Delayed asthmatic response: a new phenotype of bronchial response to allergen challenge and soluble adhesion molecules in the serum

GLUT1 mediates bronchial epithelial E-cadherin disruption in TDI-induced steroid-insensitive asthma

OBJECTIVE

Down-regulation of bronchial epithelial E-cadherin is an important of feature of severe asthma, including steroid-insensitive asthma. Yet, the mechanisms involved in E-cadherin disruption are not fully understood. This study was aimed to investigate the role of glucose transporter 1 (GLUT1) in dysregulation of E-cadherin in toluene diisocyanate (TDI)-induced steroid-insensitive asthma.

METHODS

A murine model of steroid-insensitive asthma was established by TDI sensitization and aerosol inhalation. Selective GLUT1 antagonists WZB117 and BAY876 were given to BALB/c mice after airway challenge. In vitro, primary human bronchial epithelial cells (HBECs) cultured in an airway-liquid interface (ALI) were exposed to TDI.

RESULTS

TDI exposure markedly up-regulated GLUT1 in murine lungs and HBECs. Pharmacological inhibition of GLUT1 with BAY876 decreased airway hyperresponsiveness, neutrophil and eosinophil accumulation, as well as type 2 inflammation in vivo. Besides, the TDI-induced down-regulated expression of full-length E-cadherin was also partly recovered, accompanied by inhibited secretion of soluble E-cadherin (sE-cadherin). WZB117 also exhibited mild therapeutic effects, though not significant. In vitro, treatment with GLUT1 inhibitor relieved the TDI-induced disruption of E-cadherin in HBECs.

CONCLUSIONS

Taken together, our data demonstrated that GLUT1 modulates bronchial epithelial E-cadherin dysfunction production in TDI-induced steroid-insensitive asthma.

KLF2 regulates neutrophil migration by modulating CXCR1 and CXCR2 in asthma

Neutrophils are key inflammatory cells in the immunopathogenesis of asthma. Neutrophil migration can be initiated through activation of the CXCR1 and CXCR2 receptors by CXC chemokines, such as IL-8. Although transcription factor KLF2 has been found to maintain T cell migration patterns through repression of several chemokine receptors, whether KLF2 can regulate neutrophil migration via modulation of CXCR1 and CXCR2 is unknown. Here, we aimed to explore the functions of KLF2, CXCR1 and CXCR2 in neutrophil migration in asthma and to establish a regulatory role of KLF2 for CXCR1/2. We demonstrate that with asthma aggravation, the percentages and migration rates of peripheral blood neutrophils gradually increased in asthmatic patients and the guinea pig asthma model. Correspondingly, both the KLF2 mRNA and protein levels in neutrophils were gradually reduced. While CXCR1 and CXCR2 expression was negatively correlated with KLF2. In vitro knockdown of KLF2 dramatically increased the migration of HL-60-drived neutrophil-like cells, which was accompanied by an increase in the CXCR1 and CXCR2 mRNA and protein expression levels. Taken together, our results indicate that decreased KLF2 aggravates asthma progression by promoting neutrophil migration, which is associated with the transcriptional upregulation of CXCR1 and CXCR2. The KLF2 and/or CXCR1/2 expression levels may represent an indicator of asthma severity.

Expression of surface markers on the blood cells during the delayed asthmatic response to allergen challenge

Patients with bronchial asthma develop various types of asthmatic response to bronchial challenge with allergen, such as immediate/early asthmatic response (IAR), late asthmatic response (LAR) or delayed asthmatic response (DYAR), because of different immunologic mechanisms. The DYAR, occurring between 24 and 56 hours after the bronchial allergen challenge (p < 0.01), differs from IAR and LAR in clinical as well as immunologic features. This study investigates the expression of CD molecules (markers) on the surface of particular cell populations in the peripheral blood and their changes during the DYAR. In 17 patients developing the DYAR (p < 0.01), the bronchial challenge with allergen was repeated 2-6 weeks later. The repeated DYAR (p < 0.001) was combined with recording of CD molecule expression on various types of blood cells by means of flow cytometry up to 72 hours after the challenge. The results were expressed in percent of the mean relative fluorescence intensity. The DYAR was accompanied by (a) increased expression of CD11b, CD11b/18, CD16,CD32, CD35, CD62E, CD62L, CD64, and CD66b on neutrophils; CD203C on basophils; CD25 and CD62L on eosinophils; CD14, CD16, CD64, and CD86 on monocytes; CD3, CD4, CD8, CD11a, CD18, and CD69 on lymphocytes; CD16, CD56, CD57, and CD94 on natural killer (NK) cells; and CD31, CD41, CD61, CD62P, and CD63 on thrombocytes and (b) decreased expression of CD18 and CD62L on eosinophils, CD15 on neutrophils, and CD40 on lymphocytes. These results suggest involvement of cell-mediated hypersensitivity mechanism, on participation of Th1- lymphocytes, neutrophils, monocytes, NK cells, and thrombocytes in the DYAR.

Nasal Eosinophilia and Serum Soluble Intercellular Adhesion Molecule 1 in Patients with Allergic Rhinitis Treated with Montelukast Alone or in Combination with Desloratadine or Levocetirizine

Background

Because intercellular adhesion molecule (ICAM) 1 and recruitment of eosinophils are crucial in supporting allergic inflammation, their down-regulation may bring additional benefits in patients’ recovery. We have assessed nasal eosinophilia and serum soluble ICAM-1 (sICAM-1) concentrations in relation to nasal symptoms in patients with persistent allergic rhinitis (AR) treated for 6 weeks with either desloratadine, levocetirizine, montelukast alone, or in combination.

Methods

In this single-center, randomized, double-blind, placebo-controlled, crossover, two-arm study, 40 patients with persistent AR were randomized to receive either montelukast and/or levocetirizine or placebo (n = 20) or to receive treatment with montelukast and/or desloratadine or placebo (n = 20). Nasal eosinophilia and concentration of sICAM-1 in peripheral blood were assessed before and on the last day of each treatment period.

Results

All active treatments in both arms of the study resulted in the decrease of sICAM-1 and nasal eosinophilia, which correlated with the severity of nasal symptoms. In the montelukast/levocetirizine arm, montelukast decreased nasal eosinophilia more significantly than levocetirizine, whereas in reduction of sICAM-1 all active treatment options were equally effective. However, in the desloratadine/montelukast arm, the resulting improvement of combination therapy of sICAM-1 and the influx of eosinophils was not statistically significant.

Conclusion

The improvement of nasal symptoms in patients with AR treated with antihistamines, with or without montelukast, may additionally result from the reduction of sICAM-1 and nasal eosinophilia. Because the combination therapy may bring inconclusive benefits in this area there is a strong need of further studies to find mechanisms that favor combination therapy.

T-cell receptor and carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis: understanding a hypersensitivity reaction

Ample evidence exists to support the view that drug hypersensitivity is mediated by adaptive immunity, which involves MHC-restricted drug presentation, activation and clonal expansion of T cells. The specific MHC molecules implicated in hypersensitivity have been identified; for example, HLA-B*5701 in abacavir-induced drug hypersensitivity and HLA-B*1502 in carbamazepine-induced Stevens-Johnson syndrome. However, little is known about the role of drug-specific T cells and their T-cell receptors (TCRs) in the pathogenesis of drug hypersensitivity. Using the combination of a strong HLA-B*1502 predisposition in carbamazepine-induced Stevens-Johnson syndrome and applying global analysis of the TCR repertoire, restricted and common TCR usage in the development of severe drug hypersensitivity have recently been documented. This article reviews recent advances in the understanding of the pathogenic role of drug-specific T cells and their TCRs in the development of drug hypersensitivity and provides an analysis of their potential clinical implications.

Chemokine profiles in blood associated with delayed asthmatic response to allergen challenge

BACKGROUND

Patients with bronchial asthma having been challenged with allergen develop various types of asthmatic response, such as immediate (IAR), late (LAR) or delayed (DYAR) response, due to different immunologic mechanisms. The DYAR, beginning 26-32 h, reaching maximum between 32 and 48 h and resolving within 56 h after the challenge, differs from IAR and LAR in clinical and immunologic features.

OBJECTIVES

To investigate the changes in the serum concentrations of chemokines associated with the isolated form of DYAR.

METHODS

In 22 patients the repeated DYAR (p < 0.001) was supplemented with recording of blood cell counts and serum concentrations of chemokines before, and up to 72 h after the bronchial challenge by means of enzyme-linked immunoassay, (ELISA).

RESULTS

The DYAR was associated with (a) significantly increased serum concentrations (p < 0.05) of CCL 2, CCL 3, CCL 4, CCL 7, CCL 20, CXCL 1, CXCL 8, CXCL 9, CXCL 10 and CXCL 11, and (b) significantly decreased serum concentrations, (p < 0.05) of CCL 5, CCL 11, CCL 17, CCL 22, CCL 24 and CCL 26, as compared with their pre-challenge as well as the PBS control values. No significant chemokine changes were recorded during the PBS controls (p > 0.1).

CONCLUSIONS

These results, together with changes in the blood cell counts, provide evidence for an involvement of activated Th(1), cells and NK cells (CCL-2, -3, -4, -20, CXCL-9,-10,-11), neutrophils (CCL-20, CXCL-1,-8) and monocytes (CCL-2,-3,-4, -7, CXCL-10), upon co-operation of other cell types, such as epithelial, endothelial and dendritic cells, in the immunologic mechanism(s) underlying the DYAR.

Late type of bronchial response to milk ingestion challenge: a comparison of open and double-blind challenge

Background. In some asthmatics the food allergy, for example, to milk, can participate in their bronchial complaints. The role of food allergy should be confirmed definitively by food ingestion challenge performed by an open challenge with natural foods (OFICH) or by a double-blind placebo-controlled food challenge (DBPCFC). Objectives. To investigate the diagnostic value of these techniques for confirmation of a suspected milk allergy in bronchial asthma patients. Methods. In 54 asthmatics with a positive history and/or positive skin tests for milk the 54 OFICH, and DBPCFC, were performed in combination with spirometry. Results. The 54 patients developed 39 positive late asthmatic responses (LAR) and 15 negative asthmatic responses to OFICH and 40 positive LARs and 14 negative responses to DBPCFC. The overall correlation between the OFICH and DBPCFC was statistically significant (P < 0.01). Conclusions. This study has confirmed the existence of LAR to milk ingestion performed by OFICH and DBPCFC in combination with spirometry. The results obtained by both the techniques did not differ significantly. The OFICH with natural food combined with monitoring of objective parameter(s), such as spirometry, seems to be a suitable method for detection of the food allergy in asthmatics. The DBPCFC can be performed as an additional check, if necessary.

Delayed asthmatic response to bronchial challenge with allergen-mediators, eicosanoids, eosinophil and neutrophil constituents in the blood and urine

BACKGROUND

In patients with allergic bronchial asthma, different immunologic mechanisms may participate and lead to different types of asthmatic response to allergen challenge, such as immediate/early (IAR/EAR), late (LAR) or delayed asthmatic response (DYAR).

OBJECTIVES

In 55 of 397 asthmatics, DYAR has been recorded (p < 0.001) and confirmed by repeated bronchial challenge with the same allergen (p < 0.001). DYAR began between 26 and 32 h, reached a maximum between 32 and 48 h and resolved within 56 h after the challenge. DYAR was associated with various clinical symptoms and diagnostic parameters having diverged from those recorded during the IARs/EARs and LARs.

METHODS

In 25 of 55 patients, repeated DYAR has been supplemented with the recording of leukotriene B(4) (LTB(4)), LTC(4), LTE(4), prostaglandin D(2) (PGD(2)), PGE(2), PGF(2)(α), thromboxane B(2), lipoxin A(4), eosinophil cationic protein, eosinophil-derived neurotoxin/eosinophil protein X, eosinophilic peroxidase, myeloperoxidase, histamine and tryptase in peripheral blood, and of LTC(4), thromboxane B(2), eosinophil-derived neurotoxin and 9α,11β-PGF(2) in urine, before and up to 72 h after the bronchial allergen challenge, by means of enzyme-linked immunoassay (ELISA/EIA) or ImmunoCAP.

RESULTS

DYAR was accompanied by a significant increase in the plasma concentrations of LTB(4) (p < 0.05) and myeloperoxidase (p < 0.05) at 24, 36 and 48 h after the challenge, whereas the plasma/serum or urine concentrations of the other factors did not demonstrate any significant changes (p > 0.05).

CONCLUSIONS

These results would indicate an active and prominent involvement of neutrophils, in addition to the previously demonstrated role of the Th1 lymphocytes, in the clinical DYAR.