[Changes of immune function in patients with enterovirus 71 infection].

Objective: To investigate the association of changes in immune function with enterovirus 71 (EV71) cases with different severity of the disease.

Method: Forty-six EV71-infected patients and 12 age-matched healthy children were enrolled in this study. The patients were divided into four groups according to critical degree of enterovirus 71 infection: hand-foot-and-mouth disease (HFMD); central nervous system disease (CNSD); autonomic nervous system dysregulation (ANSD) and pulmonary edema (PE). We analyzed CD14+ monocyte HLA-DR expression, lymphocyte immunophenotypes, the proportion of CD4+CD25+ Foxp3high regulatory T cells (Treg cells) and Th17 cells, cytokines (IL-1beta, TNF-alpha, IL-10, TGF-beta, IL-6, IL-17A), evaluated the mRNA levels of Foxp3 and ROR-gammat, and serum immunoglobulin and complements.

Result: (1) Serum concentrations of IL-1beta and TNF-alpha elevated in mild cases, while declined in severe cases, and were lower in PE group (P<0.05). Serum concentrations of IL-10 and IL-10/TNF-alpha ratio gradually raised with the aggravation of the disease, and higher in PE group (P<0.05). (2) Circulating CD14+ monocyte HLA-DR expression, CD3+T cells, CD4+T cells, CD8+T cells, and NK cells gradually decreased, and lower in PE group (P<0.05). There was no significant difference in B cells, immunoglobulin and complement among the four groups. (3) The proportion of CD4+CD25+ Foxp3high Treg cells, mRNA level of Foxp, and serum concentrations of TGF-beta gradually decreased with the aggravation of the disease, while the proportion of Th17 cells, serum concentrations of IL-17A, mRNA level of ROR-gammat, and IL-6 gradually increased with the aggravation.

Conclusion: Immune function changed with different illness phases. The mild cases presented systemic inflammatory response syndrome status, while critically ill cases presented compensatory anti-inflammatory response syndrome or mixed antagonist response status. Immunoregulatory treatment of patients with EV71 infection should emphasize different methods at different stage and individualization.