[Relationship between advanced lung cancer inflammation index and pathological activity index in lupus nephritis and...

Objective: To investigate the correlation between advanced lung cancer inflammation index (ALI) and renal pathological activity index (AI) in lupus nephritis (LN) patients, and to evaluate its predictive value for moderate-to-severe renal pathological activity. Methods: This cross-sectional study retrospectively included 279 LN patients who underwent renal biopsy at the First Affiliated Hospital of Xi'an Jiaotong University from January 1, 2017, to December 31, 2024. The median age of the patients was 34.0 (27.0, 45.0) years, and 234 (83.9%) were female. Based on the AI, patients were divided into a low-activity group (n=177) and a moderate-to-severe activity group (n=102). Logistic regression analysis was performed to identify the influencing factors for moderate-to-severe AI. Correlation analysis was used to explore the relationship between ALI and clinical indicators. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the predictive value of ALI for moderate-to-severe AI. Results: The ALI level in the moderate-to-severe activity group was significantly lower than that in the low-activity group (15.4 vs. 18.8, P<0.001). Multivariate logistic regression analysis showed that the 2000 Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K) score (OR=5.54, P<0.001) and serum creatinine (OR=1.01, P=0.007) were risk factors for moderate-to-severe AI; whereas hemoglobin (OR=0.98, P=0.001) and ALI (OR=0.97, P=0.048) were protective factors. Correlation analysis revealed that ALI was negatively correlated with AI (r=-0.31, P<0.001), and positively correlated with body mass index, hemoglobin, albumin, complement C4, and IgG. ALI was negatively correlated with SLEDAI-2K, white blood cell count, neutrophil-to-lymphocyte ratio (NLR), serum creatinine, blood urea nitrogen, and C-reactive protein. ROC curve analysis demonstrated that the area under the curve (AUC) of ALI for predicting moderate-to-severe AI was 0.658 (95%CI 0.592-0.724, P<0.001). The optimal cutoff value was 13.14, with a sensitivity of 72.8% and a specificity of 55.9%. The proportion of patients with moderate-to-severe LN in the ALI <13.14 group was significantly higher than that in the ALI ≥13.14 group (50.9% vs. 27.7%, P<0.001). Conclusions: ALI is closely correlated with renal pathological AI in LN and serves as a protective factor against moderate-to-severe AI. ALI holds certain predictive value and may serve as a non-invasive auxiliary tool for evaluating renal pathological activity in LN.