Validation of basophil CD164 upregulation for pollen allergy diagnosis

Pimecrolimus Is a Potent Inhibitor of Allergic Reactions to Hymenopteran Venom Extracts and Birch Pollen Allergen In Vitro

Pimecrolimus (Elidel, SDZ ASM 981) is an anti-inflammatory and immunomodulatory 33-epichloro-derivative of macrolactam ascomycin, with low potential for affecting systemic immune responses compared with other calcineurin inhibitors, cyclosporin A and tacrolimus. Despite numerous studies focused on the mechanism of pimecrolimus action on mast cells, only the single report has addressed pimecrolimus effects on other typical FcεRI-expressing cells, the basophils. Patients allergic to birch pollen (n = 20), hymenopteran venoms (n = 23) and 10 non-allergic volunteers were examined. Primary human basophils pre-treated or not with 0.5-50 μMol pimecrolimus were exposed to various concentrations of recombinant Bet v 1a allergen, bee or wasp venom extracts and anti-IgE for 20 min, and then examined for the expression of CD45, CD193, CD203c, CD63 and CD164 using flow cytometry. The externalization of basophil activation markers (CD63 and CD164) was equally inhibited through pimecrolimus in cells activated by recombinant pollen allergen, hymenopteran venom extracts and anti-IgE. Although the individual response rate was subject to strong variation, importantly, pre-treatment with pimecrolimus lowered the number of activated basophils in response to any of the stimuli in the basophils from all patients. The inhibition was concentration-dependent; approximately half of the basophils were inhibited in the presence of 2.5 mMol pimecrolimus. Pimecrolimus is a valuable new tool for the inhibition of hyper-reactive basophils in patients with pollen allergy and a history of anaphylactic reactions to bee or wasp venoms. Further research should address short-term use of pimecrolimus in vivo in a wide spectrum of allergic diseases.

Immunotherapy in allergy and cellular tests: state of art

The basophil activation test (BAT) is an in vitro assay where the activation of basophils upon exposure to various IgE-challenging molecules is measured by flow cytometry. It is a cellular test able to investigate basophil behavior during allergy and allergy immunotherapy. A panoply of critical issues and suggestive advances have rendered this assay a promising yet puzzling tool to endeavor a full comprehension of innate immunity of allergy desensitization and manage allergen or monoclonal anti-IgE therapy. In this review a brief state of art of BAT in immunotherapy is described focusing onto the analytical issue pertaining BAT performance in allergy specific therapy.

Flow cytometric analysis of the basophil cell activating impact of potential drug delivery nanoparticle-candidate

INTRODUCTION

Carbon nanotubes – as artificial nano-size ranged materials –have increasing role in the modern biomedical, diagnostic and therapeutic applications.There is a promising option for their use as more potential drug carriers. Despite the favourable properties, their impact (accumulation, elimination, etc.) on biological systems is largely unknown. The main limiting factor of medical use of nanomaterials in most cases is the potential hypersensitive side effect. It can develop in different route, but the activation of basophil granulocytes may play a central role in this process.

OBJECTIVE

Our aim was to test the direct activation ability of different, surface modified nanotubes on basophil granulocytes in vitro. In parallel we tested the effectiveness of BasoTest planned to use for this study.

MATERIALS AND METHODS

Using the blood samples of allergic and healthy volunteers we examined the basophil degranulation in the presence of nanotubes and the expression level changes of cell-surface CD63 on FACS Calibur instrument. Our results were compared to positive(fMLP, Mite, Grass) and negative control samples.

RESULTS

The test we have chosen proved to be sufficiently sensitive and specific for further study. Significant basophil activation was observed in the presence of carbon nanotubes in healthy persons and allergic patients, as well. The activating effect of nanotubes was more prevailed in allergic population.

CONCLUSION

Our experiments have proven the fact that nanotubes may play a role in the development of hypersensitive allergic reactions through their basophil granulocyte activator effect.

Evaluation of CCR3 as a basophil activation marker

OBJECTIVES

Recent reports have provided conflicting evidence on the stability of CCR3 expression on the surface of basophils. Hence we wanted to independently evaluate the diagnostic usefulness of CCR3 as a surrogate marker of basophil activation and function.

METHODS

We examined the correlative relationship between CCR3 expression on the surface of donor basophils and histamine release after donor basophils were treated with agonistic antibodies directed against the high-affinity IgE-Fc receptor and serum samples from 80 individuals displaying symptoms of chronic urticaria (CU).

RESULTS

We observed that CCR3 was significantly downregulated on donor basophils treated with the agonistic antibody and CU-patient serum that demonstrated positive "histamine-releasing activity" (HRA scores >10). However, CCR3 downregulation was also observed on donor basophils incubated with more than 40% of CU-patient serum samples with HRA scores less than or equal to 10.

CONCLUSIONS

Overall our data show that CCR3 demonstrates adequate sensitivity (83%) but weak specificity (59%) in its ability to reliably identify histamine-releasing activated basophils.

Update on the performance and application of basophil activation tests

The basophil activation test (BAT) is a flow-cytometry-based functional assay that assesses the degree of cell activation after exposure to a stimuli. Though no standardized technique currently exists, recent advances have improved the performance of this assay, including identification of new basophil-specific markers and comparisons of the expression of CD63 to CD203c during activation. The basophil activation test has also been validated for many IgE-mediated disease conditions, which have been extensively reviewed elsewhere. This review focuses on the most recent applications of this test to the diagnosis of allergy to drugs, foods, venoms, and pollens, and the evolving role of the BAT in monitoring immunotherapy.

Increased IL-5 and IL-13 cytokine level in ex vivo stimulated whole blood cells from grass pollen allergic donors correlate with seasonal exposure

There is a need for simple and physiological assays to characterize the immune status of allergic individuals. Whole blood samples from 15 adult subjects (10 with positive clinical history to grass pollen and 5 with negative clinical history) were obtained before the start (April 2010) and during the middle of the grass pollen season (June 2010). The investigators were blinded to the allergic status of the subjects. A skin prick test (SPT) to grass pollen was carried out at the end of the study. Cytokines (IL-5, IL-13, IL-10 and IFNγ) and activation of T-lymphocytes were determined after ex vivo culture of whole blood cells. IL-5, IL-10 and IL-13 cytokines were significantly elevated in allergic individuals during the middle of the season (p≤0.02) compared to the start. This assay can be a valuable tool in clinical trials especially in pediatric population where limited quantities of blood are available to study immune responses.