RT Journal Article SR Electronic T1 Recognising the spectrum of scleromyositis: HEp-2 ANA patterns allow identification of a novel clinical subset with anti-SMN autoantibodies JF RMD Open JO RMD Open FD EULAR SP e001357 DO 10.1136/rmdopen-2020-001357 VO 6 IS 2 A1 Océane Landon-Cardinal A1 Alexandra Baril-Dionne A1 Sabrina Hoa A1 Alain Meyer A1 Valérie Leclair A1 Josiane Bourré-Tessier A1 Anne-Marie Mansour A1 Farah Zarka A1 Jean-Paul Makhzoum A1 Jessica Nehme A1 Eric Rich A1 Jean-Richard Goulet A1 Tamara Grodzicky A1 Martial Koenig A1 France Joyal A1 Isabelle Richard A1 Marie Hudson A1 Ira Targoff A1 Minoru Satoh A1 Marvin J Fritzler A1 Yves Troyanov A1 Jean-Luc Senécal YR 2020 UL http://rmdopen.bmj.com/content/6/2/e001357.abstract AB Objective To describe systemic sclerosis (SSc) with myopathy in patients without classic SSc-specific and SSc-overlap autoantibodies (aAbs), referred to as seronegative scleromyositis.Methods Twenty patients with seronegative scleromyositis diagnosed by expert opinion were analysed retrospectively for SSc features at myositis diagnosis and follow-up, and stratified based on HEp-2 nuclear patterns by indirect immunofluorescence (IIF) according to International Consensus of Autoantibody Patterns. Specificities were analysed by protein A−assisted immunoprecipitation. Myopathy was considered an organ involvement of SSc.Results SSc sine scleroderma was a frequent presentation (45%) at myositis diagnosis. Myositis was the most common first non-Raynaud manifestation of SSc (55%). Lower oesophagal dysmotility was present in 10 of 11 (91%) investigated patients. At follow-up, 80% of the patients met the American College of Rheumatology/EULAR SSc classification criteria. Two-thirds of patients had a positive HEp-2 IIF nuclear pattern (all with titers ≥1/320), defining three novel scleromyositis subsets. First, antinuclear antibody (ANA)-negative scleromyositis was associated with interstitial lung disease (ILD) and renal crisis. Second, a speckled pattern uncovered multiple rare SSc-specific aAbs. Third, the nuclear dots pattern was associated with aAbs to survival of motor neuron (SMN) complex and a novel scleromyositis subset characteriszed by calcinosis but infrequent ILD and renal crisis.Conclusions SSc skin involvement is often absent in early seronegative scleromyositis. ANA positivity, Raynaud phenomenon, SSc-type capillaroscopy and/or lower oesophagal dysmotility may be clues for scleromyositis. Using HEp-2 IIF patterns, three novel clinicoserological subsets of scleromyositis emerged, notably (1) ANA-negative, (2) ANA-positive with a speckled pattern and (3) ANA-positive with nuclear dots and anti-SMN aAbs.