J ALLERGY CLIN IMMUNOL VOLUME 97, NUMBER 1, PART 3
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Abstracts
ATTENUATION OF T H E A I R W A Y S RESPONSE TO A M P BY I N H A L E D H E P A R I N IN A S T H M A T I C S : STUDY OF THE TIME-COURSE. ~. Polosa. N. Crimi. S Ma~fl. C. Vancheri. C. Ma.~truzzo. G. Panlino. A. Mistretta MD. Institute of Respiratory Diseases, University of Catania, ITALY. Inhaled heparin protects against various bronchoconsttictm stimuli in asthma possibly via an inhibition of mast cell activation. Since a d e n o s i n e 5 ' - m o n o p h o s p h a t e (AMP) elicits hronchoconstriction by augmenting mast cell mediator release, we have investigated the effect of inhaled heparin (15,000 units USP/mi, 4 mls) on the bronchoconstrictor response to this agonist and to methaeholine in a randomized double blind, placebo controlled study of 10 asthmatic subjects. We also set out a separate randomized, double blind study to look in more detail at the timecourse of this response. Inhaled heparin significantly increased the provocative concentration of AMP causing a 20% fall in forced expiratory volume in 1 second (PC20FEV1-AMP) from the post-placebo value of 22.3 mg/ml to 48.1 mg/ml (p<0.01). When compared to placebo, inhaled heparin failed to alter the airway responsiveness to methacholine, the PC20 methacholine values being 1.00 and 1.08 mg/ml respectively. When compared to placebo, the PC20 values for AMP after inhaled heparin were significantly increased up to 57.3 mg/ml and to 52.7 mg/ml at 15, and 60 rain respectively. At 180 min, heparin failed to affect AMP airway response; the PC20 AMP was not significantly different from that of placebo, with a value of 30.6 mg/ml. tleparin is effective in auenuating the airways response to AMP bul not methacholine, The time course of change in bronchial reactivity to AMP has a peak effect at 15 min and lasts up to 60 min. Possible mechanism(s) of inhaled heparin in asthma, may be related to an inhibitory modulation of mast cell activation.
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Human Eoainophils (Eos) Express RANTES mRNA and Store and Release Biologically Active RANTE$ Protein. Sun Yin~, 0 Men~. L TabordaBarata. CJ Corri~an. J Barkans. B Assoufl. R Moqbel. SR Durham, AB K@y, London U.K. Expression of RANTES mRNA in purified blood Eos obtained from atopic subjects was detected ~ RT-PCR. In sicu hybridization (ISH) with JS-riboprobes showed that 6.8-10% of Eos expressed RANTES mRNA, increasing to 25% after incubation with IFN-7, but not ionomycin in vitro. The Eos also showed specific immunoreactivity with an ~-RANTES mAb, consistent with the mRNA translation. By ELISA, blood Eos were shown to contain 5.2-8.8 ng of RANTES per I0 ° cells of which an average of 24% was released into culture supernatants after stimulation of the cells with serum-coated particles in vitro. The supernatants exhibited chemotactic activity of Eos which was inhibited (mean 68%) in the presence of an ~-RANTES Ab. Double immunocytochemistry (ICC) and ISH on biopsies obtained from allergen-induced LPR in skin showed that 55-75% of the RANTES mRNA + cells were EG2 + Eos. ICC showed that 55% of RANTES+ cells had morphological criteria of Eos. Thus, human Eos have the capacity to synthesize, store and secrete physiologically relevant quantities of RANTES, and may be an important source of this ehemokine in allergic inflammation.
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T h e A s s o c i a t i o n o f T o t a l I g E , I n d o o r and Outdoor allergen specific lgE and Asthma - The 3 Schools study. RB Sporik MD, SP Souillace MD, JM Inuram MD, W Price MD. G Rose BS, R Honsineer MD, TAE Plaits-Mills MD Phi). Charlottesville, VA. We studied three distinct populations of Middle schoolchildren aged 12-14: Buford School (Bu), Charlottesville, VA (city); Henley School (He), Albemarle County, VA (county); Los Alamos School (LA), NM (high altitude). A total of 1636 children (Bu-608, He446, LA-567) were surveyed with questionnaires and based on these 157 of the children with symptoms suggestive of asthma and 175 controls (C) were studied further with Histatnine challenge, and measurement of IgE and Specific ]gE to Indoor (Mite, Cat, Dog, Cockroach) and Outdoor (Ragweed, Rye) allergens. On the basis of symptomatic bronchial hyperreactivity (wheeze in last year + BHR < 7.8/~mols) 70 children were defined as asthmatic (Bu-31,He20,LA-19). Adjusted Odds Ratios were calculated using a multiple logistic regression model: C v. Asthma IgE >40 Indoor Outdoor
Bu 4.0* 6.9** 0.3*"
He LA Combined 0.3*" 5.1 ~ 2.8* 32.5*** 19.1"* 10.9"** 0.9" 0.05** 0.2** *p <0.05, **p<0.0l, ***p<0.00l With this model, group classification was correctly predicted in 78 to 86% of children. Although the pattern of sensitization was different in the 3 schools, indoor allergen sensitization was consistently the strongest association to asthma in this general population survey.
Superantlgens Alter Glucocorticoid Receptor Binding ( G C R ) A f f i n i t y i n V i t r o , SS P r a e e r M D . D Y M L e u n ~ MD PhD. SR Nimma~adda MD. W Surs BS. JD Soahh ~ D % n v e r CO Chronic sinusitis and other respiratory infections frequently complicates poorly controlled asthma. Staphylococcus aureus has been implicated as a pathogen in chronic sinusitis. Superantigens produced by S. aureus, such as Toxic Shock Syndrome Toxin-1 (TSST-I), induce IgE production in atopic individuals. Poorly controlled asthmatics, especially those who are steroid resistant (SR), have decreased peripheral blood mononuclear cell (PBMC) GCR binding affinity. We therefore examined the effect of TSST-I on PBMC GCR binding affinity. Baseline GCR binding affinities (Kd) were determined in PBMC from 4 poorly controlled or clinically SR asthmatics as well as 4 nonatopic controls. PBMC were also incubated with and without TSST-1 (lpg/ml) for 48 hr prior to analysis. Among the SR asthmatics, incubation with medium alone, resulted in a significant reduction in the Kd or increased steroid affinity, while incubation with TSST-1 sustained the binding defect. Incubation of PBMC from non-atopie controls with TSST-I had no effect on GCR binding affinity (see table). Subject 0 hr Kd 48 hr Kd 48 hr Kd p value Group (nM/1) + TSST- 1 No TSST-I SR Asthma *31.2 + 5.3 30.3 ± 4.2 * 11.8 + 1.8 *0.04 Non-Atopic 9.8 5:0.7 9.2 -+ 0.6 11.2 + 1.1 Data are expressed as mean GCR Kd:hSEM, p values determined by paired, 2 tailed t-test. In conclusion, this data supports the hypothesis that diminished PBMC GCR binding can be maintained following in vitro exposure to TSST-1. These observations suggest that microbial superantigens alter GCR binding affinity and could play a role in the altered glucocorticoid response observed in poorly controlled asthma.