The prognostic role of C-reactive protein to albumin ratio and anti-MDA5 antibody-positive in idiopathic inflammatory myopathy: a retrospective study

Abstract

This cohort study aimed to identify the characteristics and risk factors of adult idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) and further explore the prognostic factors of IIM-ILD. We extracted data regarding 539 patients with laboratory-confirmed idiopathic inflammatory myopathy (IIM) with or without interstitial lung disease (ILD) from the Second Xiangya Hospital of Central South University between January 2016 and December 2021. The regression analysis was conducted to identify the possible risk factors for ILD as well as mortality. Of 539 IIM patients, 343 (64.6%) were diagnosed with IIM-ILD. The median (IQR) baseline neutrophil-to-lymphocyte ratio (NLR), C-reactive protein to albumin ratio (CAR) and ferritin were 4.1371 (2.6994–6.8143), 0.1685 (0.0641–0.5456) and 393.6 (210.6–532.2), respectively. Risk factors associated with IIM-ILD were older age (p = 0.002), arthralgia (p = 0.014), lung infection (p = 0.027), hemoglobin (p = 0.022), high CAR (p = 0.014), anti-aminoacyl-tRNA synthetase (anti-ARS) antibody-positive (p < 0.001), and anti-MDA5 antibody-positive (p < 0.001). The IIM-ILD patients whose age at diagnosis of disease ≥ 59.5 (HR = 2.673, 95% CI 1.588–4.499, p < 0.001), NLR ≥ 6.6109 (HR = 2.004, 95% CI 1.193–3.368, p = 0.009), CAR ≥ 0.2506 (HR = 1.864, 95% CI 1.041–3.339, p = 0.036), ferritin ≥ 397.68 (HR = 2.451, 95% CI 1.245–4.827, p = 0.009) and anti-MDA5 antibody-positive (HR = 1.928, 95% CI 1.123–3.309, p = 0.017) had a higher mortality rate. High CAR and anti-MDA5 antibody-positive are more likely to be associated with a high mortality rate of IIM-ILD, which can be used as serum biomarkers, especially the CAR, a simple, objective tool to assess the prognosis of IIM.

The Clinical Value of the Neutrophil-to-Lymphocyte Ratio, the C-Reactive Protein-to-Albumin Ratio, the Systemic Inflammatory Index, and the Systemic Inflammatory Response Index in Patients with the Anti-Synthetase Syndrome

“…39,40 In our study, NLR was significantly higher in ASS-ILD relative to patients without ILD. In the present study, NLR, CAR, and SII are independent risk factors for ASS-ILD and have a good diagnostic value for ASS-ILD, which is consistent with the findings of Pei Zhou, 41,42 suggesting that these three biomarkers can identify ASS-ILD and reflect lung parenchymal inflammation.…”

Prognostic significance of natural killer cell depletion in predicting progressive fibrosing interstitial lung disease in idiopathic inflammatory myopathies

“…Currently, it is well known that risk factors for developing ILD during IIM are mainly associated with MSAs (such as MDA5) and ARS ( 36 ), and each IIM subgroup has its pathophysiology. Thus, we separately analyzed the immune profiles of anti-MDA5 + DM and ASS.…”