Combined assessment of 25(OH)D, CD4+/CD8+ ratio, and prognostic nutritional index for anti-dsDNA-based stratification in systemic lupus erythematosus

Background Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease in which anti-double-stranded DNA (anti-dsDNA) antibodies are closely associated with disease activity and organ involvement. However, the relationships of 25-hydroxyvitamin D 25(OH)D, CD4 + /CD8 + ratio, and prognostic nutritional index (PNI) with anti-dsDNA antibody status and titer stratification remain incompletely understood. Methods A total of 126 patients with SLE were enrolled and classified into an anti-dsDNA-negative group and an anti-dsDNA-positive group. According to anti-dsDNA titers, patients were further stratified into low-titer and high-titer groups. Clinical characteristics and laboratory parameters, including 25(OH)D, CD4 + /CD8 + ratio, and PNI, were compared among groups. Receiver operating characteristic curve analysis was performed to evaluate the discriminatory performance of 25(OH)D, CD4 + /CD8 + ratio, PNI, and their combined model. Results Compared with anti-dsDNA-negative patients, anti-dsDNA-positive patients had significantly lower levels of C3, C4, the CD4 + /CD8 + ratio, 25(OH)D, and PNI, together with a higher prevalence of renal involvement (all P 0.05). Significant differences in 25(OH)D, the CD4 + /CD8 + ratio, and PNI were also observed across the anti-dsDNA-negative, low-positive, and high-positive groups. In ROC analysis, 25(OH)D showed the highest AUC among the individual biomarkers for anti-dsDNA serostatus, whereas the combined assessment achieved the highest overall AUC. For stratifying low-positive from high-positive anti-dsDNA titers, the combined assessment showed better discriminatory performance than PNI and C3. Conclusions Combined assessment of 25(OH)D, the CD4 + /CD8 + ratio, and PNI may provide complementary value for anti-dsDNA-based stratification in SLE. Its performance was comparable to C3 for anti-dsDNA serostatus and superior to C3 for stratifying low-from high-positive anti-dsDNA titers. These findings should be considered exploratory and require validation in external cohorts.