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High prevalence of necrotising myopathy pattern in muscle biopsies of patients with anti-Jo-1 antisynthetase syndrome
L.M. Da Silva1, I.B. Borges2, S.K. Shinjo3
- Division of Rheumatology, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil.
- Division of Rheumatology, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil.
- Division of Rheumatology, Faculdade de Medicina FMUSP, Universidade de São Paulo, São Paulo, Brazil. samuel.shinjo@usp.br
CER15463
2023 Vol.41, N°2
PI 0238, PF 0246
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PMID: 36226626 [PubMed]
Received: 05/01/2022
Accepted : 19/04/2022
In Press: 11/10/2022
Published: 01/03/2023
Abstract
OBJECTIVES:
Until now, researchers have not provided a well-defined muscle histological pattern for antisynthetase syndrome (ASSD). Therefore, we aimed to analyse the muscle biopsies of patients with anti-Jo-1 ASSD.
METHODS:
This study included 26 patients with anti-Jo-1 ASSD admitted for investigation of the disease and obligatorily with muscle impairment, from 2010 to 2021, whose serial frozen muscle sections were analysed.
RESULTS:
Patients’ mean age at disease diagnosis was 42.8±11.6 years, and the female gender was most predominant. Concerning muscle biopsies, cell infiltrates were present in 76.9% of the samples, and they were mainly located at the endomysium area (70%), with a predominance of macrophages (92.9%). Fiber muscle necrosis was present in 92.3% and was diffused in 54.2%. Expression of MHC-I was seen in all samples. Samples were mostly marked by the presence of CD68+ and discreet/low CD4+ and CD8+ staining, which is consistent with a higher predominance of observed necrosis and macrophage cell infiltrates. In general, 38.5% of patients had a necrotising myopathy pattern in muscle biopsies, whereas 34.6% and 26.9% had a general inflammatory myopathy pattern and nonspecific myopathy, respectively. This necrotising myopathy pattern was not associated with the demographic, clinical, or laboratory data.
CONCLUSIONS:
Our data show that almost 40% of patients with well-defined anti-Jo-1 ASSD with objective muscle impairment have a necrotising myopathy pattern in their muscle biopsies. Although this pattern is more classically related to immune-mediated necrotising myopathies, in association with clinical manifestations and the presence of anti-Jo-1 autoantibodies, this characteristic may lead to ASSD diagnosis.
