The Diagnostic and Prognostic Role of SAA in Intrathoracic Sarcoidosis

Study Overview
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Brief Summary
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The goal of this observational study is to elucidate the role of serum amyloid A (SAA) in the diagnosis and follow-up of sarcoidosis, including its prognostic value. The main questions it aims to answer are: Whether, at the time of diagnosis, SAA is in correlation with other serum markers of granulomatous inflammation, interstitial disease and pulmonary fibrosis, lung function and radiologic characteristics of intrathoracic sarcoidosis, Whether increased serum concentrations of SAA at the time of diagnosis act as a prognostic marker of progressive granulomatous inflammation and pulmonary interstitial disease. Patients will undergo standard diagnostic procedures for intrathoracic sarcoidosis, according to WASOG (World association of sarcoidosis and other granulomatous disorders) criteria. Two additional vials of blood will be taken at diagnosis and one vial at follow-up for serum processing and biomarker analysis. Healthy blood donors will represent our group of healthy controls.

Official Title
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The Role of Serum Amyloid A in Clinical Decision-making Concerning Sarcoidosis Patients

Conditions
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Sarcoidosis, Pulmonary

Intervention / Treatment
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* Other: No intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Above 18 years of age Enrolled immediately after the first diagnostic workup and before any treatment was initiated. Exclusion Criteria: Individuals with granulomatous disease that could not be unequivocally diagnosed as sarcoidosis were excluded, as well as patients with possible confounding other known systemic inflammatory illnesses, acute infection, patients on immunosuppressive drugs or immunotherapy and patients with active cancer.

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 |
| --- | --- |
| Intrathoracic sarcoidosis cohort<br>Patients with intrathoracic sarcoidosis, confirmed according to European Respiratory Society/ World Association of Sarcoidosis and Other Granulomatous disease (ERS/WASOG) criteria | Other: No intervention<br>* No intervention, only comparison<br>|
| Healthy controls<br>Healthy blood donors | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The correlation of mean serum concentration of serum amyloid A (SAA) in patients, newly diagnosed with intrathoracic sarcoidosis to mean value in healthy controls | The mean serum concentration of serum amyloid A (SAA) (in micrograms per millilitre) in patients, newly diagnosed with intrathoracic sarcoidosis will be determined for our entire intrathoracic sarcoidosis cohort and separately first for patients in different Scadding stages (0-4) and secondly according to high-resolution computed tomography (HRCT) pattern (lymph node enlargement, peribronchovascular/perilymphatic lesions, ground-glass lesions and pulmonary fibrosis). The mean values will then be compared to the mean value of SAA in healthy controls to determine possible statistically significant differences. | 4 years for patient enrollment | 
| The correlation of serum concentrations of serum amyloid A (SAA) at the time of diagnosis of intrathoracic sarcoidosis with serum concentrations of other biomarkers of granulomatous inflammation and pulmonary interstitial disease. | We will determine whether serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis corelate to serum concentrations of granulomatous disease markers (CC chemokine ligand 18 (CCL18), monokine induced by interferon-γ (CXCL9), interferon-γ-induced protein 10 (CXCL10)) and activity of serum chitotriosidase (CTO) and serum concentrations of biomarkers of interstitial lung disease and lung fibrosis (surfactant protein D (SP-D) and cancer antigen 15.3 (CA 15.3)/Krebs von den Lungen 6 (KL-6)). | 4 years for patient enrollment | 
| Correlation of serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis to pulmonary function test results. | We will determine whether serum concentrations of SAA corelate to results of lung function tests (percentages predicted of forced vital capacity, forced expiratory volume in 1 second and diffusion capacity for carbon monoxide) at the time of diagnosis of intrathoracic sarcoidosis. | 4 years for patient enrollment | 
| Correlation of serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis to radiologic extent of disease. | We will determine whether serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis correlate with extent of disease on HRCT, expressed in percentage of pulmonary parenchyma involved (0%, 0-33%, 33-66%, 66-100%). | 4 years for patient enrollment | 
| Correlation of serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis to changes in lung function tests after 3 years of follow-up. | We will determine whether SAA concentrations at the time of diagnosis of intrathoracic sarcoidosis correlate with changes in lung function tests (percentages predicted of forced vital capacity, forced expiratory volume in 1 second and diffusion capacity for carbon monoxide) at patient follow-up after 3 years. | 3 years follow-up | 
| Correlations of serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis to changes in HRCT disease extent after 3 years of follow-up. | We will determine whether SAA concentrations at the time of diagnosis of intrathoracic sarcoidosis correlate with changes in HRCT disease extent (descriptive terms used: resolution, stagnation, progression) at patient follow-up after 3 years. | 3 years follow-up | 
| Correlation of serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis to need for recent/ongoing therapy after 3 years of follow-up. | We will determine whether serum concentrations of SAA at the time of diagnosis of intrathoracic sarcoidosis correlate with the need for recent/ongoing therapy in patients, assessed at a 3-year follow-up. | 3 years follow-up |