Lucia Vicentini

Exhaled nitric oxide and sputum eosinophil markers of inflammation in asthmatic children

Exhaled nitric oxide and eosinophil sputum markers are considered noninvasive ways in which to evaluate airway inflammation in asthma. The aim of this study was to evaluate the relationships between these methods of evaluation in asthmatic children. In a cross-sectional study of 25 mild-moderate asthmatic children (aged 6-13 yrs, 10 patients on inhaled steroids) exhaled NO was measured along with induced sputum by inhalation of hypertonic saline solution. The sputum was processed for eosinophil count and eosinophil cationic protein (ECP) determination. Serum ECP and lung function (forced expiratory volume in one second (FEV1)) were also measured. A significant correlation was observed between exhaled NO and sputum eosinophils (r = 0.438, p = 0.032) as well as between sputum eosinophils and sputum ECP (r = 0.532, p<0.01). No correlation was observed among exhaled NO and serum ECP, sputum ECP, FEV1, respectively. Furthermore no correlation was observed between sputum eosinophil (%) and serum ECP and between sputum eosinophils and FEV1. There was no correlation among the investigated parameters in children treated with inhaled steroids. In conclusion, exhaled NO and sputum eosinophil counts are concordant in evaluating the degree of airway inflammation in patients with mild-to-moderate asthma. However, the association between these two noninvasive markers becomes less in steroid treated patients.

Exhaled breath condensate eicosanoids and sputum eosinophils in asthmatic children: a pilot study.

Cysteinyl leukotrienes (cys‐LTs), LTB4 and 8‐isoprostane are increased in the exhaled breath condensate (EBC) from asthmatic patients. The aim of this study was to investigate whether the measurement of cys‐LTs, LTB4 and 8‐isoprostane in EBC can reflect the level of airway inflammation assessed by induced sputum in asthmatic children sensitized to house dust mite (HDM) during natural avoidance of HDM allergens. Twelve children were evaluated at the time of admission (T0) and after 3 months of stay (T1) at the Istituto Pio XII (Misurina, Italian Dolomites 1756  m). Sputum eosinophil percentage and measurement of cys‐LTs, LTB4 and 8‐isoprostanes in the breath condensate at T0 and T1 were evaluated. Eosinophil percentage in induced sputum was 8.5 ± 1.1% at T0 and 3.5 ± 0.4% at T1 (p = 0.011). Neutrophil percentage in sputum was 1.1 ± 0.5% at T0 and 1.5 ± 1.0% at T1 (ns). Cys‐LTs mean level was 14.24 ± 4.53 pg/ml at T0 and 4.65 ± 0.68 pg/ml at T1 (p = 0.0125). LTB4 level was 2.36 ± 0.19 pg/ml at T0 and 2.41 ± 0.23 pg/ml at T1 (ns). 8‐Isoprostane level reduced from 17.47 ± 3.18 pg/ml at T0 to 7.36 ± 3.26 pg/ml at T1 (p = 0.003). This study show that exhaled cys‐LTs and 8‐isoprostane, as well as eosinophil percentage in induced sputum, are reduced after allergen avoidance in asthmatic children suggesting a potential application of EBC for the non‐invasive evaluation of airway inflammation in asthma in allergic asthmatic children.

Mite-antigen avoidance can reduce bronchial epithelial shedding in allergic asthmatic children

Asthma is characterized by bronchial hyperresponsiveness (BHR), bronchial mucosa inflammation and airway epithelial damage.

Fgr deficiency results in defective eosinophil recruitment to the lung during allergic airway inflammation

Using a mouse model of allergic lung inflammation, we found that mice deficient of Fgr, a Src family tyrosine kinase highly expressed in myelomonocytic cells, fail to develop lung eosinophilia in response to repeated challenge with aerosolized OVA. Both tissue and airway eosinophilia were markedly reduced in fgr−/− mice, whereas mice with the sole deficiency of Hck, another Src family member, responded normally. Release of allergic mediators, such as histamine, IL-4, RANTES/CCL5, and eotaxin/CCL11, in the airways of OVA-treated animals was equal in wild-type and fgr−/− mice. However, lung eosinophilia in Fgr-deficient mice correlated with a defective accumulation of GM-CSF and IL-5 in the airways, whereas secretion of these cytokines by spleen cells in response to OVA was normal. Examination of mRNA expression in whole lung tissue allowed us to detect comparable expression of transcripts for eotaxin/CCL11, macrophage-inflammatory protein-1α/CCL3, macrophage-inflammatory protein-1β/CCL4, monocyte chemoattractant protein-1/CCL2, TCA-3/CCL1, IL-4, IL-10, IL-2, IL-3, IL-9, IL-15, and IFN-γ in OVA-sensitized wild-type and fgr−/− mice. In contrast, the increase in IL-5 and IL-13 mRNA expression was lower in fgr−/− compared with wild-type mice. These findings suggest that deficiency of Fgr results in a marked reduction of lung eosinophilia and the establishment of a positive feedback loop based on autocrine secretion of eosinophil-active cytokines. These results identify Fgr as a novel pharmacological target to control allergic inflammation.

Exhaled nitric oxide is reduced after sputum induction in asthmatic children

Exhaled nitric oxide (ENO) and eosinophil sputum markers are considered noninvasive markers of airway inflammation in asthma. The aim of this study was to evaluate whether the procedure of sputum induction can affect the level of ENO. We measured ENO before and after sputum induction by inhalation of hypertonic saline solution in 22 asthmatic children and 9 healthy controls.

Effect of montelukast on exhaled NO in asthmatic children exposed to relevant allergens

The level of exhaled nitric oxide (FENO) is increased in house dust mite (HDM)‐sensitized asthmatic children after exposure to HDM antigen, and inhaled steroids can prevent this increase. The aim of this study was to evaluate whether montelukast could prevent an increase in FENO levels in allergic asthmatic children after a brief period of exposure to relevant allergens. Sixteen children were evaluated at the residential house ‘Istituto Pio XII’ (Misurina, Bellunio, Italy) in the Italian Alps, a dust mite‐free environment. FENO levels were evaluated before (t0) and immediately after (t1) the children were exposed to HDM allergens for 2 weeks in their homes at sea level. No significant difference in FENO was observed in the fluticasone‐treated group of children after 2 weeks at sea level. In the group treated with montelukast, an increase in FENO was observed between t0 and t1, which failed to reach statistical significance. These preliminary data suggest that oral montelukast could be effective in preventing the relapse in airway inflammation in allergic asthmatic children who are occasionally exposed to relevant allergens for a short period of time.

Allergenicity of a hydrolyzed rice infant formula in a guinea pig model

BACKGROUND Because sensitization to cows milk is a common finding in children, the identification of safe alternative protein sources is important in the management of childhood allergy. OBJECTIVE To evaluate, in an animal model, the allergenicity of a novel formula based on hydrolyzed rice proteins. METHODS We conducted an experiment involving 130 guinea pigs, from 7 to 12 days old at the onset of the study. The animals were divided into 13 groups and were given, ad libitum, one of the following liquids to drink: (1) rice hydrolysate formula (RF), (2) a conventional cows milk formula (CMF), or (3) water. After a 37-day sensitization period, a challenge was given, consisting of an intravenous injection of either isolated proteins or ultracentrifuged formulas (uCMF and uRF). Specific IgG antibodies to beta-lactoglobulin, casein, and whole rice protein were measured by enzyme-linked immunosorbent assay. RESULTS When animals fed CMF were challenged with beta-lactoglobulin, casein, or whole uCMF, they showed significantly more reactions than did those fed RF when challenged with the same proteins (P < 0.001). In the groups fed RF, no reaction was observed after challenge with uRF, and only 2 mild reactions occurred after challenge with rice protein. Very low levels of specific IgG antibodies to rice protein were noted in all the groups, including the RF-fed animals, and no significant differences were evident between groups. CONCLUSIONS The findings suggest that this new formula based on hydrolyzed rice proteins has a very low sensitizing capability.

Exhaled NO reduced on allergen avoidance.

double the size of the injection bleb, and which shows signs of erythema surrounded by ̄are. The IDT is compared to a positive control (codeine phosphate: 50 mg/ml) and a negative control (saline solution). In our subjects, the rate of the mediators had increased. The prick tests to ICMs were 50% negative, whereas the IDTs were positive every time (Table 1). The severity of and time lapse in the onset of clinical signs, prior exposure, increase in tryptase level which seemed to be correlated to the severity of the reaction (3), positivity of IDTs, and reintroduction of a nonreactive ICM in cutaneous tests without incident all support the hypothesis of IgE mediation. Thus, cutaneous tests appear to be of prime importance in identifying the culprit ICM. ICMs are viscous and spread with dif®culty into the epidermis. This may explain the negativity of prick tests. On the other hand, IDTs seem to be more appropriate for a reaction that provokes every time a wheal at least double the injection wheal. However, this test is positive according to the degree of sensitivity of each patient: the more the patient is sensitized, the weaker the reactive concentration is. The test starts at 10 and goes to 10, a concentration that does not produce histamine release, even with hyperosmolar ICMs, as proved by negative IDTs at 10 for ioxitalamate (Telebrix) in nonallergic patients who presented an incident of mild severity to this ICM (1). Therefore, we suggest that patients who have had an anaphylactoid reaction to an ICM injection should have their tryptase level measured (considered as the marker of mast-cell activation) (5) and should undergo intradermal tests so as to identify and eliminate the culprit ICM in order to avoid any subsequent allergic accidents. Searching for cross-sensitization seems to be necessary. In two cases, this has enabled us to determine to which ICMs the patients were not sensitized and to inject them with these safely.

The effect of cetirizine on the integrin-dependent respiratory burst of normodense eosinophils

It has been proposed that cetirizine inhibits eosinophil migration and adherence. We evaluated the possible effect of cetirizine on integrin-induced eosinophil proinflammatory activation. Normodense eosinophils were triggered with monoclonal antibodies to integrins in the presence of different concentrations of certirizine. Proinflammatory activation was measured by evaluation of O2- production. Only at high concentrations (250 micrograms/ml) and in the first 15 min did certirizine significantly inhibit (p < 0.02) the eosinophil respiratory burst. No effect was shown for lower concentrations (50 and 100 micrograms/ml) or after 15 min. These data suggest that, only at very high concentrations, cetirizine may induce a transient inhibition of the integrin-induced eosinophil respiratory burst.

Comparison of vacuum cleaners

. AMONG INDOOR allergens, house dust mites (HDM) allergens are usually not detected airborne in undisturbed conditions, but cat allergens can remain airborne for long periods of time (1,2). The act of vacuum cleaning can increase the dispersion of particles, depending on the efficiency of the filtration devices (3). In this pilot study we aimed to compare the efficiency of three vacuum cleaners (VCs) with particular regard to mite (Der p 1) and cat (Fel d 1) allergens. VC1 was provided with water and a washable polyethylene (PE) filter (Acarbuster 2000, Envicon, Italy), VC2 with water and a high efficiency particulate air (HEPA) filter (Aida Live, Tecnovap srl, Italy), and VC3 was a conventional vacuum cleaner with a double-thickness paper bag, without exhaust filter. Air sampling was performed in a clean experimental room of 15 m volume by a Cascade Impactor Vortex Ultra (Casella Ltd, Bedfdord, UK), operating at a mean flow rate of 16.5 l/min, with a final glass-fiber filter type AP20 (Millipore, Bedford, MA). Samples of median weight 18 g containing a median concentration of Fel d 1 of 9000 mg andDer p 1 of 198 mg were collectedby thedifferentVCsoperating for 15 min. Fel d 1 and Der p 1 levels were quantified by enzyme-linked immunosorbent assay (ELISA) (Indoor Biotechnologies, Chester, UK) (4). The amount of airborne Der p 1 and Fel d 1 recovered by Vortex filter are shown in .Fig. 1. VC1 and VC2 showed lower allergen leakage than VC3, even in absence of the PE or HEPA filter. VC1 and VC2 demonstrated a markedly higher efficiency when equipped with PE or HEPA filters. PE and HEPA filters were comparable in terms of Fel d 1 and Der p 1 trapping. One main advantage of PE filters is that they can be washed in water, and do not need to be replaced as often as HEPA filters. Therefore, we suggest that PE filters in VCs could be a valid alternative to HEPA filters for controlling airborne dispersion of indoor allergens.