Analysis of peripheral blood lymphocyte subpopulations in children with severe and critical hand,foot and mouse disease

Objective To investigate the variation of peripheral blood lymphocyte subpopulations and immune function in severe hand,foot and mouse disease(HFMD)children.Methods Severe HFMD children hospitalized from May to December 2008 were enrolled into the study.Relative counts of CD3+CD19-,CD3+CD4+,CD3+CD8+,CD3-CD19+ and CD3-CD16+CD56+ of recruited children were detected on the day of admission or the next day.Peripheral blood lymphocyte subpopulations of critical HFMD children were detected again on the second day after receiving the treatment of IVIG and methylprednisolone.The differences of lymphocyte subpopulations before and after treatment and the severity of the disease were analyzed.Results One hundred and forty-five severe and critical HFMD children were enrolled.Among 24 cases aged from 2 d to younger than 12 months,17 were boys,with 13 being severe HFMD and 4 being critical HFMD.Among 7 girl cases,4 were severe HFMD and 3 were critical HFMD.One hundred and eighteen cases were younger than 6 years of age,of them 71 were boys including 32 severe HFMD cases and 39 critical HFMD cases,47 were girls including 25 severe HFMD cases and 22 critical HFMD cases.①The percentages of NK cells in 2 d-12 month group showed an increasing trend and the percentages of B cells in-6 years group also showed an increasing trend.②The percentages of B cells in severe HFMD group showed an decreasing trend,but the percentages of NK cells showed significantly increasing trend which were two times higher than normal.The percentages of T cells and NK cells in critical HFMD group all showed an decreasing trend and the percentages of B cells showed a significantly increasing trend which were two times higher than normal.The comparison between two groups showed the percentages of T cells and NK cells in critical HFMD group were significantly lower than those in severe HFMD group(P0.05).The percentages of B cells in critical HFMD group were significantly higher than those in severe HFMD group(P0.05),which were close to normal.③The percentages of T cells and NK cells in critical HFMD group increased significantly after treatment.(P0.05).The percentages of B cells in critical HFMD group after treatment were significantly lower than those before treatment(P0.05).Conclusions The increased B cells may serve as an indicator of a critical HFMD.Use of IVIG and methylprednisolone is helpful to the recovery of immune function of critical HFMD children.