A case of anti-EJ anti-synthetase syndrome (EJ-ASS) with anti-Ro-52 overlap presenting with progressive interstitial lung disease (ILD) with subtle myopathy - A case report and literature review.

backgroundAnti-EJ-anti-synthetase syndrome (ASS) is a rare yet treatable subset within the ASS spectrum, characterised by a higher prevalence of interstitial lung disease (ILD), particularly with a relapsing or rapidly progressive (RP-ILD) course. CASE: Here we present a case with predominant ILD and arthritis, presenting with skin manifestations of Mechanic's hand and Gottron's papules. She had subtle myopathy of the proximal hip muscles. She was admitted three times, mostly due to worsening ILD. Her myositis profile showed positivity for anti-EJ and anti-Ro52 antibodies. Thigh muscle MRI revealed myofasciitis; however, the muscle biopsy was normal. Repeat computer tomography of the chest revealed progression of ground-glass opacities and reticulation, suggesting non-specific interstitial pneumonia (NSIP). She was treated with high-dose steroids, cyclophosphamide, and tacrolimus, with which she had a good response.

conclusionPatients with anti-EJ myositis often present with ILD and arthritis without significant muscle involvement. When ILD occurs before other clinical features, anti-EJ positive ASS is especially prone to misdiagnosis or delayed recognition. Careful assessment of skin signs and musculoskeletal symptoms is vital, even if skin involvement appears minimal or subtle.