Elevated fecal levels of eosinophil granule proteins predict collagenous colitis in patients referred to colonoscopy due to chronic non-bloody diarrhea.

OBJECTIVE: Colonoscopy with biopsy sampling is often performed to detect collagenous colitis (CC) and lymphocytic colitis (LC) in patients with chronic non-bloody diarrhea. However, the diagnostic yield is low and incurs high costs. Fecal calprotectin (FC) and myeloperoxidase (MPO) indicate intestinal inflammation in ulcerative colitis (UC) and Crohn's disease (CD). In CC, elevated fecal levels of eosinophil protein X (EPX) and eosinophil cationic protein (ECP) have been reported. We aimed to evaluate if F-EPX, F-ECP, FC, and F-MPO could predict the diagnostic outcome in patients with chronic non-bloody diarrhea referred to colonoscopy. We also evaluated serum (S) EPX and ECP in this regard. METHODS: Of 67 included patients, 63 (94%) underwent colonoscopy with biopsy sampling. Fecal EPX, F-ECP, FC, F-MPO, S-EPX, and S-ECP were analyzed. RESULTS: Diagnostic outcome: normal: n = 46 (73%), CC: n = 9 (14%), LC: n = 4 (6%), UC: n = 2 (3%), CD: n = 2 (3%). Higher levels of F-EPX and F-ECP were found in CC compared to a normal diagnostic outcome (p = 0.01). No change was noted in any of the fecal markers in LC. When all of the fecal markers were normal the probability of a normal diagnostic outcome was 92%. We found no differences in S-EPX and S-ECP between the groups. CONCLUSION: Elevated F-EPX and F-ECP could predict CC. None of the fecal markers predicted LC. Serum-EPX and S-ECP are not useful for the diagnosis of CC, LC, UC, or CD. With normal levels in all of the analyzed fecal markers, there is a low probability of a pathologic diagnostic outcome.

Non-invasive ultrasound to identify eosinophil granule proteins in eosinophilic esophagitis.

Although traditional microbubble contrast agents are bright, the high contrast of gas bubbles and air-water interfaces in the upper gastrointestinal tract renders these agents less useful for diagnosing diseases such as eosinophilic esophagitis, a disease characterized by patchy infiltration of eosinophils into the esophagus. Here we report a first-in-class ultrasound contrast enhancement agent composed of echogenic insulin particles, which are labeled with molecular recognition elements to diagnose eosinophil-associated diseases. We prepared solid echogenic insulin particles, tethered antibodies to eosinophil granule major basic protein 1 (MBP-1) to their surfaces and experimentally evaluated binding of these agents to MBP-1 on ex vivo non-human primate esophagi. We found that insulin particles can be readily observed by ultrasound and bind to MBP-1-coated esophagi within minutes. Our results suggest the potential of this new class of solid contrast agents to image, diagnose and improve management of eosinophilic esophagitis.

Eosinophil-associated processes underlie differences in clinical presentation of loiasis between temporary residents and those indigenous to Loa-endemic areas.

BACKGROUND: Loa loa has emerged as an important public health problem due to the occurrence of immune-mediated severe posttreatment reactions following ivermectin distribution. Also thought to be immune-mediated are the dramatic differences seen in clinical presentation between infected temporary residents (TR) and individuals native to endemic regions (END). METHODS: All patients diagnosed with loiasis at the National Institutes of Health between 1976 and 2012 were included. Patients enrolled in the study underwent a baseline clinical and laboratory evaluation and had serum collected and stored. Stored pretreatment serum was used to measure filaria-specific antibody responses, eosinophil-related cytokines, and eosinophil granule proteins. RESULTS: Loa loa infection in TR was characterized by the presence of Calabar swelling (in 82% of subjects), markedly elevated eosinophil counts, and increased filaria-specific immunoglobulin G (IgG) levels; these findings were thought to reflect an unmodulated immune response. In contrast, END showed strong evidence for immune tolerance to the parasite, with high levels of circulating microfilariae, few clinical symptoms, and diminished filaria-specific IgG. The striking elevation in eosinophil counts among the TR group was accompanied by increased eosinophil granule protein levels (associated with eosinophil activation and degranulation) as well as elevated levels of eosinophil-associated cytokines. CONCLUSIONS: These data support the hypothesis that differing eosinophil-associated responses to the parasite may be responsible for the marked differences in clinical presentations between TR and END populations with loiasis.

Eosinophil granule proteins ECP and EPX as markers for a potential early-stage inflammatory lesion in female genital schistosomiasis (FGS).

BACKGROUND: Genital granulomas induced by Schistosoma haematobium eggs can manifest as different lesion types visible by colposcopy; rubbery papules (RP), homogenous sandy patches (HSP) and grainy sandy patches (GSP). Pronounced tissue eosinophilia is a candidate marker for active S. haematobium pathology, as viable schistosome egg granulomas often are eosinophil rich. Here it was investigated whether eosinophil granule proteins ECP (eosinophil cationic protein) and EPX (eosinophil protein-X) in urine and genital lavage can be used as markers for active FGS lesions. METHODS: Uro-genital samples from 118 Malagasy women were analysed for ECP and EPX by standard sandwich avidin/biotin amplified ELISA. PRINCIPAL FINDINGS: The women with RP lesions had significantly higher levels of ECP and EPX in both lavage and urine. Furthermore, women with RP lesions were significantly younger than those with GSP. This could indicate that RP lesions might be more recently established and thus represent an earlier inflammatory lesion stage. CONCLUSION: ECP in genital lavage might be a future tool aiding the identification of FGS pathology at a stage where reversibility remains a possibility following praziquantel treatment.

When is mass spectrometry combined with affinity approaches essential? A case study of tyrosine nitration in proteins.

Tyrosine nitration in proteins occurs under physiologic conditions and is increased at disease conditions associated with oxidative stress, such as inflammation and Alzheimer's disease. Identification and quantification of tyrosine-nitrations are crucial for understanding nitration mechanism(s) and their functional consequences. Mass spectrometry (MS) is best suited to identify nitration sites, but is hampered by low stabilities and modification levels and possible structural changes induced by nitration. In this insight, we discuss methods for identifying and quantifying nitration sites by proteolytic affinity extraction using nitrotyrosine (NT)-specific antibodies, in combination with electrospray-MS. The efficiency of this approach is illustrated by identification of specific nitration sites in two proteins in eosinophil granules from several biological samples, eosinophil-cationic protein (ECP) and eosinophil-derived neurotoxin (EDN). Affinity extraction combined with Edman sequencing enabled the quantification of nitration levels, which were found to be 8 % and 15 % for ECP and EDN, respectively. Structure modeling utilizing available crystal structures and affinity studies using synthetic NT-peptides suggest a tyrosine nitration sequence motif comprising positively charged residues in the vicinity of the NT- residue, located at specific surface- accessible sites of the protein structure. Affinities of Tyr-nitrated peptides from ECP and EDN to NT-antibodies, determined by online bioaffinity- MS, provided nanomolar K(D) values. In contrast, false-positive identifications of nitrations were obtained in proteins from cystic fibrosis patients upon using NT-specific antibodies, and were shown to be hydroxy-tyrosine modifications. These results demonstrate affinity- mass spectrometry approaches to be essential for unequivocal identification of biological tyrosine nitrations.

Exhaled nitric oxide is related to bronchial eosinophilia and airway hyperresponsiveness to bradykinin in allergen-induced asthma exacerbation.

Exhaled nitric oxide (FeNO) has been associated with bronchial eosinophilia and with airway hyperresponsiveness (AHR) in mild stable asthma. We previously demonstrated in a large project that allergen exposure is able to raise FeNO and to worsen AHR to bradykinin. We postulated that allergen-induced increase in FeNO could be related to heightened mucosal eosinophils and AHR to bradykinin in atopic asthma. We performed a new immunohistochemical analysis on bronchial biopsy specimens, previously obtained from the same large project, in order to assess the number of mucosal eosinophils (EG-2+ cell) and other inflammatory cells at 48 hours after diluent and allergen exposures. Inflammatory cell counts were related to FeNO and AHR to BK (expressed as logPD20 bradykinin). In 10 atopic mild asthmatics, we found that the numbers of EG-2+ and CD4+ cells in bronchial submucosa were significantly increased after allergen compared to the respective counts after diluent (p < 0.01). EG-2+ cells in the bronchial submucosa were negatively correlated with logPD20 bradykinin only after allergen challenge (rho = -0.709, p = 0.027). We also found a positive strong correlation between EG-2+ cells and FeNO values in atopic asthmatics at 48 hours after both diluent (rho = 0.746, p = 0.017) and allergen (rho = 0.644, p = 0.049) challenge. FeNO values negatively correlated with responsiveness to bradykinin only after allergen challenge (rho = -0.675, p = 0.039). This study indicates that after allergen exposure heightened level of exhaled NO may reflect augmented airway eosinophilic inflammation and airway responsiveness to bradykinin indicating loss of asthma control.

EG2 expressed by eosinophils as a clinically useful indicator of asthma.

The monitoring of airway inflammation is mandatory for the improved control of bronchial asthma. We previously reported that intracellular EG2 levels of eosinophils, a marker of bronchial asthma increased in asthma patients. In this study, we hypothesized that eosinophil EG2(+) expression increases during airway inflammation in asthmatic individuals. Eosinophil EG2(+) and percentage eosinophil EG2(+) with whole blood flow cytometry, eosinophil counts, serum total IgE, serum eosinophil cationic protein, eosinophil-derived neurotoxin, and percent of forced expiratory volume in 1 second/force vital capacity (FEV(1)/FVC) were measured in 33 asthmatic patients and 22 healthy volunteers. The relationships between these markers were evaluated. Comparisons were made on EG2(+) expression between attack and asymptomatic periods in six asthmatic patients. EG2(+) expression was significantly greater in the asthmatic patients than in healthy subjects. Furthermore, the EG2(+) expression showed a significant increase during attacks. EG2(+) expression inversely correlated with the FEV(1)/FVC. These results suggest that EG2(+) expression may be a useful clinical marker of airway inflammation in asthma.

Expression of prostaglandin D2 synthase in activated eosinophils in nasal polyps.

OBJECTIVE: To clarify the relationship between prostaglandin D2 production and eosinophil accumulation. DESIGN: Screening and diagnostic tests. SUBJECTS: Nineteen patients with chronic rhinosinusitis. INTERVENTIONS: Nasal polyps were obtained from 19 patients at endoscopic sinus surgery. Eosinophils in nasal polyps were counted after hematoxylin-eosin staining and immunostaining with antibodies against 2 eosinophil markers-major basic protein and EG2. Hematopoietic prostaglandin D2 synthase (HPGDS) expression was examined by semiquantitative Western blot analysis and by immunohistochemical staining with anti-HPGDS antibody. RESULTS: Nasal polyps were divided into 3 groups by the degree of eosinophilic infiltration. Western blot analysis revealed that HPGDS was more intensely and frequently expressed in the group with high infiltration than in the groups with low or medium infiltration. Hematopoietic prostaglandin D2 synthase was immunohistochemically found in a subpopulation of EG2-positive eosinophils that had accumulated in the nasal polyps but not in the EG2-negative resting eosinophils. The ratio of HPGDS-positive eosinophils to EG2-positive eosinophils in the group with high eosinophil infiltration (mean+/-SD, 64.8%+/-19.2%) was twice that in the group with low eosinophil infiltration (30.5%+/-13.8%). CONCLUSION: Prostaglandin D2 was actively produced by an EG2 and HPGDS double-positive subpopulation of activated eosinophils that had infiltrated into nasal polyps.

Proteomic analysis of human cervical-vaginal fluids.

The pathophysiology of vaginal conditions is still ill-defined at a molecular level. Because the proteome of the human cervical-vaginal fluid (CVF) has not been reported to date, we undertook the identification of proteins present in the cell-free fraction of these fluids. Proteins were separated bidimensionally (2-D) by isoelectrofocusing (pH 3-11) followed by SDS-polyacrylamide electrophoresis. The proteins of 147 spots were identified by matrix-assisted laser desorption/ ionization-time-of-flight-mass spectrometry (MALDI-TOF/TOF). This approach was supplemented by immunoassays for markers of neutrophils (myeloperoxidase, MPO; neutrophil gelatinase-associated lipocalin, NGAL/HNL) and eosinophils (eosinophil cationic protein: ECP) and by immunoblotting (lactoferrin, calgranulins A and B and annexins A1 and A3. Nearly half of the proteins (69/147) and protein fragments detected were found to be plasma components, on the basis of which the human CVF can be broadly considered a plasma transudate. Although the pattern of protein spots was very similar for all fluids analyzed, a relative overabundance of major plasma proteins such as albumin, transferrin, immunoglobulins, apolipoproteins, alpha-1-acid glycoprotein 1, and calgranulins was associated with the presence of a high number of polymorphonuclear leukocytes in the lavages from which those cell-free fluids had been obtained. Instead, fluids from women experiencing vulvovaginal candidiasis did not show differences in the protein maps compared with asymptomatic individuals. Neutrophil and eosinophil granule secretion proteins were also detected in variable amounts in the lavage fluids by both immunoassay and immunoblotting, indicating polymorphonuclear cell activation.

Airway mucosal inflammation in COPD is similar in smokers and ex-smokers: a pooled analysis.

Bronchial biopsy specimens from chronic obstructive pulmonary disease (COPD) patients demonstrate increased numbers of CD8+ T-lymphocytes, macrophages and, in some studies, neutrophils and eosinophils. Smoking cessation affects the rate of forced expiratory volume in one second (FEV(1)) decline in COPD, but the effect on inflammation is uncertain. Bronchial biopsy inflammatory cell counts were compared in current and ex-smokers with COPD. A pooled analysis of subepithelial inflammatory cell count data from three bronchial biopsy studies that included COPD patients who were either current or ex-smokers was performed. Cell count data from 101 subjects, 65 current smokers and 36 ex-smokers, were analysed for the following cell types: CD4+ and CD8+ T-lymphocytes, CD68+ (monocytes/macrophages), neutrophil elastase+ (neutrophils), EG2+ (eosinophils), mast cell tryptase+ and cells mRNA-positive for tumour necrosis factor-alpha. Current smokers and ex-smokers were similar in terms of lung function, as measured by FEV(1) (% predicted), forced vital capacity (FVC) and FEV(1)/FVC. The results demonstrate that there were no significant differences between smokers and ex-smokers in the numbers of any of the inflammatory cell types or markers analysed. It is concluded that, in established chronic obstructive pulmonary disease, the bronchial mucosal inflammatory cell infiltrate is similar in ex-smokers and those that continue to smoke.

Eosinophil infiltration and activation in nasal polyposis.

Conclusions. Infiltration and activation of eosinophils is a characteristic of nasal polyposis. Allergic reaction is a risk factor for the accumulation of eosinophils in this disease. T-cell-derived interleukin 5 (IL-5) and autosecretion of IL-5 from activated eosinophils may be causative reasons for the extension and persistence of eosinophil inflammation. Objectives. To investigate whether eosinophils were accumulated and activated in nasal polyposis, and the roles of IL-5, eotaxin, and T cells in this process. Materials and methods. A retrospective study was conducted on 17 tissue samples from patients with nasal polyposis with allergy and 26 cases of non-allergic polyposis. Immunohistochemical staining by specific antibodies was carried out using the alkaline phosphatase anti-alkaline phosphatase method and the avidin-biotin complex technique.Results. The number of EG1-positive cells (pan eosinophil marker) was similar to the number of EG2-positive cells (activated eosinophil marker) in all tissue samples, although EG1- and EG2-positive cells were richer in allergic patients than those in non-allergic patients. Both EG1- and EG2-positive cells were correlated with CD3-positive cells (pan T cell marker) and IL-5-producing cells in allergic or non-allergic polyposis. A large proportion of IL-5 producing cells were eosinophils. Eotaxin protein was detected in all tissue samples and dominantly located in epithelial cells. Eotaxin expression between allergic and non-allergic subjects was not significantly different.

Pattern of inflammation and impact of Staphylococcus aureus enterotoxins in nasal polyps from southern China.

BACKGROUND: This study analyzes the impact of Staphylococcus aureus enterotoxins (SAEs) and the inflammatory pattern in polyps from China. METHODS: Nasal tissue was obtained from 27 consecutive bilateral nasal polyps and 15 control patients and assayed for eotaxin, interleukin-5, soluble interleukin-2 receptor, transforming growth factor (TGF) beta, myeloperoxidase, eosinophil cationic protein, total IgE, and specific IgE to SAEs. Activated eosinophils were stained using EG2 antibodies in polyps from Chinese and comparative white patients. RESULTS: The number of EG2+ eosinophils was significantly lower in polyps from Chinese patients versus white patients. Chinese polyps showed significantly increased IgE and soluble interleukin-2 receptor versus control samples, whereas TGF-beta1 was significantly decreased. Ten of 27 samples in the polyp group versus 0 of 15 controls contained SAE-IgE (p < 0.01). TGF-beta1 was significantly down-regulated in SAE+ samples versus SAE- samples (p = 0.04). CONCLUSION: Nasal polyps from China are characterized by B- and T-cell activation, a minor eosinophilic inflammation compared with polyps from white subjects, and a decrease in TGF-beta1 in comparison with control inferior turbinate tissue. One-third of patients with polyps showed an IgE response to SAEs.

Patients with psoriatic arthritis have an increased number of lymphocytes in the duodenal mucosa in comparison with patients with psoriasis vulgaris.

OBJECTIVE: To determine if there is evidence of inflammation in the duodenal mucosa in patients with psoriatic arthritis (PsA) and to compare the results with those in patients with psoriasis vulgaris (PsV). METHODS: Nineteen consecutive patients with PsA underwent gastroduodenoscopy, and biopsy specimens were taken from the duodenal and gastric mucosa. In addition to routine processing, the duodenal mucosal specimens were stained for CD3+, CD8+ and CD4+ T lymphocytes, tryptase-positive mast cells, and EG2-positive eosinophil granulocytes. The results were compared with those in duodenal mucosal specimens from patients with PsV and patients with irritable bowel syndrome. RESULTS: Compared with PsV patients (without antibodies against gliadin), patients with PsA had a highly significant increase in intraepithelial CD3+ and CD8+ lymphocytes and also in CD4+ lymphocytes in the lamina propria in the villi. The lymphocyte increase was not related to presence of IgA antibodies against gliadin, endomysium, or transglutaminase, or to concomitant gastritis. Patients with PsA and PsV showed a pronounced increase in mast cells and eosinophil granulocytes. CONCLUSION: The increased lymphocyte infiltration in the duodenal mucosa in PsA, but not in PsV, might indicate different pathogenetic mechanisms in these psoriasis variants.

[Activated eosinophils: techniques to characterize them]. / Etude de l'activation du polynucléaire éosinophile. Apport des méthodologies classiques et récentes à la caractérisation d'une cellule complexe.

The deleterious role thought to be played by eosinophils in many situations is linked to their ability to secrete various inflammatory substances, mainly toxic proteins and lipid mediators, in body tissue. This ability is a particular feature of activated eosinophils, which have undergone numerous metabolic, functional, and phenotypic changes from their resting state. Characterizing the properties of these activated cells is an essential step in improving our understanding of their contributions to local inflammatory response, as both regulatory and effector cells. Improvements in existing methods as well as the development of new technical approaches have facilitated the ex vivo and in vitro study of activated eosinophils and their contribution to various disease states.

Wound healing after paranasal sinus surgery: neutrophilic inflammation influences the outcome.

AIMS: After failure of medical treatment, functional endoscopic sinus surgery (FESS) remains the best treatment for chronic sinusitis (CS) and nasal polyposis (NP). The precise mechanisms involved in wound healing after sinus surgery remain unclear. The aim of this study was to explore systematically the different histomorphological processes and cell populations involved in the wound repair of the paranasal mucosa. METHODS AND RESULTS: Biopsy specimens from patients operated on for CS and NP were collected 1, 2 and 6 months after surgery and compared with baseline and control specimens. A pathologist blinded to biopsy status evaluated the haematoxylin/eosin-stained sections for oedema, fibrosis and inflammatory reaction, and the immunohistochemical preparations for epithelial replication, myofibroblasts, macrophages, neutrophils and eosinophils. Samples from NP showed significantly more oedema than those from CS. At baseline, oedema showed a significant correlation with macrophages, neutrophils and eosinophils, while fibrosis was inversely correlated with neutrophils. During healing, after a short increase at month 1, oedema decreased. Fibrosis and myofibroblasts showed an inverse relationship. Finally, during the postoperative period, both macrophages and neutrophils were increased when compared with controls. CONCLUSIONS: The severity of the neutrophilic inflammation appears to influence the formation of fibrosis during wound repair after sinus surgery.

Do serum levels of eosinophil granule-derived protein change in patients undergoing pelvic radiotherapy?

AIMS: Eosinophils have an important role in the pathogenesis of inflammatory bowel disease, with faecal levels of the eosinophil granule proteins, eosinophil cationic protein (ECP) and eosinophil protein X (EPX) reflecting disease activity. Eosinophil crypt abscesses are a characteristic histological finding in acute gastrointestinal radiation-induced mucosal damage. This pilot study aimed to investigate changes in serum levels of ECP/EPX during pelvic radiotherapy. MATERIALS AND METHODS: Patients with no history of inflammatory bowel disease, starting a 5-week course of pelvic radiotherapy, had serum ECP/EPX levels measured before radiotherapy and during the fourth week of treatment. Bowel toxicity was graded at week 4 using the Common Toxicity Criteria Scale. RESULTS: Fifteen patients who were to undergo adjuvant radiotherapy for gynaecological cancer were recruited. The mean serum levels of ECP and EPX before treatment were 17.3 microg/l (range 2.0-49.3 microg/l) and 37.3 microg/l (range 12.0-94.0 microg/l), respectively. The mean serum levels during week 4 of radiotherapy for ECP and EPX were 43.0 microg/l (range 2.4-164.0 microg/l) and 38.7 microg/l (range 9.0-79.0 microg/l), respectively. Serum ECP levels increased at week 4 compared with levels before radiotherapy (P = 0.02). Acute bowel toxicity was seen in 12 patients (80%) at week 4: Grade 1 in 25% patients and Grade 2 in 75%. In this small study, no correlation was seen between acute bowel toxicity at week 4 and serum ECP or EPX levels. CONCLUSIONS: Serum ECP levels increase in response to pelvic irradiation. This may reflect the known involvement of eosinophils in the acute response to radiotherapy. Further study is required to determine when levels start to rise and their relationship to the degree of acute bowel toxicity.

Kinetics of mucosal granulocyte activation after gluten challenge in coeliac disease.

OBJECTIVE: To elucidate the dynamics of the rectal inflammatory response to rectal gluten challenge in coeliac disease by measuring inflammatory mediators released by activated neutrophils, eosinophils and mast cells/basophils. MATERIAL AND METHODS: The release of myeloperoxidase (MPO), eosinophilic cationic protein (ECP) and histamine was measured continuously during the early challenge period (3-6 h after gluten challenge) in coeliac patients (n = 9) and healthy controls (n = 5). A segmental perfusion technique was used to carry out this part of the study. Another method, the mucosal patch technique, was used to enable studies of the late challenge period (5-48 h after gluten challenge) in coeliac patients (n = 10) and healthy controls (n = 15). RESULTS: During the early challenge period the MPO levels began to increase as early as 3 h after challenge and increased progressively (p < 0.001) during the next 3 h. A decline in MPO levels was seen 15 h after challenge and another phase of increasing levels at 24 h. The MPO values declined 48 h after challenge but still remained significantly increased (p < 0.05). The ECP levels started to increase 4 h after challenge and increased progressively during the next 2 h (p < 0.05). The ECP kinetics during the late challenge period was similar as for MPO but the relative increase in ECP was more modest. No increase in histamine was found except in one patient who had a transient, early increase of histamine (3-5 h after challenge). No signs of inflammatory reaction to gluten were seen in the controls. CONCLUSIONS: There is a pronounced neutrophil activation in coeliac patients after rectal gluten challenge. This activation is apparent 4 h after challenge and remains for at least 48 h. A more modest eosinophil activation defined by ECP levels starts 1-2 h later and also remains for at least 48 h. The biphasic pattern of MPO and ECP after challenge suggests a biphasic inflammatory reaction.

Relationship between dendritic cells and activated eosinophils in induced sputum of asthmatics.

It has been suggested that dendritic cells (DCs) are critical antigen presenting cells for eosinophilic airway inflammation in a mouse model of asthma, and cysteinyl leukotrienes may play a role in DC trafficking in asthmatics. We investigated whether the number of DCs is increased in the induced sputum of both atopic and nonatopic asthmatics and is related to activated eosinophil count in the sputum. Sputum was induced by inhalation of hypertonic saline in 9 atopic and 12 nonatopic asthmatics and 10 nonatopic normal controls, and differential cell counts were performed. DCs and activated eosinophils were identified by immunocytochemistry with monoclonal antibodies (anti-CD1a and EG2, respectively). There were significantly higher percentages of eosinophils, EG2+ cells, and CD1a+ DC in the sputum of atopic and nonatopic asthmatics compared with normal controls, respectively. In asthmatics, the percentage of CD1a+ DC was significantly correlated with that of EG2+ cells (Rs=0.62, p=0.004). We demonstrated that the increased number of DCs was evident in the induced sputum of both atopic and nonatopic asthmatics, and the DC number was related to the activated eosinophil count, which suggests that DCs may contribute to the ongoing eosinophilic inflammation in asthmatic airways, and vice versa.

Airway responsiveness to hypertonic saline: dose-response slope or PD15?

The result of airway challenge test with hypertonic saline (HS) is expressed as the dose causing a 15% fall in forced expiratory volume in one second (FEV1; PD15). A noncensored measure, such as the dose-response slope (DRS), allows the evaluation of the risk of asthma for subjects with a fall in FEV1 <15%. The aim of this study was to assess the relationship between airway responsiveness to HS by PD15 or DRS, asthma symptoms and markers of eosinophilic inflammation. Data on current wheeze and airway responsiveness were obtained for 1,107 children (aged 8-13 yrs). Blood eosinophils and serum eosinophil cationic protein (ECP) were assessed in subsets (n = 683 and 485). PD15 was assessed if FEV1 fell > or =15%, and the DRS was calculated for all tests. Graphs were constructed to visualise relationships with current wheeze, blood eosinophils and serum ECP. Odds ratios and Spearman's correlation coefficients were calculated to quantify these relationships. Children with features of asthma had lower PD15 and higher DRS, and separation was most pronounced for DRS. Prevalence of current wheeze increased continuously over the entire range of DRS values. Blood eosinophils were significantly higher only for the highest values of DRS. In conclusion, the continuous relationship between airway responsiveness and asthma symptoms is in favour of a noncensored measure of airway responsiveness, such as the dose-response slope.

Relationship between Dendritic Cells and Activated Eosinophils in Induced Sputum of Asthmatics

It has been suggested that dendritic cells (DCs) are critical antigen presenting cells for eosinophilic airway inflammation in a mouse model of asthma, and cysteinyl leukotrienes may play a role in DC trafficking in asthmatics. We investigated whether the number of DCs is increased in the induced sputum of both atopic and nonatopic asthmatics and is related to activated eosinophil count in the sputum. Sputum was induced by inhalation of hypertonic saline in 9 atopic and 12 nonatopic asthmatics and 10 nonatopic normal controls, and differential cell counts were performed. DCs and activated eosinophils were identified by immunocytochemistry with monoclonal antibodies (anti-CD1a and EG2, respectively). There were significantly higher percentages of eosinophils, EG2+ cells, and CD1a+ DC in the sputum of atopic and nonatopic asthmatics compared with normal controls, respectively. In asthmatics, the percentage of CD1a+ DC was significantly correlated with that of EG2+ cells (Rs=0.62, p=0.004). We demonstrated that the increased number of DCs was evident in the induced sputum of both atopic and nonatopic asthmatics, and the DC number was related to the activated eosinophil count, which suggests that DCs may contribute to the ongoing eosinophilic inflammation in asthmatic airways, and vice versa.