Introduction:
The objective of this cross-sectional study was to evaluate the monocyte to albumin ratio (MAR), neutrophil to albumin ratio (NAR), platelet to albumin ratio (PAR), and C-reactive protein to albumin ratio (CAR) as potential biomarkers for disease activity in patients with Behçet’s disease (BD).

Material and methods:
Both BD cases and healthy controls were enrolled in this study. Demographic characteristics, disease duration, and current medications were recorded for all participants. The BD Current Activity Form (BDCAF) was utilized to assess the activity of BD. Additionally, ery­throcyte sedi­mentation rate, CRP, and serum albumin levels were measured. The MAR, NAR, PAR, and CAR were compared between the two groups. Correlation analysis and receiver operating characteristic curves (ROC) were employed to establish cut-off points for these biomarkers.

Results:
In the study, both BD cases and 45 controls were included, totaling 90 participants. Significant differences were observed in the mean ±SD values of ESR, MAR, PAR, CAR, and albumin between the BD cases and controls (p = 0.008, p = 0.009, p = 0.029, p = 0.034, p = 0.006, respectively). However, despite these differences, no significant correlation was detected between BDCAF and the parameters under investigation. The cutoff point was determined as 150.59 (sensitivity 46.67%, specificity 82.22%, p = 0.008, AUC = 0.655) for MAR; as 62,013.73 (sensitivity 60.00%, specificity 66.67%, p = 0.03, AUC = 0.629) for PAR; and as 1.16 (sensitivity 35.56%, specificity of 95.567%, p = 0.03, AUC = 0.629) for CAR. The results were not able to define any cut-off points for active-inactive BD.

Conclusions:
Significantly higher levels of MAR, PAR, and CAR were observed in patients with BD than controls. Monocyte to albumin ratio, PAR, and CAR were notably elevated in patients with active BD. This finding suggests that these parameters possess discriminative ability and could potentially serve as biomarkers to aid in the clinical evaluation of BD.