The function of CD8 +T cells in severe hand,foot and mouth disease infected by enterovirus 71 / 中国小儿急救医学

ABSTRACT

Objective To investigate the correlation between the expression of peripheral blood CD8 + T lymphocytes and the severity degree of hand,foot and mouth disease( HFMD)in children infected by enterovirus( EV)71 at different ages,and further to predict the role of the expression of CD8+ T lympho-cytes played in the occurrence of neurological complications infected by EV71. Methods A total of 138 pe-ripheral blood samples derived from the confirmed HFMD cases were collected in the department of infectious disease at Kunming Children′s Hospital between March and September in 2014,including 33 mild cases,45 severe cases,and 60 critical cases. Patient ages were 9 months to 5 years old. Flow cytometry was used to detect the expression of peripheral blood CD8 + T lymphocytes in all of above patients. Results Compared to the reference value of CD8 + T lymphocytes in normal healthy children at different age groups,the percentage of peripheral blood CD8 + T lymphocytes elevated or increased slightly in patients of all ages,except the obvi-ously increasing expression in the age group of ~2 years and decreasing expression in critical cases of the age group of ~5 years. The expression of peripheral blood CD8+ T lymphocytes significantly increased in mild and severe patients but slightly increased in critical patients of the age group of 9 to 15 months,gradually de-creased in the age group of ~2 years and slightly increased in mild and severe cases but decreased in critical patients of the age group of ~5 years. There were significant differences between the patients in mild condi-tion and in severe condition or critical condition respectively within the age group of ~2 years( P﹤0. 05 ), and there were no significant differences in other age groups between different severity of disease. Conclusion There are correlations between the expression of CD8+ T cells and the severity of HFMD in patients at different ages. Especially,the patient′s condition developing into severe degree is associated with the rapid decreasing of CD8 + T cells in HFMD patients of the age group of ~2 years. CD8+T cells play an important role in antiviral immune response in HFMD patients of ~2 years old.