Outcomes and prognostic factors of patients with anti-melanoma differentiation-associated protein 5 and anti-aminoacyl-RNA synthetase antibodies positive idiopathic inflammatory myopathies in intensive care unit

Abstract Background: This study aims to identify prognostic factors for mortality of patients with anti-melanoma differentiation-associated protein 5 (anti-MDA5) or anti-aminoacyl-RNA synthetase (anti-ARS) antibodies positive and acute respiratory failure in the intensive care unit.Methods: Clinical characteristics, laboratory test findings, imaging performance, and management were retrospectively collected in all cases with anti-MDA5 and anti-ARS antibodies positive, as well as follow-up survival data. Risk factors related to prognosis were identified by Cox regression analysis.Results: The 28-day mortality of all patients was 68.8% (n=44/64). The patients who died were more likely to have anti-MDA5 antibody(p<0.001), presented more Gottron papules(p=0.021) or heliotrope rash(p=0.008), had a relatively lower level of WBC(p=0.038), CRP(p=0.004), and had a higher level of LDH(p=0.029), serum ferritin(p=0.002). The main risk factors associated with 28-day mortality were anti-MDA5 antibody positive [HR 10.827 (95% CI: 4.261-27.514), p<0.001], presence of Gottron papules [2.299 (1.203-4.394), p=0.012], heliotrope rash [3.423 (1.773-6.606), p<0.001], and arthritis/arthralgia [2.365 (1.130-4.948), p=0.022). At a median of 14 (IQR 6.33-35.0) months of follow-up, the overall mortality of all patients was 75.0% (n=48/64). The non-survivors were more likely to own anti-MDA5 antibody(p<0.001), had a higher rate of Gottron papules(p=0.020) or heliotrope rash(p=0.014), had lower PFR(p=0.032) while ICU admission, and existed a higher level of serum ferritin(p=0.005). Main risk factors associated with overall mortality were consistent with risk factors for 28-day mortality. Conclusions: Anti-MDA5 antibody positive, presence of Gottron papules, heliotrope rash, or arthritis/arthralgia were the main independent risk factors of poor prognosis for IIM patients admitted to the ICU due to acute respiratory failure.