Objective:To investigate the expression level and clinical significance of interferon-γ-inducible protein 10 (IP-10) in the plasma of children with hand-foot-mouth disease (HFMD). Methods:Seventy-four children with hand-foot-mouth disease and 30 healthy controls were enrolled in this study. The infectious cases were divided into severe group and common group,respectively, according to whether patients were accompanied with nervous system symptoms. The flow cytometry technology was performed to detect IP-10 expression in plasma. Meanwhile,the lymphocyte subsets ratio,immunoglobulin and routine blood tests were also detected. The indicators were compared among the healthy controls,the general infection group and the severe group. The correlation among IP-10,rash days and lymphocyte subsets ratios were analyzed. Results:The number of white blood cell increased in the common HFMD group and the severe group,but had no statistical difference compared to the healthy controls. The expression of IP-10 significantly increased in the disease groups (both P < 0.001); however,the expression of IP-10 in the severe group was slightly lower than that of the common group of infection (P > 0.05). T lymphocyte cell ratio decreased significantly in both two disease groups (P < 0.001),in which the CD4+ T lymphocyte cells and CD8+ T lymphocyte cells also obviously reduced (both P < 0.05). On the contrary,B lymphocyte cell proportion increased remarkably (P < 0.001). The IgA increased while IgG reduced in the infectious groups compared with the healthy controls without statistical difference (P > 0.05). The skin rash days was negatively correlated with IP-10 expression,notably in the general infection group (P < 0.05),but was no statistical difference compared to the severe group. The proportion of CD4+ T lymphocyte cells was significantly positively related to IP-10 expression in the severe group (P < 0.01). Conclusion:The expression of IP-10 and B lymphocyte cell ratio significantly increased and T lymphocyte cell ratio significantly decreased in children with HFMD,which were negatively correlated with skin rash days.