Seasonal 25-hydroxyvitamin D levels in new childhood-onset SLE: associations with disease activity and peripheral lymphocyte subsets

Objective This study aimed to compare 25-hydroxyvitamin D (25-(OH)D) levels and peripheral lymphocyte subsets between children with new childhood-onset SLE and healthy controls across different seasons, and to explore the relationships of seasonal 25-(OH)D concentrations with the disease activity and peripheral lymphocyte subsets in paediatric patients with SLE. Methods A retrospective study was conducted, enrolling 285 patients with new childhood-onset SLE and 175 healthy children. All participants were divided into a winter-spring group and a summer-autumn group according to sampling seasons. Serum 25-(OH)D levels and peripheral lymphocyte subsets were detected and quantified. Results Compared with healthy controls, patients with SLE presented with significantly higher proportions of CD8 + T cells (p+ T cells and Natural Killer(NK) cells, reduced CD4 + /CD8 + ratio and decreased serum 25(OH)-D levels (all p Conclusions Serum 25-(OH)D levels are affected by seasonal changes and closely correlated with disease activity in children with SLE. Patients with new childhood-onset SLE manifest abnormal peripheral lymphocyte subsets and insufficient 25-(OH)D.