Clinical data
Sixty-six children with EBV-HLH diagnosed and treated at the Seventh Affiliated Hospital of Sun Yat-Sen University, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, and Huizhou First Hospital from 2008 to 2019 were included in the study (EBV-HLH group; 28 males and 38 females, age 1.5–17 years, median age 5 years). Fifty-eight healthy children diagnosed as EBV-seropositive during the same period were included as the control group (32 males and 26 females, age 1–16.7 years, median age 4.3 years).
The inclusion criteria for EBV-HLH subjects were: (i) a diagnosis of HLH and exclusion of congenital HLH[6], and (ii) diagnosis of EBV infection (positive for EBV antibodies or significantly increased EBV-DNA in tissues or peripheral blood).