Antisynthetase syndrome M33.1

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

In addition to muscle involvement, interstitial lung involvement occurs characteristically, which also determines the disease pattern prognostically and clinically. Complaints include increasing stress dyspnea, muscle weakness, macular or maculo-papular exanthema. Palmar and plantar hyperkeratoses (hands like a mechanic, feet like a hiker) are not uncommon.

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

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.