Which inflammatory marker might be the best indicator for sacroiliitis?

Abstract This study aimed to investigate the potential of inflammatory markers, including platelet‐to‐lymphocyte ratio (PLR), neutrophil‐to‐lymphocyte ratio (NLR), lymphocyte‐to‐monocyte ratio (LMR), and C‐reactive protein‐to‐lymphocyte ratio (CLR), in identifying sacroiliitis. Present retrospective study was conducted at the Abant Izzet Baysal University Hospital, including patients diagnosed with sacroiliitis between August 2020 and March 2023. Control subjects with normal sacroiliac joints were also included. Sacroiliitis patients were further categorized into active and chronic sacroiliitis groups. Demographic data and laboratory characteristics, such as erythrocyte sedimentation rate (ESR), C‐reactive protein (CRP), and various blood parameters, were recorded. Inflammatory markers were calculated, including PLR, NLR, LMR, and CLR. Statistical analyses were performed to compare the study groups and evaluate the diagnostic performance of these markers. A total of 226 subjects, including 132 sacroiliitis patients and 94 control subjects, were included in the study. Serum CRP levels were significantly higher in sacroiliitis patients compared to the control group. NLR, PLR, and CLR values were elevated in sacroiliitis patients, while LMR was decreased. There were significant correlations between these markers and established inflammatory markers. Receiver operating characteristic (ROC) analysis demonstrated moderate diagnostic performance for NLR, PLR, LMR and CLR in detecting sacroiliitis. Inflammatory markers, specifically NLR, PLR, LMR and CLR, showed significant differences between sacroiliitis patients and the control group. In addition PLR is useful in distinguishing active and chronic sacroiliitis. These markers, in conjunction with established inflammatory markers, may serve as supportive diagnostic tools for sacroiliitis.