MedPath

Regulatory Lymphocytes in Patients Treated With Specific Immunotherapy

Phase 4
Completed
Conditions
Immunotherapy
Seasonal Allergic Rhinitis
Interventions
Other: placebo
Drug: Allergovit
Registration Number
NCT01475188
Lead Sponsor
Ministry of Science and Higher Education, Poland
Brief Summary

The purpose of this study is to determine whether specific subcutaneous immunotherapy affects fractions of regulatory T lymphocytes and histamine H2 receptor expression and ZAP70 in regulatory T lymphocytes.

Detailed Description

Allergy constitutes an important problem worldwide thus effective treatment is crucial for the reduction of symptoms severity, patients' activity and quality of life as well as for the reduction of direct and indirect costs of the disease. Specific allergen immunotherapy (SIT) is a potentially curative and specific method of treatment for allergic diseases, particularly for intermittent allergic rhinitis. Specific subcutaneous immunotherapy induce peripheral tolerance and suppress inflammation in tissue. In periphery, effector T cells unresponsiveness to antigens is mediated mainly by allergen specific regulatory T cells. Regulatory T cells induced peripherally comprise IL-10 producing type 1 regulatory T cells (Tr1) and regulatory T cells subset arising in vitro from CD4+CD25- and in vivo from peripheral memory T cells whereas naturally occurring Tregs (nTregs)originate in thymus and represent about 5% of the peripheral CD4 T cells and constitutively express high levels of the high-affinity IL-2 receptor (CD25hi). They coexpress Forkhead Box Protein P3 (Foxp3), glucocorticoid induced tumor necrosis factor receptor (GITR), cytotoxic T lymphocyte associated antigen (CTLA-4), and display low expression of alpha chain of the IL-7 receptor. Although clinical and immunological outcomes of SIT, that are associated with regulatory T cells functions were profoundly studied, little is known about the molecular mechanisms that are crucial for nTregs activation and function in the course of SIT. Since histamine is a key mediator in allergy that exerts its effect through 4 types of histamine receptors we decided to investigate the expression of histamine 2 receptor, that has potent immunomodulatory properties, in regulatory lymphocytes in patients treated with SIT. Furthermore, since T cell receptor activation is essential for T effector lymphocytes activation we wanted to check the expression of zeta chain associated protein (ZAP70), that constitutes a linker between TCR and lower levels of intracellular downstream signal transduction, in regulatory T cells in the course of SIT.

This is a 3-year prospective, placebo controlled, double blind trial of grass SIT. 41 patients with seasonal allergic rhinitis were randomized to receive SIT (n = 21) or placebo (n = 20) and 15 healthy were included as a control. The primary and secondary outcomes were assessed at baseline and during the treatment period - before the start of the pollen season, at the height of the pollen season and after the end of the pollen season.Results were compared between the treatment year and baseline and between the groups treated with SIT, placebo and healthy control.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
41
Inclusion Criteria
  • seasonal allergic rhinitis with or without allergic conjunctivitis
  • sensitization to grass pollen allergens (confirmed with skin prick tests, conjunctival provocation test, specific IgE)
  • symptoms of allergic rhinitis with or without conjunctivitis for at least 2 years before the study
Exclusion Criteria
  • sensitization to allergens, that could interfere with grass pollen
  • asthma
  • cystic fibrosis
  • ciliary dysmotility syndrome
  • bronchiectasis
  • smoking
  • tuberculosis
  • neoplastic disease
  • chronic sinusitis and nasal polyps
  • systemic glucocorticosteroids treatment
  • treatment with immunotherapy in the past

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
placeboplacebo20 patients with intermittent allergic rhinitis sensitized to grass pollen allergens
Specific subcutaneous immunotherapyAllergovit21 symptomatic patients with intermittent allergic rhinitis sensitized to grass pollen allergens
Primary Outcome Measures
NameTimeMethod
numbers of regulatory T lymphocytes (nTregs)Change from the baseline year to the 2nd year of immunotherapy.

Numbers of regulatory T cells (nTregs) at baseline year both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen season and in the 2nd year of immunotherapy both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen.

Secondary Outcome Measures
NameTimeMethod
Expression of zeta chain associated protein (ZAp70) in regulatory lymphocytes (nTregs)Change from the baseline year to the 2nd year of immunotherapy

Expression of zeta chain associated protein (ZAP70) in regulatory T cells (nTregs) at baseline year both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen season and in the 2nd year of immunotherapy both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen.

Expression of histamine H2 receptor in regulatory lymphocytes (NTregs)Change from the baseline year to the second year of immunotherapy

Expression of histamine H2 receptor in regulatory T cells (nTregs) at baseline year both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen season and in the 2nd year of immunotherapy both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen.

Rhinoconjunctivitis symptom scoreChange from the baseline year to the second year of immunotherapy

Change of the rhinoconjunctivitis symptoms score from the baseline year to the 2nd year of immunotherapy

Nasal eosinophiliaChange from the basline year to the 2nd year of immunotherapy

Numbers of eosinophils in nasal lavage during the baseline year both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen season and in the 2nd year of immunotherapy both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen.

Concentration of nitric oxide in exhaled airChange from the baseline year to the 2nd year of immunotherapy

Concentration of nitric oxide in exhaled air during the baseline year both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen season and in the 2nd year of immunotherapy both 6 weeks before the start of the pollen season, at the height of pollen season and 6 weeks after the termination of the pollen.

Consumption of rescue medicationsChange from the baseline year to the second year of imunotherapy

Comparison of the rescue medication intake during the baseline year and during the treatment

Trial Locations

Locations (1)

Department of Pneumonology and Allergy, Medical University of Lodz

🇵🇱

Lodz, Poland

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