Requirement for etoposide in the initial treatment of Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis.

Haemophagocytic lymphohistiocytosis (HLH) is a severe, even fatal, inflammatory condition. Epstein-Barr virus (EBV) infection-associated HLH (EBV-HLH) is one of the most common types of secondary HLH. Etoposide is a key drug in HLH-94/04 regimen. We sought to identify the importance of etoposide in the initial treatment of EBV-HLH. Ninety-three patients with EBV-HLH of all ages admitted to our centre in 2017 were divided into two groups according to whether the initial treatment contained etoposide or not. The survival of the group whose initial therapy included etoposide (Group 1, 52 patients; 6-month survival rate 0·769) was significantly better than that of the group whose initial therapy did not include etoposide (Group 2, 41 patients; 6-month survival rate 0·269) (P < 0·001). In patients aged <18 years old, the survival of Group 1 patients was not significantly better than that of Group 2 patients (P = 0·447), in contrast to patients aged ≥18 years, where the survival of Group1 patients was significantly better than that of Group 2 patients (P < 0·001). We concluded that including etoposide in the initial treatment of EBV-HLH patients can improve their prognosis, especially adult patients. This may be because that adult patients are recognized as "higher risk" patients.