Background: The goal was to explore the value of neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR) in evaluating the risk of hip involvement in patients with ankylosing spondylitis (AS).
Methods: The study included 188 AS patients (Based on BASRI-hip score, patients were classified as hip involvement group (BASRI-hip ≥ 2; n = 84) and non-hip involvement group (BASRI-hip ≤ 1; n = 104), 173 patients with osteoarthritis (OA) of the hip and 181 age- and gender-matched healthy controls (HCs). The value of NLR and MLR in different groups were observed.
Results: The NLR and MLR in AS patients with hip involvement were significantly higher than in the non-hip involvement group (p < 0.05), and patients with moderate and severe hip involvement were significantly higher than mild hip involvement (p < 0.05). The analysis of receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) of NLR, MLR, and the combination of NLR and MLR for AS patients with hip involvement were 0.817, 0.840, and 0.863, respectively (each p < 0.001) and the AUC values for predicting AS patients with moderate and severe hip involvement in patients with AS were 0.862, 0.847, and 0.889, respectively (each p < 0.001), which showed their significance in clinical settings. Also, NLR and MLR of AS patients were positively correlated with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) (each p < 0.01).
Conclusions: Therefore, NLR and MLR may be diagnostic hematological indexes in evaluating AS patients with hip involvement, particularly in the patients with moderate and severe hip involvement and higher diagnostic efficiency when combined analysis is done.