ABSTRACT
Objective:To investigate the predictive value of serum amyloid A/albumin (SAA/ALB) in the activity and prognosis of systemic lupus erythematosus (SLE).Methods:97 SLE patients initially diagnosed in Jincheng People′s Hospital from January 2018 to December 2020 were selected. According to whether the SLE disease activity index (SLE-DAI) was ≥5, SLE patients were divided into active and stable periods. The clinical data of active and stable SLE patients were compared. The independent influencing factors of active SLE were analyzed by logistic regression. The predictive value of SAA, ALB, SAA/ALB on active SLE and severe active SLE was analyzed by receiver operating characteristic(ROC) curve; Kaplan Meier survival curve was used to analyze the prognosis of patients with different SAA/ALB.Results:There were 97 SLE patients, including 64 in active phase and 33 in stable phase.Compared with the stable phase, the SLE-DAI, alanine aminotransferase (ALT) and α-Hydroxybutyrate dehydrogenase (α- HBDH), lactate dehydrogenase (LDH), SAA, SAA/ALB≥0.52 mg/g, urinary microalbumin/creatinine (ACR) in SLE patients of active phase were all higher, while the ALB, albumin/globulin (A/G) and complement (C3) levels were all lower, with statistically significant difference (all P<0.05). LDH, SAA/ALB ≥0.52 mg/g, A/G≥1.18 and C3≥0.60 g/L were all independent influencing factors of active SLE, and the OR were 1.321, 1.401, 0.744 and 0.663 respectively (all P<0.05). The area under the curve (AUC) of SAA and SAA/ALB in predicting active SLE were 0.755 and 0.861, respectively. AUC SAA/ALB>AUC SAA, with statistically significant difference ( P<0.05). The AUC of ALB in predicting stable SLE was 0.743. The AUC of SAA and SAA/ALB in predicting severe active SLE were 0.699 and 0.746, respectively. AUC SAA/ALB>AUC SAA, with statistically significant difference ( P<0.05). The AUC of ALB in predicting non severe active SLE was 0.671. Among the 64 active SLE patients, 21 had poor prognosis. The AUC of poor prognosis predicted by SAA/ALB was 0.736, and the best cut-off value was 0.78 mg/g. There was significant difference in the duration of remission between the high and low SAA/ALB groups (χ 2=6.507, P<0.05). Conclusions:SAA/ALB ≥0.52 mg/g was an independent factor for active SLE. SAA/ALB had a high predictive value for active SLE, severe active SLE and poor prognosis.