Infusion of leukocytes from HLA haplo-identical familial donors as an adjuvant in the HLH-2004 protocol to treat the virus-associated adult hemophagocytic lymphohistiocytosis: a retrospective study of 26 patients.

Adult hemophagocytic lymphohistiocytosis (HLH) is a fatal disease with poor survival and a limited role of drug therapies. To help to recognize virus and enhance survival, we infused leukocytes derived from human leukocyte antigen (HLA) haplo-identical familial donors to patients. We retrospectively investigated 26 adult virus-associated hemophagocytic syndrome (VAHS) patients' medical records from 2006-2017. Eleven of the 26 patients accepted relatives' derived leukocytes infusions in addition to drug therapies recommended in the HLH-2004 protocol. The leukocyte doses ranged from 0.75 to 3.30×10 per kilogram of body weight. The other 15 patients accepted immunosuppressive and supportive therapies referred to in the HLH-2004 protocol. We compared the treatment outcomes of the two groups of patients. Patients in the cell infusion group had a lower viral load (P = 0.023) and better laboratory results and prolonged overall survival (60.44 vs. 20.18 weeks, P = 0.047). A factor that might relate to overall survival is platelet count (P = 0.032), except for the leukocyte infusions (P = 0.012). For patients without acceptable donors, infusions of leukocytes from HLA haplo-identical familial donors could be a feasible treatment to prolong overall survival as an adjuvant to drug therapies.