Abstract: Objective To analyze the expression of serum 25-hydroxyvitamin D (25-hydroxyvitamin D, 25-OH-D) and antineutrophilic cytosolic antibody (Anti-neutrophil cytosolic antibodies, ANCA) in patients with systemic lupus erythematosus (systemic lupus erythematosus, SLE). Methods In the study, 62 patients with SLE were admitted to the hospital from April 2022 to April 2023 were the study observers, and 60 healthy volunteers in the same period were included as the control group to detect 25-OH-D and ANCA between the groups, and compare 25-OH-D and ANCA between the active patients in the observation group. Meanwhile, the factors of SLE disease activity were analyzed by Logistic. Results 25-OH-D was lower than the control group, and the difference was statistically significant (P<0.05); active SLE patients 25-OH-D lower than inactive SLE, ANCA higher than inactive SLE patients, and the difference was statistically significant (P<0.05); 25-OH-D expression and ANCA as independent variable, continuous variable; SLE activity degree as dependent variable (mild=0, severe=1), Logistic regression analysis. The results showed that 25-OH-D and ANCA influenced the degree of SLE activity (P<0.05); with SLE disease as the independent variable, 25-OH-D, ANCA and the joint levels, the optimal cut-off value was 0.089 (area under curve, AUC) was 0.702 (0.646~0.758), 0.713 (0.651~0.779), 0.879 (0.782~0.991). Conclusion 25-OH-D has low expression level in SLE patients, and ANCA shows high expression level. 25-OH-D and ANCA are the main influencing factors of SLE disease activity period, with high application value in clinical SLE disease diagnosis and disease activity degree prediction, so clinical use is recommended.

Key words: 25-OH-D, ANCA, systemic lupus erythematosus, degree of disease activity