils in the bronchial mucosa in intrinsic asthma. Relationship to symptoms and bronchial responsiveness.

Using immunohistochemistry and a panel of monoclonal antibodies, we have compared T-lymphocyte, eosinophil, macrophage, and neutrophil infiltration in bronchial biopsies from 10 intrinsic (nonallergic) asthmatics (IA) and seven extrinsic (allergic) asthmatic (EA), with similar degrees of disease severity. The results were compared with 12 normal healthy nonatopic controls (NC). All subjects were nonsmokers and were not taking oral or inhaled corticosteroids. An intense mononuclear cell infiltrate was identified in IA with an increase in the number of CD45+ cells (total leukocytes), CD3+ and CD4+ lymphocytes, and CD68+ macrophages (p < 0.03, p < 0.01, p < 0.03, and p < 0.03, respectively), compared with NC. Increases were also found in CD4+ (p < 0.05) and CD68+ (p < 0.05) cell numbers between IA and EA. IL-2 receptor-bearing cells (CD25+) and the number of total (MBP+) and actively secreting (EG2+) eosinophils, were also increased in IA compared with NC (p < 0.01, p < 0.01, and p < 0.01, respectively). Similar increases in EG2+ eosinophils and CD25+ (IL-2 receptor-positive) cells were observed in EA (p < 0.01 and p < 0.02, respectively). No differences were detected in the three groups for the number of elastase-positive cells (neutrophils). EG2+ numbers in IA correlated with the Aas asthma symptoms score (r = 0.65, p < 0.05), whereas EG2+ cell numbers in all asthmatics (IA + EA) correlated with airway methacholine responsiveness (r = -0.55, p < 0.03) and with the Aas asthma symptom score (r = 0.54, p < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗