. 2017 Feb 15;16:6. doi: 10.1186/s12941-017-0179-z

Table 1.

Diagnostic criteria for HLH used in the HLH-2004 trial

Five of the eight criteria listed below should be fulfilled

Fever ≥38.5 °C

Splenomegaly

Cytopenias (affecting at least 2 of 3 lineages in the peripheral blood)

Hemoglobin <9 g/dL (in infants <4 weeks: hemoglobin <10 g/dL)

Platelets <100 × 10³/mL

Neutrophils <1 × 10³/mL

Hypertriglyceridemia (fasting, >265 mg/dL) and/or hypofibrinogenemia (<150 mg/dL)

Hemophagocytosis in bone marrow, spleen, lymph nodes, or liver^a

Ferritin >500 ng/mL

Elevated sCD25 (α-chain of sIL-2 receptor)

Low or absent NK-cell activity

^aFindings in up to two-thirds of initial bone marrow aspirates may be nondiagnostic; an additional bone marrow finding includes dyserythropoiesis, which has been observed in the absence of hemophagocytic histiocytes [24]