Fever in the initial stage of IIM patients: an early clinical warning sign for AE-ILD

Abstract Background Fever is a common symptom of Idiopathic inflammatory myopathies (IIM). However, the exact correlation between fever and the prognosis of IIM is still unclear. This study aims to clarify if the IIM patients initiated with fever are associated with poorer outcomes. Methods This was a single-center retrospective cohort study. Data were collected from 79 newly diagnosed, treatment-naive IIM patients in the Affiliated Wuxi People’s Hospital of Nanjing Medical University (Wuxi, Jiangsu, China) from November 2016 to June 2020. According to the presence or absence of fever at the onset, the IIM patients were divided into two groups(fever group n = 28, without fever group n = 51) Clinical characteristics, laboratory data, treatment, and outcomes were recorded. The Kaplan-Meier and log-rank tests were used to compare the all-cause mortality, relapse rate, and acute exacerbation of interstitial lung disease (AE-ILD) incidence. The association of fever with the outcomes was assessed in the unadjusted and adjusted forward logistic regression model. Results Compared with the non-fever group, the age at onset of the fever group was higher, and mechanic’s hands (MH) and interstitial lung disease (ILD) were more common. Systemic inflammation (CRP and ESR) was significantly higher in the fever group, while the level of albumin(ALB) and muscle enzymes were lower. The fever group seemed to be received more aggressive treatment, with higher dose glucocorticoids and higher rates of intravenous immunoglobulins(IVIG) use. The all-cause mortality rate and the incidence rate of AE-ILD were higher in the fever group. Even adjusted for the age at onset and treatments, fever was significantly associated with AE-ILD and all-cause mortality. Conclusion Our study has demonstrated that fever at initial diagnosis is associated with AE-ILD and mortality. Fever should serve as an early clinical warning sign for poor outcomes in IIM patients.