Macrophages, GM-CSF and MARS Proteinosis (MacroMARS)

Assistance Publique - Hôpitaux de Paris

Status: Completed

Conditions: Genetic Mutation; Pulmonary Alveolar Proteinosis (PAP); MARS

Treatments: Biological: Blood collection; Biological: Bronchoalveolar lavage fluid collection

Study type: Observational

Funder types: Other

Identifiers

NCT04811274

APHP201476

2020-A02750-39 (Other Identifier)

Details and patient eligibility

About

Mutations in the MARS gene encoding methionyl-tRNA synthetase are responsible for a genetic form of alveolar proteinosis (PAP), but the pathophysiological mechanisms of the respiratory phenotype are not known.

The main hypothesis is that the PAP phenotype in these patients is secondary to a defective clearance of the surfactant by the alveolar macrophages.

The main objective of the study is to study the clearance capacity of lipoproteinaceous material by macrophages of patients with MARS related PAP. This will be investigate in cultured macrophages derived from peripheral blood monocytes of patients (patients with MARS related PAP) and controls (patients without MARS related PAP).

Full description

Pulmonary alveolar proteinosis (PAP) is a rare respiratory disease characterized by the accumulation of lipoproteinaceous material within the pulmonary alveoli, resulting in the majority of cases from a defective clearance of the surfactant by intra-alveolar macrophages.

Mutations in the MARS gene encoding methionyl-tRNA synthetase are responsible for a genetic form of alveolar proteinosis, but the pathophysiological mechanisms leading to mutations in the respiratory phenotype are not known.

The main hypothesis is that the alveolar proteinosis phenotype in these patients is secondary to a defective clearance of the surfactant by the alveolar macrophages.

The main objective of the study is to study the clearance capacity of lipoproteinaceous material by macrophages of patients with MARS related PAP. This will be investigate in cultured macrophages derived from peripheral blood monocytes of patients (patients with MARS related PAP) and controls (patients without MARS related PAP).

The subjects and the controls will be included during a hospitalization during which a blood sample and a bronchoscopy with broncoalveolar lavage must be performed as part of their care.

Enrollment: 20 patients

Sex: All

Ages: Under 17 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Minors from 0 to 17 years hospitalized for their care at Necker Enfants Malades hospital and for whom a blood sample and a bronchoscopy with bronchoalveolar lavage must be performed as part of their care
• Information and consent of the holders of parental authority and the patient

Exclusion criteria

- Refusal of holders of parental authority or patient

Trial design

20 participants in 2 patient groups

Patients

Description:

Minor patients with alveolar proteinosis by mutations of the MARS gene.

Treatment:

Biological: Bronchoalveolar lavage fluid collection

Biological: Blood collection

Controls

Description:

Minors patients without alveolar proteinosis.

Treatment:

Biological: Bronchoalveolar lavage fluid collection

Biological: Blood collection