DOI: 10.12890/2025_005154
Full recovery over one year of the overlap syndrome scleromyositis to maintenance therapy with mycophenolate mofetil and rituximab, which relapsed within 8 months of discontinuation
Authors
marta-m.v@hotmail.com
Keywords
Scleromyositis, inflammatory myositis, systemic sclerosis, interstitial lung disease, digital sclerosisAbstract
Scleromyositis (SM) is an emerging, distinct entity within the spectrum of diffuse systemic sclerosis (SSc) and autoimmune inflammatory myopathies. It can carry a poorer prognosis due to multisystem involvement and extramuscular complications, with no consensus on treatment strategies currently available.
We report on a 20-year-old woman with a history of recurrent infections over the past year, who presented with persistent myalgias for four months. On examination, she exhibited muscle weakness in the scapular and pelvic girdles, along with sclerodactyly. Laboratory results showed elevated creatine kinase (13,000 U/l), aldolase (15.6 U/l), lactate dehydrogenase (1,481 U/l) and myoglobin (4,400 ng/ml). Autoimmune screening was positive for antinuclear antibodies, anti-PM-scleroderma (anti-PM-Scl) 75 and 100, and anti-CENP-B antibodies. An MRI of the pelvic girdle indicated acute/subacute myositis, and electromyography revealed both distal and proximal myopathy. Muscle biopsy showed extensive necrosis with minimal inflammatory infiltration. Nailfold capillaroscopy demonstrated an early scleroderma pattern, while CT and spirometry revealed mild interstitial restrictive lung disease. Initial treatment involved intravenous immunoglobulin (IVIG), mycophenolate mofetil (MMF) and prednisolone. This was followed by maintenance therapy with MMF and rituximab (RTX) every six months for the first year. Over six months, the patient showed progressive improvement in muscle strength and normalisation of muscle enzyme levels.
In conclusion, SM presents with variable phenotypes, ranging from mild to extensive systemic involvement. This case underscores the importance of individualised patient stratification and highlights the need for structured induction and maintenance therapy due to the disease’s extensive activity.
References
- Giannini M, Ellezam B, Leclair V, Lefebvre F, Troyanov Y, Hudson M, et al. Scleromyositis: a distinct novel entity within the systemic sclerosis and autoimmune myositis spectrum. Implications for care and pathogenesis. Front Immunol 2023;13:974078.
- Marche Fernandez OA, Becerril Mendoza LT, Pinto Garcia LJ, Hernandez Garcia JG, Diaz Garcia JD. Scleromyositis: a novel entity beyond systemic sclerosis and autoimmune myositis. Cureus 2023;15:e44292.
- van den Hoogen F, Khanna D, Fransen J, Johnson SR, Baron M, Tyndall A, et al. 2013 classification criteria for systemic sclerosis: an American college of rheumatology/European league against rheumatism collaborative initiative. Ann Rheum Dis 2013;72:1747–1755.
- Jablonska S, Blaszczyk M. Scleromyositis: a scleroderma/polymyositis overlap syndrome. Clin Rheumatol 1998;17:465–467.
- Lefebvre F, Giannini M, Ellezam B, Leclair V, Troyanov Y, Hoa S, et al. Histopathological features of systemic sclerosis-associated myopathy: a scoping review. Autoimmun Rev 2021;20:102851.
- De Lorenzo R, Pinal-Fernandez I, Huang W, Albayda J, Tiniakou E, Johnson C, et al. Muscular and extramuscular clinical features of patients with anti-PM/Scl autoantibodies. Neurology 2018;90:e2068–e2076.
- Meyer A, Leclair V, Landon-Cardinal O, Ellezam B, D’Aoust J, Giannini M, et al. ACR/EULAR Criteria for Myositis and Systemic Sclerosis Lack Sensitivity for Scleromyositis [abstract]. Arthritis Rheumatol 2019;71:389.
- Selva-O’Callaghan A, Simeon-Aznar CP. The scleromyositis phenotype. Lessons from a multicentre international cohort of anti-PM/Scl-positive patients. Rheumatology (Oxford) 2021;60:4956–4957.
- Jacquier M, Mousson C, Rebibou JM, Lakomy D, François S, Martin L, et al. Scleroderma renal crisis in a systemic sclerosis with anti-PM/Scl antibodies. Kidney Int Rep 2019;4:1499–1502.
- Álvarez Troncoso J, Nuño González A, Martínez Robles E, Sorriguieta Torre R, Robles Marhuenda Á. Tofacitinib is an effective treatment for refractory scleromyositis associated with anti-PM/Scl. Cureus 2023;15:e34125.
