Table 3.

Diagnostic guidelines for HLH. Adapted from Hayden et al. [47].

HLH- 2004 Criteria. Either 1 or 2 are Fulfilled:
(1) A molecular diagnosis consistent with HLH
(2) Diagnostic criteria for HLH fulfilled (5 out of the 8 criteria below):
(A) Initial diagnostic criteria: - Fever - Splenomegaly - Haemophagocytosis in bone marrow or spleen or lymph nodes - Hypertriglyceridemia and/or hypofibrinogenemia: Fasting triglycerides ≥3.0 mmol/L (i.e., ≥265 mg/dL); Fibrinogen ≤1.5 g/L - Cytopenias (affecting ≥2 of 3 lineages in the peripheral blood): Haemoglobin <90 g/L (in infants <4 weeks <100 g/L); Platelets <100 × 109/L; Neutrophils <1.0 × 109/L
(A) New diagnostic criteria: - Low or absent NK- cell activity - Ferritin ≥500 mg/L - Soluble CD25 (i.e., soluble IL-2 receptor) ≥2400 U/mL