305 In vivo studies of kinin receptors in allergic rhinitis

216

Abstracts

IN VIVO STUDlES OF KJNIN RECBPTORS IN ALLERGIC RHINITIS. J.A. R.M. Na D. proudphs, Baltimore, Maryland. Two bradykinin (K) receptor subtypes, termed 81 and B2, have heen described. On B1 receptors the kinii metabolite, Des(Arg9)-K @), is more potent than the parent peptide but on B2 receptors, this metabolite is inactive. Animal studies suggestthat Bl receptors are upregulated during inflammatory conditions. To determine if such an upregulation occurs during allergic rhinitis. 8 asymptomatic atopic subjects were challenged with diluent and with increasing dosesof K or D before and after undergoing an allergen (A) challenge. Symptom scores(SS) and the levels of albumin @ISA, @ml), TAMEesterase activity (TAME; cpm x 103) and histamine (HIS; nj$nl) in nasal lavages were recorded. Results (median p&k changesfrom &luent challenge) were: Before Allergen 4 h post 24 h post K !2 A-K A-D K D

307 H.C. Kaulbach, R.J. H&man, D.B. Peden, and MA. Kaliner. Bethesda, MD. Antimicrobial activity is present in a var~c~yoi proteins contained in nasal secretions. ‘These inclutk the vascular proteins IgG and serum IgA. as well as the glandular proteins, lactofenin, lysozyme, and secretory IgA. To determine if additional antimicrobiai factors exist, full strength bilateral nasal secretions were collected from 50 volunteers after gustatory rrflex stimulation with hot chili peppers. Secretions went pooled, centrifuged to remove the mucus, and passed through membrane filters with a 10,000 MW cutoff. Screening for antimicrobial activity was accomplished by dropping varying concentrations of the resulting filtrate onto a thin lawn of bacteria and observing zones of inhibition. Results showed growth inhibition of Pseudomonas aeruginosa, Escherichia coli, Klebsicllrt pneumoniae, Streptococcus pneumoniae, and Haemouhilus influenzae. No inhibition of Vibrio cholerae, Salmonella tvphimurium, and Shirrella flexneri was observed. To yuantitate the antimicrobial activity. mixtures of El. aeruginosa and 10 K filtrate from 3 individuals were prepared, incubated, spread-@& and enumerated. Plate counts dropped to 0 colony fomling units/ml when filtrates were concentrated 2- !o IO.fnld. The bactericidal activity against Pseudomonas wa4 equivalent to that of gentamicin, 0.2 un/ml. The antimicrobial factor eiutes as a single pak from a gel filtration column at an elution volume corresponding to a !vIW less than 1000. These data sugge-estthat nasal secretions contain a low MW antimicrobial molecule which is being further characterized.

6?5 75 -0ps 2.‘4 7”, t: 53 7.53 72’4 10 5 2i.6 9 5 -0.5 1.3 t&E 325 0.2 66:3 96:5 147 3.7 HSA 257 -i.l 1.3 1.5 HIS Resuonsesto A were not different for anv uarameter on K and D’days. No increasesin HIS were sein;pon kinin challenge. For all challenges with K the responsesfor each parameier were similar. go response to D was seenat any time point. To determine if a chronic inflammatory state was necessaryfor B1 induction, 8 symptomatic, mass allereic subjects-werese&lly chalieng&l &ring the-grassseas& with diluent, 1 mg of D and 100 I.L~of K. No increasesabove diluent were-seenfor any peter upon challenge with D, while K induced increases of 1.5,21.5 cpm x 10-3,and 62.2 pg/ml in SS, TAME and HSA, respectively. We conclude that B1 receptors are not upregulated during allergic rhinitis and that kinin effects in the nose are mediated via B2 receptors.

306

BIOCHEMICAL ANALYSIS OF NASAL SECRETIONS INDUCED BY ASPIRIN {ASA) CHALLENGES IN PATIENTS WITH ASA $BNSITIVITY. NASAL POLYPS AND CHRONIC RHiNOSXNUSM?S.M. Kowalski, B. Woiciechowska, M Sliwimka-Kowalska, P. Bravton. Y. Inarashi, H. Kaulbach. M. White. J. Rozniecki and M. Kaliner, L&z, Poland and Bethesda, Maryland Aspirin (ASA) induces nasal symptoms in a subset of patients with asthma and/or chronic rhinosinusitis and nasal polyps, and the mechanism of the reaction is obscure. In this study, three groups of patients: Group A (7 ASA-sensitive patients), Group B (9 ASA-tolerant patients with nasal polyps), and Group C (9 ASA-tolerant patients with chroni‘c &n&s) were cl&en&d orally with ASA (threshold ASA doses in Group A and IO0 mg of ASA in Groups B and C). Timed nasal lavages were obtained before and after challenges and were assayed for total protein, albumin, lysozyme, lactoferrin, histamine, PGD,. and LTCfi,. In Grout A. ASA challenges induced severe rhinorrhea/congestionand significant increasesin mean concentrationsin nasal lavages of total protein (mean increase 3.8x), albumin (4x), lysozyme (2.7x). lactoferrin (3.8x), and LTC&TD, (3.6x). Histamine and PGD, (mast cell/basophil activation markers) rose by 410% and 160%, respectively. In two control groups (B and C) ASA did not induce clinical symptoms, and insignificant changes in biochemical markers of nasal secretions were observed. Our study indicates that ASAinduced nasal reactions involve increased vascular permeability, glandular secretions, and possible mast cell activation. I

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308

HYPERRESPONSIVENESS TO LOW DOSE ALLERGEN AFTER NASAL ALZ$ROE CHALLBNGE. Y. &am&i, M.D.. H. C. Kaalbach, M.Dy G. L, Piacentini. M.D., 3. K. Hahn. R.N., M. A. Kaliner, M.D. arid M. V. white, M.D., Bethesda, MD Allergic symptoms are often exacerbated by repeated antigen exposures. To determine whether ongoing allergic reactions elicit hyperresponsiveness, responses to nasal provocations were compared pre- and post-nasal allergen challenge. Atopic subjects were studied on three consecutive days. Seventeen subjects were challenged with relevant (11 experimental subjects) or irrelevant (6 control subjects) allergens. On days 1 and 3 each subject received a single low dose (133 AU) allergen, while on day. 2 they received a higher dose (1330 AU). The nasal cavity was sequentially lavaged from 3 minutes to 8 hours later, and the lavage fluids were assayed for prostaglandin(PG)D~ None of the control subjects responded to either high or low dose allergen (PGD, ~30 pg/ml). The eleven experimental subjects had PGD, values of 39Sk95 pg/ml (range=50-1200 pg/ml) in the lavage within 30 minutes after the allergen challenge on day 2. Four of these subjects, who had relatively minor responses (PGD, 200 pg/ml on day 2. In this group, five showed higher responses to low dose allergen challenge on day 3 as compared to day 1, which was statistically significant (peO.05, x2 test). The remaining two subjects, who did not increase hyperresponsiveness, had very high PGD, levels (>600 pgfml) after the initial low dose allergen challenge on day 1. These results suggest that allergen exposure can increase the response to subsequent a&ergen challenge depending on the initial sensitivity of the subject.