Study Comparing Chronic Beryllium Disease to Pulmonary Sarcoidosis

Study Overview
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Brief Summary
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Inhalation of beryllium can induce specific sensitization and diffuse pulmonary granulomatosis called chronic beryllium disease (CBD). The clinical, radiographic, and anatomopathological features of CBD are very similar to those of sarcoidosis, another granulomatosis, making its diagnosis difficult. In addition, the progression of CBD is poorly understood. The investigators hypothesis is that there are specific clinical, biological, anatomopathological, and radiological presentation specificities of CBD, as well as a worse prognosis compared to pulmonary sarcoidosis.

Detailed Description
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Inhalation of beryllium can induce specific sensitization and diffuse pulmonary granulomatosis called chronic beryllium disease (CBD). The clinical, radiographic, and anatomopathological features of CBD are very similar to those of sarcoidosis, another granulomatosis, making its diagnosis difficult. In addition, the progression of CBD is poorly understood . The investigators hypothesis is that there are specific clinical, biological, anatomopathological, and radiological presentation specificities of CBD, as well as a worse prognosis compared to pulmonary sarcoidosis.

Official Title
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Retrospective Multicenter Case-control Study Comparing Chronic Beryllium Disease to Pulmonary Sarcoidosis

Conditions
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Pulmonary Sarcoidosis, Chronic Beryllium Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 years Sufficiently documented medical record. Informed patients who did not object to participating in the research, or for deceased patients, did not object to the use of their data. Cases: Patients followed for confirmed chronic beryllium disease by expert teams based on the ATS 2014 criteria, i.e., a history of exposure to beryllium, positivity of two abnormal lymphocyte proliferation tests (LPT) in blood and/or an abnormal LPT in bronchoalveolar lavage, granuloma found in pulmonary biopsy associated by compatible clinical, radiological or spirometric abnormalities. Controls: Patients followed for sarcoidosis according to the ATS/ERS/WASOG criteria, i.e., (i) a compatible presentation, (ii) the presence of non-necrotizing granulomatosis in one or more tissues (except Löfgren's syndrome or Heerfordt syndrome), (iii) and exclusion of alternative causes of granulomatous diseases with pulmonary parenchymal involvement on thoracic CT and/or chest radiography. Controls: without occupational exposure to beryllium. Exclusion Criteria: Patients under trustee.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients without professional exposure to beryllium<br>Patients without professional exposure to beryllium | |
| Patients with chronic pulmonary berylliosis<br>Patients with chronic pulmonary berylliosis | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The phenotypic profile at inclusion will be based on clinical data | symptoms at diagnosis | baseline | 
| The phenotypic profile at inclusion will be based on clinical data | general signs(number and type of organs affected) | baseline | 
| The phenotypic profile at inclusion will be based on biological data | serum angiotensin-converting enzyme assay (hydrolysis of one micromole of substrate per minute) | baseline | 
| The phenotypic profile at inclusion will be based on biological data | blood calcium(mmol/L) | baseline | 
| The phenotypic profile at inclusion will be based on biological data | calciuria (mmol/kg/J) | baseline | 
| The phenotypic profile at inclusion will be based on biological data | blood lymphocytes(mm3) | baseline | 
| The phenotypic profile at inclusion will be based on biological data | gamma globulinemia (g/L) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | extra-functional explorations with measurement in absolute value and as a percentage of the theoretical value of total lung capacity (L) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | residual volume (%) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | forced vital capacity (L) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | maximum exhaled volume (L) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | Tiffeneau (%) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | carbon monoxide diffusion capacity (%) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | transfer coefficient (%) | baseline | 
| The phenotypic profile at inclusion will be based on functional data | 6-minute walk test (m) | baseline | 
| The phenotypic profile at inclusion will be based on radiological data | extent and description on chest CT of elementary lesions activity lesions (mm) | baseline | 
| The phenotypic profile at inclusion will be based on radiological data | fibrosis patterns (absence/presence) | baseline | 
| The phenotypic profile at inclusion will be based on radiological data | signs of pulmonary hypertension (absence/presence) | baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Survival without transplantation | Survival without transplantation will be measured from the date of inclusion until death and/or lung transplantation, or the date of last follow-up. | From date of baseline until the date of death,or date of lung transplantation or date of last visit whichever came first | 
| The occurrence of comorbidities and complications related to the disease and to treatment | The occurrence of comorbidities will correspond to the presence of comorbidities (smoking, alcoholism, obesity, diabetes, hypertension, other medical history) | baseline | 
| Therapeutic management | Therapeutic management will be studied by immediate indication of treatment | baseline | 
| Psycho-social consequences | Psycho-social consequences will be evaluated by the number of sick leaves, the existence of professional reclassification, and the number of hospitalizations | baseline and last visit in 2022 | 
| Respiratory functional evolution | Respiratory functional evolution will correspond to the absolute variation of the respiratory function parameters extra-functional explorations with measurement in absolute value and as a percentage of the theoretical value of total lung capacity, residual volume, forced vital capacity, maximum exhaled volume, Tiffeneau, carbon monoxide diffusion capacity, transfer coefficient, 6-minute walk test, PaO2, PaCO2 | baseline and last visit in 2022 | 
| CT scan evolution | CT scan evolution will study the data from the latest available thoracic CT scan | last visit in 2022 |