The effect of allergen-induced bronchoconstriction on concentration of 5-oxo-ETE in exhaled breath condensate of house dust mite-allergic patients.

BACKGROUND: Arachidonic acid metabolites regulate several aspects of airway function including inflammation, muscle contraction and mucous secretion. OBJECTIVE: The aim of this study was to evaluate concentration of selected 5-lipoxygenase- and cyclooxygenase-derived eicosanoids in exhaled breath condensate (EBC) during allergen-induced bronchoconstriction. METHODS: The study was performed on 24 allergic rhinitis/asthma patients sensitized to a house dust mite (HDM) Dermatophagoides pteronyssinus (Dp) and 13 healthy controls (HCs). Bronchial challenge with Dp extract was performed only in the allergic patients. EBC samples were collected before (T0 ) and during Dp-induced bronchoconstriction (TEAR ). Eicosanoid concentration was measured using HPLC-tandem mass spectrometry. RESULTS: Significant bronchoconstriction after Dp challenge was demonstrated in 15 patients (Rs), while in 9 patients (NRs) no asthmatic response could be detected. At T0 the most abundant eicosanoids in EBC of HDM-allergic patients were LTB4 and 5-oxo-ETE, while in HCs EBC concentration of LTB4 was significantly greater than that of 5-oxo-ETE. Allergen challenge resulted in significant increase in EBC concentration of 5-oxo-ETE, LTD4 and 8-iso-PGE2 only in Rs. At TEAR , the relative change of 5-oxo-ETE concentration in EBC correlated with decrease of peripheral blood eosinophilia (R = -0.774; P = .0012). Moreover, the relative increase of 5-oxo-ETE in EBC at TEAR significantly correlated with the severity of the subsequent late asthmatic response (R = 0.683, P = .007). CONCLUSION: Our study demonstrates significant up-regulation of 5-oxo-ETE synthesis in HDM-allergic patients and indicates possible involvement of that mediator in the pathogenesis of allergic asthma.

Induced sputum supernatant bioactive lipid mediators can identify subtypes of asthma.

BACKGROUND: Induced sputum (IS) allows to measure mediators of asthmatic inflammation in bronchial secretions. The specific role of induced sputum supernatant (ISS) endogenous bioactive lipid mediators in subtypes of asthma is not well understood. OBJECTIVE: To investigate the interactions between airway inflammation and clinical phenotypes of asthma, we integrated induced sputum supernatant (ISS) eicosanoids and quantitative assessment of infiltrating cells into new subtypes with the means of latent class analysis (LCA). METHODS: One hundred and thirty-nine asthmatics with and without aspirin hypersensitivity underwent sputum induction. High-performance liquid chromatography or gas chromatography coupled with mass spectrometry was used to profile eicosanoids. Nineteen variables covering clinical characteristics, IS inflammatory cells and eicosanoids were considered in the LCA. RESULTS: Four phenotypic asthma classes were distinguished. Class 1 with mild-to-moderate asthma, chronic rhinosinusitis (CRS), high PGA2 in ISS and almost equal distribution of inflammation cell patterns. Class 3 subjects also had mild-to-moderate asthma but without upper airway symptoms. Induced sputum was often paucigranulocytic with low levels of lipid mediators. Classes 2 and 4 represented severe asthma with CRS and impaired lung function despite high doses of steroids. High blood and sputum eosinophilia was in line with high cysteinyl leukotrienes and PGD2 in ISS only in class 2. Class 4 subjects tended to have increased sputum neutrophilia and PGE2 in ISS. Aspirin hypersensitivity was most frequent among class 2 subjects. CONCLUSIONS & CLINICAL RELEVANCE: The LCA revealed four distinct asthma classes differing in eicosanoid pathways.

Lack of association of ALOX12 and ALOX15B polymorphisms with psoriasis despite altered urinary excretion of 12(S)-hydroxyeicosatetraenoic acid.

BACKGROUND: Pro- and anti-inflammatory metabolites of arachidonic acid - eicosanoids - participate in skin homeostasis, affecting the growth and differentiation of keratinocytes. Alterations of 12-lipoxygenase (LOX) and 15-LOX and their metabolites have been described in the epidermis of patients with psoriasis, but systemic production of 12-LOX and 15-LOX eicosanoids has not been studied in the disease. OBJECTIVES: To ascertain the frequencies of the genetic variants ALOX12 rs1126667 and ALOX15 rs11568070 in cases and controls, and to compare urinary metabolites of 12(S)-hydroxyeicosatetraenoic acid (HETE) between patients with psoriasis and healthy controls. METHODS: Patients with psoriasis (n = 200) were stratified depending on the severity of their dermal lesions. Genotyping was performed using a 5'-nuclease real-time assay. The concentrations of 12(S)-HETE, its metabolites and 15(S)-HETE were determined in urine samples using high-performance liquid chromatography-tandem mass spectrometry. RESULTS: Tetranor-12(S)-HETE metabolite excretion was significantly higher in urine of patients with psoriasis, while excretion of 12(S)-HETE was decreased. Neither 12(S)-HETE nor tetranor-12(S)-HETE correlated with the type of disease or severity score. No difference in urinary 15(S)-HETE was found between the study groups. Genotype distribution of the ALOX12 rs1126667 or ALOX15 rs11568070 polymorphisms did not discriminate for the disease or its severity. CONCLUSIONS: Systemic metabolism of 12(S)-HETE is accelerated in psoriasis because excretion of the tetranor-12(S)-HETE inactivation product is elevated. No correlation with the severity or extent of psoriasis is detectable. We propose that in patients with psoriasis, 12(S)-HETE to tetranor-12(S)-HETE conversion could be at least a marker for this disease, in which inflammation of the skin can induce microsomal beta-oxidation of this eicosanoid.

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

BACKGROUND: 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. OBJECTIVES: To investigate the influence of inhaled lysyl-aspirin on sputum supernatant concentration of eicosanoids during the bronchial challenge test. Subjects with asthma hypersensitive to nonsteroidal anti-inflammatory drugs were compared with aspirin-tolerant asthmatic controls. METHODS: Induced sputum was collected before and following bronchial challenge with lysyl-aspirin. Sputum differential cell count and sputum supernatant concentrations of selected lipoxygenases products: 5-,12-,15-hydroxyeicosatetraenoic acid, cysteinyl leukotrienes, leukotriene B4 , 11-dehydro-thromboxane B2 , and prostaglandins E2 , D2 , and F2α and their metabolites, were measured using validated methods of chromatography-mass spectrometry. RESULTS: Aspirin precipitated bronchoconstriction in all AERD subjects, but in none of the aspirin-tolerant asthmatics. Phenotypes of asthma based on the sputum cytology did not differ between the groups. Baseline sputum eosinophilia correlated with a higher leukotriene D4 (LTD4 ) and leukotriene E4 (LTE4 ) concentrations. LTC4 , PGE2 , and 11-dehydro-TXB2 did not differ between the groups, but levels of LTD4 , LTE4 , and PGD2 were significantly higher in AERD group. Following the challenge, LTD4 and LTE4 increased, while PGE2 and LTB4 decreased in AERD subjects only. CONCLUSIONS: During the bronchial challenge, decrease in PGE2 and its metabolite is accompanied by a surge in bronchoconstrictory cysteinyl leukotrienes produced at the expense of LTB4 in AERD subjects. Bronchial PGE2 inhibition in AERD seems specific and sensitive to a low dose of aspirin.

12-hydroxy-eicosatetraenoic acid (12-HETE): a biomarker of Churg-Strauss syndrome.

BACKGROUND: Churg-Strauss syndrome (CSS) shares similarities with asthma and hypereosinophilic syndrome (HES). Eicosanoids--important inflammatory and signaling molecules--are present in exhaled breath condensate (EBC) and broncho-alveolar lavage fluid (BALF). OBJECTIVES: To assess eicosanoid profile both in EBC and BALF of CSS subjects searching for a pattern characteristic of this syndrome. METHODS: EBCs from 23 CSS patients, 30 asthmatics, 12 HES patients and 54 healthy controls (HC) were assessed quantitatively for 19 eicosanoids by a high-performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). In addition, in 21 of 23 CSS subjects and in nine asthmatics, eicosanoids were determined in BALF. RESULTS: EBC from CSS patients showed markedly elevated levels of 12-HETE as compared with other studied groups. BALF was characterized by a significant elevation of 12-HETE and its metabolite 12-tetranor HETE in CSS as compared with asthma. Clinical activity of CSS correlated with 12-HETE and its metabolites levels in BALF, but not in EBC. CONCLUSION AND CLINICAL RELEVANCE: CSS is clearly distinguished from bronchial asthma, and HES by a marked increase in 12-HETE concentration in both EBC and BALF. This points to a possible new pathogenic mechanism in CSS and may help in future in establishing the diagnosis of CSS.

Serum tryptase level is a better predictor of systemic side effects than prostaglandin D2 metabolites during venom immunotherapy in children.

OBJECTIVES: We performed a prospective study to analyze mast cell mediators as predictors of systemic adverse reactions during rush venom-specific immunotherapy (VIT) in children. PATIENTS AND METHODS: Nineteen children aged 5-17 years received VIT with Venomenhal (HALAllergy). We analyzed serum tryptase (CAP, Phadia), plasma prostaglandin (PG) D2 metabolites (9alpha, 11beta-PGF2), and urine PGD2 metabolites (9alpha, 11beta-PGF2, tetranor-PGD-M) using gas chromatography mass spectrometry before and after the rush protocol. RESULTS: Three boys with high baseline serum tryptase values (>7.76 g/L) (P < .001) and low 9alpha, 11beta-PGF2 concentrations developed grade III systemic adverse reactions during VIT. Baseline serum tryptase was lowest in children who had a Mueller grade II reaction (1.93 [0.36]) before VIT and highest in children with a Mueller grade III reaction (6.31 [4.80]) (P = .029). Repeated measures analysis of variance confirmed that, in children who developed systemic adverse reactions during VIT, serum tryptase was higher both before and after desensitization and increased significantly following the procedure. Analysis of PGD2 metabolites in the prediction of systemic adverse reactions during VIT was inadequate (sensitivity 67% and specificity 0.53%), whilst prediction based on serum tryptase was accurate. CONCLUSIONS: In children with severe systemic adverse reactions to Hymenoptera sting, the evaluation of baseline tryptase levels should be a standard procedure. Children with Apis mellifera venom allergy and baseline tryptase levels higher than 7.75 g/L are at risk of anaphylaxis during buildup. Lower baseline values of plasma and urinary PGD2 metabolite concentration in patients with systemic adverse reaction during VIT suggest that prostaglandin catabolism is altered.

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-11alpha-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.

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

BACKGROUND: Prostaglandin D(2) (PGD(2)) is a major cyclooxygenase product generated by activated mast cells during an allergic response. Assessment of PGD(2) 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 9alpha,11beta-PGF(2), a primary PGD(2) metabolite, were assessed by gas chromatography/mass spectrometry. Serum tryptase levels were measured by fluoroenzyme immunoassay and urinary leukotriene E(4) (LTE(4)) 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 PGD(2) metabolite and serum tryptase levels were found in asthmatics or controls. Asthmatic patients had significantly higher urinary LTE(4) levels. Allergen challenge resulted in a significant early increase in the mean plasma 9alpha,11beta-PGF(2) level and only a borderline but significant increase in the urinary 9alpha,11beta-PGF(2) level within 2 hours after provocation. The challenge did not produce statistically significant changes in serum tryptase levels. Urinary LTE(4) levels remained significantly increased 4 hours after provocation. CONCLUSIONS: PGD(2) is actively involved in the early asthmatic response to allergens. Measurement of 9alpha,11beta-PGF(2) release into plasma rather than urine following allergen challenge is a sensitive marker of enhanced PGD(2) synthesis, most probably due to mast cell activation.