BMC Musculoskeletal Disorders (Mar 2023)

Anti-signal recognition particle positive necrotizing myopathy-sjogren’s syndrome overlap syndrome: a descriptive study on clinical and myopathology features

  • Li Xu,
  • Meng-ge Yang,
  • Liya Hu,
  • Huajie Gao,
  • Suqiong Ji

DOI
https://doi.org/10.1186/s12891-023-06354-5
Journal volume & issue
Vol. 24, no. 1
pp. 1 – 13

Abstract

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Abstract Background and objective The aim of this study was to elucidate the clinical and myopathological characteristics of patients with anti-signal recognition particle (SRP) positive immune-mediated necrotizing myopathy (IMNM) overlap Sjogren’s syndrome (SS). Materials and methods We retrospectively analyzed the data of anti-SRP positive IMNM patients admitted in the Neurology Department of Tongji Hospital between January 2011 to December 2020. Patients were divided into two groups: anti-SRP IMNM overlap SS group and anti-SRP IMNM control group. The clinical features, laboratory results, histological features, treatment, and prognosis were compared between the two groups. Results A total of 30 patients with anti-SRP IMNM were included, including six anti-SRP IMNM overlap SS patients (two males, four females), with a median age of 39 years, and 24 anti-SRP IMNM patients (ten males, fourteen females), with a median age of 46 years. The anti-SRP IMNM overlap SS group had a lower prevalence of muscle atrophy (0 vs 50%, p = 0.019), and a higher prevalence of extramuscular manifestations, including cardiac abnormalities and ILD (Interstitial lung disease). CD4 + and CD68 + inflammatory infiltrations were significantly increased in anti-SRP IMNM overlap SS patients, with an increased presence of CD4 + cells in both necrotic(p = 0.023) and endomysial areas (p = 0.013), and more CD68 + cells (p = 0.016) infiltrated the endomysial area. Deposition of membrane attack complex (MAC) on sarcolemma (p = 0.013) was more commonly seen in the anti-SRP IMNM overlap SS group. Conclusion Our data revealed that anti-SRP IMNM-SS overlap patients may present with milder muscular manifestation, but worse extramuscular manifestations compared to anti-SRP IMNM patients without SS. CD4 + and CD68 + inflammatory infiltrations and MAC deposition were remarkably increased in anti-SRP IMNM-SS overlap patients.

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