Duplication in CHIT1 Gene and the Risk for Aspergillus Lung Disease in CF Patients
Condition: Cystic Fibrosis; Chit1
MeSH terms: Cystic Fibrosis; Lung Diseases; Fibrosis
Study type: Observational

Summary: 
      Title: Duplication in Chitotriosidase (CHIT1) Gene and the Risk for Aspergillus Lung Disease
      in CF Patients.

      Aim: To evaluate the link between CHIT1 duplication in CF patients and the predisposition to
      ABPA or persistent Aspergillus infection.

      Patients: 40 CF patients. Design: Observational, single visit. Methods: All patients will be
      assessed for pulmonary function tests (PFT), sputum cultures, and blood tests for: CHIT1
      duplication, immunoglobulin E (IgE) and Eosinophils levels. Part of the patients will be
      assessed for RAST, skin prick test.

      Primary outcome measure is the difference in CHIT1 genotyping between the groups.
    

Detailed description: 
      Title: Duplication in Chitotriosidase (CHIT1) Gene and the Risk for Aspergillus Lung Disease
      in CF Patients.

      Introduction: Chitinases are the enzymes that digest the chitin polymer. Plants use CHIT1 as
      an important innate defense mechanism against fungi. CHIT1 is the major chitinase in the
      human airways.Variation in the coding region, with 24-bp duplication allele results in a
      reduced CHIT1 activity. Recently, CHIT1 duplication was found in 6/6 patients with severe
      asthma and fungal sensitization Aspergillus often persists in the respiratory tract of
      patients with Cystic Fibrosis (CF) and may cause allergic broncho pulmonary aspergillosis
      (ABPA).

      Aim: to evaluate the link between CHIT1 duplication in CF patients and the predisposition to
      ABPA or persistent Aspergillus infection.

      Patients: 40 CF patients divided to three groups .Group 1: patients who have neither ABPA nor
      Aspergillus infection in the past (the control group).Group 2: patients with persistent
      Aspergillus infection, without ABPA. Group 3: patients with current or past ABPA.

      Design: Observational, single visit. Methods: All patients will be assessed for pulmonary
      function tests (PFT), sputum cultures, and blood tests for: CHIT1 duplication, IgE and
      Eosinophils levels.

      Patient's characteristics including demographics, CF mutations, pancreatic status and sweat
      test will be derived from the charts.

      Patients with ABPA as well as Aspergillus infection had also radioallergosorbent test (RAST)
      for molds, as well as skin prick test for Aspergillus and blood Galactomannan.

      The primary outcome measure is the difference in CHIT1 genotyping between the groups.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        40 Cystic Fibrosis patients: Group 1: 22 CF patients who had neither ABPA nor Aspergillus
        infection in the past.

        Group 2: 12 CF patients with persistent Aspergillus infection, without ABPA. Group 3: 6 CF
        patients with current or past ABPA
      
Keywords: Chit1; Cystic Fibrosis; Allergic Bronchopulmonary Aspergillosis (ABPA); Aspergillus