A team of Italian clinicians report the observation of a 77-year-old woman presenting with a classic picture of dermatomyositis (DM) with positive anti-Mi-2 autoantibodies:
- study of a biopsy muscle fragment nevertheless revealed very marked abnormalities in the mitochondria, in addition to the characteristic lesions usually found in DM (extensive perifascicular atrophy),
- the patient did not respond to conventional treatment of DM and, on the other hand, experienced a modest improvement in her symptoms with anti-JAK1,
- in general, associated mitochondrial abnormalities are rare in myositis, with the exception of inclusion myositis (IM) and certain forms of polymyositis.
The authors emphasise the value of anti-JAK1 treatment in these very unusual forms of DM.
