2. . Characterization of subgroups of patients according to the following information: Ferritin and its glycosylated fraction, documented infections , fever, MOF , hepatomegaly, splenomegaly, haemophagocytosis (when bone marrow aspirate available), thrombocytosis, anemia, leukopenia, neutropenia, liver enzymes, hypertriglyceridemia, coagulopathy, hypofibrinogenemia, VS / CRP.