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Completed

NCT Number: NCT01839591

Bronchial Thermoplasty: Effect on Neuronal and Chemosensitive Component of the Bronchial Mucosa

In severe bronchial asthma the mechanism of inflammation and bronchospasm is complex and still not clarified. The smooth muscle cells play an important role from the mechanical point of view, as a culmination of neurogenic stimuli and inflammatory cytokines that determine as final effect the bronchospasm and over time a hypertrophy of the muscular coat. There are some other hypothesis that the smooth muscle cells may play a role as central regulator of chemical mediators that cause bronchospasm and inflammation, although there are currently no firm conclusions 2 According to other studies3,the nerve receptors TRANSIENT RECEPTOR POTENTIAL VANILLOID TYPE 1 have a great importance in the complex mechanism of airway inflammation too. (There are at least 4)

These receptors would intervene according to the following mechanism:

1. Irritants on the bronchial mucosa stimulate the TRANSIENT RECEPTOR POTENTIAL VANILLOID TYPE 1 present on afferent endings of sensory fibers, unmyelinated C (chemiosensitive neurons) 2. On the same afferent axon acting factors with the activation effect (lowering the activation threshold, increase the expression, promote the translocation of TRPV1 receptor on the membrane). Among these factors the neurotrophins of which the most important NERVE GROWTH FACTOR (NGF) 3. The activation of TRPV1 (through release of Ca2 + +) determines two efferent responses:

1. CENTRALLY-MEDIATED 2. LOCAL AXON Reflex

Investigators hypothesized that BT may have a strong influence on the destruction of nerve receptors TRPV1 and unmyelinated nerve fibers located in the mucosa going to stop reflections both central and local authorities responsible for the activation of bronchospasm. In support of this hypothesis, there are some anatomical studies4, which show that these receptors are more numerous at the level of main bronchi which are the main target of BT. Please note in this context that it is already known that in thermoablations commonly used in cardiology it is used a radio frequency with development of heat controlled to 65 °, as in the BT, able to interrupt the circuit nervous responsible for the activation of the circuit causing the abnormal 'arrhythmia.

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Key information

Conditions

Severe Persistent Asthma

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

REGGIO EMILIA IRCCS, Santa Maria Nuova Hospital

Reggio Emilia, Italy, 42024

About this study

The mechanism of action the bronchial thermoplasty exerts the positive action demonstrated by the studies through is not yet well understood yet. The only action on the denaturation and destruction of the smooth muscle layer of the bronchi at intermediate and high caliber perhaps not fully explain its action, taking into account that most of the smooth muscle loading of the small airways is minimally altered by the procedure. From the premises outlined in the section on the mechanism of inflammation we hypothesized that BT may have a strong influence on the destruction of nerve receptors TRPV1 and unmyelinated nerve fibers located in the mucosa going to stop reflections both central and local authorities responsible for the activation of bronchospasm. In support of this hypothesis, there are some anatomical studies4, which show that these receptors are more numerous at the level of main bronchi which are the main target of BT. Please note in this context that it is already known that in thermoablations commonly used in cardiology it is used a radio frequency with development of heat controlled to 65 °, as in the BT, able to interrupt the circuit nervous responsible for the activation of the circuit causing the abnormal 'arrhythmia.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patient with severe persistent asthma uncontrolled found in stable for at least 3 weeks
  • Patient receiving regular treatment with inhaled corticosteroids (beclomethason> 1000 mcg or equivalent) and LABA (salmeterol> = 100 mcg or equivalent)
  • AQLQ score <6.25
  • FEV1> = 60% predicted
  • Patients not smoking for at least one year

Exclusion criteria

  • acute asthma with life threatening
  • concomitant respiratory diseases (eg, COPD or emphysema)
  • use of ß-blocker drugs
  • severe active infection in the last 2 weeks
  • Pacemaker, internal defibrillator or other implanted electronic device.
  • Known sensitivity to medications used to perform bronchoscopy, including lidocaine, atropine and benzodiazepines.
  • Currently known bleeding disorder is not well controlled.
  • Inability to stop prior to the procedure taking anticoagulants, antiplatelet agents, aspirin or non-steroidal anti-inflammatory drugs
  • 18 years
  • Pregnant women

Treatment and study plan

catheter ALAIR

Device

Catheter ALAIR Radiofrequency 65°

Other names: Catheter ALAIR Boston Scientific, M005ATS25010 MOd ATS 2-5

Primary outcomes

  1. analysis of the risk and benefit profile with questionnaire ACT and AQLQ

    Time frame: Change from Baseline in ACT and AQLQ Questionaire one year after the end of the procedure

    Evaluation of symptom control through the questionnaire ACT (ASTHMA CONTROL TEST) and AQLQ (Asthma quality life Questionaire) according to GINA criteria.

    The questionnaires AQLQ and ACT will be collected 3 months before the TB, the day before the procedure, and 3, 6, 12 months after the end of the procedure.

Secondary outcomes

  1. Analyze the changes in the state of innervation and nerve receptors before and after BT on histological samples of the bronchial mucosa

    Time frame: biopsies every 4 weeks( during the treatment)

    first biopsies in left lower lobe non yet treated; second biopsies in right lower lobe already treated; third biopsies in upper lobe already treated;

Other outcomes

  1. Evaluate the effect of BT on the run neurogenic inflammation by analysis of the chemical mediators of inflammation on histological samples of the bronchial mucosa.

    Time frame: biopsies every 4 weeks (during the treatment)

    first biopsies in left lower lobe non yet treated; second biopsies in right lower lobe already treated; third biopsies in upper lobe already treated;

Sponsors and collaborators

Lead sponsor

Azienda USL Reggio Emilia - IRCCS

Other Gov

Registry information

Official study title

Treatment of Bronchial Severe Asthma With Bronchial Thermoplasty. Assessment of Efficacy and Safety of Treatment, Study of Effects on Neuronal and Chemosensitive Component of the Bronchial Mucosa Pre and Post Treatment

Acronym: BT-ASMN

Important dates

Study start
2013
Primary completion
2015
Study completion
2016
First posted
Apr 25, 2013
Registry last updated
Jun 25, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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