ANTISYTHETASE SYNDROME-RELATED ILD - OVERVIEW
OVERVIEW
Antisynthetase syndrome is an autoimmune idiopathic inflammatory myopathy (IIM) characterized by autoantibodies against an aminoacyl transfer RNA (tRNA) synthetase.1 The consequence is abnormal activation of both innate and adaptive immunity that target multiple systems in genetically susceptible individuals.2
EPIDEMIOLOGY
In the United States, approximately 3250 people have antisynthetase syndrome.3 Onset of disease typically occurs in individuals in their 50s.4
RISK FACTORS AND MORTALITY
RISK FACTORS:5
- Women are 2-3 times more likely to develop the disease than men
- Genetic predisposition:
- Specific human leukocyte antigen (HLA)-DRB1, -DQA1, and -DQB1 alleles
MORBIDITY/MORTALITY
- Antisynthetase syndrome displays relatively higher morbidity and mortality rates than other forms of inflammatory myopathies5
- This is due to the higher rates of interstitial lung disease seen in antisynthetase syndrome4,5
CLINICAL FEATURES
- Interstitial lung disease (ILD)—much higher prevalence than seen in polymyositis (PM) or dermatomyositis (DM)1
- Nonerosive arthritis1
- Myositis1
- Raynaud’s phenomenon1,5
- Unexplained fever1
- Mechanic’s hands1,5
- Gottron’s papules5
- Metacarpo- or interphalangeal joint lesions5
DIAGNOSIS FOR ANTISYTHETASE SYNDROME1
Established diagnosis of antisynthetase syndrome OR Comprehensive medical history + physical exam + serologies (anti- aminoacyl tRNA synthetase (anti-ARS); anti-Jo1) + muscle biopsy
ANTISYNTHETASE SYNDROME-ILD EPIDEMIOLOGY
- Because antisynthetase syndrome is not commonly studied as a distinct entity from the other PM/DM, the prevalence of ILD in patients with antisynthetase syndrome is difficult to determine1
- One study found the prevalence of ILD in antisynthetase syndrome patients to be 86%1
- ILD is often a presenting symptom in antisynthetase syndrome1,4
