Anna Gielicz

Plasma 9α,11β-PGF2, a PGD2 metabolite, as a sensitive marker of mast cell activation by allergen in bronchial asthma

Background: Prostaglandin D2 (PGD2) is a major cyclooxygenase product generated by activated mast cells during an allergic response. Assessment of PGD2 and its metabolites in patients with asthma has mostly been performed in urine, bronchoalveolar lavage fluid and induced sputum, whereas human plasma determinations have been performed only sporadically. Methods: In 32 patients with allergic asthma and 50 healthy non-allergic controls, baseline plasma and urinary levels of 9α,11β-PGF2, a primary PGD2 metabolite, were assessed by gas chromatography/mass spectrometry. Serum tryptase levels were measured by fluoroenzyme immunoassay and urinary leukotriene E4 (LTE4) by ELISA. In a subgroup of 10 asthmatics (randomly selected from the 32 study patients) in whom bronchial allergen challenges with specific allergens (Dermatophagoides pteronyssinus, n = 4, mixed grass pollens, n = 6) were carried out, measurements were taken both before and after provocation. Results: At baseline no significant differences between mean plasma and urinary levels of the PGD2 metabolite and serum tryptase levels were found in asthmatics or controls. Asthmatic patients had significantly higher urinary LTE4 levels. Allergen challenge resulted in a significant early increase in the mean plasma 9α,11β-PGF2 level and only a borderline but significant increase in the urinary 9α,11β-PGF2 level within 2 hours after provocation. The challenge did not produce statistically significant changes in serum tryptase levels. Urinary LTE4 levels remained significantly increased 4 hours after provocation. Conclusions: PGD2 is actively involved in the early asthmatic response to allergens. Measurement of 9α,11β-PGF2 release into plasma rather than urine following allergen challenge is a sensitive marker of enhanced PGD2 synthesis, most probably due to mast cell activation.

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.

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.

Nasal versus bronchial and nasal response to oral aspirin challenge: Clinical and biochemical differences between patients with aspirin-induced asthma/rhinitis

BACKGROUND Aspirin-induced asthma/rhinitis (AIAR) is characterized by the altered metabolism of leukotrienes and proinflammatory prostaglandins. The basal and postchallenge levels of eicosanoids might reflect the clinical and biochemical characteristics of patients with distinct types of hypersensitive responses to aspirin. OBJECTIVE We compared clinical and eicosanoid profiles of patients with AIAR showing both bronchial and nasal versus isolated nasal responses to aspirin challenge. METHODS Twenty-three patients with AIAR underwent the single-blind, oral, placebo-controlled aspirin challenge. The bronchial response (BR) was evidenced by dyspnea and spirometry, whereas the nasal response (NR) was evidenced by nasal symptoms and acoustic rhinometry and/or rhinomanometry. Urinary leukotriene E4 (uLTE4), serum and urinary stable prostaglandin D2 metabolite, and 9alpha,11beta-prostaglandin F2 (9alpha,11beta-PGF2), were determined at baseline and after the aspirin challenge. RESULTS Fifteen subjects showed BR and NR (BNR), whereas 8 showed NR only. Basal uLTE4 in the BNR group was significantly higher than in the NR group. After aspirin challenge, it increased significantly in both groups. Serum 9alpha,11beta-PGF2 increased after aspirin challenge in the BNR group only. The patients with BNR had more severe AIAR. CONCLUSIONS BNR to aspirin in AIAR indicates a more advanced disease and more profound underlying eicosanoid metabolism disturbances.

Omega-3 fatty acid supplementation influences the whole blood transcriptome in women with obesity, associated with pro-resolving lipid mediator production.

The n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may reduce low-grade inflammation associated with obesity. The relationship between therapeutic response to n-3 PUFAs and modification of the transcriptome in obesity or metabolic syndrome remains to be explored. Blood samples were obtained from women with obesity before and after three-months supplementation with a moderate dose of n-3 PUFAs (1.8g EPA+DHA per day) or from controls. n-3 PUFAs (GC) and plasma concentrations of lipoxins, resolvins, protectin X (GC-MS/MS) and inflammatory markers (ELISA) were measured. Whole blood transcriptome was assayed using microarray. Women supplemented with n-3 PUFAs for 3months had significantly higher levels of EPA and DHA in plasma phosphatidylcholine. n-3 PUFA supplementation, in contrast to placebo, significantly decreased the concentrations of several inflammatory markers (SELE, MCP-1, sVCAM-1, sPECAM-1, and hsCRP), fasting triglycerides and insulin and increased the concentrations of pro-resolving DHA derivatives in plasma. The microarray data demonstrated effects of n-3 PUFAs on PPAR-α, NRF2 and NF-κB target genes. N-3 PUFAs increased DHA-derived pro-resolving mediators in women with obesity. Elevated resolvins and up-regulation of the resolvin receptor occurred in parallel with activation of PPAR-α target genes related to lipid metabolism and of NRF2 up-regulated antioxidant enzymes.

Induced sputum eicosanoids during aspirin bronchial challenge of asthmatic patients with aspirin hypersensitivity

Altered metabolism of eicosanoids is a characteristic finding in aspirin‐exacerbated respiratory disease (AERD). Bronchial challenge with lysyl‐aspirin can be used as a confirmatory diagnostic test for this clinical condition. Induced sputum allows to measure mediators of asthmatic inflammation in bronchial secretions.

Influence of dietary fatty acids on differentiation of human stromal vascular fraction preadipocytes.

Mediators such as cytokines, eicosanoids, nitric oxide and growth factors may regulate adipogenesis as well as inflammation. It is well documented that production of some form of eicosanoids activates lipid synthesis during adipogenesis but also contributes to the formation of factors maintaining low-level systemic inflammation. Developing nutrients for reduction of adipogenesis and inflammation can enhance preventive efficacy of daily diet. This study examined the effects of free fatty acid influence on changes in lipid biosynthesis and corresponding gene expression during differentiation of human subcutaneous adipose tissue stromal vascular fraction (SVF) cells. Proadipogenic conditions promoted SVF cell differentiation and lipid droplet (LD) formation up to 15 days. This correlated with gene expression of adipocyte differentiation markers as well as inflammatory cytokines and their receptors. Addition of free fatty acids to differentiation medium increased their incorporation during the first period of differentiation (48 h). Presence of eicosanoid acid (EPA) during the initial period of differentiation by elevation of Perilipin 3 protein (TIP47), may be responsible for smaller LD formation. Presence of arachidonic acid (AA) tends to deposit lipids in large form of LDs. Prolongation of differentiation up to 15 days decreased AA or EPA in cellular lipids. PUFA through up-regulation of both phospholipase 2 and enzymes related to eicosanoid production influenced type and quantity of eicosanoids which regulated the extent of SVF cell differentiation. Formation of small LDs and reduction of pro-inflammatory mediators in adipose tissue are the consequence of eicosanoid production with anti-inflammatory potential from EPA.

Aspirin provocation increases 8-iso-PGE2 in exhaled breath condensate of aspirin-hypersensitive asthmatics

BACKGROUND Isoprostanes are bioactive compounds formed by non-enzymatic oxidation of polyunsaturated fatty acids, mostly arachidonic, and markers of free radical generation during inflammation. In aspirin exacerbated respiratory disease (AERD), asthmatic symptoms are precipitated by ingestion of non-steroid anti-inflammatory drugs capable for pharmacologic inhibition of cyclooxygenase-1 isoenzyme. We investigated whether aspirin-provoked bronchoconstriction is accompanied by changes of isoprostanes in exhaled breath condensate (EBC). METHODS EBC was collected from 28 AERD subjects and 25 aspirin-tolerant asthmatics before and after inhalatory aspirin challenge. Concentrations of 8-iso-PGF2α, 8-iso-PGE2, and prostaglandin E2 were measured using gas chromatography/mass spectrometry. Leukotriene E4 was measured by immunoassay in urine samples collected before and after the challenge. RESULTS Before the challenge, exhaled 8-iso-PGF2α, 8-iso-PGE2, and PGE2 levels did not differ between the study groups. 8-iso-PGE2 level increased in AERD group only (p=0.014) as a result of the aspirin challenge. Urinary LTE4 was elevated in AERD, both in baseline and post-challenge samples. Post-challenge airways 8-iso-PGE2 correlated positively with urinary LTE4 level (p=0.046), whereas it correlated negatively with the provocative dose of aspirin (p=0.027). CONCLUSION A significant increase of exhaled 8-iso-PGE2 after inhalatory challenge with aspirin was selective and not present for the other isoprostane measured. This is a novel finding in AERD, suggesting that inhibition of cyclooxygenase may elicit 8-iso-PGE2 production in a specific mechanism, contributing to bronchoconstriction and systemic overproduction of cysteinyl leukotrienes.

Mast cell activation after adenosine inhalation challenge in patients with bronchial asthma

A total of 7.5% of the males and 2.2% of the females had persistent wheezing complaints. Wheezing symptoms were found to be significantly high among males and smokers. The prevalence of allergic rhinitis and dermatitis were 24.1% and 6.8% respectively. Rhinitis rates were 16.5% among males and 7.6% among females. The eczema rate was 5.2% among males and 1.6% among females. Prevalence of having a pet at home was 11.7% and family history of atopy was 11.9%. Pet ownership [OR: 1.25 (0.94–1.65)] and family history of atopy [(OR: 3.77(2.88–4.94)] were significantly associated with rhinitis. Smoking rate was 23.3% in the whole group, 20.3% in males and 3.0% in females. Wheezing, asthma-like symptoms, cumulative asthma, current asthma and rhinitis were less common related in students who did not smoke. The rates of asthma, and asthma-like symptoms were found to be higher among smoking students than in non-smoking students, statistically. The low prevalence of asthma in our low-income population may depend on geographical and climatic variation, as well as to the low socioeconomic status of our population. The higher prevalence of rhinitis may depend on that some students may have confused the question about rhinitis and some with sinusitis or other nonallergic rhinitis complaints may have answered the same question with yes , because nonallergic rhinitis patients may have the same complaints like allergic rhinitis patients (5). In conclusion, asthma and/or asthmalike symptoms among university students in the eastern region of Turkey are lower than the developed countries, and habitual smoking is an important risk factor for allergic diseases.