BACKGROUND:There are two isoforms of cyclo-oxygenase (COX), namely COX-1 and COX-2. COX-1 is constitutively expressed in most tissues and in blood platelets. The metabolites derived from COX-1 are probably involved in cellular housekeeping functions. COX-2 is expressed only following cellular activation by inflammatory stimuli and is thought to be involved in inflammation.METHODS:The expression of COX-1 and COX-2 isoenzymes has been studied in the bronchial mucosa of 10 normal and 18 asthmatic subjects, 11 of whom had aspirin-sensitive asthma (ASA) and seven had non-aspirin-sensitive asthma (NASA) RESULTS: There was a significant fourfold and 14-fold increase, respectively, in the epithelial and submucosal cellular expression of COX-2, but not of COX-1, in asthmatic patients. There was no significant difference in the total number of cells staining for either COX-1 or COX-2 between subjects with ASA and NASA, but the number and percentage of mast cells that expressed COX-2 was significantly increased sixfold and twofold, respectively, in individuals with ASA. There was a mean fourfold increase in the percentage of COX-2 expressing cells that were mast cells in subjects with ASA and the number of eosinophils expressing COX-2 was increased 2.5-fold in these subjects.CONCLUSION:COX-2-derived metabolites may play an essential part in the inflammatory processes present in asthmatic airways and development of drugs targeted at this isoenzyme may have therapeutic potential in the treatment of asthma. Mast cells and eosinophils may also have a central role in the pathology of aspirin-sensitive asthma.

SummaryBackground Aspirin‐induced asthma (AIA) affects one in 10 individuals with adult‐onset asthma. It is not known if aspirin sensitivity is due to immune mechanisms or to interference with biochemical pathways.Objective The study aimed to test for possible involvement of the genes of the Major Histocompatibility Complex (MHC) in AIA.Methods HLA‐DPB1 and HLA‐DRB1 genotyping was carried out by DNA methods in 59 patients with positive challenge tests for AIA and in 48 normal and 57 asthmatic controlsResults The DPB 1*0301 frequency was increased in AIA patients when compared with normal controls (19.5% vs 5.2%, Odds Ratio = 4.4, 95% Confidence Interval (CI) 1.6–12.1, P= 0.002), and compared with asthmatic controls (4.4%, OR = 5.3, 95%CI= 1.9–14.4, P= 0.0001). The frequency of DPB 1*0401 in AIA subjects was decreased when compared with normal controls (28.8% vs 49.0%, OR = 0.42, 95%CI = 0.24–0.74, P= 0.003) and asthmatic controls (45.6%, OR = 0.48, 95%CI = 0.28–0.83, P= 0.008). The results remained significant when corrected for multiple comparisons. There were no significant HLA‐DRB 1 associations with AIA.Conclusion The presence of an HLA association suggests that immune recognition of an unknown antigen may be part of the aetiology of AIA.

BACKGROUND:The aspirin-induced bronchoconstriction in patients with aspirin-sensitive asthma is caused by cysteinyl leukotriene release. The cellular source of the leukotrienes is unknown. The inflammatory cell infiltrate in bronchial biopsy samples from seven aspirin-sensitive asthmatic (ASA) subjects and eight non-ASA subjects before and after local challenge with lysine aspirin was therefore examined.METHODS:Using flexible bronchoscopy, airway mucosal biopsy samples were taken and lysine aspirin solution was placed directly onto a carina of the contralateral lung. Twenty minutes later a second series of biopsy samples was taken from the site of the local endobronchial lysine aspirin challenge. The biopsy samples were double immunostained with a rabbit polyclonal antibody to the enzyme 5-lipoxygenase and monoclonal antibodies to mast cells (AA1), neutrophils (NP57), macrophages (EBM11), T lymphocytes (anti-CD3), and total (BMK13) and activated eosinophils (EG2).RESULTS:A decrease in both absolute mast cell numbers staining with mast cell tryptase (AA1) and the percentage of mast cells co-immunostaining with 5-lipoxygenase was seen in the ASA patients after lysine aspirin challenge compared with the non-ASA control group. There was also an increase in the numbers of activated eosinophils (EG2) in the ASA subjects compared with the non-ASA group. No changes were observed in the total numbers of macrophages (EBM11), neutrophils (NP57), total eosinophils (BMK13), and T lymphocytes (anti-CD3) after challenge with lysine aspirin.CONCLUSIONS:The decrease in numbers of mast cells staining for tryptase and the increase in activated eosinophils after endobronchial challenge with lysine aspirin may represent degranulation of these cell types, and may be an early event associated with aspirin-sensitive reactions in ASA subjects.

The inflammatory cell infiltrate in bronchial biopsies of 12 aspirin-sensitive asthmatic (ASA) subjects and eight non-aspirin-sensitive (non-ASA) control subjects have been compared. Biopsies were taken from a right middle or lower lobe segmental carina using fiberoptic bronchoscopy. The biopsies were snap-frozen in OCT, and sections 5 microns thick were doubled immunostained using a rabbit polyclonal antibody to the enzyme 5-lipoxygenase (5-LO) and with a monoclonal antibody to neutrophils (NP57), macrophages (EMB11), and total (BMK13) and activated eosinophils (EG2), mast cells (AA1), and T-lymphocytes (anti-CD3). There was no significant difference in the total numbers of cells staining for 5-LO between the two groups of subjects. As a percentage of total 5-LO cells, there were significantly more mast cells (12.9 +/- 3.8% versus 3.4 +/- 3.1%; p = 0.039) and total eosinophils (34.7 +/- 9.4% versus 11.1 +/- 3.8%; p = 0.044) and significantly fewer macrophages (23.3 +/- 6.1% versus 39.8% +/- 5.3; p = 0.041) in the bronchial biopsies from ASA subjects as compared with non-ASA patients. The numbers of neutrophils, T-lymphocytes, and activated eosinophils were similar for the two groups. The increased numbers of eosinophils and mast cells identified in the bronchial tissue from aspirin-sensitive asthmatic subjects may be the source of the enhanced cysteinyl leukotriene production observed in these subjects.

Aspirin-intolerant asthma (AIA) is associated with local and systemic release of the cysteinyl leukotrienes (cLT), histamine and tryptase.It is also associated with eoslnophilia and an influx of eosinophils into the airway after segmental challenge with indomethacin.The role of cytokines in AIA and the eosinophilia associated with it is unknown.To address the role of cytokines in this process, 4 aspirin-intolerant asthmatics (AIA), 4 aspirin-tolerant asthmatics (ATA) and 6 normals, were evaluated.Subjects were characterized by oral aspirin challenge and underwent bronchoscopy with baseline lavage and then instillation of indomethacin and lavage 15 minutes later.RANTES, GM-CSF, IL-5 and TNF alpha were measured.Rantes levels increased in BALF as did eosinophils in AIA and some ATA.(Spearman's rho=0.53,p=.051).Levels of GM-CSF, IL-5 and TNF alpha did not change.PERCENT (PG/ML EOSINOPHILS 5 ~ BALF) l(~r ~ p--O.O7 ,~ p--O.o60 N. ATA A~A ATA AIAWe conclude that RANTES, a potent eosinophil chemoattractant, as well as the cLTs or other novel eicosanoids, may be playing a role in the influx of eosinophils seen after indomethacin.

BACKGROUND:Paranasal sinus disease and bronchial asthma are frequently associated. Patients with asthma often have chronic inflammatory changes of the paranasal mucosa rather than acute bacterial sinusitis. Our aim was to compare the rankings of A-mode ultrasonography and standard radiography as routine screening procedures in the diagnostic workup of these patients. METHODS:We compared the evaluation of the maxillary sinuses by A-mode ultrasonography and standard radiographs. Computed tomography served as a gold standard in 19 patients with asthma who had no history of sinus surgery. RESULTS:Computed tomography showed at least some minimal mucosal thickening in any of the paranasal sinuses in 74% and of the maxillary sinuses in 61% of the patients. Compared with the results of computed tomography, plain-view radiography gave a specificity of 86.7% for the maxillary sinuses. Although all cases of severe mucosal thickening were detected, sensitivity for minimal mucosal hyperplasia was low, at 52.2%. In contrast, A-mode ultrasonography demonstrated a sensitivity of 70% but a specificity of only 22%. CONCLUSIONS:Even symptom-free patients with asthma show a high prevalence of at least limited mucosal thickening in the paranasal sinuses. Acute sinusitis is not a common finding. A-mode ultrasonography does not allow sufficient evaluation of this mucosal hyperplasia and is therefore not suitable for initial screening in these patients. It may prove helpful as a follow-up in selected patients with known anatomic characteristics, however, especially when antral fluid is involved. For routine screening in patients with asthma, a conventional Waters' view radiograph should be used in conjunction with direct visualization of the ostial-meatal area by fiberoptic or rigid rhinoscopy. This combination provides information about the degree of mucosal hyperplasia as well as mucosal inflammation and secretion.

Urinary leukotriene E4 (LTE4) increases during exacerbations of asthma and following antigen challenge. We determined whether urinary LTE4 excretion reflects sulphidopeptide leukotrienes in the airways of asthmatic patients. Urinary LTE4 concentration was measured prior to and 1.5 and 3.5 h following inhalation of bronchoconstrictive doses of leukotriene C4 (LTC4) or LTE4 in eight asthmatic subjects. Increasing doses of agonist were inhaled until a 35% fall in specific airways conductance (sGaw) was achieved. There was no significant difference between the 53 +/- 3% (mean +/- SEM) fall in sGaw following inhalation of LTC4 (63.1 ng geometric mean, GM, range 5.8-527.5 ng) and the 43 +/- 4% fall in sGaw following inhalation of LTE4 7.94 ng/GM (range 132-3701 ng). The LTE4 excretion rate increased significantly from 2.95 (range 0.6-17.5) ng.h-1 to 4.67 (range 0.8-20) ng.h-1 at 1.5 h following LTC4 inhalation; and from 1.8 (range 0.07-6.7) ng.h-1 to 6.9 (range 2.9-27.3) ng.h-1 at 1.5 h following LTE4 inhalation; and had returned from baseline by 3.5 h. There was a correlation between the dose of LTC4 inhaled and LTE4 excreted in the urine (r = 0.82 and r = 0.72, respectively). The % recovery of LTE4 in the urine, of the total dose of inhaled LTC4 or LTE4 administered, was 6.9 +/- 4.1% and 0.8 +/- 0.3%, respectively. Thus, inhalation of bronchoconstricting doses of LTC4 or LTE4 alter urinary LTE4 excretion in a dose-dependent fashion. This indicates that urinary LTE4 can be used as a marker of sulphidopeptide leukotriene synthesis in the lungs of patients with asthma.

We wanted to determine whether the airway response to inhaled leukotriene C4 (LTC4) is similar to inhaled leukotriene E4 (LTE4) in aspirin-sensitive asthma and, therefore, determined airway responsiveness to histamine, LTC4 and LTE4 in seven aspirin-sensitive subjects and 13 control asthmatic subjects, who were tolerant of aspirin. The concentration of inhaled lysine-aspirin which produced a 15% fall in forced expiratory volume in one second (FEV1) (PC15) was determined in aspirin-sensitive asthmatic subjects. The dose of histamine, LTC4 and LTE4 which produced a 35% fall in specific airways conductance (PD35sGaw) was determined by linear interpolation from the log dose response curve. There was no correlation between the PC15 for lysine-aspirin and the airway reactivity to inhaled LTC4 or LTE4. There was no difference in airway response to histamine and LTC4 between any of the groups of asthmatic subjects. There was a rank order of potency LTC4 > LTE4 > histamine in both groups, with LTC4 approximately 1,000 fold more potent than histamine in both groups. Aspirin-sensitive asthmatic subjects were significantly more responsive to LTE4 (p = 0.02) than aspirin-tolerant asthmatic subjects. The relative responsiveness of LTE4 to histamine (PD35 histamine/PD35 LTE4) was significantly greater in aspirin-sensitive asthmatic subjects compared to aspirin-tolerant asthmatic subjects (p = 0.05). There was no difference in relative responsiveness of LTC4 to histamine between aspirin-sensitive or aspirin-tolerant asthmatic subjects. We conclude that the airways of aspirin-sensitive asthmatic subjects demonstrate a selective hyperresponsiveness to LTE4, which is not observed for LTC4.

61 patients suffering from intrinsic (idiotypic) or extrinsic (allergic) asthma were investigated for signs of complement activation and for C3 phenotype distribution. Activation of both the classical and alternative pathway of the complement system and generation of the membrane attack complex could be assessed by ELISAs for the activation-specific protein-protein complexes C1rsC1 inhibitor, C3b(Bb)P and SC5b-9, respectively. A possible deficiency of the complement regulatory proteins C1 inhibitor, factor H and factor I was excluded. In contrast to earlier studies, C3 allele frequencies did not differ from those found in the healthy population. Our results support the role of complement activation during bronchial asthma and, thereby, provide further evidence for the inflammatory nature of the disease.

The FEV1 and urinary leukotriene E4 (LTE4) concentrations were determined in six aspirin-sensitive and six non-aspirin-sensitive asthmatic subjects before and after inhalation challenge with lysine-aspirin or placebo solution. Lysine-aspirin produced a mean fall in FEV1 of 26.7 +/- 4.9% (mean +/- SEM) in subjects with aspirin sensitivity and of 8.5 +/- 6.5% (mean +/- SEM) in non-aspirin-sensitive asthmatic subjects. The mean baseline urinary LTE4 concentration of 83 pg/mg creatinine (geometric mean [GM], range 15 to 326 pg/mg creatinine) in aspirin-sensitive subjects was significantly higher than the 33.8 pg/mg creatinine (GM, range 10 to 111 pg/mg creatinine) in non-aspirin-sensitive subjects (p = 0.02). In aspirin-sensitive subjects, inhalation challenge with lysine-aspirin produced a significant increase in urinary LTE4 concentration to 240 pg/mg creatinine (GM, range 60 to 1,113 pg/mg creatinine), which was not observed after placebo challenge. There was no significant change in urinary LTE4 concentration after inhalation challenge with either lysine-aspirin or placebo solution in non-aspirin-sensitive asthmatic subjects. Thus, sulfidopeptide leukotrienes are released after inhalation of lysine-aspirin in aspirin-sensitive asthmatic patients.

Aspirin-sensitive asthma and aspirin-sensitive rhinosinusitis can only be identified by provocation with analgesics because there are no appropriate in-vitro-methods. In the USA the oral challenge is the preferred provocation method. However, due to possible side effects we use the bronchial provocation with lysine-aspirin in the Hochgebirgsklinik Davos-Wolfgang since 1979. In a pilot study in 1989 and a following controlled study we developed and then investigated the sensitivity, specificity and side effects of a nasal provocation test using lysine-aspirin. All aspirin-sensitive asthmatics had a decrease in nasal flow >40% following nasal lysine-aspirin, with no reaction to lysine control of appropriate pH and osmolality. Control groups of normals, hayfever, perennial rhinitis and non-ASA-sensitive asthma did not react to lysine-aspirin nasal challenge. No bronchopulmonary nor other side effects were recorded. Nasal provocation may be employed to diagnose aspirin-sensitive asthma, and is especially useful in those cases where oral and bronchial provocation are contraindicated.

We have determined IgG subclass concentrations in 100 patients with aspirin-induced asthma and 80 healthy controls. Patients on chronic corticotherapy (n = 64) had significantly lower total IgG levels than patients not receiving steroids (n = 36) or controls. Corticotherapy was not associated with changes in the subclass distributions. In patients, the most striking finding was elevation of IgG4. It was not related to corticotherapy or serum IgE levels. The rise in IgG4 was accompanied by a modest, though statistically significant, depression of IgG1. No changes of IgG2 and IgG3 concentrations were observed. Thus, aspirin-induced asthma is characterized by a distinct pattern of distributions of IgG subclasses. It is suggested that in aspirin-induced asthma elevation of IgG4 might result from chronic antigenic stimulation, of viral origin, and that determination of IgG subclass distribution might be of clinical interest.

Soon after its introduction into therapy in 1899, aspirin became an extremely successful analgesic and anti-inflammatory agent. Recently, its clinical applications have increased dramatically and include coronary artery disease and several related cardiovascular disorders. In patients with unstable angina or transient ischemic attacks aspirin favourably affects the course of disease, probably through its anti-platelet action (Reilly and Fitzgerald 1988). In acute myocardial infarction it significantly lowers mortality (isis-2 Collaborative Group 1988). Indeed, aspirin is now recognized as the most popular drug in the world.

Quantitation of serum IgG subclass proteins is of interest in evaluation of patients with recurrent infections, atopic and autoimmune diseases.We have determined IgG subclass protein concentrations in 80 adult patients with aspirin-induced asthma (AIA) and in 75 sex-and age-matched controls.Patients were in stnble clinical

There have been several reports on alterations of platelet function and raised plasma heparin levels in symptom-free atopic subjects. Either of these can affect formation of thrombin in vivo. In 25 symptom-free atopic patients and 32 healthy volunteers we studied the generation of thrombin in blood emerging from a standardized skin microvasculature injury, which also served to determine bleeding time. Generation of thrombin was delayed in atopics. They produced significantly less thrombin (P < 0.0 1) during the early and central phase of haemostasis. The amount of thrombin generated was inversely correlated to bleeding time, which in atopics was on average 50 sec longer than in controls (P = 0.055). Two hours after ingestion of 500 mg aspirin, this difference increased up to 150 sec, although the individual responses varied markedly (P = 0.08), while the generation of thrombin became strongly depressed in both groups. The possible clinical relevance of the delayed formation of thrombin in atopy awaits further studies.