Study On The Relationship Between Immune Characteristics And Prognosisin Children With Severe Hand, Foot And Mouth Disease By EV71 Infection

ObjectiveIn order to reduce the mortality and morbidity of the hand, foot and mouth disease(HFMD) by EV71 infection and improve the prognosis of them, the changes of humoral and cellular immune function and the levels of CRPin children with severe disease were studied, and the relationship between the body's immune function and the pathogenesis as well as disease progression was analyzed.MethodsWith our hospitalized children with severe HFMD by EV71 infection and mild control subjects as the research object, the classification and differentiation of immune cells was determined by flow cytometry, immunoglobulin,complement and the C- reactive proteinwas determined by ELISA, and PCT was determined by double antibody sandwich chemiluminescence immunoassay. The correlation of the body's immune function and the pathogenesis as well as disease progression was tested. And then the correlation factorsinfluencing prognosis of disease were analyzed.Results1. The expression of T lymphocytes and their subsets: CD3+, CD4+, CD8+ and CD4+ / CD8+ in peripheral venous blood were determined. Significantly higher the numbers of T cells and the percentage of CD4+, CD8+ T lymphocytes were observed for severe patients compared with controls(P<0.05),while significantly lower the ratio of CD4+/CD8+ were observed(P<0.05).2. The expression of NK cells and their subsets: NK%, CD16, CD16+CD56+ and CD56+ in peripheral venous blood were detmined. Significantly lower the number of NK cells and the percentage of CD16+NK cells were observed for severe patients compared with controls(P<0.05),while the number of CD16+CD56+ and CD56+ had no significant difference(P>0.05).3. The expression of B lymphocytes and immunoglobulin and complement: CD19+, Ig A, Ig M, Ig G, C3 and C4 in peripheral venous blood were determined.Significantly higher the ratio of B lymphocytes and the expression of IgA, IgM and Ig G were observed for severe patients compared with controls(P<0.05),while significantly lower the level of C3 and C4 were observed(P<0.05).4. The determination of inflammatory indicators: CRP and PCT in peripheral venous blood were determined. Significantly higher the level of CRP was observed for severe patients compared with controls(P<0.05). the level of PCT rose,however, had no significant difference(P>0.05).5.Multivariate Cox hazard regression model analysis showed that CD4, CD8, CD16, Ig M,Ig G and CRP were the prognosis factors of the severe HFMD by EV71 infection.Conclusion1. More severe disease was, more significantlythe number of mature T cellsdecreased, and T cell subtype ratio was imbalanced,function of NK cell was inhibited, and the cellular immune was damaged.2. More severe disease was, more significantlyactivated and proliferatedthe B lymphocyte was, that caused humoral immune disorder, includingthe hyperfunctionand the increase of synthesis of immunoglobulin.3. More severe disease was, more significantlyincreased the intensity of inflammatory reaction, caused severe damage of tissue, and generated alarge number of CRP.4. CD4, CD8, CD16, Ig M, Ig G and CRP were the prognosis factors of the severe HFMD by EV71 infection.