Comparison of immune responses in children with infectious mononucleosis caused by Epstein-Barr virus at different infection stages

Infectious mononucleosis (IM) is a common infectious disease in children mainly caused by Epstein-Barr virus (EBV) infection, followed by abnormal immune response, and resulting in serious complications. However, there are few clinical analyses of immune responses in children with IM at different stages. This study combined EBV serological test and EBV DNA test to diagnose the infection status of children with IM, and the infection status was divided into primary acute IM infection (AIM), primary late IM infection (LIM) and reactivation IM infection (RIM). The results revealed that the absolute numbers of leukocytes and CD8 T lymphocytes in primary IM infection were significantly higher than those in reactivation infection, while the frequencies of CD4 T lymphocytes and B cells were significantly lower than those in reactivation infection. In addition, the activities of ALT, AST, α-HBDH and LDH in liver function indicators in primary infection were significantly increased compared with reactivation infection. Similarly, the EBV DNA levels of the primary infection were significantly higher than that of the reactivation infection. There are differences in immune response at different stages of infection, which can provide guidance for effective treatment in children with IM infection.