Explorative Study on the Molecular Pathology of Lung Fibrosis by Combination of Clinical Assessment and System Biology
Condition: Pulmonary Fibrosis
MeSH terms: Pulmonary Fibrosis; Fibrosis
Study type: Observational

Summary: 
      RESOLVE's objective is to identify and characterize validated molecular targets capable of
      shifting primary organ repair towards fibroproliferative wound healing.

      Work package 2 (WP2) of RESOLVE includes the clinical study protocols within the RESOLVE
      system evaluating different forms of pulmonary repair in humans ranging from normal repair
      over mainly inflammatory to predominantly fibroproliferative repair.

      Hypothesis

      Fibrosis of the lung is an aberrant and intensified form of wound healing. It is the result
      of an unresolved disturbance of both initiation and control of repair which is partly
      age-related. As a result of the relentlessly activated wound healing reaction, mechanisms of
      inflammation largely representing the condition of chronic inflammation within the peripheral
      bronchial tree will aggravate this abnormal form of repair.

      A systematic comparison of the molecular pathology of fibrotic repair representing

        -  Varying intensity of fibrosis related to the pathology of usual interstitial pneumonia
           (UIP),

        -  Varying inflammatory mechanisms (UIP vs. Hypersensitivity pneumonitis [HP], acute and
           chronic), and

        -  Varying stages of age (Normal pulmonary repair in young and old individuals vs.
           acute/chronic HP vs. UIP) will be able to

        -  identify molecules capable of shifting regular repair towards fibroproliferative repair
           and

        -  elucidate their interrelationship with other molecules forming coordinated yet
           misdirected metabolic responses characteristic for fibroproliferative repair.
    

Detailed description: 
      Background

      After reaching adulthood, the organs of the human body preserve their shape and function over
      a long period, making directed repair one of the most important mechanisms throughout
      lifetime. Regular wound healing after an injury consists of a well-ordered sequence of
      overlapping phases: inflammation, formation of supportive new tissue, re-epithelization and
      final regeneration of epithelial and endothelial lining cells, and essentially repeats the
      complex process of organ development. In young adults, damage to an organ is frequently
      answered by fully regenerative wound healing repeating mechanisms of embryonic organ growth
      called "primary" wound healing. Repeated damage in younger individuals may cause "secondary"
      wound healing in form of scar formation serving as a rescue program to maintain surface
      integrity once epithelial and/or endothelial reorganization has failed.

      Organ failure in the ageing organism, however, is different and essentially represents the
      loss of its capacity to achieve an orderly reactivation of organ development. This different
      quality of wound healing consists of a combination of chronic inflammation and
      fibroproliferative, non-regenerative repair. Its pathology refers to a large group of
      diseases involving every organ of the human body.

      In the lung, its most prominent form is characterized by a well-defined histopathology named
      usual interstitial pneumonia (UIP). Unfortunately, this histopathology, while identifying a
      particularly aggressive phenotype of the fibroproliferative repair response itself, does not
      allow for an unambiguous clinical diagnosis, as the UIP "pattern" may be found in different
      fibrotic diseases of the lung, such as hypersensitivity pneumonitis (HP), especially in its
      chronic form.

      In addition, various mechanisms of inflammation which are partly related to the wound healing
      response itself, may profoundly intensify the aberrant wound healing response. As a result,
      the mechanisms leading to this condition and maintaining its characteristic clinical
      appearance are unknown.

      The current investigation belongs to the work package 2 of the RESOLVE study system
      (FP7-HEALTH-F4-2008 Contract no. 202047) which contains the clinical study protocol
      evaluating different forms of fibrotic repair in the human lung. RESOLVE's main objective is
      to identify and characterize clinically validated molecular targets capable of shifting
      primary organ repair towards fibroproliferative wound healing. In this pilot study, different
      forms of repair of the lung will be prospectively analyzed by means of a concomitant clinical
      and biological analysis guided by evaluated functional and radiological measures of clinical
      development. The assessments will be made at the beginning of the study period (visit 1),
      after three months of prospective observation (visit 2), and after 12 months (end of study)
      allowing for a clinically relevant correlation of all biological data obtained.

      Three general conditions of repair will be chosen for systematic biological analysis as a
      result of their clinical diagnosis (histopathology, radiology) and their association with
      age:

        -  Usual interstitial pneumonia (UIP) occurring almost exclusively at an age of 55-80
           years,

        -  Hypersensitivity Pneumonitis (HP), both acute and chronic, occurring at an age of 20-55
           years, and

        -  Normal repair in young (18-40 years) and old (older than 55 years) individuals.

      Methods

      After securing the diagnosis (see below: inclusion/exclusion criteria) and following informed
      consent during the screening visit, patients lacking any previous immunosuppressive treatment
      (therapy-naïve patients) will receive an immunosuppressive therapy with prednisolone (daily
      dose of 1 mg/kg BW) for at least three months in order to exclude pathologies dominated by
      mechanisms of inflammation. During the screening visit, the results of the histopathological
      analysis will be secured, and the clinical and functional history of the disease recorded.
      This will include previous medication, the results of previous pulmonary function tests (PFT)
      as well as the results of radiological analysis (computed tomography including HR-CT) and lab
      testing (excluding collagen vascular disease and securing HP serology).

      Three months after the screening visit, at visit 1, the functional and radiological stage of
      the pulmonary fibrosis will be assessed again, and the patients will be finally enrolled into
      the study. In accordance with the findings obtained at the screening visit, and due to the
      functional and radiological results obtained at visit 1, the patients will be stratified into
      the following investigational groups:

      Group A:

      (Limited UIP) Patients with proven UIP and functionally and radiologically less advanced
      pulmonary fibrosis (n=12) as defined by histopathology (assessment by two independent and
      experienced pathologists not involved in the study) and/or radiology (computed tomography
      [CT] scans incl. high-resolution CT, independently assessed by an experienced radiologist not
      involved in the study) and pulmonary function tests (PFT). PFT will consist of spirometry,
      measurement with bodyplethysmograph, single-breath measurement of carbon monoxide diffusion
      capacity and full cardiopulmonary exercise testing including assessment of pulmonary
      ventilation and gas exchange at rest and on exertion;

      Group B:

      (Advanced UIP) Patients with proven UIP (n=12) in a significantly more advanced stage of the
      disease as determined by PFT (FVC at least 10 percent and DLCO at least 15 percent lower than
      in group A) and CT scan;

      Group C:

      (Chronic fibrosing Hypersensitivity Pneumonitis, HP) Patients with chronic fibrosing HP
      (n=12) diagnosed by histopathology, radiology and lab testing;

      Group D:

      (Acute HP) Patients with acute HP (n=9) diagnosed by histopathology, radiology and lab
      testing (Group D: acute HP);

      Group E:

      Regular Pulmonary Repair 9 young (18-40 years of age) without any clinically evident
      pathology and 9 old volunteers (55-80 years of age) without pulmonary fibrosis will serve as
      controls.

      All patients with UIP and HP will be followed during for a study period of 12 months. The
      study period starts with visit 1. In addition to visit 1, two additional visits will be
      performed after 3 months (visit 2, functional assessment) and after 12 months (visit 3, end
      of study).

      At all three visits, the following investigations will be performed:

        -  Clinical examination

        -  ECG

        -  PFT

        -  Cardiopulmonary exercise test

        -  Blood drawing

        -  CT scan

        -  Bronchoscopy with removal of 5 transbronchial biopsies for biological assessment from
           areas suggesting maximum disease activity in the CT scan will only be performed at
           visits 1 and 3.

      Relevant inclusion criteria applying to Group A (limited UIP):

        -  Informed consent

        -  Histologic proof of lesions consistent with UIP in surgical lung biopsies and/or

        -  Radiological signs suggestive of UIP

        -  No signs of widespread ground-glass opacities in CT scans

        -  No symptoms suggestive of chronic bronchitis/bronchiolitis, such as coughing and signs
           of bronchial obstruction or hyperinflation

        -  Difference of forced expiratory vital capacity (FVC) values ≤ 10% predicted to normal

        -  Difference of carbon monoxide diffusion capacity (DLCO) at rest of ≤ 15% predicted to
           normal

        -  Previous or current treatment with immunosuppressive drugs

      Relevant inclusion criteria applying to Group B (advanced UIP) (other than Group A):

        -  Signs of widespread ground glass opacities in CT scans

        -  Symptoms suggestive of chronic bronchitis, such as coughing and signs of bronchial
           obstruction or hyperinflation, may be present

        -  Forced expiratory vital capacity (FVC) values in difference > 10% predicted to normal

        -  Reduction of carbon monoxide diffusion capacity (DLCO) at rest of < 15% predicted

      Relevant inclusion criteria applying to Group C:

        -  Informed consent

        -  Histologic and/or cytologic proof of lesions consistent with chronic HP in
           transbronchial and/or surgical lung biopsies, transbronchial biopsies or bronchoalveolar
           lavage (BAL) samples

        -  Radiological signs suggestive of chronic HP

        -  Signs of widespread ground glass opacities in CT scans

        -  Symptoms suggestive of active bronchitis/bronchiolitis, such as coughing and signs of
           bronchial obstruction or hyperinflation, may be present

        -  Serological proof of hypersensitivity, if possible

        -  Forced expiratory vital capacity (FVC) values in difference ≥ 10% predicted to normal

        -  Reduction of carbon monoxide diffusion capacity (DLCO) at rest of ≥ 15% predicted

        -  Previous or current treatment with immunosuppressive drugs

      Relevant inclusion criteria applying to Group D (other than Group C):

        -  Informed consent

        -  Histologic and/or cytological proof of lesions consistent with acute HP in
           transbronchial and biopsies and/or bronchoalveolar lavage (BAL) samples

        -  Radiological signs suggestive of acute HP

      General exclusion criteria

        -  Functionally significant cardiovascular morbidity

        -  Respiratory insufficiency (PaO2 < 55 mmHg; PaCO2 > 50 mmHg)

        -  Significant pulmonary hypertension

        -  Significant pulmonary emphysema

        -  Non-functional contralateral lung

        -  Cancer

        -  Significant coronary heart disease

        -  Coagulation dysfunction

        -  Pregnancy, or planning pregnancy during the trial or within three month period
           thereafter

        -  Known drug or alcohol abuse within 3 years of screening

        -  Presumed non-compliance

        -  Known legal incapacity or limited legal capacity at screening

      Biopsies

      The lung specimens for biological analysis will be derived from both diagnostic surgical lung
      biopsies and transbronchial lung biopsies taken during the bronchoscopies performed at visit
      1 and 3. In total, five transbronchial biopsies will be taken at each visit for biological
      analysis. All transbronchial lung specimens will be removed under radiologic control from
      peripheral lung areas previously specified in accordance with the latest CT scan. The
      biopsies taken at visit 3 will be performed in the same lung segment as those taken at visit
      1.

      Except for the results of the latest CT scan, the investigator performing the bronchoscopy
      will be blinded for all clinical results obtained during the visits.

      Molecular Biology Assessment

      Biological analysis will be independently performed. All investigators involved in biological
      analysis will be blinded for diagnosis and clinical course of the patients and volunteers.
      The participants will be solely identifiable by their study identification number (ID). The
      study samples will be numbered according to patient ID and sample description provided by the
      LIMS. Biologic assessment will include measurement of whole genome transcriptomics, protein
      analysis by mass spectrometry and EIA, analysis of DNA methylation status, and microRNA
      analysis. The measurements will be based on lung specimens derived from diagnostic surgical
      lung biopsies, if possible, and/or from transbronchial biopsies (TbX) taken during a
      bronchoscopy at visit 1 and 3 of the study (month 0 and month 12). In addition, BAL fluid
      will be stored and used for detection of proteins and lipids. Materials for DNA methylation
      analysis will be obtained from both lung tissue and whole blood samples.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        The participants are chosen from patients lists of participating center.
      
Biospecimen description: 
      Transbronchial biopsies and Video-assisted throracoscopic biopsies
    
Keywords: Biology of Fibrosis