Substance P induced histamine release from nasal mucosa of subjects with and without allergic rhinitis.

OBJECTIVE AND DESIGN: There is evidence that substance P (SP) is involved in events related to allergic and nonallergic rhinitis. Furthermore, some effects of SP seem to be greater in subjects suffering from allergic rhinitis than in nonallergic subjects. To investigate if these effects may be partly mediated by histamine release (HR) we studied the influence of SP on HR from nasal mucosa of subjects with and without allergic rhinitis using an in vitro organ culture system. SUBJECTS: Nasal mucosa of the inferior turbinate was obtained from ten patients suffering from allergic rhinitis and eighteen non-allergic subjects receiving surgical therapy for nasal obstruction. METHODS: Tissue samples of nasal mucosa were stimulated with 10(-5) M SP or with 10(-5) M Ca-ionophore A23187 for 120 minutes, and the histamine content was determined in the culture supernatant. RESULTS: Both SP and Ca-ionophore A23187, caused a significantly higher HR from the samples of the non-allergic group (p < 0.01) compared to baseline controls (spontaneous release). The same effect was seen in the allergic group (p < 0.01 and p = 0.036). Comparing the increase in HR from allergic and non-allergic mucosa, in allergics the HR stimulated by SP was significantly higher (p = 0.031), whereas Ca-ionophore A23187 did not show this effect. CONCLUSION: These findings suggest a role of SP in inducing release of histamine from human nasal mucosa, thereby influencing physiologic and pathophysiologic nasal conditions, especially in allergic inflammatory processes.

Heparin, derived from the mast cells of human lungs is responsible for the generation of kinins in allergic reactions due to the activation of the contact system.

BACKGROUND: In a recent study mast cell heparin proteoglycan (HepPG) of a cell line derived from a mouse mastocytoma was isolated. Glycosaminoglycans proved to be an initiating surface for starting contact activation and could explain kinin generation present in allergic reactions. It is the aim of the present study to prove that HepPG or glycosaminoglycan derived from human mast cells is also capable of acting as a physiologic macromolecule and to induce contact activation. METHODS: HepPG molecules were isolated by anionic column chromatography. Their ability to accelerate reciprocal activation of factor XII was investigated by spectrophotometry. The anticoagulant effect was demonstrated by an increase in partial thromboplastin time. HPLC was performed to correlate these effects with molecular weight (MW). RESULTS: The isolated heparin showed high contact-activating and anticoagulant potency. Both actions were suppressed by incubation with heparinase I. The maximum contact activation peak appeared at a lower MW than the anticoagulant effect. CONCLUSION: These in vitro results explain the results of in vivo allergen challenge studies where a high degree of kinin generation occurs. Heparin derived from human mast cells therefore seems to represent the physiological macromolecule capable of activating the contact system and could be a missing link between cellular and humoral responses in allergic reactions.

Kinin generation in acute pneumonia and chronic bronchitis.

Kinins are potent inflammatory mediators, liberated from kininogens by different kininogenases. The aim of this study was to investigate the kinin generation pathways in acute and chronic inflammation of the lower airways. We studied bronchoalveolar lavage fluid (BALF) of patients with acute pneumonia, patients with chronic bronchitis and healthy controls. Kinins were determined by radioimmunoassay (RIA). Plasma kallikrein (pl-Kal), alpha2-macroglobulin (alpha2-M) and toluenesulphonylarginine methyl ester (TAME) esterase activity (TAME-ea) were studied in BALF before and after gel filtration chromatography. Plasma kallikrein and alpha2-M were measured using two newly developed sandwich enzyme-linked immunosorbent assays (ELISAs). TAME-ea was measured by a radiochemical assay. After gel filtration, inhibition of TAME-ea with benzamidine, soy-bean-trypsin inhibitor (SBTI) and aprotinin was performed. Kinins and TAME-ea did not differ significantly between acute pneumonia and chronic bronchitis, whereas pl-Kal and alpha2-M values were significantly higher in acute pneumonia. Gel filtration revealed the highest TAME-ea peak in acute pneumonia corresponding with the first alpha2-M peak at approximately 800 kDa, whereas in chronic bronchitis the highest peak was found at approximately 40 kDa. The inhibition test showed that the TAME-ea peak at approximately 800 kDa was due to pl-Kal and the TAME-ea peak at approximately 40 kDa was mainly due to tissue kallikrein. High peaks of alpha2-M and pl-Kal were found in pneumonia and only small peaks were seen in chronic bronchitis. We conclude that in acute airway inflammation kinins seem to be mainly generated by plasma kallikrein whereas in chronic inflammation, kininogenases other than plasma kallikrein, such as tissue kallikrein, seem to be more important.

Mast cell derived heparin activates the contact system: a link to kinin generation in allergic reactions.

Contact activation occurs when plasma comes in contact with negatively charged manmade surfaces but no substance that initiates contact activation in vivo has been identified. We have isolated a mast cell heparin proteoglycan (MC-HepPG) from a Furth mouse mastocytoma-derived cell line that is analogous to human tissue-type mast cell HepPG. This material and other glycosaminoglycans (GAGs) were tested for their ability to accelerate the reciprocal activation of factor XII and prekallikrein and the autoactivation of factor XII. Quantitative analysis showed the MC-HepPG to be as active as dextran sulfate on a weight basis; hog intestine heparin, dermatan sulfate, keratan polysulfate and chondroitin sulfate C were less active, other sulfated polysaccharides were essentially inactive. Incubation of MC-HepPG in 1:4 diluted plasma resulted in complete cleavage of high molecular weight kininogen in a factor XII-dependent reaction. All of the MC-HepPG dependent reactions described above were inhibited by preincubation of MC-HepPG with heparinase I and II but not by pretreatment with heparitinase, chondroitinase ABC or the serine protease inhibitor aPMSF thus indicating that heparin proteoglycan is indeed acting as an initiating 'surface'. We analysed the proteoglycan preparation by HPLC gel filtration. Fractions spanning a molecular weight range of > 400000-8000 were active initiators. Comparison of the chromatograms obtained before and after cleavage of GAG side chains from the protein core suggested that dissociated GAGs in the MW range 69000-17000 are the most active species rather than the complete proteoglycan. MC-HepPG GAGs therefore represent a physiologic macromolecule with activity comparable to non-physiological surfaces in a purified system and with the capability to induce activation of the contact system in diluted plasma. Its ability to promote kinin generation links cellular and humoral inflammatory responses in the perivasculature and provides a possible explanation for the elevated kinin levels observed after allergen exposure.

Comparison between two automated systems to determine specific IgE: CAP and ELItest.

BACKGROUND AND OBJECTIVE: The ELItest is a newly developed system to measure specific IgE based on allergen bound to paper rings and an alkaline phosphatase conjugated second antibody detection system. It was compared to the CAP system, a method based on allergen conjugated to an encapsulated cellulose polymer and a beta-galactosidase conjugated fluorescence detection system. METHODS: Sera of 300 patients with positive history and positive skin-prick tests to common allergens (birch, timothy-grass, cat dander, dermatophagoides ptronyssinus, wasp venom) and 30 negative controls were tested in both systems. Serial dilutions of high titre sera were measured; inter- and intraassay coefficients of variation (cv) were determined. RESULTS: The CAP system proved to be more sensitive (92.3%) compared to ELItest (84%) but marginally less specific (94.7% for CAP versus 96.7% for ELItest). Intraassay cv were slightly lower in the ELItest (7.2% CAP versus 6.4% ELItest), whereas the interassay cv was roughly twice as high for ELItest (20.1%) than for the CAP system (11.4%). Linearity over an 8-fold dilution was good in both tests (r2 0.979 ELItest versus 0.996 CAP), although ELItest levelled off at higher allergen concentrations. Similarly, correlation analysis between both systems revealed that ELItest consistently measured lower values, especially at higher concentrations of specific IgE. The slope of the linear regression line of a log/log plot of measured IgE concentrations was significantly lower than 1 in birch, cat and wasp; the y-intersect was significantly lower than 0 in all analysed allergens. CONCLUSION: These results suggest that the ELItest system for the measurement of specific IgE is not quite as reproducible and sensitive as the CAP system but slightly more specific, and that higher concentrations of specific IgE are measured lower in the ELItest. One potential reason might be that the amount of allergen bound to a paper ring might be smaller than that bound to a cellulose polymer, but further experiments are necessary to prove this hypothesis.

Substance-P-induced histamine release from human nasal mucosa in vitro.

There is growing evidence that substance P (SP) is one of the main neuropeptides involved in neurogenic inflammation of the airways. However, a number of studies were not able to demonstrate histamine release from human mucosal mast cells after SP administration. Since cultures of isolated cell systems provide only a partial picture of the inflammatory processes in vivo, organ culture models promise to offer physiologically relevant assay systems for studying tissue interactions. Thus, we examined the influence of SP on histamine release and its morphological effects on human nasal mucosa using a previously described histoculture technique. Compared to controls, the histamine content in the culture bath was significantly elevated after SP stimulation (p < 0.05). Histomorphometry showed a decreased density of mast cells and an increased percentage of degranulated mast cells. These findings were dose and time dependent and support the hypothesis of a close interaction between C-sensory nerves and mast cells implying that these interactions are of pathogenetic importance in nasal mucosa inflammation.

Gelatin sponge-supported histoculture of human nasal mucosa.

Considerable progress has recently been made in the understanding of airway inflammation by cell culture assays and in vivo provocation studies. Inasmuch as ethical considerations limit experimental work in humans, physiologically relevant in vitro models are required to better understand cellular and molecular tissue interactions in human nasal mucosa. Here we describe a human nasal mucosa culture model utilizing a simple gelatin sponge-supported histoculture system at the air-liquid interface. Viable mucosa was preserved for at least 48 h, as shown by morphology and immunohistochemical staining with Ki-67 as marker for proliferation. Pro-inflammatory mediators (kinins, histamine, thromboxane B2, prostaglandin F2 alpha, and substance P) are detectable in serum-containing as well as serum-free culture medium. Incubation with 10(-8) M substance P increases the number of degranulated mast cells after 48 h by 26% (P < 0.01). In this model, biochemical responses can be correlated with histologic alterations of the target tissue. Inflammatory parameters can be examined and compared in various patient groups and different stimulators/inhibitors. This culture method provides a valuable research tool for analyzing all compartments present in nasal mucosa under physiologically relevant conditions, and for studying complex interactions and responses of mucosal cell populations in their natural tissue environment.

Measurement of allergen-specific IgD and correlation with allergen-specific IgE.

A new method for the measurement of allergen-specific IgD (as-IgD) was developed by modifying the ImmunoCAP assay (Pharmacia), and amplification of the signal with a goat anti-human/rabbit anti-goat detection system. The assay was sensitive enough to measure as-IgD in serum samples. The specificity of the assay was examined using inhibition tests with excess corresponding and non-corresponding allergens. For the different allergens inhibition rates between 56% (house dust mite) and 88% (cat) could be achieved. Non-corresponding allergens did not inhibit the as-IgD binding. Total IgE and allergen-specific IgE (as-IgE) was measured using the ImmunoCAP system. Total IgD was measured using a sandwich ELISA. As-IgD was measured in serum samples from 51 atopic and 23 non-atopic subjects, and the correlation with as-IgE was examined. As-IgD was detected in both atopics and non-atopics but at higher levels in atopics. As-IgD against birch pollen and timothy pollen allergen was found to be increased in atopics with IgE directed against these allergens compared to atopics without IgE against these allergens (P < 0.02 and P < 0.03). As-IgD against birch pollen allergen was higher in atopics with IgE specific to this allergen than in non-atopics (P < 0.02). In contrast to total IgE and total IgD, significant correlations were observed between as-IgD and as-IgE against timothy pollen (r = 0.34, P < 0.04), birch pollen (r = 0.38, P < 0.05) and cat dander allergen (r = 0.52, P < 0.01). The observed correlations between as-IgD and IgE suggest that IgD and IgE may be similarly regulated, and thus the measurement of as-IgD may give further insight into the regulation of IgE.

Activation of human Hageman factor (factor XII) in the presence of zinc and phosphate ions.

Hageman factor (FXII, HF) is a monomeric plasma zymogen that is capable of autoactivation to the serine protease FXIIa in the presence of negatively charged surfaces such as glass, kaolin, ellagic acid and dextran sulfate. FXIIa activates prekallikrein to kallikrein which in turn digests high molecular weight kininogen (HK) to produce the vasoactive peptide bradykinin (BK). Known natural activators of FXII and the contact system include heparin, sulfatides, phospholipids, endotoxin, and urate crystals. We now present evidence that FXII can undergo activation in the presence of phosphate ions (P(i)) and certain divalent metal ions. FXII (1 microgram/ml) and prekallikrein (1 microgram/ml), in HEPES buffered saline, pH 7.4, were incubated with 0-100 mM sodium phosphate, 0-200 microM zinc chloride, and 0.6 mM Chromozym-PK; absorbance at 405 nm was monitored. Graphic analysis of the data indicated reciprocal activation of the two enzymes within 60 min which was dependent upon Zn(II) and P(i). While Ca(II) did not replace Zn(II) as an activator it significantly enhanced Zn(II)- and P(i)-dependent activation of FXII. Maximum activation occurred at 1-10 mM P(i) and approximately 25 microM Zn(II). Co(II), Cu(II) and Ca(II) were negative while Fe(II) was positive in the presence of 1 mM P(i). Cl-, SO4= and CO3=/HCO3- ions were negative when tested in the presence of 50 microM Zn(II). P(i) and Zn(II) ions promoted activation of FXII alone (but not prekallikrein) and the kinetics of this reaction suggested autoactivation. These data therefore suggest that physiological concentrations of P(i) and Zn(II) may be sufficient for a low-level turnover of the contact system in plasma which in turn may be responsible for the background levels of cleaved HK and BK found in normal plasma.

Measurement of membrane bound IgD and IgM on B lymphocytes.

An assay system for the determination of the membrane bound IgD (mIgD) and IgM (mIgM) on B lymphocytes was developed by the combination of two new ELISA methods with the results of flow cytometry after labeling with specific antibodies. The mIgD and mIgM of B lymphocytes were prepared by incubating mononuclear cells (MNCs) in Tween 20 containing buffer and repeated freeze/thaw cycles. Optimal results were achieved with 0.2-0.4% Tween 20 and two freezing cycles. With biotin-streptavidin amplification the sensitivity of the ELISA was 30 microU/ml for IgD and 0.5 ng/ml for IgM. In healthy persons 3.5 +/- 0.5 mU mIgD were detected on 10(6) IgD+ cells and 57.1 +/- 5.9 ng mIgM on 10(6) IgM+ cells. The mIgD/mIgM ratio was 0.065 +/- 0.005 mU/ng. The developed ELISA systems utilize only commercially available reagents and therefore provide a convenient reproducible tool for determining membrane bound IgD and IgM on B lymphocytes.

Human Hageman factor (factor XII) and high molecular weight kininogen compete for the same binding site on human umbilical vein endothelial cells.

Factor XII (FXII, plasma concentration 375 nM) is a critical member of the plasma contact activation system and is the zymogen form of FXIIa, a serine protease involved in intrinsic coagulation, complement activation, activation of factor VII, and generation of the vasoactive peptide bradykinin. As such its interaction with cells involved in inflammatory pathways can be of physiologic and pathologic significance. We have studied the binding of FXII to cultured human umbilical vein endothelial cells (HUVEC). HUVEC were incubated with 125I-FXII, and cell-bound factor FXII was measured. FXII bound to HUVEC saturably in a zinc-dependent manner. The optimal zinc concentration was 50-60 microM. Binding of labeled FXII was drastically reduced when a 200-fold molar excess of unlabeled FXII was included in the incubation mixture at time zero or when added at 60 min during a 150-min time course experiment. Quantitative binding experiments indicated a dissociation constant of 144 nM with 10-12 million binding sites/endothelial cell. Unlabeled high molecular weight kininogen (HK) inhibited the binding of labeled FXII with a Ki of 98 nM, whereas unlabeled FXII inhibited the binding of labeled HK to HUVEC with a Ki of 152 nM. SDS-polyacrylamide gel electrophoresis and autoradiography of cell-bound 125I-FXII showed that factor XII underwent limited proteolysis and the molecular weights of the fragments were similar in size to activated FXII. The cell-bound activated factor XII was also able to activate prekallikrein. These data suggest that (i) FXII binds to HUVEC specifically, saturably, and reversibly in a zinc-dependent manner, (ii) HK and FXII may compete with each other for the same cell-surface receptor/s, and (iii) cell-bound FXII is capable of undergoing activation to FXIIa.

Bronchial hyperreactivity in patients with moderate pulmonary circulation overload.

The clinical course of congestive heart failure (CHF) and mitral valve stenosis (MVS) is accompanied by episodes of dyspnea, wheezing, and cough, symptoms also observed in patients with bronchial hyperreactivity. However, it is still controversial whether bronchial hyperreactivity is demonstrable in patients with chronic overload of the pulmonary circulation. In order to examine the effects of CHF on the respiratory function, we performed pulmonary function tests, titrated bronchial acetylcholine provocations, and left and right heart catheterization in 21 patients with impaired left ventricular function (mean ejection fraction, 37 percent, NYHA class 3), 5 patients with MVS, and 17 control patients with coronary artery disease (mean ejection fraction, 63 percent). Bronchial hyperresponsiveness was defined as an obstructive response to increased doses of inhaled acetylcholine. A 20 percent fall in forced expiratory volume in the first second (FEV1), a 100 percent increase in total airway resistance (Rtot), and a 60 percent reduction of pulmonary conductance (SGtot) were considered positive. Patients with impaired left ventricular function showed significantly higher airway resistance, and lower airway conductance at the maximal tolerated acetylcholine dose compared with control patients. Patients with MVS had a significant lower airway conductance. The induced bronchial obstruction was completely reversible upon inhalation of a beta 2-mimetic. We conclude that chronic overload of the pulmonary circulation is accompanied by bronchial hyperreactivity that may augment the symptoms of dyspnea in patients with CHF and MVS.

Activation of factor XI in plasma is dependent on factor XII.

The activation of factor XI initiates the intrinsic coagulation pathway. Until recently it was believed that the main activator of factor XI is factor XIIa in conjunction with the cofactor high molecular weight kininogen on a negatively charged surface. Two recent reports have presented evidence that in a purified system factor XI is activatable by thrombin together with the soluble polyanion dextran sulfate. To assess the physiological relevance of these findings we studied the activation of factor XI in normal and factor XII-deficient plasma. We used either kaolin/cephalin or dextran sulfate as a surface for the intrinsic coagulation pathway, tissue factor to generate thrombin via the extrinsic pathway, or the addition of alpha-thrombin directly. 125I-factor XI, added to factor XI-deficient plasma at physiologic concentrations (35 nmol/L), is rapidly cleaved on incubation with kaolin. The kinetics appear to be exponential with half the maximum cleavage at 5 minutes. Similar kinetics of factor XI cleavage are seen when 40 nmol/L factor XIIa (equal to 10% of factor XII activation) is added to factor XII-deficient plasma if an activating surface is provided. Tissue factor (1:500) added to plasma did not induce cleavage of factor XI during a 90-minute incubation, although fibrin formation within 30 seconds indicated that thrombin was generated via the extrinsic pathway. Adding 1 mumol/L alpha-thrombin (equivalent to 50% prothrombin activation) directly to factor XII deficient or normal plasma (with or without kaolin/cephalin/Ca2+ or dextran sulfate) led to instantaneous fibrinogen cleavage, but again no cleavage of factor XI was observable. We conclude that in plasma surroundings factor XI is not activated by thrombin, and that proposals of thrombin initiation of the intrinsic coagulation cascade are not supportable.

Bronchodilatory effect of inhaled zardaverine, a phosphodiesterase III and IV inhibitor, in patients with asthma.

Zardaverine is a newly developed selective phosphodiesterase III and IV inhibitor. This study investigates the bronchodilatory properties of zardaverine, administered by inhalation. Twelve patients with reversible bronchial obstruction (increase in forced expiratory volume in one second (change FEV1 % predicted) at least 15% after 200 micrograms salbutamol, median age 31 yrs, range 21-54 years) entered the double-blind, crossover study. Four puffs of either zardaverine (total dose 6 mg) or placebo were inhaled at 15 min intervals. Pulmonary function (specific airway conductance (sGaw) and FEV1 was measured by body plethysmography at regular intervals (5 and 12 min after each puff and, in addition, 30, 60, 120, 180 and 240 min after the last puff). Compared to placebo, sGaw and FEV1 increased significantly during the first hour of repeated inhalations, but not during the entire observation period of almost 5 h. The maximum mean difference between zardaverine and placebo for FEV1 was 0.3 l or 12% and occurred approximately 1 h after inhalation of the first puff. In seven patients FEV1 increased by > 15%. The duration of action varied considerably between patients. Three patients complained of side-effects (headache, drowsiness, vertigo, nausea), and one of these dropped out of the study due to vomiting. We conclude that inhalational administration of zardaverine has a modest and short-lasting bronchodilating activity.

Comparison between MAGIC LITE- and CAP-system: two automated specific IgE antibody assays.

The MAGIC LITE system, a newly developed immunochemiluminometric assay for specific and total IgE antibody using paramagnetic particles coupled with standardized allergens as solid phase, was compared to the CAP system, a recently introduced immunoassay based on a cellulose polymer encased in a capsule. A total of 357 serum samples of patients with suspected inhalant allergies and a positive skin prick test (SPT) to common allergens (birch, timothy-grass, mugwort, cat dander, Dermatophagoides pteronyssinus, Alternaria) were investigated. Fifty SPT negative subjects served as controls (total number of tests in each assay = 1600). Both assays were highly precise (overall intra-assay and inter-assay coefficients of variation were 2.9% and 4.5% in MAGIC LITE, 4.7% and 5.5% in CAP) and showed excellent linearity (mean r2 of eightfold log2 serum dilutions were 99.7% and 99.3% in MAGIC LITE and CAP). Good correlations were found between the absolute specific IgE antibody values detected by both methods (correlation coefficient r: birth 0.86, grass 0.93, mugwort 0.96, cat 0.91, D. pteronyssinus 0.73, Alternaria 0.90). Excellent specificity (greater than or equal to 98%) occurred in both assays and with all allergens, and sensitivity was related to the allergen (MAGIC LITE/CAP): birch 91%/89%, grass 83%/90%, mugwort 50%/69%, cat 83%/83%, D. pteronyssinus 72%/78%, Alternaria 75%/81%. Our results indicate that both in vitro tests are useful tools for the detection of specific IgE antibody.

Factors affecting the rate of contact activation in human plasma.

The rate of high molecular weight kininogen cleavage in human plasma treated with dextran sulfate depends largely on the length of preincubation at 37 degrees C and the sample size during preincubation. The longer the preincubation with aliquots < 100 microliters, the more refractory to contact activation the plasma became. This effect is not due to prekallikrein or factor XII consumption/inhibition since both proteins are functional in clotting assays and detectable in immunoblots even after prolonged incubation times at 37 degrees C.

Bradykinin and other inflammatory mediators in BAL-fluid from patients with active pulmonary inflammation.

We evaluated the levels of bradykinin, albumin, TAME-esterase activity, histamine, PGD2 and LTC4 in bronchoalveolar lavage fluid from asthmatics and from patients with pneumonia, sarcoidosis, fibrosis, and chronic bronchitis. Compared with the results of healthy volunteers and atopic asymptomatic asthmatics the bradykinin levels and TAME-esterase activity were significantly elevated. In all other groups, histamine was additionally elevated in asymptomatic asthmatics, whereas albumin was elevated in symptomatic asthmatics and fibrosis patients, and decreased in chronic bronchitis and pneumonia patients. Following local intrabronchial allergen challenge of mild grass pollen asthmatics out of season bradykinin levels increased significantly, correlated with albumin, histamine and TAME-esterase activity. In contrast to the increased mediator concentrations in the early phase reaction there was no change of BAL cells in asthmatics compared to baseline and healthy volunteers. The presence of bradykinin in the bronchoalveolar space of patients with active pulmonary inflammations and bradykinin generation in asthmatics as a result of intrabronchial allergen challenge provides strong evidence that kinins are involved in inflammatory disorders of the lower airways.

Nasal challenge studies with bradykinin: influence upon mediator generation.

Previous studies have shown that nasal allergen provocation leads to dose-dependent increases of inflammatory mediators, e.g. histamine, kinins, LTC4 and PGD2 in nasal lavages. To investigate further the interaction of these mediators, a titration study with intranasal bradykinin (Bk) application (maximal dose 100 nmol/nostril) and consecutive lavage were performed in eight grass-pollen-allergic patients out of season, and five controls. The nasal lavages were analysed for albumin, N-alpha-tosyl-L-arginine methyl ester (TAME) esterase activity, histamine, 9 alpha,11 beta-PGF2, and LTC4. The clinical reactions were measured with a subjective symptom score. A dose-dependent elevation of albumin was found which was significantly higher in patients with allergic and non-allergic rhinitis compared with normal volunteers. TAME-esterase activity also increased in relation to the dosage of Bk given without significant difference between the various groups. No influence on histamine, LTC4 and 9 alpha,11 beta-PGF2, release (PGD2 metabolite) was seen. Short-lasting clinical symptoms like irritation, sneezing, and obstruction were noticed after the two highest Bk dosages (10 and 100 nmol). We conclude that intranasally applied Bk induces a dose-dependent plasma leakage into the nasal cavity, which is significantly higher in patients with seasonal allergic rhinitis out of season compared to normals. Bk does not seem to affect the mast cell since histamine, LTC4 and 9 alpha,11 beta-PGF2 levels do not alter. The ability to induce relevant symptoms of rhinitis provides strong support for the hypothesis that kinins may be important mediators of inflammatory disorders of the upper airways.

Diagnosis of nasal allergy to the house dust mite.

Twenty-five patients with perennial rhinitis and a positive skin prick test (SPT) for Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) were submitted to nasal provocation and the radioimmunosorbent test (RAST) for specific IgE-antibodies. We found a significant correlation in the reaction to both allergen extracts for all parameters examined. In addition, there was a significant correlation among the SPT, the RAST and the nasal provocation for Dp and between the SPT and the RAST for Df. In patients with perennial rhinitis we recommend the combination of all three methods to differentiate unspecific rhinitis from an allergic rhinitis. Only the patients with proved allergic rhinitis could benefit from a specific hyposensitisation.