Antisynthetase syndrome M33.1

w:m=2/3:1 (Mirrakhimov AE 2015)

In addition to muscle involvement, interstitial lung involvement (non-specific interstitial pneumonia (NISP)) characteristically occurs, which also determines the prognosis and clinical picture of the disease. Complaints include increasing exertional dyspnea, muscle weakness, macular or maculo-papular exanthema. Palmar and plantar hyperkeratosis (hands like a mechanic, feet like a hiker) are not uncommon.

In addition, clinically there may be polyarthritis and other symptoms similar to the clinical picture of other collagenoses. Like polymyositis and dermatomyositis, Jo-1 syndrome may present in so-called myositis overlap syndromes (in such cases, detection of U1 RNP antibodies).

Diagnostic for anti-synthetase syndrome (ASS) is the presence of serum autoantibodies against aminoacyl-tRNA synthetases (anti-ARS is involved in protein synthesis). Anti-synthetase antibodies include: anti-histidyl (anti-Jo-1), anti-threonyl (anti-PL-7), anti-alanyl (anti-PL-12), anti-isoleucyl (anti-OJ), anti-glycyl (anti-EJ), anti-asparaginyl (anti-KS)Anti-Wa, anti-tyrosil (anti-YRS), anti-phenylalanyl transfer RNA synthetase (anti-Zo), and anti-SRP. Anti-Jo-1 is the most common anti-synthethase antibody (in 20-30% of patients with dermatomyositis and polymyositis) (Witt LJ et al (2016).

In patients with anti-synthetase syndrome, compared to dermatomyositis and polymyositis, inflammatory myopathies, with which they may phenotypically overlap, there is a higher prevalence and increased extent of interstitial lung disease.

A 64-year-old man had been complaining for 5 weeks of increasing stress dyspnea, muscle weakness, symmetrical pain in the wrists and a trunk marked macular non-itching exanthema.

In addition, there were acral, wart-like hyperkeratoses of the hands and flat hyperkeratoses in the areas of the soles of the feet exposed to pressure.

Clearly elevated were CRP, CK, BSG. Detection of anti-Jo-1 antibodies.

Under treatment with high-dose glucocorticoids the arthritic symptoms and exanthema disappeared within 4 days. Respiratory distress and hyperkeratosis also improved significantly within 14 days.

1. Cojocaru M et al (2016) New Insights into Antisynthetase Syndromes. Maedica (Buchar) 11:130-135.

2. Johnston G (2017) Antisynthetase syndrome. Clin Med (London) 17:591.

3. Mirrakhimov AE (2015) Antisynthetase syndrome: a review of etiopathogenesis, diagnosis and management. Curr Med Chem 22:1963-1975.

4. Witt LJ et al (2016) The Diagnosis and Treatment of Antisynthetase Syndrome. Clin Pulm Med 23:218-226.