RESUMEN
PURPOSE: To evaluate the albumin-fibrinogen ratio (AFR) and C-reactive protein-albumin ratio (CAR) as inflammatory markers in rheumatoid arthritis (RA) and to investigate their association with disease activity correlating with musculoskeletal ultrasonographic findings. PATIENTS AND METHODS: A total of 125 cases of RA patients were consecutively enrolled in a multicenter cross-sectional study compared to 100 healthy controls, all subjects were investigated for fibrinogen, albumin, CRP, erythrocyte sedimentation rate, AFR, and CAR measurements. Patients' disease activity was assessed by disease activity score (DAS28-ESR), and they were subjected to high-frequency ultrasound both in greyscale and power Doppler. RESULTS: RA patients had lower AFR and higher CAR than those in the control group (P < 0.001). A positive correlation was demonstrated between CAR and DAS score (r=0.589, P = 0.0001), whilst there was a precise negative correlation between AFR and DAS 28-ESR (r=-0.74, p<0.001). ROC curve analyses revealed fibrinogen showed the best sensitivity (92.1%) for the area under the curve of 0.928, at a criterion of 2.47, while AFR has an area under the curve of 0.826 with sensitivity and specificity (86.84% and 75%, respectively) at cut-off value 1.46. Actively diseased patients had elevated CAR than those in remission (P < 0.001). Patients with synovial thickening and bone erosions had lower AFR than those without, CAR was higher in patients with power doppler changes than those without (p=0.015). CONCLUSION: Higher CAR and lower AFR were expressed in active RA than those in remission. CAR and AFR could be useful markers of ongoing inflammation and joint affection detected by musculoskeletal ultrasonography.