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PubMed1995

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) concentrations in serum and bronchial lavage fluid in asthma. Effect of prednisolone treatment.

BACKGROUND: Eosinophil granule proteins may contribute to bronchial hyperresponsiveness in asthma. OBJECTIVE: To measure eosinophil cationic protein (ECP) and eosinophil protein X (EPX) in serum and bronchial lavage fluid from 20 asthmatics and 16 control subjects. To assess the effect on these eosinophil proteins of corticosteroid treatment of asthma. To determine whether serum ECP and EPX measured weekly in a longitudinal study for 10 weeks reflected changes in lung function. METHODS: Eosinophil granule proteins were measured by radioimmunoassay of bronchial wash (BW), bronchoalveolar lavage (BAL) and serum. RESULTS: Eosinophils were elevated in BAL (P < 0.01), BW (P < 0.01) and blood (P < 0.01) from asthmatics compared with control subjects. Eosinophils cationic protein concentration was significantly elevated in BAL (P < 0.05) and BW from asthmatics (P < 0.01) and EPX was increased in BAL (P < 0.05) and BW (P < 0.01). These changes were also reflected in elevated serum ECP (P < 0.01) and EPX (P < 0.01) concentrations in asthmatic subjects. There was no significant difference between subjects receiving prednisolone and the placebo group, but there was a fall in ECP in BW (P < 0.05) and serum (P < 0.01) and in EPX in BW (P < 0.01) and serum (P < 0.01) within the group receiving prednisolone. In the longitudinal study there was only a significant difference between ECP values associated with highest and lowest peak expiratory flow rate (PEFR) (P < 0.05). CONCLUSIONS: These data confirm a role for eosinophil activation in the airway in asthma pathogenesis, and add some support to the hypothesis that corticosteroids may inhibit eosinophil activation in asthma.

Adult↗
PubMed2004

Eosinophil infiltration, gastric juice and serum eosinophil cationic protein levels in Helicobacter pylori-associated chronic gastritis and gastric ulcer.

INTRODUCTION: Helicobacter pylori is one of the main causes of gastroduodenal diseases, such as chronic gastritis and peptic ulcer. It has been shown that eosinophils increase in the stomach in H. pylori infection. Eosinophilic cationic protein (ECP) is a cytotoxic molecule secreted by the activated eosinophils. However, there are no sufficient data about the role of ECP in H. pylori infection and its effect on ulcer development. In this study we investigated the gastric eosinophilic infiltration, gastric juice and serum ECP levels in patients with chronic gastritis and gastric ulcer associated with H. pylori. MATERIALS AND METHODS: Forty-four H. pylori-positive and 20 H. pylori-negative patients who underwent upper gastrointestinal system endoscopy after admitting with dyspeptic complaints were enrolled in the study. Twenty-one of the H. pylori-positive patients had gastric ulcer while 23 patients had none. During endoscopy, multiple gastric biopsies and juices were taken. In gastric biopsies, H. pylori and eosinophilic infiltration were assessed. Additionally, gastric juice and serum ECP levels were measured. RESULTS: Eosinophil infiltration, gastric juice ECP levels, and gastric juice/serum ECP ratios in the H. pylori-positive group were greater than in the H. pylori-negative group (p < 0.01). There was no statistically significant difference regarding serum ECP levels between the two groups (p > 0.05). When H. pylori-positive patients were compared with regard to gastric ulcer presence, however, there was no significant difference in gastric eosinophil infiltration, gastric juice ECP levels, serum ECP levels, and gastric juice/serum ECP ratios (p > 0.05). CONCLUSION: The results of this study suggest that eosinophils and eosinophil-released ECP may contribute to inflammatory changes seen in chronic gastritis, whereas there is no proof that they play a role in ulcer development.

Adult↗
PubMed1997

Expression of apoptosis-related antigen on eosinophils in chronic eosinophilic pneumonia.

We examined the expression of apoptosis-related antigens Fas and bcl-2 on eosinophils from peripheral blood (PB) and bronchoalveolar lavage (BAL) in patients with chronic eosinophilic pneumonia (CEP). The expression of those antigens was assessed before and after culture with or without eosinophil chemotactic factors derived from an established T-cell line (STO-2-derived ECFs; ECF-PI5, 6, 7, 8, and 9), granulocyte-macrophage colony stimulating factor, and interleukin 5 (IL-5). We found that the expression of these antigens on eosinophils from PB increased after 24 h culture without any stimulation. In contrast, little or no change was observed even after 24 h culture in eosinophils from BAL. All STO2-derived ECFs and IL-5 suppressed Fas expression on eosinophils from PB. Furthermore, we found that eosinophils which were attracted by ECF-PI9 expressed Fas and bcl-2 more highly than those attracted by other ECFs and IL-5. Such a heterogeneous response of eosinophils to respective ECFs suggests the possibility of a heterogeneous population of eosinophils in patients with CEP.

Adult↗
PubMed1996

Eosinophil cationic protein and immunoglobulin levels in bronchoalveolar lavage fluid obtained from patients with chronic eosinophilic pneumonia.

In chronic eosinophilic pneumonia (CEP), histopathological evidence exists for the degranulation of eosinophils and the release of various toxic proteins. In vitro studies have demonstrated the degranulation of eosinophils in response to aggregated and complexed immunoglobulins. The aims of this study were to investigate: 1) whether the eosinophil cationic protein (ECP) and immunoglobulin (Ig) levels in bronchoalveolar lavage (BAL) fluid from patients with CEP are increased compared to those of healthy controls; 2) and whether a relationship is present between immunoglobulin levels and ECP levels in BAL fluid from patients with CEP. The BAL from 12 patients with CEP was selected, retrospectively, from all BAL analyses performed in our centre between 1986 and 1992. ECP levels were measured using a radioimmunoassay in BAL fluid of patients with CEP and 10 healthy controls. ECP levels and immunoglobulin levels in BAL fluid from patients with CEP were found to be elevated compared to controls (p < 0.001). A relationship was found between IgA levels and ECP levels in BAL fluid from patients with CEP (r = 0.72; p = 0.043). In conclusion, eosinophil cationic protein and immunoglobulin levels were found to be increased in bronchoalveolar lavage fluid from patients with chronic eosinophilic pneumonia. The relationship found between immunoglobulin A levels and eosinophil cationic protein levels may suggest that immunoglobulin A could be involved in the degranulation of eosinophils in chronic eosinophilic pneumonia.

Blood Proteins↗
PubMed2002

Prolonged endurance challenge at moderate altitude: effect on serum eosinophil cationic protein, eosinophil dynamics, and lung function.

BACKGROUND: Eosinophils contain granule proteins such as eosinophil cationic protein (ECP) that have proinflammatory effects on airways. ECP may be released on activation of eosinophils into the plasma and is widely used as a marker of bronchial hyperreactivity and allergic inflammation. Environmental factors as well as intense physical exertion may influence eosinophil-related bronchial hyperreactivity. STUDY OBJECTIVES: To investigate the effect of endurance exercise at moderate altitude on levels of circulating eosinophils, serum ECP, serum osmolality (sOS), and dynamic pulmonary function parameters in healthy mountaineers. SETTING: Alpine field study performed in the Alps of Upper Styria in Austria. Type of exercise: Ascent of a mountain at maximal speed. PARTICIPANTS: Thirty healthy male volunteers from a troop of military mountaineers. RESULTS: Mean ECP concentration increased by 66% at the summit checkpoint (H2) and remained at 63% above baseline (base checkpoint [H0]) after descent (H4), while the blood eosinophil count decreased concomitantly from 250/microL at H0 (preexercise) to 118/microL (53%) at H2 and to 22/microL (81%) at H4. The total serum ECP concentration adjusted to sOS correlated negatively with blood eosinophil count (r = - 0.37; p < 0.0001) and PaO(2) (r = - 0.34; p < 0.001), but positively with the peak expiratory flow (PEF) [r = 0.45; p < 0.0001]. Although sOS correlated with serum ECP at H2 (r = 0.47; p = 0.02) and at 12 h after the start of the experiment (H12) [r = 0.57; p = 0.003], the relationship between total ECP and sOS (r = 0.19; p = 0.034) was less pronounced. FEV(1) in percentage of FVC (%FEV(1)/FVC) [the Tiffenau test], forced expiratory flow rate at 25% of vital capacity, and PEF were significantly higher at H2 than at H0 and H4. %FEV(1)/FVC decreased to 88% (p < 0.01) and 83% (p < 0.001) predicted at H12 and 24 h after start of the experiment, respectively. CONCLUSION: Results provide strong evidence for nonspecific activation of blood eosinophils during prolonged intense aerobic exercise at moderate altitude, modifying both eosinophil dynamics and regulation of ECP release in healthy subjects.

Adult↗
PubMed2001

Eosinophils are a major source of nitric oxide-derived oxidants in severe asthma: characterization of pathways available to eosinophils for generating reactive nitrogen species.

Eosinophil recruitment and enhanced production of NO are characteristic features of asthma. However, neither the ability of eosinophils to generate NO-derived oxidants nor their role in nitration of targets during asthma is established. Using gas chromatography-mass spectrometry we demonstrate a 10-fold increase in 3-nitrotyrosine (NO(2)Y) content, a global marker of protein modification by reactive nitrogen species, in proteins recovered from bronchoalveolar lavage of severe asthmatic patients (480 +/- 198 micromol/mol tyrosine; n = 11) compared with nonasthmatic subjects (52.5 +/- 40.7 micromol/mol tyrosine; n = 12). Parallel gas chromatography-mass spectrometry analyses of bronchoalveolar lavage proteins for 3-bromotyrosine (BrY) and 3-chlorotyrosine (ClY), selective markers of eosinophil peroxidase (EPO)- and myeloperoxidase-catalyzed oxidation, respectively, demonstrated a dramatic preferential formation of BrY in asthmatic (1093 +/- 457 micromol BrY/mol tyrosine; 161 +/- 88 micromol ClY/mol tyrosine; n = 11 each) compared with nonasthmatic subjects (13 +/- 14.5 micromol BrY/mol tyrosine; 65 +/- 69 micromol ClY/mol tyrosine; n = 12 each). Bronchial tissue from individuals who died of asthma demonstrated the most intense anti-NO(2)Y immunostaining in epitopes that colocalized with eosinophils. Although eosinophils from normal subjects failed to generate detectable levels of NO, NO(2-), NO(3-), or NO(2)Y, tyrosine nitration was promoted by eosinophils activated either in the presence of physiological levels of NO(2-) or an exogenous NO source. At low, but not high (e.g., >2 microM/min), rates of NO flux, EPO inhibitors and catalase markedly attenuated aromatic nitration. These results identify eosinophils as a major source of oxidants during asthma. They also demonstrate that eosinophils use distinct mechanisms for generating NO-derived oxidants and identify EPO as an enzymatic source of nitrating intermediates in eosinophils.

Eosinophil Peroxidase↗
PubMed1988

Eosinophilic gastroenteritis: ultrastructural evidence for a selective release of eosinophil major basic protein.

Ultrastructural study of mucosal eosinophils in a case of eosinophilic gastroenteritis involving stomach, duodenum and ileum showed an altered structure in ulcerated duodenal areas. The electron core density of eosinophil granules was inverted or disappeared and tubulovesicular structures occurred. Using immunogold staining with specific antibodies, major basic protein was detected diffusely in the matrix of eosinophil granules and out of the granules in tight association with extragranular membrane formations. In contrast, eosinophil cationic protein and eosinophil peroxidase were normally distributed in the granule matrix. When compared with the eosinophils in macroscopically normal duodenal mucosa in the same patient, these changes support a role for major basic protein in tissue damage in eosinophilic gastroenteritis. The diffusion of one granule protein from the granules to the exterior of the cells favours the view of a selective release of eosinophil mediators.

Adult↗
PubMed1984

Mechanisms for eosinophil degranulation; release of the eosinophil cationic protein.

Mechanisms for degranulation in human eosinophils were evaluated. Release of eosinophil cationic protein (ECP), a unique eosinophil granule constituent, was measured upon exposure of purified eosinophils to a large surface consisting of Sephadex beads coated with serum, which leads to complement activation. Extracellular release of approximately 15% of the cellular ECP occurred both with eosinophils from patients with eosinophilia and normal people. Almost all eosinophils isolated from patients with eosinophilia and normal people adhered to serum-treated Sephadex. The data suggest that interaction through C3 receptors is a prerequisite for ECP release from eosinophils when exposed to serum-treated Sephadex. Both cytochalasin B, cytochalasin D and hydrocortisone reduced the release of ECP. Neither the cytochalasins nor hydrocortisone inhibited the adherence of eosinophils to the Sephadex beads. Thus the inhibitory effect of these agents on ECP release is a direct effect on the degranulation process. ECF-A, histamine and colchicine did not affect the release mechanism. No direct relationship was found between degranulation and oxidative burst inasmuch as some soluble mediators induced a high respiratory burst without a concomitant ECP release. Our data suggest that mechanisms for degranulation are not fully identical in eosinophils and neutrophils.

Antigen-Antibody Complex↗
PubMed1983

Purification and characterization of a new cationic protein--eosinophil protein-X (EPX)--from granules of human eosinophils.

The isolation and characterization of a new eosinophil-derived protein, eosinophil protein X (EPX) is here described. The purified EPX is a highly basic glycoprotein and shows one band on sodium dodecyl sulphate polyacrylamide gel electrophoresis and on agarose electrophoresis. The molecular weight of the unreduced protein was 23,000 and after reduction 19,000. EPX did not precipitate antibodies prepared to other eosinophil-derived proteins such as eosinophil cationic protein (ECP) or major basic proteins (MBP) or antibodies prepared to a number of neutrophil-derived proteins. The eosinophil origin of EPX was indicated by the linear correlation between the amount of EPX and the percentage of eosinophils in mixed leucocyte extracts prepared from normal individuals. The EPX content was estimated to be on average 10 micrograms/10(6) normal eosinophils. EPX from normal eosinophils and from eosinophils from one patient with hypereosinophilia seemed to be identical.

Amino Acids↗
PubMed1992

Immunopathological study of eosinophils in eosinophilic granuloma of bone: evidence for release of three cationic proteins and subsequent uptake in macrophages.

Eosinophils from two patients with eosinophilic granuloma of bone (EGB) were studied by combined immunohistochemical and immuno-ultrastructural methods with antibodies directed against three eosinophil granule proteins: major basic protein, eosinophil cationic protein, and eosinophil peroxidase. Immunohistostaining showed the presence and distribution of large numbers of eosinophils in the granuloma. Immuno-ultrastructural methods showed alterations of eosinophil fine structure associated with some steps in the release of granule proteins. No granule extrusion was seen, but rather cationic proteins diffused within cytoplasmic tubulo-vesicular structures. Furthermore, the three granule proteins were found within phagolysosomes of surrounding macrophages, suggesting an interaction between eosinophils and phagocytic cells at the destructive stage of EGB.

Adolescent↗
PubMed1992

Decreased expression of eosinophil peroxidase and major basic protein messenger RNAs during eosinophil maturation.

We evaluated the levels of mRNAs encoding cationic proteins in peripheral blood eosinophils (PBE) purified from patients with eosinophilia and in eosinophils differentiated from cord blood cells (CBC) by culture with recombinant human interleukin-3 (rhIL-3), rhGM-CSF, and rhIL-5. Messenger RNAs encoding eosinophil peroxidase (EPO), major basic protein (MBP), eosinophil-derived neurotoxin (EDN), and eosinophil cationic protein (ECP) were detected by Northern blot hybridization with the respective specific oligonucleotide probes. In mature PBE, MBP mRNA appeared to be absent, whereas EPO mRNA was barely detectable in only 5 of the 19 patients. In contrast, EDN and ECP mRNAs were observed in the PBE of all patients. In CE, EPO, and MBP, mRNAs were abundant in immature eosinophils and their amounts decreased after differentiation toward eosinophils. ECP and EDN mRNAs followed the same patterns, but mRNAs were less abundant at all timepoints studied. Study of mRNA t1/2 during the time course of differentiation indicated that changes in the stability of the different mRNAs were not responsible for the variations observed in the steady-state levels. Together, these results suggest that regulation of expression differs among EPO, MBP, EDN, and ECP mRNAs during the time course of eosinophil differentiation.

Actins↗
PubMed1992

Eosinophil as antigen-presenting cell: activation of T cell clones and T cell hybridoma by eosinophils after antigen processing.

We have studied the role of murine eosinophils as antigen-presenting cells (APC). Eosinophils have several characteristics that support the hypothesis of its function as potential APC: they have phagocytic capacity, express adhesion molecules and major histocompatibility complex (MHC) class II antigens and can produce and release interleukin-1 (IL-1). We have obtained several T cell clones specific for Mesocestoides corti antigens and used T cell hybridoma specific for ovalbumin (OVA) to test this hypothesis. Granulocyte-macrophage colony-stimulating factor-activated pure eosinophils (99.9%), express class II antigens and are able to present M. corti antigens to specific T cell clones or OVA to T cell hybridoma 3DO 11.10, inducing the proliferation of T cell clones and IL-2 release by the T cell hybridoma. Proliferation of T cells clones is dependent on the number of eosinophils used as APC. We have compared the efficiency of the same number of macrophages and eosinophils as APC, and have found that macrophages are more efficient than eosinophils. Lysosomotropic agents, such as chloroquine and ammonium chloride, that inhibit antigen processing, impaired eosinophil presentation. This presentation is restricted by MHC class II and inhibited by anti-I-Ad monoclonal antibody. The present study provides clear evidence of APC function for eosinophils. Our investigation points to a new role for eosinophils in the immune response.

Ammonium Chloride↗
PubMed1992

Morphology and density features of eosinophil leukocytes in eosinophilic pneumonia. A case report.

We compared the morphological characteristics and density properties of eosinophil leukocytes obtained from the blood and bronchoalveolar lavage fluid of a 29-year-old patient with chronic eosinophil pneumonia during exacerbation. The lavage eosinophils were significantly increased in size when compared with blood cells (surface area: 208 +/- 12 microns 2 versus 161 +/- 13 microns 2). Moreover, eosinophils contained slightly more granules (23.4 versus 20.7 per cell surface area), but no difference was found when the number was corrected for cell size. Electron microscopy revealed a loss of granule contents in eosinophils from both blood and bronchoalveolar lavage. Finally, 61% of the lavage eosinophils were hypodense (with a density less than 1.085 g/ml), whereas 96.3% of the blood cells were normodense. In conclusion, our data demonstrate that in chronic eosinophil pneumonia, eosinophils obtained from bronchoalveolar lavage and blood show differences in both their morphology and density, suggesting that eosinophils during migration into the lung may become activated.

Adult↗
PubMed1982

Enhancement of human blood eosinophil cytotoxicity by semi-purified eosinophil colony-stimulating factor(s).

Purified human blood eosinophils, when incubated in human placental conditioned medium (a source of colony-stimulating factors) [CSF]) demonstrate an enhanced ability to damage antibody- or complement-coated schistosomula. This enhancement represents a 4- to 10-fold increase of eosinophil schistosomicidal ability and a 10-fold lowering of the threshold for antibody or complement required in the killing reaction. The activity that enhances eosinophil cytotoxicity and the eosinophil colony-stimulating activity in the placental conditioned medium are eluted in the same fraction (CSF-alpha) after chromatography on Sephadex G-100 and phenyl-Sepharose columns, suggesting that these two activities might be associated with the same molecule. CSF-alpha enhances the adherence step of the killing reaction: antibody-coated larvae were frequently found covered by several layers of eosinophils in tubes containing CSF-alpha. Such a degree of adherence was rarely seen in control tubes lacking CSF-alpha. This enhancement of the eosinophil adherence is detectable 45-60 min after addition of CSF-alpha to the culture. It is not affected by washing the cells after a short time of preincubation with CSF-alpha, and it occurs in the absence of protein synthesis, whereas colony-stimulating activity requires continuous protein synthesis and ceases when CSF is removed from the culture. Finally, CSF-alpha enhances the temperature-dependent reaction that insures the irreversibility of eosinophil attachment to schistosomula. These observations suggest that eosinopoietic factors could be responsible for some of the modified properties of blood eosinophils in eosinophilic individuals.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1991

CD4-mediated stimulation of human eosinophils: lymphocyte chemoattractant factor and other CD4-binding ligands elicit eosinophil migration.

Lymphocyte chemoattractant factor (LCF) is a tetrameric glycoprotein of 56,000 relative molecular mass produced by activated T lymphocytes. LCF binds to CD4 and has previously been found to stimulate migration of CD4+ lymphocytes and monocytes. Because human eosinophils, like T cells and monocytes, express CD4, we examined functional responses of eosinophils to LCF. Recombinant LCF (rLCF) expressed in COS cells was purified on a CD4 affinity column. Migration of eosinophils was elicited by rLCF at low concentrations: the 50% effective dose (ED50) was 10(-12) to 10(-11) M, concentrations 100- to 1,000-fold lower than the ED50s for the recognized eosinophil chemoattractants C5a and platelet-activating factor. Two other ligands which bound to CD4, human immunodeficiency virus-1 envelope glycoprotein gp120 and monoclonal antibody OKT4, also stimulated eosinophil migration. Monovalent OKT4 Fab competitively inhibited eosinophil responses to rLCF. rLCF did not influence other functional responses of eosinophils tested, including degranulation, superoxide generation, leukotriene C4 production, in vitro survival, or surface expression of the adherence receptor CR3 (CD11b), human histocompatibility leukocyte antigen DR, or interleukin 2 receptor p55 (CD25). We conclude that CD4 on eosinophils is capable of transducing a migratory stimulus and serves as a receptor for a chemoattractant lymphokine LCF. T cell-derived LCF may contribute to recruitment of eosinophils and CD4+ mononuclear cells concomitantly at inflammatory reactions.

CD4 Antigens↗
PubMed2002

Eosinophils, eosinophilic cytokines (interleukin-5), and antieosinophilic therapy in asthma.

Eosinophils are believed to be key effector cells in producing the bronchial mucosal inflammation characteristic of allergic asthma. Given the perceived importance of eosinophils in allergic inflammation, they have been logical therapeutic targets. As knowledge of eosinophil biology increases, eosinophils are targeted with specific therapies blocking their maturation, activation, and chemotaxis. Therapeutic targets include eosinophil-specific cytokines, primarily interleukin-5, and chemokines, eg, eotaxin. Several studies over the last year have reported on therapies effective at reducing eosinophil numbers in asthmatics, including two humanized monoclonal antibodies against interleukin-5 and recombinant human interleukin-12. Surprisingly, despite their effectiveness at depleting eosinophils, there was no evidence of clinical improvement in any of the parameters studied. These and all other relevant studies published within the last year are reviewed by this article. After publication of these studies, some commentators questioned the role of eosinophils in allergic inflammation. Current evidence for and against eosinophils as effector cells in asthma is reviewed.

Animals↗
PubMed2002

Eosinophil adhesion to cholinergic nerves via ICAM-1 and VCAM-1 and associated eosinophil degranulation.

In vivo, eosinophils localize to airway cholinergic nerves in antigen-challenged animals, and inhibition of this localization prevents antigen-induced hyperreactivity. In this study, the mechanism of eosinophil localization to nerves was investigated by examining adhesion molecule expression by cholinergic nerves. Immunohistochemical and functional studies demonstrated that primary cultures of parasympathetic nerves express vascular cell adhesion molecule-1 (VCAM-1) and after cytokine pretreatment with tumor necrosis factor-alpha and interferon-gamma intercellular adhesion molecule-1 (ICAM-1). Eosinophils adhere to these parasympathetic neurones after cytokine pretreatment via a CD11/18-dependent pathway. Immunohistochemistry and Western blotting showed that a human cholinergic nerve cell line (IMR-32) expressed VCAM-1 and ICAM-1. Inhibitory experiments using monoclonal blocking antibodies to ICAM-1, VCAM-1, or CD11/18 and with the very late antigen-4 peptide inhibitor ZD-7349 showed that eosinophils adhered to IMR-32 cells via these adhesion molecules. The protein kinase C signaling pathway is involved in this process as a specific inhibitor-attenuated adhesion. Eosinophil adhesion to IMR-32 cells was associated with the release of eosinophil peroxidase and leukotriene C(4). Thus eosinophils adhere to cholinergic nerves via specific adhesion molecules, and this leads to eosinophil activation and degranulation; this may be part of the mechanism of eosinophil-induced vagal hyperreactivity.

Acetylcholine↗
PubMed1995

Surface antigens on eosinophils in bronchial asthma and eosinophilic pneumonia.

Surface antigens on peripheral blood eosinophils from 23 patients with bronchial asthma, 6 with eosinophilic pneumonia and 8 controls were examined using a new direct method. Peripheral blood eosinophils in bronchial asthma and eosinophilic pneumonia showed higher complexity and/or granularity than those from controls. The percentage expression of HLA DR, CD4 and CD45RO on peripheral blood eosinophils from patients with bronchial asthma were increased compared with those from patients with eosinophilic pneumonia and from the controls. These results suggest that peripheral blood eosinophils in bronchial asthma may play a role in immunoregulation via the expression of human leukocyte antigens, such as HLA-DR, CD4 and CD45RO, that interact with lymphocytes, and may function as antigen-presenting cells. Furthermore this study suggests that there may be different phenotypes of eosinophils with differing surface antigens and intercellular reactions between eosinophils and lymphocytes.

Adult↗