The interleukin-1 family of cytokines as diagnostic biomarkers of rotator cuff injury.

Abstract

Rotator cuff injury (RCI) can be caused by local inflammation and fibrosis of musculotendinous cuff. Here, we investigated the diagnostic role of IL-1 family cytokines in predicting disease severity and pain of RCI. This study included 48 patients with RCI. Seven interleukin-1 (IL-1) family members (including IL-1α, IL-1Ra, IL-1β, IL-18, IL-33, IL-37, IL-38) in the shoulder joint synovial fluid were measured by ELISA. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic value of IL-1 family cytokines for RCT. Correlations between IL-1 family cytokines and RCT severity, visual analog scale (VAS) scores, and functional scores were analyzed using Pearson's correlation coefficient analysis. Higher levels of IL-1α, IL-1β, IL-18, and IL-33 were found in more severe tear groups than those in the small tear group, while IL-1Ra was reduced in the massive tear group. IL-33 demonstrated strong diagnostic potential of severity (AUC = 0.7229, 95 % CI: 0.5773-0.8685, <i>P</i> = 0.0083). The levels of IL-1α, IL-18, and IL-33 were positively correlated with preoperative VAS scores (p < 0.01), while IL-1Ra levels were negatively associated with preoperative VAS scores. IL-1α (AUC = 0.7684), IL-1Ra (AUC = 0.7724), IL-18 (AUC = 0.7762), and IL-33 (AUC = 0.8330) had strong diagnostic potential of preoperative pain. IL-1α, IL-18, IL-37, and IL-38 were negatively associated with postoperative ASES scores and UCLA scores. IL-33 was negatively associated with preoperative ASES scores (r = -0.3577, p = 0.0126), and postoperative UCLA scores (r = -0.7242, p < 0.0001). IL-1Ra had positive associations with postoperative ASES scores and UCLA scores. IL-1Ra had negative associations with IL-1α and IL-33, while IL-33 was positively associated with IL-1α and IL-18. IL-1 family cytokines, including IL-1α, IL-1Ra, IL-18, and IL-33, are promising diagnostic biomarkers for RCI, with close associations with the degree of pain and postoperative functional recovery.