Objective  To explore levels of serum interleukin-6(IL-6), Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal pathway and changes of immune function in children with viral bronchiolitis.

  Methods  A total of 112 children initially diagnosed with viral bronchiolitis were chosen as study objects, including 50 mild children, 40 moderate children and 22 severe children, another 30 healthy children were selected as control group. Serum IL-6 was detected by enzyme-linked immunosorbent assay (ELISA), relative expressions of phosphorylated JAK(p-JAK) and phosphorylated STAT (p-STAT) protein in peripheral blood mononuclear cells (PBMCs) were detected by Western blot, serum immune globulin(Ig)A, IgG and IgM were detected by immunoturbidimetry, and percentages of CD4⁺ and CD8⁺ were detected by flow cytometry.

  Results  Compared with the control group, the levels of IL-6, p-JAK and p-STAT in mild and moderate children were significantly increased, IgA, IgG and IgM, CD4⁺ and CD8⁺ percentage were significantly decreased (P < 0.05); IL-6, p-JAK and p-STAT in severe viral bronchiolitis children were significantly higher, and IgA, IgG and IgM, CD4⁺ and CD8⁺ percentages were significantly lower than those in mild and moderate children (P < 0.05); there were no differences of the above indexes in mild and moderate viral bronchiolitis children (P > 0.05).

  Conclusion  Higher expression of IL-6 and activation of JAK/STAT signal pathway may be involved in the occurrence and development of viral bronchiolitis, and are closely related to disorder of humoral and cellular immune function in children, which can provide a theoretical basis for new target of disease treatment.