Improving Outcomes for Patients With Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of uncontrolled immune activation often triggered by genetic defects in the primary form, and also by infection, rheumatic diseases, and malignancy in the secondary form. It is characterized by fever, hyperferritinemia, cytopenias, hepatosplenomegaly, and multiorgan dysfunction. 1,2 .