Development of a Prediction Score for the Occurrence of Death or Lung Transplantation in Patients With Emphysema Secondary to Alpha-1-anti-tripsin Deficiency

Context. Emphysema secondary to alpha-1-anti-trypsin deficiency (AATD) is a genetic rare disease, but with pejorative events such as death or lung transplantation (LT) which affect up to 15% of patients. Aside from standard medical care for COPD management, the only specific treatment as augmentation therapy for severe AATD, is weekly intravenous alpha-1 antitrypsin (IV-AAT) which is still expensive and restrictive. Several prognostic scores for tobacco-related COPD have been developed but, none of them have been validated in AATD, neither have included quantitative chest CT imaging while they have been associated with mortality in emphysema. Therefore, we aim to develop a prediction model combining clinical, biological, functional and quantitative CT data (including radiomics) for mortality or LT to identify at-risk patients with emphysema secondary to AATD.

Methods: From several French hospitals, we'll conduct a multicenter retrospective study based on data collected in usual care among patients over 18-year-old, with an available chest CT. We'll collect clinical data (BMI, mMRC dyspnea scale), respiratory function parameters and quantitative imaging data (including radiomics) from the initial CT from AATD patients secondary to ZZ, Znull, ZMalton, Z and rare mutations. We'll then validate our results on an independent external database from the European AADT cohort (EARCO), with specific dedicated funding.

Perspectives: To develop a prediction model to identify the AATD patients at risk of clinical deterioration, defined by death or LT allowing for personalized care, in order to: 1. anticipate registration on the transplant list, 2. optimize overall management, including pharmacological (IV-AAT) and non-pharmacological management. 3. to avoid cost-prohibitive and constraining IV-AAT infusion for low risk patients For Health policy, finding a way to target high-risk patients may help a better access for IV-AAT to appropriate individuals.

• Inclusion criteria:

• diagnosed between 2010 and 2025
• in the pulmonology department
• diagnosis of emphysema and COPD secondary to alpha-1 antitrypsin deficiency ZZ, Znull, ZMalton, Z and rare mutations,
• emphysema according to the initial thoracic CT scan (+/- 12 months after diagnosis).
• Exclusion criteria:

• Age <18 years
• Patient opposed to the use of their data for research purposes
• Patient deprived of liberty by judicial decision
• Patient not affiliated with a social security scheme
• no CT scan available
• no lung function test available the year around CT scan