The potential value of fibrinogen to albumin ratio (FAR) in the assessment of inflammation in spondyloarthritis

BACKGROUND: Fibrinogen to albumin ratio (FAR) is a newly investigated indicator for inflammation. The study aimed to explore the potential ability of FAR in assessing the severity of inflammation in spondyloarthritis. METHODS: The clinical data of 196 spondyloarthritis (SpA) patients, 66 osteoarthritis (OA) patients, and 81 healthy controls (HC) were collected in this retrospective study. The SpA group included 69 psoriatic arthritis patients, 47 reactive arthritis patients and 80 ankylosing spondylitis patients. Chi-square test and Mann–Whitney U test, Spearman’s correlation test, regression analysis, and ROC analyses were used for the analysis of FAR. RESULTS: FAR level in group SpA was higher than in OA or HC. In the SpA group, the reactive arthritis group was characterized by the highest FAR level. After matching the erythrocyte sedimentation rate, a significant difference occurred between groups SpA and OA, but not in SpA subgroups. The FAR level was significantly related to erythrocyte sedimentation rate and C-reactive protein. After regression and receiver operating characteristics analysis, FAR was considered the most potential pointer to evaluate inflammation in SpA with the area under curve of 0.95. The recommended cut-off value of FAR was 9.44 for serious inflammation and 8.34 for mild conditions. CONCLUSION: FAR is closely related to inflammatory biomarkers and can be a potential indicator in the assessment of inflammation in spondyloarthritis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-022-05797-6.