Abstract: Objective To explore the changes and significance of serum interleukin-23 (IL-23) and macrophage inflammatory protein-3α (MIP-3α) levels in children with IgA vasculitis (IgAV) after respiratory tract infection. MethodsA total of 47 patients with acute IgAV were divided into two groups: Group IgAV1 without respiratory tract infection and Group IgAV2 with respiratory tract infection. Meanwhile, another 23 patients with respiratory tract infection and 20 healthy controls were enrolled into the study. There were 90 patients in total. The levels of serum cytokines were semi-quantitatively detected by antibody array (n=16). Potential biomarkers were screened out. Furthermore, the levels of serum IL-23 and MIP-3α were measured by enzyme-linked immunosorbent assay (ELISA) (n=74). ResultsIL-23 and MIP-3α were screened out as potential biomarkers. The level of serum IL-23 in children with IgAV ［(48.56±34.27) ng/L］ was significantly higher than that in normal control group ［ (5.85±3.69) ng/L］ (P<0.01). The levels of serum IL-23 in Groups IgAV1, IgAV2 and the respiratory tract infection group were significantly elevated, compared with the normal control group (P<0.05). Group IgAV2 presented a substantially higher level of IL-23 than Group IgAV1 and the respiratory tract infection group (P<0.05). There was no significant difference in serum MIP-3α level between Groups IgAV1 and IgAV2 and the normal control group (P>0.05). ConclusionsMIP-3α is not associated with the pathogenesis of IgAV. Abnormally elevated serum IL-23 levels may be involved in the immunopathogenesisof IgAV. Respiratory tract infection may contribute to elevated serum IL-23 levels and cause immunological disorder which then induces IgAV.