Pilot Study of Etoposide-based Therapy and Hematopoietic Cell Transplantation for Hemophagocytic Lymphohistiocytosis

Inclusion Criteria: * Patients whose clinical findings satisfy 5 or more criteria out of the following 8 ones 1. Fever ≥ 38.5 ℃ for ≥ 7 days 2. Splenomegaly ≥ 3 FB below left subcostal margin 3. Cytopenias affecting ≥ 2 of 3 lineages in PB Hb \< 9 g/L Platelet \< 100 x 109 /L ANC \< 1.0 x 109 /L 4. Hypertriglyceridemia and/or hypofibrinogenemia (fasting triglycerides ≥ 265 mg/dL, fibrinogen ≤ 1.5 g/L) 5. Hemophagocytosis in BM or spleen or LN 6. Low or absent NK-cell activity ( according to local laboratory reference) 7. Serum-ferritin ≥ 500 mcg/L 8. Soluble CD25(sIL-2 receptor) ≥ 2,400 U/ml * 18 years of age and over. * All patients (or his/her family when the patient cannot sign the consent form because of his/her general conditions) give written informed consent according to guidelines at institution's committee on human research. Exclusion Criteria: * HLH from malignancy (such as lymphoma, myeloma, leukemia, and other solid tumor) * HLH from rheumatic disorder (such as SLE, AOSD, antiphospholipid antibody syndrome) * Patients with psychiatric disorder or mental deficiency severe as to make compliance with the treatment unlike, and making informed consent impossible * Nursing women, pregnant women, women of childbearing potential who do not want adequate contraception * Male patient who reject the methods of avoiding pregnancy via methods such as abstinence, barrier method (condom etc). * Patients with a diagnosis of prior malignancy unless disease-free for at least 5 years following therapy with curative intent (except curatively treated nonmelanoma skin cancer, in situ carcinoma, or cervical intraepithelial neoplasia)