The power of albumin: unraveling its role as an inflammatory biomarker in systemic lupus erythematosus activity

Abstract Introduction Albumin-based indices, including albumin-to-globulin ratio (AGR), fibrinogen-to-albumin ratio (FAR), and Glasgow Prognostic Score (GPS), have been proposed as inflammatory markers, but their utility in reflecting systemic lupus erythematosus (SLE) activity is not yet well established, therefore, we aimed to evaluate the association and diagnostic performance of these markers in assessing disease activity in lupus patients. Methods This cross-sectional study included 179 patients with SLE. Disease activity was assessed using the SLE Disease Activity Score (SLE-DAS). Albumin-based indices, including albumin-to-globulin ratio (AGR), fibrinogen-to-albumin ratio (FAR), and Glasgow Prognostic Score (GPS), were calculated. Results A total of 179 SLE patients were included; 32.9% were in remission/low activity, 35.8% had mild activity, and 31.3% had moderate-to-severe disease. Serum albumin and AGR decreased significantly with increasing disease activity, while globulin, fibrinogen, FAR, and GPS increased (all p ≤ 0.002).Albumin and AGR were inversely correlated with SLE-DAS ( r = − 0.46 and − 0.52), whereas fibrinogen, FAR, and GPS were positively correlated, with FAR showing the strongest association ( r = 0.55; p < 0.001). FAR demonstrated the best diagnostic performance for moderate-to-severe disease (AUC = 0.80, 95% CI: 0.73–0.87), outperforming AGR, albumin, and GPS.FAR remained independently associated with SLE-DAS (β = 2.31; p < 0.001) with added value in discrimination of moderate-to-severe activity. Conclusion Albumin-based indices, particularly FAR, were significantly associated with disease activity in SLE and demonstrated promising diagnostic utility. Prospective multicenter studies are needed to confirm their clinical applicability.