Plasma Interleukin 33 Level in Patients With Osteonecrosis of Femoral Head: An Alarmin for Osteonecrosis of the Femoral Head?

Objectives This study examines plasma interleukin 33 (IL-33) levels in patients with osteonecrosis of the femoral head (ONFH) and explores the possible use of IL-33 as a marker for early diagnosis and progression of ONFH. Methods One hundred twenty-five ONFH patients and 126 control subjects were recruited for this study. The plasma IL-33 levels were measured using a commercially available enzyme-linked immunosorbent assay kit. Effects of disease stage and risk factors on IL-33 level were also assessed. Results Plasma IL-33 levels were significantly higher in the 125 ONFH patients (174.33 [SD, 65.73] pg/mL) than in the 126 control subjects (90.50 [SD, 25.17] pg/mL, P < 0.001). Plasma IL-33 levels were significantly higher in patients with stage III/IV ONFH (184.17 [SD, 43.75] pg/mL) than in patients with stage I/II ONFH (158.24 [SD, 50.11] pg/mL, P < 0.001). There was no significant difference in IL-33 levels between alcohol-induced, idiopathic, and steroid-induced cases. Conclusions Plasma IL-33 may be an alarmin for ONFH, and its levels may be related to disease progression.