Evaluation of Circulating Neutrophils in Antisynthetase Syndrome

Study Overview
=================
Brief Summary
-----------------
Antisynthetase syndrome (ASyS) is a rare and heteregeneous overlapping connective tissue disease, characterized by myositis, interstitial lung disease (ILD), joint involvement, Raynaud's phenomenon and cutaneous manifestations (mechanic's hands). Over 50% of patients develop ILD, which is the leading cause of death. The role of neutrophils - innate immune cells involved in inflammatory processes and induced in particular by cytokines of the Th17 pathway - during AS is unknown. Direct pathogenic role of neutrophils has been described during idiopathic inflammatory myopathies, with an increase of netosis correlated with disease activity and muscle damage. During ASyS, a higher number of alveolar neutrophils has been observed in patients with rapidly progressive ILD. There are few data on the specific evaluation of circulating neutrophils in ASyS. Investigators suppose that circulating neutrophils level could represent a simple and accessible severity biomarker in patients with ASyS. The main objective is to evaluate the diagnostic performance of the circulating neutrophils level (> 7000/mm3) at diagnosis on ASyS severity. The secondary objectives are: to define a threshold for circulating neutrophils levels at diagnosis allowing to predict ASyS severity and to assess the diagnostic performance of this threshold. to study the correlation between the level of circulating neutrophils and ASyS severity at diagnosis of the disease. to compare the circulating neutrophils level at ASyS diagnosis and after 1 year of treatment. to compare patients characteristics according to ASyS severity at diagnosis. to compare BAL fluid neutrophils level according to ILD severity at ASyS diagnosis in patients with ILD.

Official Title
-----------------
Evaluation of Circulating Neutrophils in Antisynthetase Syndrome: a Multicenter Retrospective Study

Conditions
-----------------
Antisynthetase Syndrome

Intervention / Treatment
-----------------
* Diagnostic Test: circulating neutrophils


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients with ASyS diagnosis according to Connors criteria Exclusion Criteria: Active infection at ASyS diagnosis Evolutive cancer at ASyS diagnosis Corticosteroid therapy initiation before circulating neutrophils evaluation

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ASyS patients<br>Patients with antisynthetase syndrome | Diagnostic Test: circulating neutrophils<br>* evaluation of circulating neutrophils level<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| circulating neutrophils level > 7000/mm3 |  | baseline (J0) | 
| number of patients with global severity | global severity defined as presence of severe ILD (PaO2 < 600 mmHg or rapidly progressive ILD), and/or presence of severe myositis (bedrest, or MMT8 score < 30, or MRC muscle testing < 3/5, or swallowing disorers, or dysphagia) and/or presence of myocarditis on cardiac MRI | baseline (J0) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| circulating neutrophils level |  | baseline (J0) | 
| FVC | FVC percentage | baseline (J0) | 
| DLCO | DLCO percentage | baseline (J0) | 
| grade of MRC muscle testing |  | baseline (J0) | 
| CK level |  | baseline (J0) | 
| circulating neutrophils level |  | 12 months | 
| BAL fluid neutrophils level |  | baseline (J0) |