Lennart Greiff

A double-blind, randomized, placebo-controlled trial of macrolide in the treatment of chronic rhinosinusitis

Objectives: The antiinflammatory effect of macrolide antibiotics has been well‐established, as has their role in the treatment of certain disorders of chronic airway inflammation. Several studies have suggested that long‐term, low‐dose macrolides may be efficacious in the treatment of chronic rhinosinusitis; however, these studies have lacked a control group. To date, this effect has not been tested in a randomized, placebo‐controlled study.

The‘nasal pool’device applies controlled concentrations of solutes on human nasal airway mucosa and samples its surface exudations/secretions

A‘nasal pool’(NP) device, a compressible plastic container with an adapted nozzle, was used to perform a continuous 10‐min nasal provocation and lavage. This novel technique brings known concentrations of agents into contact with a large and defined area of the nasal mucosal surface for extended periods of time. Simultaneously, the surface exudations/secretions of the same nasal mucosa are effectively sampled by the NP fluid. A concentration‐response study of histamine (80, 400 and 2000 μg/ml) was performed in 12 normal subjects on three different occasions. Exudation of plasma albumin into the lavage fluid was measured to quantitate the histamine‐induced airway inflammation. The effect of the dwell time on exudation was examined using histamine (400 μg/ml) instilled in the nasal cavity for time periods from 10 sec to 10 min. The time course of histamine‐induced plasma exudation response was studied by exposing the mucosa to histamine (400 μg/ml) for 12 min, with the NP renewed every minute. Allergen‐provocations were performed in subjects with hay fever and TAME‐esterase activity in the returned lavage fluid was determined to indicate the degree of response. Histamine produced a concentration‐dependent increase in albumin levels in the NP fluid; 123·3 ± 25·6, 213·8 ± 19·7 and 430·2 ± 32·0 μg/ml (mean ± s.e.m.), respectively. The time‐course study demonstrated that plasma exudation into the lumen occurred promptly and that the exudation response reached a maximum after exposure to histamine for 6–10 min. The dwell‐time experiments supported this finding. After 10 min the exudation appeared to decline despite the continued presence of histamine. Allergen provocation resulted in a concentration‐dependent increase in TAME‐esterase activity of the NP‐fluids. It is concluded that the NP technique provides new possibilities in studies of pathophysiology and pharmacology of human airway mucosa. With the NP technique controlled concentrations of mediators, drugs, tracers, etc. can be applied for desirable lengths of time on a well‐defined mucosal surface area. This particular area is gently and effectively lavaged during the presence of the NP fluid and when the fluid is recovered by decompressing the NP device.

Plasma exudation as a first line respiratory mucosal defence

A great variety of provocations of the airway mucosa produce extravasation of plasma from the abundant subepithelial microvessels. A plasma exudate has important actions through its volume, its specific and unspecific binding proteins, its enzyme systems, and its potent peptides (of kinin. complement, coagulation, fibrinolysis and other systems). If allowed to operate on the surface of an intact mucosa the plasma exudale would have important roles in normal airway defence. Recent observations in guinea‐pig tracheo‐bronchial airways and in human nasal airways suggest that the mucosal exudation of plasma into the airway lumen is a non‐injurious fully reversible process. Threshold exudative responses thus resulted in the appearance of an ‘unfiltered’ plasma exudate not only in the lamina propria but also on the surface of an undisrupted mucosa. Even after extensive luminal entry of exudate the epithelial lining was intact, as judged by light, fluorescence and electron microscopy. Hence, the epithelial barrier was reversibly permeable when approached from beneath by the plasma exudate. This was a distinct increase in outward permeability, because even during the exudation of plasma the mucosa remained a barrier to luminal solutes. It is possible that the exudate itself, by a slight compressive action on the basolateral aspect of epithelial cells, creates intercellular pathways for its entry into the lumen. Contrary to current beliefs, we propose that plasma exudation should be considered a first line respiratory defence mechanism operating together with other systems of the mucosal surface.

Prevalence of nasal symptoms and their relation to self-reported asthma and chronic bronchitis/emphysema

Little information is available on associations between rhinitis and chronic bronchitis/emphysema (CBE). Self-reported upper airway symptoms, asthma, and CBE were examined in 12,079 adults living in southern Sweden. The response rate was 70% (n=8,469), of whom 33% reported significant nasal symptoms: a blocked nose was reported by 21%; sneezing by 18%; nasal discharge by 17%; and thick yellow nasal discharge by 5.7%. Nasal symptoms and combined nasal and self-reported bronchial disease were generally more common among smokers than nonsmokers. There was little overlap between asthma and CBE, but 46% of those with asthma and 40% of those with CBE had significant nasal symptoms. Best predicting factors (odds ratios >3) for asthma and CBE were nasal symptoms due to exposure to animals and damp/cold air, respectively. One-third of an adult, southern Swedish population, had significant allergic and/or nonallergic nasal symptoms. Nasal symptoms were frequently found to coexist with both asthma and chronic bronchitis/emphysema, suggesting that pan-airway engagement is common in both diseases. Differing associations between types of nasal symptoms and allergic and irritant triggers of nasal symptoms, with regard to asthma and chronic bronchitis/emphysema, emphasize the different natures of these bronchial diseases.

Cytolysis and piecemeal degranulation as distinct modes of activation of airway mucosal eosinophils

BACKGROUND Cytotoxic eosinophil granule proteins are considered important in the pathogenesis of inflammatory airway diseases, including asthma, rhinitis, and polyposis. However, little is known about the mechanisms involved in the deposition of these tissue-damaging granular products in vivo. OBJECTIVE We sought to determine the occurrence of degranulating eosinophils, those with morphologic evidence of cytolysis with associated clusters of free eosinophil granules (Cfegs), and to identify the frequency of apoptotic eosinophils in inflamed upper airway tissue. METHODS Eosinophil-rich nasal polyps were processed for transmission electron microscopy and for light microscopic evaluation of whole-mount preparations subjected to deep tissue staining for eosinophil peroxidase. RESULTS The mean proportion of eosinophil subtypes were intact and resting (6.8%), intact but degranulating (83%), cytolytic or Cfegs (9.9%), and apoptotic (0.0%). All degranulating eosinophils exhibited piecemeal degranulation. The occurrence of Cfegs was confirmed in nonsectioned whole-mount preparations. Depending on the appearance of their core and matrix, the specific granules were divided into four subtypes, and a degranulation index (altered per total granules) was calculated for each eosinophil. Cytolytic eosinophils had a much lower degranulation index than intact eosinophils present in the same tissue (P < .001). CONCLUSIONS These data indicate that eosinophil cytolysis is present in human airway mucosa, that its occurrence is not an artifact of the means of tissue handling, and that cytolysis of eosinophils may occur without prior extensive degranulation. We suggest that eosinophil cytolysis is a major activation mechanism, which occurs along with, but is distinct from, other types of degranulation.

Contribution of Plasma-Derived Molecules to Mucosal Immune Defence, Disease and Repair in the Airways

This review discusses recent observations, in health and disease, on the release and distribution of plasma‐derived molecules in the airway mucosa. Briefly, the new data on airway mucosal exudation mechanisms suggest that the protein systems of plasma contribute significantly to the mucosal biology, not only in injured airways but also in such mildly inflamed airways that lack oedema and exhibit no sign of epithelial derangement. Plasma as a source of pluripotent growth factor, adhesive, leucocyte‐activating, etc., molecules may deserve a prominent position in schemes that claim to illustrate immunological and inflammatory mechanisms of the airway mucosa in vivo.

Degranulation patterns of eosinophil granulocytes as determinants of eosinophil driven disease

BACKGROUND Degranulation of eosinophils in target tissues is considered a key pathogenic event in major chronic eosinophilic diseases. However, because of a lack of appropriate methods, little is known about degranulation of eosinophils in common eosinophilic diseases. METHODS Using transmission electron microscopic (TEM) analysis, a novel approach has been devised and validated to quantify eosinophil degranulation in human tissues (assessed in individual cells as percentage granules with structural signs of protein release). Biopsy specimens from patients with inflammatory bowel disease, allergic rhinitis, asthma, and nasal polyposis were evaluated. RESULTS All conditions displayed a similar degree of local tissue eosinophilia, with no differences being observed in eosinophil numbers in the airway mucosa of patients with airway diseases and the colonic mucosa of those with inflammatory bowel disease (IBD). In contrast, marked differences in the mean (SE) extent of eosinophil degranulation were observed between the patient groups; IBD 9.3 (1.4)% altered granules, artificial and natural allergen challenge induced allergic rhinitis 67.8 (6.8)% and 86.6 (3.0)%, respectively, asthma 18.1 (2)%, and nasal polyposis 46.6 (7.6)%. CONCLUSIONS This study provides the first quantitative data which show that different eosinophilic conditions, despite having similar numbers of tissue eosinophils, may exhibit markedly different degranulation patterns. The present assessment of piecemeal degranulation would thus make it possible to delineate the conditions under which eosinophils are likely to contribute to disease processes. This novel type of analysis may also guide and validate anti-eosinophilic treatment options.

Effects of orally inhaled budesonide in seasonal allergic rhinitis

It has previously been demonstrated that topical nasal treatment with glucocorticosteroids has significant effects on the bronchial airways. Less is known about effects on nasal disease by topical bronchial treatment with these drugs. The present study examined effects on nasal allergic disease of inhaled budesonide (avoiding nasal deposition of the drug). Patients with seasonal allergic rhinitis, but without asthma, were thus given inhalations of budesonide (600 microg b.i.d.) or placebo. The aim of the design was to allow the study of eosinophilic airway disease in a part of the airway other than the directly treated locus. Moderate to high birch pollen levels were recorded during the study season, and nasal symptoms were significantly increased in both treatment groups, although they were milder in patients receiving budesonide than in the placebo group (p<0.05). Nasal brush eosinophils and nasal lavage fluid levels of eosinophil cationic protein as well as blood eosinophils were increased during the season (p<0.05), but these increases were prevented by the inhaled budesonide. Nasal lavage fluid levels of alpha2-macroglobulin were particularly elevated in the placebo group but did not differ between patients receiving placebo and budesonide. Budesonide prevented the seasonal development of increased bronchoconstrictor responses to methacholine challenge (p<0.05). In conclusion, budesonide reduced the seasonal eosinophilia both in the circulation and in the nose along with an attenuation of seasonal nasal symptoms. Hence, at a daily dose of 600 microg b.i.d., known to cause no, or minimal, adverse effects, inhaled budesonide produces clinically significant anti-inflammatory effects in the entire airways, including the nasal mucosa, which is not exposed topically to the drug. We suggest that nasal and systemic anti-eosinophil actions are produced at commonly employed dose levels of orally inhaled budesonide.

Nasal cytokines in common cold and allergic rhinitis

Coronavirus‐induced common cold and allergen‐induced rhinitis are characterized by nasal mucosal exudation of bulk blood plasma. The mucosal exudation process involves ‘flooding’ of the lamina propria with plasma‐derived binding proteins and it is possible that subepithelial inflammatory cytokines and mediators may be moved by the exudate to the mucosal surface. In this study, we have analysed cytokine levels in nasal lavage (NAL) fluids from non‐allergic subjects inoculated with coronavirus (n= 20) and from subjects with allergic (birch pollen) rhinitis subjected to additional allergen challenge (samples were obtained 35min post challenge) in the laboratory (n= 10). Ten of the 20 inoculated subjects developed common cold and 10 remained healthy. Interferon‐γ (IFN‐γ), interleukin‐1β (IL‐1β), granulocyte‐macrophage colony‐stimulating factor (GM‐CSF), IL‐4, and IL‐6 were analysed in unprocessed NAL fluids using immunoassays. The subjects who developed common cold had increased NAL fluid levels of IFNγ (P < 0.05) that correlated well with the symptoms (P < 0.001). IFNγ did not increase in subjects with allergic rhinitis. IL‐1β levels were similar in NAL fluids obtained from all inoculated subjects. In the subjects with allergic rhinitis NAL fluid levels of both IL‐1β and GM‐CSF were increased (P < 0.05). GM‐CSF was not detected in common cold. IL‐4 and IL‐6 were not detectable in any of the NAL fluids. The present cytokines may not only emanate from superficial mucosal cells. By aiding plasma exudation subepithelial cytokines may potentially also be retrieved on the mucosal surface. Our study provides original in vivo data supporting the notion that a TH‐1 profile of cytokines, notably IFNγ, is present in viral infection and further supporting the view that GM‐CSF is an important cytokine in allergic airways disease.

Effects of formoterol on histamine induced plasma exudation in induced sputum from normal subjects

BACKGROUND A number of studies have shown that β2 agonists, including formoterol, inhibit plasma exudation induced by the inflammatory stimulus in animal airways. Whether clinical doses of β2 agonists inhibit plasma exudation in human bronchial airways is unknown. METHODS In order to explore the microvascular permeability and its potential inhibition by β2 agonists in human bronchial airways a dual induction method was developed: plasma exudation induced by histamine inhalation followed by sputum induction by hypertonic saline (4.5%) inhalation. Sixteen healthy subjects received formoterol (18 μg) in a placebo controlled, double blind, crossover study. Sputum was induced on five occasions: once at baseline and four times after histamine challenge (30 minutes and eight hours after both formoterol and placebo treatments). Sputum levels of α2-macroglobulin were determined to indicate microvascular-epithelial exudation of bulk plasma. RESULTS Histamine induced plasma exudation 30 minutes after placebo was considerably greater than at baseline (median difference 11.3 μg/ml (95% confidence interval 0.9 to 90.0)). At 30 minutes after formoterol the effect of histamine was reduced by 5.1 (0.9 to 61.9) μg/ml compared with placebo. At eight hours histamine produced less exudation and inhibition by formoterol was not demonstrated. CONCLUSION This study shows for the first time an anti-exudative effect of a β2 agonist in healthy human bronchial airways. Through its physical and biological effects, plasma exudation is of multipotential pathogenic importance in asthma. If the present findings translate to disease conditions, it suggests that an anti-exudative effect may contribute to the anti-asthmatic activity of formoterol.