Table 2.

Revised haemophagocytic lymphohistiocytosis (HLH) 2004 diagnostic criteria.

The diagnosis of HLH can be established if one of either 1 or 2 below is fulfilled

1.A molecular diagnosis consistent with HLH

2.Diagnostic criteria for HLH fulfilled (five of eight criteria below)

Initial diagnostic criteria

1.Fever

2.Splenomegaly

3.Cytopenia affecting at least two of the three lineages in the peripheral blood

Haemoglobin <90 g/l (in neonates haemoglobin <100 g/l)

Platelets <100 × 10˄9/l

Neutrophils <1·0 × 10˄9/l

4.Hypertriglyceridaemia and/or hypofibrinogenaemia

Fasting triglycerides ≥3·0 mmol/l (i.e. ≥265 mg/dl)

Fibrinogen ≤1·5 g

5.Haemophagocytosis in bone marrow, spleen or lymph nodes

No sigh of malignancy

Additional criteria

6.Low/absent natural killer cell activity

7.Hyperferritinaemia

Ferritin >500 µg/l

8.High soluble interleukin 2 receptor levels

sIL-2R ≥2400 U/ml

Additional comments (Table 2)

1.If bone marrow aspirate shows no haemophagocytosis look for evidence in other organs or perform serial marrow aspirates

2.Diagnosis would be supported by:

(a)Spinal fluid pleiocytosis (mononuclear cells) and/or elevated spinal fluid protein

(b)Liver biopsy showing findings consistent with chronic persistent hepatitis

3.Other clinical and laboratory findings which would point towards the diagnosis of FHL are: cerebromeningeal symptoms, lymph node enlargement, jaundice, oedema, skin rash, hepatic enzyme abnormalities, hypoproteinaemia, hyponatraemia, elevated very low-density lipoproteins (VLDL) and low high-density lipoproteins (HDL)