Evaluation of Peripheral Neutrophils in Antisynthetase Syndrome

Antisynthetase syndrome (AS) is a rare overlapping myositis characterized by cellular and humoral autoimmune responses directed against aminoacyl-tRNA synthetases. A pathogenic role of neutrophils was described during inflammatory myopathies, with increased netosis correlated with disease activity and muscle damage. Higher number of alveolar neutrophils was observed in patients with rapidly progressive forms of interstitial lung disease.

Peripheral neutrophils could represent a simple biomarker of severity and activity in patients with antisynthetase syndrome.

The main objective is to compare circulating neutrophils between severe and non severe patients with antisynthetase syndrome. Secondary objectives are: 1) to evaluate correlation between circulating neutrophils and organ-specific severity, 2) to compare circulating neutrophils at time of diagnosis and circulating neutrophils after 6 months of treatment in patients with antisynthetase syndrome.