Unveiling IL-41: A novel biomarker for polymyositis and dermatomyositis diagnosis

Polymyositis (PM) and dermatomyositis (DM) are two common subtypes of idiopathic inflammatory myopathies (IIM). The concentration of serum interleukin (IL)-41 in patients with PM/DM has not been reported. This study aims to investigate the levels of IL-41 in the serum of individuals diagnosed with PM/DM.

A total of 118 participants were enrolled in the study, comprising 80 patients with PM/DM and 38 healthy controls (HC). Comprehensive clinical data for each participant were collected through physical examinations and detailed clinical histories. The levels of IL-41 were quantified using the enzyme-linked immunosorbent assay (ELISA). Spearman's correlation analysis was employed to examine the relationship between IL-41 levels and various clinical parameters. The diagnostic potential of IL-41 was assessed using the receiver operating characteristic (ROC) curve.

Serum IL-41 levels were significantly elevated in PM/DM patients with interstitial lung disease (ILD) compared to HC [1001.03 (572.95, 1604.83) pg/mL vs 361.03 (302.24, 541.06) pg/mL, P < 0.0001]. Furthermore, a significant difference was also observed in serum IL-41 levels between PM/DM patients without ILD and HC [561.81 (407.94, 827.34) pg/mL vs 361.03 (302.24, 541.06) pg/mL, P = 0.0139]. IL-41 exhibits substantial diagnostic potential for PM/DM, and its combination with lactate dehydrogenase enhances diagnostic efficacy. Moreover, IL-41 acts as an independent risk factor for the onset of PM/DM.

This study revealed that serum IL-41 levels are elevated in patients with PM/DM, suggesting that IL-41 could serve as a novel biomarker for the identification of these conditions.