Case of the Month #49 Hyperinflammatory State in the Intensive Care Unit

Published 23/05/2024

How is HLH diagnosed?

  • Diagnosis often follows exclusion of other diagnoses
  • Diagnosis is often made in view of clinical context as well as laboratory values
  • Scoring system is commonly used – Hscore and HLH-2004
  • Definitive diagnosis via Bone Marrow Biopsy

 

HLH-2004 DIAGNOSTIC CRITERIA. DIAGNOSIS ESTABLISHED IF CRITERION 1 OR 2 IS FULFILLED

CRITERION 1

A molecular diagnosis consistent with HLH
CRITERION 2 (FULFILLED IF 5 OF 8 PRESENT)

Fever

Splenomegaly

Cytopenias (affecting ≥2 of 3 lineages in peripheral blood

  • Hb <90 g/L
  • Platelets <100 x 109/L
  • Neutrophils <1.0 x 109/L

Hypertriglyceridaemia and or hypofibrinogenemia

  • Fasting triglycerides ≥3.0mmol/L
  • Fibrinogen ≤1.5g/L

Haemophagocytosis in bone marrow / spleen / lymph nodes. No evidence of malignancy

Low or no NK cell activity

Ferritin ≥500ug/L

Soluble CD35 (IL-2 receptor) ≥2400 U/mL

 

HLH SCORE

Parameter

Points (criteria for scoring)

Known underlying immunosuppression

0 (no)

18 (yes)

Temperature ℃

0 (<38.4)

33 (38.4-39.4)

49 (>39.4)

Organomegaly

0 (no)

23 (hepatomegaly or splenomegaly)

38 (hepatomegaly and splenomegaly)

Number of cytopenias

0 (1 lineage)

24 (2 lineages)

34 (3 lineages)

Ferritin μg/L

0 (<2000)

35 (2000-6000)

50 (>6000)

Triglyceride mmol/L

0 (<1.5)

44 (1.5-4)

64 (>4)

Fibrinogen g/L

0 (>2.5)

30 (<2.5)

Aspartate aminotransferase (U/L)

0 (<30)

19 (>30)

Haemophagocytosis on bone marrow aspirate

0 (no)

35 (yes)