Marek Sanak

Relationship between bleeding time, aspirin and the PlA1/A2 polymorphism of platelet glycoprotein IIIa

A single nucleotide T to C transition of the gene encoding glycoprotein IIIa leads to a common diallelic polymorphism Leu‐33→Pro (PLA1/A2). We studied the relationship between the PlA1/A2 polymorphism and platelet function in 80 healthy men, aged 20–25 years. Before aspirin ingestion, bleeding time (BT) was shorter in carriers of the PlA2 than in carriers of the PlA1/A1 allele. At 4 h after ingestion of 300 mg of aspirin, BT became prolonged, and the intergroup difference was enhanced. In seven out of 26 PLA2 allele carriers, aspirin shortened BT on average by 30 s, compared with only one among 54 subjects with the PlA1/A1 genotype. Thus, BT both at baseline and after aspirin depends on the PlA1/A2 polymorphism of glycoprotein IIIa. Carriers of the PlA2 allele appear to be more resistant to the antithrombotic action of aspirin.

The Presence of Rhinovirus in Lower Airways of Patients with Bronchial Asthma

RATIONALE The common cold virus, human rhinovirus (HRV), is the most frequent cause of asthma exacerbations. However, a possible contribution of HRV to the pathogenesis of chronic, persistent asthma has not been defined. OBJECTIVES To determine if patients with stable asthma, who are free of clinical signs of a respiratory infection for at least 3 weeks, harbor HRV in their bronchi more frequently than nonasthmatic control subjects, and whether clinical features of asthma are associated with the presence of HRV. METHODS Immunohistochemistry and the indirect in situ reverse transcription-polymerase chain reaction method were used to detect the presence of HRV in bronchial mucosal biopsies in patients with asthma and nonasthmatic control subjects. MEASUREMENTS AND MAIN RESULTS HRV was found by immunohistochemistry in 9 of 14 bronchial biopsies from subjects with asthma (64.3%) and 2 of 6 nonasthmatic control subjects (33.3%) (P = 0.38). With the more sensitive indirect in situ reverse transcription-polymerase chain reaction method, HRV was found in the mucosal biopsies of 73% of patients with asthma and 22% of nonasthmatic control subjects (P < 0.001). Subjects positive for HRV had lower pulmonary function, higher numbers of blood eosinophils and leukocytes, and eosinophilic infiltration in bronchial mucosa. CONCLUSIONS HRV was detected in the lower airway tissue of patients with asthma significantly more often than in nonasthmatic subjects, and its presence was associated with clinical features of more severe disease.

Prostaglandin E2 systemic production in patients with asthma with and without aspirin hypersensitivity

Background: A special regulatory role for prostaglandin E2 has been postulated in aspirin-induced asthma. A study was undertaken to investigate the effects of aspirin on the systemic production of prostaglandin E2 and cysteinyl leucotrienes in patients with asthma. Methods: The urinary concentrations were determined of two main prostaglandin E2 metabolites (13,14-dihydro-15keto-PGE2 using a commercial enzyme immunoassay and 9,15-dioxo-11α-hydroxy-2,3,4,5-tetranor-prostane-1,20-dioic acid by gas chromatography/mass spectrometry) and leucotriene E4 using an immunoassay. Determinations were performed at baseline and following oral aspirin and celecoxib challenges in two well-defined asthma phenotypes: aspirin-sensitive and aspirin-tolerant patients. Results: Aspirin precipitated bronchial reactions in all aspirin-sensitive patients but in none of the aspirin-tolerant patients. Celecoxib 400 mg was well tolerated by all patients except for one with aspirin-induced asthma. At baseline, the mean levels of prostaglandin E2 metabolites did not differ between the groups. Following different aspirin provocation doses, the mean levels of the two main prostaglandin E2 metabolites were decreased in the aspirin-tolerant group but remained unchanged in the aspirin-sensitive group. The dose of aspirin had no effect on the magnitude of the response on the prostaglandin E2 metabolites and its duration. In both groups, urinary prostaglandin E2 metabolites decreased following celecoxib challenge. No correlation was found between prostaglandin E2 metabolites and leucotriene E4. Conclusions: Aspirin-precipitated asthmatic attacks are not associated with changes in the systemic production of prostaglandin E2. In contrast, the systemic production of prostaglandin E2 becomes depressed by aspirin in non-sensitive patients. This different response might indicate COX-1-dependent prostaglandin E2 control of inflammatory cells in aspirin-induced asthma. Thus, PGE2 is released during the clinical reactions to aspirin through an alternative COX-2 pathway. The clinical implications of this finding are in line with current observations of good tolerance of the selective COX-2 inhibitors in aspirin-sensitive patients.

Clinical and genetic features underlying the response of patients with bronchial asthma to treatment with a leukotriene receptor antagonist.

Background Treatment with antileukotriene drugs results in clinical improvement in many, though not all, patients with asthma. It can be hypothesized that the subpopulation of asthmatic patients, characterized by aspirin intolerance and cysteinyl‐leukotriene overproduction, might profit most from antileukotriene treatment.

A moderate and unspecific release of cysteinyl leukotrienes by aspirin from peripheral blood leucocytes precludes its value for aspirin sensitivity testing in asthma.

Aspirin‐induced asthma (AIA) is a clinical syndrome related to cysteinyl leukotriene overproduction in airways. The confirmation of the diagnosis requires inconvenient provocation tests with acetyl salicylic acid (ASA).

Aspirin desensitization in patients with aspirin-induced and aspirin-tolerant asthma: A double-blind study

BACKGROUND Numerous open trials have demonstrated the beneficial clinical effects of aspirin desensitization (AD) in patients with aspirin-induced asthma (AIA). These beneficial effects might be attributable to aspirins potent anti-inflammatory properties, but that supposition requires further corroboration. OBJECTIVE We sought to compare the clinical and biochemical responses to chronic oral AD in 20 patients with AIA and 14 patients with aspirin-tolerant asthma (ATA). All of the patients had chronic rhinosinusitis and nasal polyposis, and these responses were investigated in a pilot, double-blind, placebo-controlled study. METHODS Twelve patients with AIA and 6 patients with ATA were randomly assigned to receive 624 mg of aspirin, and 8 patients with AIA and 8 patients with ATA received placebo. Both aspirin and placebo were administered once daily for 6 months. Nasal symptoms, Sino-Nasal Outcome Test (SNOT20) scores, peak nasal inspiratory flows, Asthma Control Questionnaire scores, spirometric parameters, peak expiratory flows, blood eosinophilia, and corticosteroid doses were assessed on a monthly basis. Levels of urinary leukotriene E4 and the stable plasma prostaglandin (PG) D2 metabolite 9α,11β-PGF2 were evaluated at baseline and after 1, 3, 5, and 6 months. RESULTS Only the patients with AIA subjected to AD reported improvements in smell and reductions in sneezing and nasal blockade. The SNOT20 and Asthma Control Questionnaire scores of these patients decreased, and their peak nasal inspiratory flows increased. The dosages of inhaled corticosteroids were reduced. There were no changes in leukotriene E(4) or 9α,11β-PGF(2) levels after AD. CONCLUSION The clinically beneficial effects of AD on nasal and bronchial symptoms occurred only in the patients with AIA.

Targeted eicosanoids lipidomics of exhaled breath condensate in healthy subjects.

BACKGROUND Exhaled breath condensate collection is a non-invasive method of sampling the respiratory tract that can be repeated several times in a wide range of clinical settings. Quantitation of non-volatile compounds in the condensate requires highly sensitive analytical methods, e.g. mass spectrometry. OBJECTIVE To validate cross-platform measurements of eicosanoids using high performance liquid chromatography or gas chromatography coupled with mass spectrometry in exhaled breath condensate sampled from 58 healthy individuals. METHODS Twenty different eicosanoid compounds, representing major arachidonic acid lipoxygenation and cyclooxygenation pathways were measured using a stable isotope dilution method. We applied a free palmitic acid concentration as a surrogate marker for the condensate dilution factor. RESULTS Eicosanoids concentrations in the condensates were consistent with their content in other biological fluids. Prostaglandin E(2) was the most abundant mediator, represented by its stable metabolite tetranor-PGEM. Prostaglandin D(2) products were at low concentration, while hydroxyacids derived from lipoxygenation were abundant. 5-HETE was elevated in current tobacco smokers. Leukotriene B(4) has the highest concentration of all 5-LO products. 15-LO analogues of cysteinyl leukotrienes-eoxins were detectable and metabolized to eoxin E(4). Two main vascular prostanoids: prostacyclin and thromboxane B(2) were present as metabolites. A marker for non-enzymatic lipid peroxidation, 8-iso-PGF(2alpha) isoprostane was increased in smokers. CONCLUSION Presented targeted lipidomics analysis of exhaled breath condensate in healthy subjects justifies its application to investigation of inflammatory lung diseases. Measurements of non-volatile mediators of inflammation in the condensates might characterize disease-specific pathological mechanisms and responses to treatment.

Genetic polymorphisms associated with acute pulmonary embolism and deep venous thrombosis.

Frequently an inherited predisposition to thrombosis remains clinically silent until an additional environmental factor intervenes. The present study aimed to assess distribution of inherited risk factors of venous thrombosis in patients with venous thromboembolism (VTE). The prevalences of factor V Leiden (FV Leiden), prothrombin factor II G20210A (FII G20210A), C677T and A1298C of methylenetetrahydrofolate reductase (MTHFR) mutations were studied in 149 VTE patients and 100 controls. The following key risks were established: previous deep venous thrombosis or pulmonary embolism (23.5%), bed rest (34.2%), immobilisation of lower limb (10.1%), hospitalisation (30.9%) and obesity (28.9%). In 29 (19%) patients and in three (3%) controls FV Leiden was found. A significant association between VTE and FV Leiden was established. There were six (4%) carriers of the FII G20210A among VTE patients and one in the controls. No associations between VTE and MTHFR polymorphisms (C677T, A1298C) were found. In three of 149 patients both FV Leiden and FII G20210A polymorphisms were observed. The mean protein C activity was slightly, though nonsignificantly, smaller in VTE patients. In conclusion, there was a positive association between venous thromboembolism and factor V Leiden. Only a weak trend favouring a relationship between prothrombin factor II G20210A and venous thrombolism was present. No associations between common polymorphisms of methylenetetrahydrofolate reductase and venous thromboembolism were found.

Two Different Transcription Factors Discriminate the −315C>T Polymorphism of the FcεRIα Gene: Binding of Sp1 to −315C and of a High Mobility Group-Related Molecule to −315T

The α-chain is a specific component of FcεRI, which is essential for the cell surface expression of FcεRI and the binding of IgE. Recently, two single nucleotide polymorphisms (SNPs) in the α-chain promoter, −315C>T and −66T>C, have been shown by statistic studies to associate with allergic diseases. The effect of −66 SNP on GATA-1-mediated promoter activity has been already indicated. In the present study, to investigate roles of the −315 SNP on the α-chain promoter functions, the transcription activity was evaluated by reporter assay. The α-chain promoter carrying −315T (minor allele) possessed significantly higher transcriptional activity than that of −315C (major allele). EMSA indicated that the transcription factor Sp1, but not Myc-associated zinc finger protein (MAZ), was bound to the −315C allele probe and that a transcription factor belonging to a high mobility group-family bound to the −315T allele probe. The chromatin immunoprecipitation assay suggested that high mobility group 1, 2, and Sp1 bound around −315 of FcεRIα genomic DNA in vivo in the human basophil cell line KU812 with −315C/T and in human peripheral blood basophils with −315C/C, respectively. When cell surface expression level of FcεRI on basophils was analyzed by flow cytometry, basophils from individuals carrying −315T allele expressed significantly higher amount of FcεRI compared with those of −315C/C. The findings demonstrate that a −315 SNP significantly affects human FcεRI α-chain promoter activity and expression level of FcεRI on basophils by binding different transcription factors to the SNP site.

Advanced phenotyping in hypersensitivity drug reactions to NSAIDs

Non‐steroidal anti‐inflammatory drugs (NSAIDs) are the medications most frequently involved in hypersensitivity drug reactions. Because NSAIDs are prescribed for many conditions, this is a world‐wide problem affecting patients of all ages. Various hypersensitivity reactions have been reported, mainly affecting the skin and/or the respiratory airways. The most frequent of these is acute urticaria, which can be induced by several different NSAIDs. Both specific and non‐specific immunological pathways have been proposed as underlying mechanisms. This review presents the clinical phenotypes and the drugs involved in NSAID hypersensitivity. Five major clinical syndromes can be distinguished: aspirin‐exacerbated respiratory disease (AERD), aspirin‐exacerbated cutaneous disease (AECD), multiple NSAID‐induced urticaria/angioedema (MNSAID‐UA), single NSAID‐IgE reactions and single NSAID T cell responses. However, further classification is possible within these five major entities, by detailed descriptions of the clinical characteristics enabling more phenotypes to be defined. This detailed differentiation now seems required in order to undertake appropriate pharmacogenetic studies.